ANESTHESIA (narcosis; Greek, nerke numbness, numbness +-osis; syn. general anesthesia) - artificially induced by pharmacological or electrical means deep sleep (reversible inhibition of the cells of the central nervous system), accompanied by a loss of consciousness, analgesia, relaxation of skeletal muscles and inhibition of reflex activity. In its original meaning, the term "anesthesia" meant stupor.

Story

Anesthesia with the help of various intoxicants (mandrake, belladonna, opium, Indian hemp, etc.) was known in ancient Egypt, India, China, Greece and Rome. Much later (in the 13th-15th centuries), the analgesic effect of ethyl alcohol was discovered, as well as a mixture of opium with scopolamine, to-rye, along with use in honey. purposes were given to criminals before execution. However, the scientific history of N. begins only in the middle of the 19th century, when for several years (from 1842 to 1847) Long (C. W. Long), Wells (H. Wells), W. Morton, J. Simpson, F. I. Inozemtsev and N. I. Pirogov, independently of each other, begin to test ether and chloroform as painkillers in various operations, first ether and chloroform, and then nitrogen recording, using them by inhalation. Subsequently, general anesthesia with ether, chloroform and nitrous oxide became widely used and made it possible to carry out previously impossible operations. The discovery by S. P. Fedorov and N. P. Kravkov in 1904 of the narcotic properties of intravenously administered hedonal served as the beginning of the development of non-inhalation N. methods, which are widely used in modern practice, using barbiturates, steroid anesthetics, sodium oxybutyrate, epontol, etc. Intravenous N. complements inhalation, and it is widely used for rapid introduction into N., and along with this, they continue to develop as an independent method. 50-60s 20th century were marked by opening and introduction in a wedge., practice of new inhalation anesthetics, among to-rykh halogen-containing substances (trilene, halothane, methoxyflurane and etran) take the central place. The use of muscle relaxants, analgesics, neuroleptics, as well as combinations of anesthetics with different properties, has opened up the possibility of obtaining and enhancing the desired effects of anesthesia, while avoiding, if possible, the harmful and toxic effects of each of the substances used. This is how the method of combined anesthesia was born.

Pharmacol, surveys of the 60s. led to the discovery and introduction into the wedge, the practice of substances with a narrowly focused action - powerful analgesics, antipsychotics, as well as substances with a multifocal type of action, large and small tranquilizers, sedatives, to-rye began to be widely and successfully used in anesthesiology. The use of numerous means for N. in combination with the development of methods of artificial ventilation of the lungs and intensive care provided opportunities for the further development of surgery.

Theories of anesthesia

Throughout the scientific history of N., numerous attempts have been made to create a unified theory of N. that satisfactorily explains the mechanism of its occurrence. Almost all theories of N. were based on the assumption that the mechanism of action of all known drugs for N. is practically the same, since the effect they cause is the same. Attempts were also made to identify common to all means used for N., physical, physical and chemical. or chem. properties or features of the structure, in connection with which they are able to cause general anesthesia. These attempts were not crowned with success and now have only historical interest. Nevertheless, the results of these studies and certain established provisions are truly scientific and influence modern ideas about the mechanisms of N. and its essence. Only the postulate remains undeniable that N. is the result of the interaction between the agent for N. and c. n. N of page, edges participates in this interaction at the level of a neuron and interneuronal synaptic connections.

Consideration of the main theories of N. shows that none of them is able to satisfactorily explain all the observed effects of general anesthesia and, consequently, the mechanisms of the occurrence of N. However, there is no reason to completely reject the old theories, since the lipid theory, for example, correlates better with representation of the minimum alveolar concentration of anesthetic than others.

coagulation theory. In 1864, W. Kuhne and in 1875 K. Bernard described the phenomenon of coagulation of cell protoplasm under the action of ether vapor and chloroform. K. Bernard then suggested that it was the reversible coagulation of the protoplasm of nerve cells that occurs under the influence of anesthetics that is responsible for the development of N. Trying to explain the physical. the mechanism of N., K. Bernard associated its occurrence with a change in surface tension, permeability of the cell membrane, a change in the viscosity of protoplasm, and other possible effects caused by ether and chloroform. However, later, in particular, P. V. Makarov (1938), it was shown that during general anesthesia, the concentration of the agent for N. in the cell is so small that it not only does not change the colloidal state of its protoplasm, but does not even have a significant effect on intracellular conduction of excitation. With this, the colloidal theory was essentially refuted.

lipid theory. In 1866, Hermann suggested that N. may be the result of a physical interaction of anesthetic agents with intracellular lipids. The establishment of this point of view was largely facilitated by the establishment by G. Meyer and Overton (Ch. E. Overton) in 1899 and 1901. (independently of each other) the fact of a direct correlation between the severity of the narcotic effect of a given drug and its solubility in fats. The theory of distribution of means for N. in fat and water according to degree of its dissolution in these environments (so-called coefficient of distribution oil/water) was developed, according to a cut the narcotic force of substance is in direct proportion to the value of this coefficient. This dependence was convincingly confirmed for fat-soluble anesthetics by E. I. Eger et al., in 1965. However, the patterns postulated by the lipid theory are valid only for compounds of one homologous series - non-cyclic hydrocarbons and inert gases and do not apply to other means for N., for example, barbiturates, steroid anesthetics, etc. In this regard, the lipid theory has no universal significance.

protein theory. In 1904-1905. Moore and Roaf (Moore, Roaf) established that nek-ry anesthetics (eg, chloroform, ethylene, cyclopropane) form unstable chemical with cellular proteins. compounds or physical aggregates. At the same time, the degree of connection of these compounds depends on the partial pressure of narcotic drugs in the solution and, therefore, determines the direct dependence of the depth of N. on the concentration of the anesthetic in the body. However, the exact significance of the association of anesthetic agents with proteins in the mechanism of the development of anesthesia remains unclear.

The theory of boundary tension. A number of substances, primarily saturated hydrocarbons and alcohols, have the ability to reduce the surface tension of liquids, including cellular media, depending on the strength of their narcotic effect (Traube's theory, 1904, 1913). Further, the works of Clements (J. A. Clements, 1962) established that inhalation anesthetics and certain inert gases are able to reduce the surface tension of the lipoprotein membranes of the pulmonary alveoli, and this effect is manifested in direct proportion to the strength of the narcotic effect of the substance. The theory based on the effect of a change in surface tension and the associated change in the permeability of cations through the cell membrane is also not universally valid, since it has become known that many inhalation anesthetics (for example, halogenated hydrocarbons) do not affect surface tension at all, while while other surfactants (eg, silicon compounds) do not have a narcotic effect.

adsorption theory is based on the fact that part of the anesthetic agent is adsorbed on the surface of cell membranes, and the degree of inhibition of funkts, cell activity, including the nervous one, depends on the number of molecules of the drug for N. adsorbed by the membrane [Lev (S. Loewe) , 1912]. D. N. Nasonov and V. Ya. Aleksandrov (1940) proposed the concept of "adsorption blockade", referring to the inability of any cell to bind any substances, i.e., to fully participate in metabolic processes, in the presence of an anesthetic. O. Warburg (1914) suggested that the main effect of the agent for N., adsorbed on the surface of the cell membrane, is the inhibition of the enzymatic activity of the cell. The theory has many exceptions and does not explain the processes occurring in the cell during N.

Thermodynamic theory (or the theory of inert gases). In 1939, J. K. W. Ferguson formulated the position that the narcotic power of inert gases and volatile anesthetics is proportional to the partial pressure of their vapors. On this basis, it was concluded that N. is the result of a physical rather than a chemical interaction between the nerve cell and the anesthetic, since in this interaction the total effective volume of the anesthetic molecules is more important than their number. This theory does not explain the specific mechanisms of change in funkts, cell activity in the state of N.

Theory of water microcrystals. Attempts to open N.'s mechanism were expressed also in studying fiz.-chem. interactions between the anesthetic and the protoplasm of the cell. Based on x-ray structural analysis (see), it was found that atoms and molecules of a number of inert gases, as well as ethane, cyclopropane, chloroform, etc., form microcrystals in the form of various polyhedra in aqueous solutions, in which water molecules, connected by hydrogen bonds, are, according to Claussen (Claussen, 1951), L. Pauling (1961), grouped molecules of various inert gases and anesthetics held in the center of these crystals by means of Van der Waals forces. Another pattern is also clear - the dependence of this effect on temperature. Since at body temperature the possibility of the formation of water microcrystals is practically excluded, L. Pauling pointed out the role of other chemistries in this process. compounds, in particular, the side chains of protein molecules that carry an electric charge, which, in cases of interaction between an anesthetic and a nerve cell at body temperature, play the role of catalysts for this process, but at lower temperatures (25 °) they can independently form water microcrystals in the protoplasm of cells. In zones of synaptic communication, micro-crystals can interrupt the process of conducting excitation. A serious defect in the theory of aqueous microcrystals was revealed by the establishment of the following fact: many anesthetic agents (for example, ether, halothane and methoxyflurane) do not form aqueous microcrystals at all at 0 °, normal atmospheric pressure and their high partial pressure in a mixture (close to the values ​​of the partial pressure of each of these anesthetics under given conditions). Another objection to this theory was that many fluorine-containing anesthetics do not fit into the linear relationship between their concentration and the number of microcrystals that exists for other anesthetics.

Theory of violation of oxidative processes. M. Ferworn in 1912 suggested that the action of anesthetics is associated with a violation of redox processes in the cell, leading to a funkt, its insolvency at sufficiently high concentrations of anesthetics in the body. In experiments in vitro, Brody, Bain (T. M. Brody, J. A. Bain, 1951) found that a number of substances with anesthetic activity reduce oxygen consumption by brain tissue without increasing the concentration of intermediate metabolic products - lactate, pyruvate, etc .; that barbiturates uncouple the processes of oxidation and phosphorylation and reduce the formation of ATP, but do not affect the total oxygen consumption of the brain. ATP production is reduced under the influence of barbiturates, primarily as a result of a slowdown in the rate of oxidation in mitochondria. At the same time, it has also been established that changes in cellular metabolism are not parallel to the degree of inhibition of functions, the activity of individual cellular structures and, in particular, inhibition of the conduction of excitation through the sympathetic ganglion. This primarily applies to ether, cyclopropane and nitrous oxide, to-rye in concentrations that block the conduction of excitation along axons, do not have any noticeable effect on oxygen consumption. It is known that almost all general anesthetics cause certain disturbances of metabolic functions, however, these disturbances are not parallel to the severity of the narcotic effect and cannot fully explain the mechanisms of the emergence and maintenance of the narcotic state. Moreover, it became known that, despite * the disturbances in separate nodes of a metabolic chain arising owing to action of the general anesthetics, nek-ry from them, napr, barbiturates and ftorotane, are capable to increase stability of c. n. with. to hypoxia and anoxia.

membrane theory. In the 70s. interest in the idea of ​​explaining N.'s mechanisms has been revived in terms of the effect of general anesthetics on the properties of the cell membrane. The idea that they act on the cell membrane, changing its fiziol, permeability, was expressed at the beginning of the 20th century. Heber (Heber, 1907), Winterstein (H. Winterstein, 1916). However, after the work of the English scientists A. Hodgkin, E. Huxley, who theoretically substantiated and experimentally confirmed the doctrine of the physiology of the cell membrane in 1949-1952. and awarded for these works of the Nobel Prize in 1963, the membrane theory of N. receives a serious scientific basis. Under the influence of general and local anesthetics and a number of other substances, the permeability of the cell membrane to sodium, potassium and chlorine changes. This causes a change in the polarization of the cell membrane and makes it impossible to generate action potentials that are capable of self-propagation through the nerve cell and are the main substrate for the specific function of the cell. In addition to general and local anesthetics, a decrease in membrane permeability, its stabilization and subsequent decrease in the action potential can be caused by steroid substances that do not have specific hormonal activity, for example, Viadryl. There is also a point of view, according to which the general anesthetic causes a long and persistent depolarization of the cell membrane, which again results in the inability to generate an action potential. However, in both cases, the starting point of the effect of the substances under consideration is the inhibition of membrane permeability for ions under their influence. Since almost all anesthetics behave in the body, from a biochemical point of view, they are quite inert, that is, they do not actively enter into chemical reactions. compounds, it was suggested that the interaction of general anesthetics with cell membrane molecules is not chemical, but physical in nature. While not all fiziol, the phenomena arising at action of anesthetic substances can be explained from the point of view of the membrane theory. Despite the fact that the general effect of all anesthetics, as already proven, is a violation of ionic membrane permeability (see), the mechanism of inhibition of the functions of nerve cells is not the same for all anesthetics. As one of the arguments of this position, one can cite a different physical and chemical. tropism of various anesthetics to substances of lipid and protein nature. Studies of N.'s mechanisms in the framework of the interaction of an anesthetic with the cell membrane, cell organelles, and other elements of the cell are only at the initial stage; in the USSR they were undertaken by T. M. Darbinyan et al. (1972).

Types of anesthesia

Inhalation anesthesia is carried out by inhalation of one or two (mixed N.) gaseous or liquid volatile anesthetics through the mask of the anesthesia machine or through the endotracheal tube (see Inhalation anesthesia).

Non-inhalation anesthesia is carried out by introducing one or more solutions of anesthetic and analgesic drugs into a vein (see Non-inhalation anesthesia). Non-inhalation N. methods also include methods when the anesthetic is administered intramuscularly (ketamine), rectally (narcolan). The rectal method of N. is for the first time offered by N. I. Pirogov; most often it is used in pediatric practice.

Electronarcosis is carried out with the help of special devices that generate weak currents of a sinusoidal, rectangular or triangular shape, to-rye affect the patient's brain through electrodes applied to the head (see Electroanesthesia).

In modern anesthesiology, in the vast majority of cases, combined types of anesthesia are used, seeking to reduce the adverse effects of each individual drug and enhance their positive properties (combined, or mixed, N.). Unlike the combined N., carried out by one any drug, is called mononarcosis.

They speak of basic anesthesia in the case of combining drugs for N., when a non-inhalation agent is used first, and then a gaseous or volatile anesthetic. In some cases, the simultaneous use of several drugs for N. in significantly reduced concentrations provides adequate general anesthesia due to the mutual enhancement of the action of the drugs (potentiated anesthesia).

Means for anesthesia

Inhalation anesthetics

Non-inhalation anesthetics

Maintaining adequate gas exchange(see. Gas exchange) is achieved both with the patient's spontaneous breathing during PI., and during artificial ventilation of the lungs. To do this, use the method of assisted breathing (with insufficient own), select respiratory mixtures containing the optimal amount of oxygen, and choose a ventilation mode that provides not only maximum oxygenation of the blood, but also optimal removal of carbon dioxide.

Maintaining adequate circulation(see Circulation) is aimed at ensuring optimal systemic and organ blood flow and oxygen transport. During N., general methods of regulating hemodynamics are used by maintaining a sufficient volume of circulating blood, compensating for blood loss by transfusion of donor blood, plasma and various blood substitutes, and conducting controlled hemodilution (see). It is extremely important to maintain the stability of myocardial contractility and maintain adequate cardiac output. One of the effective methods is the regulation of total peripheral resistance with the help of vasopressors or vasodilators. An important element of maintaining adequate blood circulation is to ensure sufficient venous return, which in some cases (when performing major operations and in patients in serious condition) is controlled by the magnitude of the central venous pressure. Adequate diuresis during N. (not lower than 50 ml/hour) reflects a satisfactory volume of renal and, consequently, general blood flow.

Metabolic regulation is one of the most complex components of anesthesia. In the vast majority of cases, this is achieved by regulating the already described components (adequacy of gas exchange and blood circulation) and is ensured by timely compensation for shifts in acid-base and electrolyte balance. To ensure the normal course of protein and energy metabolism, the body has sufficient reserves that fully satisfy the metabolic functions during the operation and H. Outside the anesthetic and operating period, it becomes necessary to additionally introduce solutions of carbohydrates and protein preparations (mainly amino acids) into the body. An important element in the regulation of metabolism is the prevention of heat loss by the body during N.'s period and after it. To a certain extent, this problem is solved by the active warming of the patient after N. still on the operating table. In some cases, to reduce the intensity of metabolic processes during the operation, the method of moderate hypothermia is used, with a cut, the body temperature is artificially reduced by external cooling under N. conditions and complete muscle relaxation, which ensures the shutdown of the body's thermoregulatory activity and the possibility of effective cooling (see Artificial hypothermia).

At separate operations quite often there is a need of maintenance of special conditions of N. So, for example, at operations on lungs one-lung N. and blockade of one of bronchial tubes are sometimes necessary; in neurosurgical practice, it is often necessary to pre-dehydrate the brain with osmodiuretics (urea, mannitol) or remove cerebrospinal fluid from the ventricles of the brain; in patients with diseases of the conduction system of the heart during the N. period, pacing is sometimes needed.

Indications for anesthesia

When choosing between local anesthesia and N., one should be guided by the principle: the more severe the patient's condition, the more indications for P., which allows you to most fully maintain homeostasis by providing narcotic sleep, analgesia, neurovegetative blockade and gioreflexia, muscle relaxation-tspi and the ability to control functions circulation and respiration. So, if hemodynamic disorders were the result of a violation of the contractile function of the heart (myocardial infarction), the best way to anesthetize during life-saving operations is N., and not local anesthesia, since only N. in conditions of artificial lung ventilation provides the ability to control body functions. In traumatic shock, N. is indicated both as an anesthetic and as a way to stabilize a number of other functions - hemodynamics, metabolism and respiration.

In patients in serious condition, correctly selected and performed N. usually leads to an improvement in the condition and, therefore, creates favorable conditions for the operation. For small-scale, low-traumatic operations that do not require control of body functions, preference may be given to local or epidural anesthesia.

Anesthesia technique

Preparing for anesthesia. Distinguish the general preparation for N. and special pharmakol, preparation - premedication. General preparation includes preliminary sanitation of the oral cavity, emptying the intestines and stomach (if it contains contents), normalization of water and electrolyte balance, elimination of deficiency of blood volume components and normalization of blood circulation.

The patient's condition before N. is assessed according to the following indicators: arterial and central venous pressure, frequency and nature of breathing, ECG, circulating blood volume, blood and urine composition, biochemical, blood composition, electrolytes in blood and urine, acid-base balance and gas blood composition, etc. In severe hemodynamic disorders, measures are taken to eliminate them. Hypovolemia) is eliminated by blood transfusion or infusion of medium molecular weight dextrans (polyglucin) or colloid solutions. During dehydration, patients are repeatedly injected with saline solutions and isotonic solutions of glucose, with metabolic alkalosis for several days before N. and surgery - solutions of potassium chloride and glucose with insulin. The introduction of sodium into the body in any form with metabolic alkalosis is contraindicated.

Premedication has the main goal of relieving psycho-emotional stress before surgery, facilitating the introduction into N., maintaining N.'s stability and an easier way out of it. Sufficient premedication eliminates the patient's anxiety, relieves his internal tension, causing drowsiness, and suppresses the secretion of bronchial contents and saliva. Important appointment of a premedication is the prevention patol, reflexes, hl. arr. cardiac arrhythmias, to-rye may occur during N. due to the direct effect of volatile anesthetics and muscle relaxants, and also be the result of afferent effects from the upper respiratory tract and visceral organs, on which the operation is currently being performed. Narcotic analgesics used for premedication, in addition to the main analytical effect, reduce tachypnea caused, for example, by trichlorethylene, and also suppress the patient’s possible motor activity resulting from excitation of the extrapyramidal system associated with the use of barbiturates, for example, thiopental-sodium. The inclusion of phenothiazine preparations (chlorpromazine) in the composition of premedication drugs reduces the level of body heat production.

For premedication use: a) sedatives - barbiturates (phenobarbital, sodium amytal, etc.), phenothiazine preparations (chlorpromazine, diprazine); increasingly used diazepam (seduxen), to-ry not only gives a good tranquilizing effect, but also has a wide breadth of therapeutic action and is therefore quite safe; b) narcotic analgesics - morphine, synthetic drugs promedol and fentanyl; c) antipsychotic drugs - dehydro-benzperidol (droperidol); d) parasympatholytics - atropine and Scopolamine.

The most common options for premedication are simple: 1) sodium amytal 0.2 g at night, promedol 10-20 mg and atropine 0.7 mg intramuscularly for 40-50 minutes. before the beginning of N.; 2) at night, 10-15 mg of diazepam inside, 1 hour before the start of anesthesia, 5-10 mg of diazepam solution intramuscularly and 30 minutes before. 1.5-2 ml of thalamonal and 0.5-0.7 mg of atropine intramuscularly. After premedication, the patient is not allowed to get out of bed and is taken to the operating room on a gurney.

Induction anesthesia (anesthesia induction)- a way to start anesthesia, with Krom they provide a quick, safe and effective loss of consciousness, loss of pain sensitivity and muscle relaxation without the stage of arousal of the patient and the necessary depth of anesthesia, which allows the transition to maintaining anesthesia at a constant predetermined level. During the period of development of mask essential and chloroform N., the so-called method was widely used. raush-narcosis, at Krom the patient was allowed to briefly inhale the anesthetic in high concentration, to-ry poured a simple mask for anesthesia on the gauze (see). From modern positions, this method is considered as "hypoxic suffocation", extremely dangerous, antiphysiological; is of historical interest only.

Introductory N. begin in the operating room or a special preoperative room after appropriate preparation of anesthesia equipment and anesthesia table (Fig. 1). Prior to the widespread use of the classical method of induction anesthesia using solutions of barbiturates, neuroleptanalgesics, propanidide, etc., in combination with muscle relaxants, induction N. was used for a long time, gradually introducing an inhalation anesthetic to the patient - ether, cyclopropane, chloroform, and halothane through an anesthetic mask. apparatus to a level that provides not only loss of consciousness and turning off pain sensitivity, but also muscle relaxation, which allows for tracheal intubation (see Intubation). This method of induction is used in pediatric anesthesiology, since it is technically simpler in a child and easier to tolerate than intravenous induction N. In adults, induction N. sodium, hexenal), neurolegtanalgesics (thalamonal, or separate administration of fentanyl and dehydrobenzperidol) in combination with diazepam or other tranquilizers, as well as intravenous administration of tropanidide. Muscle relaxation is achieved by intravenous administration of succinylcholine or pavulon (pancuronium bromide). Within a short period from the moment of loss of consciousness and until the development of complete muscle relaxation, artificial ventilation of the lungs is carried out using an anesthesia machine through a mask with a mixture of 50% oxygen and 50% nitrous oxide. Introductory N. and the entire subsequent period of N. are documented in a special anesthesia card, which reflects the dynamics of heart rate, blood pressure and other data from monitoring the patient's condition and the main measures for managing N. at various stages. Introductory N. is the most dangerous period of anesthesia, since it is at this time that the body quickly passes from one fiziol, state to another with the reflex responses not yet extinguished. The main complications are reflex disorders of hemodynamics and heart rhythm, airway obstruction (bronchiospasm, laryngospasm), vomiting and regurgitation. An important role in the development of hypotension (see Arterial hypotension) during the introductory N. with the help of barbiturates is played by the cardio-depressor effect of the latter. In this regard, it is advisable to administer barbiturates in concentrations not exceeding 1-2%. Even with a favorable course of induction of anesthesia after tracheal intubation, a short period of hypertension is often observed (see. Arterial hypertension), the origin of the cut can most likely be associated with a reflex resulting from irritation of the trachea by the endotracheal tube. Local anesthesia of the tracheal mucosa at the time of intubation significantly reduces its reflex excitability, but does not completely eliminate it. Less commonly, the cause of hypertension is hypoxia (see) and hypercapnia (see) during the period of introductory N., developing due to inadequate ventilation of the lungs preceding tracheal intubation. The most common cause of bronchiolospasm that develops with introductory N. (see Bronchospasm) is insufficient depth of anesthesia. Predisposing factors for the development of bronchiolospasm are insufficient blockade of the parasympathetic part of the c. n. S., the use of sulfur-containing barbiturates, cyclopropane, as well as irritation of the respiratory tract with an endotracheal tube in conditions of insufficiently deep anesthesia. Bronchiospasm is manifested by a sharp decrease in lung compliance, a small respiratory volume, convulsive movements of the whole body, difficulty in inhaling and exhaling, and wheezing. To eliminate it, inhalations of halothane in small concentrations, sometimes trilene or ether, intravenous administration of novocaine, aminophylline, succinylcholine, promedol are used. A satisfactory result is also given by the introduction of isadrin. Ventilation of the lungs during the period of bronchial spasm is carried out manually with an anesthesia machine bag, while 100% oxygen is insufflated. The method of lung massage for the treatment of wide wedge bronchiolospasm has not found application. Vomiting (see) and ch. arr. regurgitation of gastric contents (see Reflux) can occur in any period of N., but most often this happens during induction. This complication becomes especially dangerous if it goes unnoticed. The acidic contents of the stomach, pH to-rogo is below 2.5, getting into the trachea, bronchi and bronchioles, causes chem. burn of the mucous membrane of the respiratory tract with the subsequent development of the so-called. aspiration) pneumonitis, exudative and purulent tracheobronchitis, diffuse or focal pneumonia. This complex of phenomena is known as the Mendelssohn syndrome. The main measure for the prevention of vomiting and regurgitation during N.'s period is the emptying of the stomach in front of N., the position of the patient with a raised head (Fowler's position), blocking the lumen of the esophagus by pressing on the cricoid cartilage of the larynx during the entire period of introductory N. and intubation of the trachea (Sell and ka reception). ). One of the measures to prevent regurgitation and leakage of stomach contents into the trachea is gastric probing (see. ) for the period of N., refusal to use cuffless endotracheal tubes and complete refusal of the method of tamponade of the pharyngeal cavity. If aspiration of gastric contents nevertheless occurred, regardless of whether the patient had vomiting or regurgitation, the following are carried out to lay down. measures: 1) immediately intubate the patient's trachea (if intubation has not been performed earlier); 2) aspirate the contents from the trachea and bronchi; 3) in the intervals between periods of suction, artificial ventilation of the lungs is carried out to completely eliminate hypoxia; 4) through the endotracheal tube, the trachea and bronchi are repeatedly washed with 4% solution of bicarbonate, which is administered in 15-20 ml and immediately aspirated (lung lavage); 5) after each lavage, and also at the end of N. before extubation, 100-200 mg of hydrocortisone in solution is injected into the trachea and bronchi; in the postoperative period, hydrocortisone is prescribed intramuscularly for several days; b) eufillin is administered intravenously to prevent and treat bronchospasm; 7) after extubation (or in the presence of an endotracheal tube in the trachea) produce rentgenol, chest control to detect lung atelectasis; 8) if there is a suspicion of the presence of food masses and any other conglomerates in the bronchi, which cannot be removed by simple suction, bronchoscopy is performed (preferably by an injection bronchoscope), with a cut, the whole complex of the above measures is carried out.

During the period of induction of anesthesia, both with inhalation and with the intravenous method, a cough is possible (especially often in smokers). Its occurrence may be associated with irritation of the larynx during inhalation of an anesthetic (especially ether) in high concentrations, as well as with an irritating effect on the larynx of gastric contents or saliva. Prevention is a gradual increase in the concentration of inhalation anesthetic, as well as the elimination of leakage of liquid contents into the larynx. Cough can also be interrupted by the rapid immobilization of the patient by the introduction of muscle relaxants.

Maintenance period of anesthesia coincides with the duration of the operation. For short-term interventions, anesthetics and muscle relaxants with a short period of action (propanidide, barbiturates, nitrous oxide, halothane, succinylcholine) are used, for long-term operations, drugs for neuroleptanalgesia, halothane or ether in combination with nitrous oxide, sodium oxybutyrate, tubocuraria or pavulon are administered fractionally. The main goal of N. during the maintenance period is to protect the patient from surgical trauma and provide the best working conditions for the surgeon. To do this, the anesthesiologist must continuously monitor the depth of anesthesia, its adequacy to the nature and stage of the intervention, maintain optimal gas exchange, evaluate and compensate for blood loss, prevent unwanted neurovegetative reactions, and correct hemodynamic shifts.

Withdrawal from anesthesia begins with the cessation of the introduction of anesthetics into the body. Although the return of consciousness coincides with the restoration of compensatory and adaptive mechanisms, the exit from N. does not end there. Even with the restoration of consciousness in a patient for several minutes and even hours (depending on the type and duration of N.), respiratory depression, adynamia and muscle weakness remain.

At the same time, during this period, the central thermoregulatory mechanisms are restored, the patient begins to feel chills, which, from the point of view of compensation of functions, helps to restore normal temperature homeostasis. In connection with activation of functions the patient needs the increased amount of oxygen, a cut can be provided only in the conditions of the restored breath.

The duration of N. is determined by the specifics of the operation, the depth of anesthesia and the time of removal of the anesthetic from the body. With ethereal and methoxyfluranic N., the process of leaving N. begins earlier than with halothane. With neuroleptanalgesia, fentanyl is stopped administering 20-30 minutes. before the end of the operation. Favorable and fast exit from N. in many respects depends on skill of the anesthesiologist. It is necessary that the elements of consciousness (the ability to answer the simplest questions and follow elementary instructions), adequate breathing and basic protective reflexes (cough and pharyngeal) are restored even on the operating table. The criterion for the adequacy of breathing is a tidal volume of at least 400-500 ml, as well as a satisfactory level of pO 2 , pCO 2 and blood pH. The main reasons for the slow recovery of adequate spontaneous respiration: 1) artificial lung ventilation during N.'s period in hyperventilation mode, with Krom the level of CO 2 in the blood decreases and by the end of N. does not reach the threshold necessary for normal excitation of the respiratory center; 2) a shift in the acid-base balance of the blood towards acidosis, which slows down the hydrolysis of depolarizing relaxants and inhibits the excretory function of the kidneys; 3) suppression of neuromuscular conduction by an anesthetic that has not yet had time to leave the body; 4) deepening of the neuromuscular blockade after the introduction of antibiotics during the operation; 5) overdose or excessive accumulation of muscle relaxants in the body.

After the use of non-depolarizing muscle relaxants, decurarization is carried out. Its meaning lies in the fact that with the introduction of anticholinesterase drugs (prozerin), favorable conditions are created for the accumulation of the mediator acetylcholine in the zone of the myoneural synapse, which provides direct transmission of the impulse from the nerve to the muscle. Decurarization is carried out only when the patient has elements of spontaneous respiration. Usually, 0.04-0.05 mg/kg of prozerin is slowly administered intravenously (sometimes fractionally) after the preliminary administration of atropine to relieve the parasympathomimetic effect, prevent bradycardia and asystole. In some cases, the awakening of the patient is forced (and the adequacy of his breathing is controlled) by intravenous administration of 2-3 ml of the solution of cordiamine or water-soluble camphor. These drugs are primarily powerful respiratory analeptics, although their effect is not very long. After neuroleptanalgesia, fortral (pentazocine) is often used as a respiratory analeptic, using, in addition to the analgesic effect, its antagonistic effect on fentanyl. For the same purposes, nalorphine is used - a drug with a pronounced antagonistic effect in relation to morphine and morphine-like drugs.

Extubation of the trachea is performed only after the restoration of consciousness, reflexes and the initial volume of pulmonary ventilation. Before extubation, the contents are aspirated from the trachea and oral cavity.

The main signs of complete awakening after N., the cessation of curarization and the restoration of spontaneous breathing are as follows: the patient talks, freely moves his limbs at the request, can tear off the back of his head from the headrest; able to cough; can take a few deep breaths. instructions of the anesthesiologist; the patient has no cyanosis; the movements of the diaphragm and the rib cage of the chest are synchronous (there is no paradoxical breathing); minute volume of pulmonary ventilation is not less than the initial one.

In the presence of all these signs, the patient can be transferred to the postoperative intensive care unit. Before transferring, the anesthesiologist must once again evaluate blood loss and the effectiveness of blood replacement, listen to heart sounds, measure blood pressure and evaluate peripheral circulation, diuresis and make sure that the oral cavity is free of contents. In the intensive care unit, an x-ray of the lungs is required to detect possible atelectasis and other complications.

Clinical picture of anesthesia

N. any anesthetic develops according to certain patterns (staging) specific to each anesthetic or a combination of them. In connection with the introduction into widespread practice of muscle relaxants, which made it possible to conduct anesthesia at the superficial stages, and also in connection with the use of not one, but several anesthetics with a multidirectional type of action that complement each other during N., the classical concept of "anesthesia clinic" has lost its former meaning. This, in turn, made it difficult to assess the depth of anesthesia and its adequacy, increased the requirements for the qualification of an anesthesiologist and led to the creation of new objective methods for assessing anesthesia (electroencephalography, myography). The clinical picture and staging of N.'s development can be most fully traced on the example of ethereal N. There is a classification of Godel (A. E. Guedel), providing four stages of ethereal N.:

I - analgesia;

II - excitation;

III - surgical stage (tolerant);

IV - agonal.

Mashin (W. W. Mushin) identifies three levels in the surgical stage of N. (superficial, medium and deep), and I. S. Zhorov instead of the agonal stage proposes to distinguish the stage of awakening. Stage I (analgesia) occurs in 3-8 minutes. ether inhalation at its concentration in the blood of 0.18-0.35 g/l. The patient loses orientation in the environment, becomes talkative, then gradually falls into a drowsy state, from which it can be easily brought out by loud appeal. At the end of stage I, consciousness turns off and analgesia sets in. Stage II (excitation) is characterized by the activation of all fiziol, processes and manifestations - the patient is excited, breathing is noisy, the pulse quickens, blood pressure rises, all types of reflex activity increase. In the III (surgical) stage excitation stops and fiziol, functions are stabilized. The range of the surgical stage is great - from superficial N. with the preservation of most reflexes to deep, when the activity of the respiratory and vasomotor central regulatory mechanisms is suppressed. In stage III 1 (superficial, first, level of the surgical stage), calm, even sleep occurs with the preservation of corneal and pharyngeal-laryngeal reflexes and muscle tone. At this stage, only short-term and low-traumatic surgery can be performed. Operations on the organs of the abdominal, thoracic cavities and some others are possible only with the introduction of muscle relaxants. In stage III2 (intermediate level of the surgical stage), with the disappearance of reflex activity and muscle tone against the background of satisfactory hemodynamics and respiration, it becomes possible to perform operations on the abdominal organs without the use of muscle relaxants. In stage III3 (deep level), the toxic effect of the ether on the body begins to manifest itself, with Krom, a gradual expansion of the pupils occurs, their reaction to light fades, the rhythm and depth of breathing are disturbed, tachycardia increases, blood pressure decreases, complete muscular atony develops. N.'s deepening to stage III3 (with mononarcosis) is permissible only for a short period of time in somatically healthy subjects with obligatory assisted breathing. Stage III4 (allocated by Godel) is characterized by extreme inhibition of fiziol, functions with paralysis of the intercostal muscles, suppression of contractility of the diaphragm, hypotension, paralysis of the sphincters. More or less long-term maintenance of N. at this level is impossible, since soon it passes into the agonal stage with a deep respiratory disorder, the disappearance of the pulse and the subsequent cessation of blood circulation. With a wedge, N.'s positions in stage III3 for a long period is unacceptable. N. in stage III4 is unacceptable under any circumstances. The awakening stage, which begins with the complete cessation of the flow of anesthetics into the body, is characterized by an almost sequential passage of all stages of N. in the reverse order, but in a somewhat reduced form (there is almost no, for example, excitation), until consciousness is fully restored.

Inhalation mononarcosis with nitrous oxide carried out with the patient breathing with a mixture of nitrous oxide and oxygen in a ratio of 4: 1 with a total gas flow of 8-10 l / min. After 5-6 min. after the start of inhalation of such a mixture, loss of consciousness occurs with a certain motor and speech excitement, sometimes laughter (this gave reason to call nitrous oxide laughing gas). After another 2-3 min. comes N. in stage III1. It is usually not possible to obtain a deeper level of anesthesia. An increase in the concentration of nitrous oxide in the respiratory mixture is unacceptable, because it entails hypoxia. The level of analgesia achieved is satisfactory, but sufficient muscle relaxation does not develop, therefore, under conditions of mononarcosis with nitrous oxide, only minor operations that do not require muscle relaxation can be performed. In modern anesthesiology, nitrous oxide is widely used as an obligatory anesthetic of any combined N. Due to its beta-adrenergic effect, it not only affects cardiac activity, but also neutralizes to a certain extent the negative inotropic effect of some anesthetics, for example, halothane.

Nitrous oxide in combination with oxygen is widely used when carrying out to lay down. anesthesia, to-ry was developed by B. V. Petrovsky and S. Efuni as a method of postoperative anesthesia. The patient in the postoperative period is carried out using a mask or nasal catheters for inhalation of a gas-narcotic mixture of nitrous oxide with oxygen in the ratios O 2: N 2 O - 1: 1, 1: 2, 1: 3.

Flow halothane mononarcosis are divided into three stages: I - initial, II - transitional (similar to the stage of excitation during ether anesthesia) and III - surgical. The initial stage, which develops with inhalation of 1.5-2-3 vol.% halothane in the respiratory mixture, is short-lived (1.5-3 minutes) and ends with calm breathing and stable blood circulation with loss of consciousness. The transitional stage with halothane N. is observed very rarely, and if it occurs, it lasts no more than 1 minute. and is manifested by slight excitement and sluggish attempts of the patient to get up from the table. In a surgical stage, at a cut performance of operational interventions is possible, allocate two or three levels. Already in stage III1 of ftorothane anesthesia, patients develop satisfactory muscle relaxation against the background of initial signs of a decrease in reflex activity and a certain decrease in blood pressure and mild bradycardia. It has been established that the hypotensive effect observed in all stages of halothane N. is primarily due to the cardiodepressant effect of the anesthetic and the associated decrease in cardiac output. Stage III2 is characterized by further fading of reflex activity, significant muscle relaxation, hypotension and bradycardia; a nek-swarm increase in the respiratory rate can be observed with a weakening of the costal and increased diaphragmatic breathing. At this stage, complete muscle relaxation occurs, significant respiratory depression, both costal and diaphragmatic; the skin remains dry and warm to the touch, the color of the skin and nail beds is ordinary pink, and only with significant respiratory depression develops acrocyanosis, and sometimes general cyanosis. In stage III3, severe hypotension, bradycardia develops, pupils begin to dilate. At all stages of N. halothane there is a progressive decrease in cardiac output of cardiodepressor genesis, a cut is only slightly compensated by an increase in total peripheral resistance or is not compensated at all, which explains arterial hypotension. However, in the deep stages of ftorotane N., the total peripheral resistance is always increased, and this leads to a satisfactory effect of the so-called. centralization of blood circulation, at a cut satisfactorily perfusion of vital organs (a brain, a liver, heart and kidneys), and also skin (pink and warm skin) even at low volumes of cordial emission remains. Since halothane hypotension has a cardiodepressant character, the use of elevated concentrations of halothane to obtain the so-called. the managed hypotension with Kliniko-fiziol, positions cannot be justified.

Etranovy N. (with inhalation of an anesthetic in the amount of 2-3 vol.% in the inhaled mixture) is characterized by the rapid onset of narcotic sleep without a period of excitation and is accompanied by moderate arterial hypotension, caused from the very beginning by N. (unlike N. halothane) Ch. arr. vasolegia with very moderate cardiodepression, which occurs only during the period of deep N. There is usually no clear staging in the wedge, during etran N., since there is an extremely rapid change in wedge, signs. In general, N. etranom proceeds with good stability of hemodynamic parameters without signs of respiratory function depression and with satisfactory muscle relaxation, which allows minor operations to be performed without the use of muscle relaxants. However, the insufficient analytical properties of etran (even less pronounced than with N. halothane) make it necessary to supplement H. with one of the analgesics.

In order to reflect the narcotic power of one or another inhalation anesthetic and express it in terms of the percentage concentration of the anesthetic in the inhaled mixture, i.e., to find the equipotentiality of anesthetics, the concept of the minimum alveolar concentration has been introduced. The concentration of inhalation anesthetic in the respiratory mixture is taken as the minimum, with a cut in 50% of cases, the pain reflex response to a skin incision is suppressed. In the study of this indicator in humans, the following values ​​were established for various anesthetics: diethyl ether - 1.92 vol.%, halothane - 0.765 vol.%, methoxyflurane - 0.16 vol.%, ethran - 1.6 vol.%, cyclopropane - 9.2 vol.%, nitrous oxide - 101 vol.% (i.e., 100% concentration of nitrous oxide in most cases is not enough to prevent a reflex pain response to a skin incision).

The wedge, N.'s picture, caused by a specific inhalation drug - ether, halothane, etran, etc., has, as indicated above, its own specific features. Each stage and level of N. corresponds to a certain concentration of anesthetic in the blood. When using ether as the main anesthetic, stage I (analgesia) develops when the ester concentration in venous blood reaches 18-35 mg per 100 ml; Stage II of essential N. (excitation) is achieved by increasing the content of ether in venous blood to 40-90 mg per 100 ml; Stage III of essential N. is characterized by the content of ether in the venous blood at a concentration of 90-110 to 140-180 mg per 100 ml.

Stage I ftorotanovy N. develops when the concentration of the drug in the venous blood reaches 8-9 mg per 100 ml. The surface level of stage III of halothane N. is characterized by the concentration of halothane in the venous blood of 9-11 mg per 100 ml. The average level is 12-17 mg per 100 ml. A deep level of ftorotane N. (III) develops at a concentration of ftorotane in venous blood of 21–31 mg per 100 ml.

The creation of the necessary concentrations of anesthetics in the body and the maintenance of appropriate levels of N. are facilitated by the use of anesthesia machines and precise evaporators for inhalation drugs. On fig. 2 shows the apparatus for anesthesia "Nar-kon-P", which allows the use of ether, halothane and nitrous oxide as an anesthetic both separately and in various combinations with each other, and as a carrier gas - pure oxygen or oxygen-air mixture containing 45 vol. % O 2 , as well as ordinary air.

On fig. 3 shows a more advanced model of the anesthesia machine - "Polynarcon", which is designed for the use of ether, halothane, trichlorethylene, cyclopropane and nitrous oxide. "Poly-narcon-2" is intended for carrying out inhalation N. by various means; it, like "Narcon-P" and "Polynarcon", provides high accuracy and stability of maintaining the required concentration of anesthetic vapors (due to the evaporator) over a wide range of changes in the flow rate of the carrier gas (Fig. 4). Use of devices for carrying out inhalation N. with exact evaporators creates the best conditions for carrying out N.

Clinic N. non-inhalation drugs(short and ultrashort-acting barbiturates - sodium thiopental, hexenal, baytinal, kemital) is characterized by the rapid development of narcotic sleep, the almost complete absence of excitation, a weak analgesic effect and insufficient muscle relaxation. It is customary to divide the course of barbituric N., achieved by intravenous slow administration of 1-2% solution (up to 500-700 mg of the drug), into three stages. Stage I is achieved already with the introduction of 150-200 mg of the drug and is characterized by a quick calm falling asleep of the patient with some respiratory depression, increased laryngeal and pharyngeal reflexes with hemodynamic stability. In stage II, there is a nek-swarm expansion of the pupils, the preservation of reflex activity, which completely excludes the possibility of tracheal intubation without relaxants, and respiratory arrhythmia, sometimes up to short periods of apnea. Possible motor reaction to pain stimulation. In stage III (surgical), the reaction to pain completely disappears, moderate muscle relaxation occurs, and breathing becomes shallow. At this stage, depression of the contractile function of the myocardium develops, which is manifested by progressive hypotension, which, with further deepening of N., can turn into apnea and asystole. The cardiodepressant effect and the threat of apnea in barbituric N. are not so much associated with the total dose of anesthetic administered over a significant period of time, but with its high concentration (5% or 10%) and very rapid administration. In this regard, the use of barbiturates in concentrations exceeding 2% is unacceptable. In the vast majority of cases, barbiturates are used only for introductory H.

Adequacy of anesthesia (methods of control)

The overall assessment of the adequacy of anesthesia, i.e. its compliance with the nature, trauma and duration of the operation, is based on the assessment of individual components in terms of the general condition of the patient, reflex activity, hemodynamics, gas exchange and oxygen transport, kidney function, muscle relaxation, electrical activity of the brain, etc. The multicomponent nature of N. makes it difficult to determine the depth of narcotic sleep according to the usual generally accepted parameters. At the same time, the trend towards the use of predominantly superficial levels of anesthesia, which significantly increases the safety and effectiveness of N., eliminates the need for an accurate assessment of the level and depth of anesthesia. In modern conditions, a number of general clinical indicators are used to assess the adequacy of N. (such as heart rate, blood pressure, skin color, striated muscle tone, etc., supplementing them with special studies (electroencephalography, electromyography, determining the gas composition of the blood, the volume of circulating blood , cardiac output, etc.), the need for to-rykh arises in special situations.

Heart rate. After sedation, a cut almost always includes atropine, moderate tachycardia (approx. 90-100 beats / m in) is a common condition. Bradycardia on the background of m-anticholinergic blockade with atropine, especially in combination with arterial hypotension, indicates a significant deepening of N., bordering on an overdose of anesthetic. With halothane anesthesia, mild bradycardia is common; it develops from the very beginning of N., but becomes pronounced (up to 50-40 beats / min), if N. is deepened excessively. Such bradycardia is a prognostically unfavorable sign. Increasing tachycardia, especially if it is combined with hypertension, is characteristic of insufficient analgesia even in conditions of satisfactory reflex blockade and muscle relaxation.

Arterial pressure is an integral indicator and is directly dependent on cardiac output and total peripheral resistance. Thus, this indicator only indirectly reflects systemic blood flow, but is valuable in combination with the assessment of other hemodynamic parameters (eg, central venous pressure, pulse, ECG). For introductory N., especially for the period of tracheal intubation and for a short time after it, moderate hypertension is characteristic as a reflection of reflex activity that has not yet been suppressed.

For most types of N. (with its average depth that meets surgical requirements, and good muscle relaxation), normal blood pressure is characteristic. Hypertension that develops during N. (with confidence in the absence of hypercapnia) almost always indicates a lack of analytical effect of general anesthesia and requires either deepening of N. or supplementing it with analgesics. Hypotension during N. (if it is not caused artificially with the help of ganglioblockers) is undesirable and almost always (in the absence of hypovolemia) reflects too deep a level of N. In most cases, hypotension is due to a decrease in myocardial contractility under the influence of an anesthetic and a decrease in cardiac output, less it is a consequence of secondary anesthetic vasodilation.

Monitoring with periodic ECG recording on tape is an important method for monitoring the adequacy of anesthesia and the entire course of N. There are various undesirable forms of ECG changes - from elementary constants (in the form of tachycardia or bradycardia) or periodic rhythm disturbances (in the form of various extrasystoles) to complex disorders conduction, general ischemia and myocardial hypoxia or local disorders of the coronary circulation. Periodic arrhythmias are not prognostically dangerous and disappear in most cases with a change in the general mode of N. and its individual components. Changes in myocardial nutrition are more typical for elderly patients, have a more serious basis and are associated with N.'s regimen only indirectly, that is, they can develop at any level of anesthesia.

Determining cardiac output is a sophisticated method for assessing anesthesia; it is performed only according to indications. A thermodilution method is used, which involves preliminary catheterization of the pulmonary artery with a special floating Swan-Ganz probe and dilution of the dye by the X amyl tone method.

Assessment of spontaneous ventilation of the lungs is based on taking into account the frequency and depth of breathing, its nature (costal, diaphragmatic or mixed type), minute respiratory volume (MOD), determined using a gas meter (see) - ventilometer. The wedge is also taken into account, the symptoms are the appearance of cyanosis, sweating, tachycardia, hypertension, etc. The main parameter in the assessment of respiration is the MOD, which, after being determined with a ventilometer, must be compared with the proper MOD values ​​found by the Radford nomogram. With the suppression of spontaneous respiration and a decrease in MOD, assisted respiration or artificial lung ventilation is indicated.

The assessment of artificial lung ventilation is made on the basis of the due MOD theoretically found for this patient according to the Radford nomogram according to the indicators of the ventilometer - an apparatus that determines the amount of exhaled air. Use also an indicator pCO 2 bloods, to-ry should not go beyond 32-42 mm of mercury. Art.

Assessment of oxygenation and transport function of blood. The presence of cyanosis and a decrease in pO 2 in arterial blood (in extreme cases, capillary blood taken after warming the finger) below 80 mm Hg. Art., as well as a decrease in oxygen saturation of arterial blood below 90-92% indicate the development of hypoxia and require improvement of oxygenation conditions either by increasing the volume of pulmonary ventilation, or by increasing the oxygen content in the inhaled mixture (but not more than 50-60%). Insufficient ventilation of the lungs, in addition to hypoxia, is always expressed by hypercapnia (pCO 2 above 45 mm Hg. Art.). Cyanosis as a symptom of hypoxia appears only in cases where the hemoglobin content of the blood is not lower than the normal level.

The degree of myorelaxation can be assessed by the nature of the relaxation of the abdominal muscles and other muscles, as well as by the absence of patient movements during pain stimulation. More accurately, muscle relaxation is assessed using electromyographic control of the neuromuscular block according to special indications during N. and for the differential diagnosis of postoperative apnea.

Electroencephalographic control of the depth of anesthesia. In connection with the spread of methods of combined anesthesia with muscle relaxants, which eliminated the need for deep stages of N., numerous wedges and symptoms characteristic of mononarcosis disappeared, and it became necessary to fine-tune the depth and adequacy of anesthesia according to the bioelectrical activity of the brain. It is established that at N.'s deepening on EEG (see the Electroencephalography) the accurate dynamics characteristic for each stage and for each separate anesthetic comes to light. At essential N. allocate five stages, to-rye were brought into conformity with classification a wedge, N.'s stages according to Godel (fig. 5, at the left). Stage II, characterized by mixed fast-wave and slow-wave activity, and stage III (slow wave stage) allow operations to be performed. Stage IV (the stage of silent electrical zones) is characterized by the alternation of delta waves with areas of silence and is on the border of complete extinction of the electrical activity of the brain. It corresponds to the 3rd-4th level of the surgical stage of N. according to Godel. With inhalation of nitrous oxide at the maximum allowable concentration (80%) after 5-10 minutes. only the stage of transition of the alpha rhythm into slow-wave activity with a frequency of 4-b cycles with an increase in the amplitude of the waves up to 50-70 microvolts can be achieved. Changes on EEG at ftorotanovy N. are expressed rather essentially and unlike those, to-rye are observed at N. by ether. There are seven EEG stages of halothane N. (Fig. 5, center). Loss of consciousness is observed already in stage I of the fast low-voltage rhythm. Muscle relaxation, slowing of breathing and cessation of eyeball movement with stable hemodynamics is observed during the transition of low-voltage fast activity to slow-wave activity with an oscillation frequency of 4-6 sec. with an average amplitude (II EEG stage). In the III EEG stage, there is a tendency to arterial hypotension and moderate bradycardia. IV and V EEG stages of halothane anesthesia are characterized by slow-wave activity of predominantly high amplitude and correspond to deep wedges, stages of N. Maintaining N. in the V EEG stage is undesirable, and in stages VI and VII it is unacceptable.

The patterns of development of barbituric N. according to the EEG are similar to the dynamics of the EEG during inhalation anesthesia and go through the activation of the electrical activity of the brain, slowing down the frequency of oscillations and increasing their amplitude with the transition to all lengthening periods of silence (Fig. 5, right). Characteristic for barbituric anesthesia is the appearance of spike activity in the I EEG stage.

Anesthesia in emergency surgery

The lack of sufficient information about the patient's condition, the state of shock, and so-called. a full stomach are the main problems that arise during emergency N. The task of the anesthesiologist is, if possible, a quick and complete examination of the patient to determine the func- tions , the state of various organs and systems. However, even with the most urgent need to obtain additional information about the patient's condition, the anesthesiologist has no right to delay the start of anesthesia with absolute indications for an emergency operation. The general rule in emergency anesthesiology is probing and complete emptying of the stomach before the onset of N. Prevention of regurgitation and aspiration of gastric contents is to place the patient in the Fowler position and use the Sellick technique. Inadmissible in emergency anesthesiology, as well as in other situations, is the tamponade of the pharynx with a gauze swab when using an endotracheal tube without a cuff. In patients in a state of shock, the advantage should be given to N., which does not have a significant effect on cardiac output, peripheral vascular resistance and hemodynamics in general. To the greatest extent, these requirements are met by the method of neuroleptanalgesia and various methods of combined anesthesia with the addition of morphine, pentazocine, diazepam and other narcotic and sedative drugs.

The anesthesia in out-patient conditions can be carried out at various diagnostic procedures, mainly endoscopies, in stomatol. practice during the extraction of teeth, as well as when processing them for prosthetics, short-term and non-traumatic surgical and gynecological, operations and procedures (opening abscesses, curettage of the uterine cavity, dressings, etc.). One of the main requirements, as in emergency anesthesiology, is the emptying of the stomach. Another condition is the possibility for the patient to leave the clinic soon after N. (after 30 minutes). Apply inhalation mask N. with nitrous oxide and halothane, as well as intravenous N. with sombrevin.

Anesthesia in pediatric surgery

When conducting N., face masks, breathing bags and absorbers of anesthesia machines, endotracheal tubes, laryngoscopes, injection needles, tubes for cannulating vessels, aspiration catheters should be of the appropriate size for each age group of children.

General somatic preparation for N. is aimed at the possible correction of existing violations of the main vital functions of the body. Psychological preparation is especially important for children older than 3 years. The anesthesiologist gets to know the child in advance, convinces him that surgery under N. is painless, sometimes it is useful for older children to explain the individual stages of anesthesia - oxygen inhalation through a mask, intravenous injections. A small child is warned that he will be transferred to another room, allowed to breathe through a mask, “warmed up”, etc.

Premedication for children who do not suffer from severe allergies, most often consists of intramuscular administration for 15-20 minutes. before the beginning of N. promedol and atropine. In children under the age of 6 months. promedol depresses respiration. Therefore, after the introduction of this drug, the child should be under constant supervision. Children prone to allergic reactions are additionally prescribed at night and on the day of surgery, ataractic, antihistamine, antipsychotic, hypnotic drugs. A good premedication effect is achieved by the administration of atropine with thalamonal, a combination of atropine, droperidol and diazepam. It is very convenient to use a combination of atropine and droperidol or atropine and diazepam with ketamine as a premedication. After 8-10 min. after intramuscular administration of ketamine at a dose of 2.5 mg/kg, the child falls asleep and can be transferred to the operating room. In essence, premedication with ketamine provides not only preparation, but also induction in N. Preliminary administration of diazepam and droperidol reduces the side effects of ketamine - increased blood pressure, tachycardia and convulsive readiness.

Doses of medicinal substances in milligrams per body weight in children are usually somewhat higher than in adults. The table shows the approximate total doses of drugs used for premedication in children of different ages.

Table. Doses of drugs prescribed for premedication of children of different ages

A drug	Doses given to children at different ages (mg)
	newborns	6 months
Atropine sulfate, 0.1% solution
Diphenhydramine
Diprazine
Droperidol
Meprotan
Metacin, 0.1% sol.
Sodium oxybutyrate	10 0 - 1 50 mg/kg intramuscularly
Promedol
Diazepam
Suprastin
Talamonal	0.1 ml per year of life

Introductory N. to children under 5 years old is most often carried out with the help of inhalation anesthetics: halothane and nitrous oxide. If a child, on the background of premedication, is oriented in the environment, then a mask cannot be forcibly applied. Initially, it is held at a distance of 5-8 cm from the child's face and pure oxygen is supplied through it. You can use a special mask-toy. The mask is gradually brought closer and placed on the child's face. Within 40-60 sec. produce oxygen inhalation, then set the supply of 60-70 vol.% nitrous oxide and 40-30 vol.% oxygen, and after another 60-90 sec. halothane is added to the respiratory mixture, gradually increasing its supply from 0.5 to 1.5-2.0 vol.%. As a powerful anesthetic in the absence of halothane, ether up to 3-4 vol.% or cyclopropane 12-15 vol.% can be used. Against the background of premedication with neuroleptic drugs or ketamine, induction in N. is possible with the help of inhalations of nitrous oxide with oxygen in a ratio of 2: 1 .

Children with well-marked veins or in those cases where cannulation of the vein was performed the day before, introductory N. can be carried out with 1-2% solutions of hexenal or 1% solution of thiopental-sodium administered intravenously. Introductory intravenous N. can be carried out with sombrevin (propanidide). The drug is administered at a dose of 5 - 7 mg / kg to children over 8-10 years old in 5% solution, and for younger children, the concentration of the solution is reduced by 2 times. Introductory N. can be obtained by intravenous administration of sodium hydroxybutyrate (GHB) at a dose of 100–150 mg/kg. The official 20% solution is diluted in 10-20 ml of 5% glucose solution. The drug is administered slowly over 2-4 minutes. Sleep usually comes in 3-4 minutes. after drug administration.

Young children often use inhaled N. with nitrous oxide, halothane, and oxygen to maintain anesthesia. The gas-narcotic mixture should contain at least 30-40 vol.% oxygen and not more than 1.0-1.5 vol.% halothane. If it is necessary to deepen N., it is better to use narcotic analgesics: promedol at a dose of 1.0-2.0 mg/kg.

The most adequate anesthesia is provided when using large doses of narcotic analgesics: administration of promedol during the operation at a dose of 2-3 mg/kg in combination with premedication with GHB or diazepam or inhalation of nitrous oxide with oxygen. After such N., artificial ventilation of the lungs is required for 8-12 hours.

Endotracheal N.'s carrying out in combination with muscle relaxants is shown in the following cases: 1) at operations with opening of a pleural cavity; 2) for large and prolonged operations, when a good relaxation of the muscles is required; 3) during operations in children who are in serious condition, when respiratory failure, cardiovascular activity is possible; 4) during operations on the head, mouth, neck; 5) during surgical interventions, when it is necessary to create an antiphysiological position on the side, on the stomach with the head down; 6) in most operations on newborns.

Due to the increased vulnerability and the risk of subsequent swelling of the subglottic space, tracheal intubation in children should be carried out carefully and atraumatically. It should be remembered that in young children the epiglottis is shorter. Tracheal intubation is carried out with complete relaxation of the muscles after the introduction of muscle relaxants. Only newborns can sometimes perform this manipulation under N. without muscle relaxants after forced hyperventilation of the lungs. For tracheal intubation in children, smooth tubes without cuffs must be used. The length of the endotracheal tube is approximately one and a half distances from the corner of the mouth to the earlobe. During operations in the oral cavity, tracheal intubation through the nose is indicated. To do this, a smooth tube is inserted under N. without effort, preferably through the right lower nasal passage into the oral cavity, then after the introduction of muscle relaxants under the control of a laryngoscope, it is passed through the glottis. Specially curved intubation forceps Medzhilla are convenient for this manipulation, to-rymi take the mouth end of a tube.

Muscle relaxants in children are used for short-term and long-term muscle relaxation. Young children are more resistant to depolarizing and, conversely, sensitive to non-depolarizing muscle relaxants. Single doses (in mg/kg) of depolarizing muscle relaxants (succinylcholine, listenol, muscle relaxin) for children are slightly higher than for adults. Before tracheal intubation, depolarizing muscle relaxants are administered at a dose of 2-2.5 mg/kg; doses of 1.0-2.0 mg/kg are used to maintain myoplegia. Usually, one or more injections of depolarizing muscle relaxants and moderate hyperventilation of the lungs against the background of the surgical stage of N. provide good relaxation of the muscles and switching off breathing. Non-depolarizing muscle relaxants (tubocurarine) are used at a dose of 0.25-0.4 mg/kg. This dose causes apnea for 10-20 minutes. and provides good muscle relaxation for 30-40 minutes. Subsequent doses are V2-2/3 of the original. As a rule, muscle relaxants are administered intravenously, but in cases where the veins are poorly defined, they are administered intramuscularly or under the tongue. In this case, the doses of depolarizing muscle relaxants should be increased to 3-4 mg/kg. The effect of such an introduction occurs in 90-120 seconds. and continues for 5-7 minutes. Tubocurarine is administered intramuscularly at a dose of 0.3-0.5 mg/kg.

Neuroleptanalgesia is indicated during operations for children with impaired renal and hepatic function and shifts in the basic constants of the body. For 40-60 min. before the start of the operation, thalamonal is administered intramuscularly at a dose of 0.25-1.0 ml, atropine at age-specific dosages. On the operating table, 0.2-0.4 ml of thalamonal a is re-introduced intravenously against the background of inhalation of nitrous oxide and oxygen in a ratio of 2:1. After the introduction of the muscle relaxant, tracheal intubation is performed. In the future, general anesthesia is maintained by fractional administration of fentanyl at a dose of 0.3-1.0 ml every 20-30 minutes. and droperidol 2.0-5.0 ml every 1/2-2 hours. After the cessation of inhalation of nitrous oxide in children, consciousness is restored very quickly.

In large and traumatic operations, it is advisable to use ketamine for premedication and induction in N., and against this background, carry out endotracheal N. with nitrous oxide with low concentrations of halothane (0.5-0.7 vol.%). Ketamine N. in its pure form (mononarcosis) is most indicated for emergency operations lasting 40-60 minutes, if artificial lung ventilation is not required. The advantage of this type of anesthesia is a quick and easy induction in N., the absence of a hypotensive and emetic effect.

N. at newborns has the features. For premedication, it is advisable to use only atropine at a dose of 0.1 ml. For induction in N. and maintenance of anesthesia, nitrous oxide with oxygen and halothane are used. In traumatic operations, the concentration of halothane should be reduced and promedol should be used at a dose of 0.5-0.8 mg/kg. In debilitated patients with a lack of weight, tracheal intubation can be carried out after the administration of atropine before the onset of N. In "strong" newborns with good muscle tone, it is better to intubate the trachea after the onset of N. and the introduction of muscle relaxants.

It is very important during N. at the operated child to maintain normal body temperature, for which they use a heated operating table, warming and moistening the gas-narcotic mixture and intravenous administration of solutions warmed to body temperature. Blood loss must be replaced with a similar volume of fluids (“drop by drop”). Blood loss up to 10% of blood volume (25-30 ml) is compensated with rheopolyglucin, polyglucin, 5-10% glucose solution. With blood loss, St. 10% of the volume of circulating blood must be compensated for the lost volume with blood and blood substitutes in a ratio of 1: 1. In addition to compensating for blood loss, liquid is additionally administered in a volume of 4-8 ml / kg per hour.

Anesthesia in the elderly and senile age

Old age is not considered a contraindication for N. In a planned operation, preparation with sedative drugs (diazepam or chlordiazepoxide) is started 2-3 days before the operation. To ensure a good night's sleep, sleeping pills are prescribed, preferably barbiturates - phenobarbital, etaminal sodium, etc. Opium derivatives (morphine, omnopon) should not be prescribed to elderly and senile patients, since these drugs depress breathing and suppress the cough reflex. The choice of the method of main anesthesia is determined by the patient's condition: the more severe the condition, the more superficial anesthesia should be with sufficient analgesia. Often, inhalation of nitrous oxide with oxygen in a ratio of 3: 1 or 4: 1 is quite satisfactory. Neuroleptanalgesia gives good results against the background of inhalation of nitrous oxide with oxygen. If the use of halothane is inevitable, its concentration in the respiratory mixture should not exceed 1.5 vol.%. Steroid N. (viadryl, algesin) and sodium oxybutyrate are successfully used. To ensure postoperative analgesia, it is advisable to administer pentazocine (fortral).

Anesthesia in the military field

Anesthesia in the field conditions was first carried out by N. I. Pirogov in 1847 during the military operations of the Russian army in the Caucasus (with ether, and then with chloroform). During the war of 1914-1918, despite the advantages of local anesthesia revealed by that time, general anesthesia methods were mainly used in military field surgery. Chloroform, ether, chloroethyl, and a combination of these anesthetics served as the means for her. During the Second World War, the approach to the choice of anesthesia in the armies of the warring countries was different. Soviet military field surgeons used mainly local anesthesia, and at the beginning of the war they resorted to general anesthesia in only 15-20% of operations. By the end of World War II, the use of general anesthesia methods increased, and N. was used in 30-35% of operations. In the armies of the United States and England, from the very beginning of the war, general anesthesia was given the main place, and it was mainly provided by specially trained doctors and paramedical staff.

In the post-war period, in connection with the successful development of anesthesiology and the staffing of this specialty in military medicine, prerequisites appeared for the use of more advanced methods of general anesthesia. In modern conditions for its carrying out in the majority of armies are provided in the state of military field to lay down. institutions of anesthesiologists and anesthetists. Special kits, anesthetic, breathing apparatus and some other technical means necessary for general anesthesia were adopted for equipment. The arsenal of pharmacol, means for N. has significantly increased: ether, halothane, trichlorethylene, nitrous oxide, barbiturates (hexenal and thiopental-sodium), preparations for neuroleptanalgesia, long-term and short-acting muscle relaxants, etc.

In military field conditions, general anesthesia is indicated for the surgical treatment of extensive soft tissue wounds, during operations for most penetrating wounds and closed injuries of the chest and abdominal cavities, common burns, injuries with damage to large bones and joints, main vessels, and amputations of limbs, major neurosurgical and maxillofacial operations and some other interventions, as well as complex and painful dressings. N. is indicated in cases where the affected before the operation have violations of vital functions (respiration, blood circulation) or these violations can occur during the operation, as well as during operations undertaken before removing the affected from the state of shock.

A distinctive feature of N. in military field conditions is the relative unpreparedness of the affected to N. and the dependence of methods and means of anesthesiology, help from honey. conditions, stage honey. evacuation and the nature of the task to be solved by the stage. At the stage of qualified surgical care, simple N. methods prevail - mask and intravenous with spontaneous breathing or with artificial ventilation of the lungs with air; at the stage of specialized surgical care - combined methods of general anesthesia with artificial ventilation of the lungs with a gas-narcotic mixture, controlled ganglionic blockade, hypothermia, etc.

At the choice of a method - N. and technique of its carrying out basic provisions remain in force, to-rymi anesthesiologists in peacetime are guided. Along with it the features arising from an originality of working conditions field to lay down are considered. institutions. Preference is given to simpler, but quite effective methods that allow you to quickly provide the necessary degree of anesthesia and quickly awaken the affected person after surgery. When choosing and conducting anesthesia, it should be taken into account that many affected patients arrive at the operating table in a state of shock, with large blood loss, and respiratory failure. At the same time, the anesthesiologist does not have enough time for a comprehensive assessment of their condition and preoperative preparation, he is limited in the choice of pharmacol, means and technical support for anesthesia.

Premedication in most cases has to be carried out on the operating table. Moreover, the doses and time of injection of painkillers and sedatives received by the affected at the previous stages are taken into account. In the absence of a pronounced residual effect, morphine (10 mg) is administered intravenously in combination with atropine (0.5-0.8 mg) and diprazine (25 mg) or droperidol (2.5-5.0 mg).

The main anesthetics for induction are short-acting barbiturates. Hexenal or thiopental-sodium is administered at a dose of 200-400 mg in 1% or 2% solution. Severely affected, with hypersensitivity to barbiturates, the drug must be administered more slowly and at a lower dose. For induction in N. with success it is possible to use halothane inhalation in combination with nitrous oxide or azeotron mixture.

Against the background of relatively stable indicators of gas exchange and blood circulation, most short-term operations can be performed with independent breathing of the affected person without transfusion of fluid and the introduction of any additional pharmacol, agents. Hexenal or sodium thiopental, ketamine, an azeotropic mixture, halothane, or its combination with nitrous oxide can be used as the sole or main anesthetic.

With long and significant operations, it is advisable to use the endotracheal) method of general anesthesia in combination with artificial lung ventilation. At the same time, the introduction of pharmacol, agents aimed at improving blood circulation, gas exchange and correcting possible metabolic disorders can be shown to those who are seriously injured with hemodynamic and respiratory disorders. Means of choice for maintaining en to tracheal N. are drugs for neuroleptanalgesia (fentanyl, Droperidol) in combination with insufflation of nitrous oxide, ether, or an azeotropic mixture. With combined radiation injuries, non-inhalation methods of N. are preferable; doses of anesthetics and muscle relaxants should be reduced by 15-20%.

In military field conditions, cases are not ruled out when N. will be forced to carry out persons who do not have special training in this area. Under such circumstances, it is advisable to use the simplest, albeit imperfect, method of ethereal N. with the help of Esmarch's mask or anesthesia apparatus, as was done during the Great Patriotic War.

From additional materials

ANESTHESIA(- artificially induced by pharmacological or electrical means, accompanied by loss of consciousness, suppression of pain sensitivity, relaxation of skeletal muscles and inhibition of reflex activity. There are no absolute contraindications to anesthesia. operational stress.

Contraindications in specific clinical situations are primarily associated with the clinical and pharmacological characteristics of the anesthetic agent. Optimal anesthesia involves an exhaustive assessment of the patient's condition before surgery, the correct choice of the type of anesthesia and means for its implementation at all stages from premedication and induction of anesthesia to the period of maintenance and exit from anesthesia. Tables 1 and 2 show the main clinical and pharmacological information about inhalation and non-inhalation anesthetics: physicochemical characteristics, pharmacological action, main indications and contraindications for use, side effects and complications,.

Table 1. BASIC CLINICAL AND PHARMACOLOGICAL INFORMATION ABOUT INHALATION ANESTHETICS

The name of the drug. Typed in italics are published as independent articles	Physico-chemical characteristic	pharmachologic effect		Narcotic concentration, vol. % (ml/100ml)		Concentration in blood, mg/100 ml, causing		Side effects and complications	Contraindications	The main forms of release and methods of storage
				introductions		stage of surgical anesthesia	stop
Nitrous oxide	Gas, colorless, with a slight sweet smell. Relative density 1.527; i ° kip -89 °. Does not burn, but supports combustion and enhances the explosion in mixtures with ether and other substances	In terms of narcotic activity, it is 25 times weaker than ether, it has a wide range of narcotic effects. Creates a pronounced analgesia in concentrations that do not cause loss of consciousness. Easily absorbed, diffuses through cell membranes, readily soluble in water, tissue fluids, and blood. The period of induction into anesthesia is very short. The exit from anesthesia occurs after 3-5 minutes. after cessation of inhalation. It is characterized by rapid excretion from the body: it is excreted unchanged by the lungs after 10-15 minutes. after cessation of inhalation. Causes hypoxia in a mixture with oxygen at a percentage (nitrous oxide) above 80%. Inadequately relaxes skeletal muscles	Inhalation anesthesia for all types of operations in a semi-open and semi-closed system. For relief of pain in myocardial infarction, acute coronary insufficiency, pancreatitis. For pain relief in childbirth, pain relief in the postoperative period (the so-called therapeutic anesthesia), for instrumental studies					Diffuse hypoxia, increased bleeding, depression of bone marrow function with prolonged use		Metal gray cylinders with gas in a condensed (liquid) state under a pressure of 50 atm
Methoxyflurane	Colorless transparent liquid with a specific pleasant smell, reminiscent of the smell of fruits. Relative density 1.42; *°Kip 10 5°. Non-flammable and non-explosive at clinical concentrations	In subnarcotic doses, it causes analgesia, and in higher concentrations it has a powerful anesthetic effect. The effect develops in 10-15 minutes. and lasts 15 - 60 minutes. The analgesic effect persists after the restoration of consciousness. Post-narcotic depression completely disappears after 2-3 hours. Provides good muscle relaxation, maintains a stable heart rate	Inhalation anesthesia for all types of operations, especially on the heart and blood vessels. For general anesthesia and analgesia for anesthesia in obstetrics and dentistry, for endoscopy, catheterization, etc. For analgesia for pain syndromes of various origins, including pain relief in the postoperative period. Anesthesia can be carried out in a semi-open, semi-closed or closed system using a vaporizer (the safest method is using a special vaporizer outside the circulation circle), as well as in an open drip system using a simple Esmarch mask					The long period of introduction to an anesthesia, during to-rogo excitation is observed. Moderate decrease in blood pressure. Slight respiratory depression. Moderate and reversible inhibition of liver and kidney function. Expressed post-drug depression. Actively penetrates into the rubber parts of anesthesia machines with subsequent reverse diffusion	Diseases of the kidneys, liver. Severe myocardial disease, pheochromocytoma	Dark glass bottles of 100 ml. Store in tightly closed bottles in a cool place (sp. B)
T richlorethylene	Colorless transparent liquid with a characteristic odor. Relative density 1.462-1.466; t° kip 86-88°. Non-flammable and non-explosive at clinical concentrations	The narcotic effect develops quickly (after 1-2 minutes) and ends after 2-3 minutes. after cessation of inhalation. Already in small concentrations (the first stage of anesthesia) causes strong analgesia. Well relaxes skeletal muscles, increases the frequency of breathing and heart rate	For short-term anesthesia and pain relief in surgery and obstetrics, dentistry, painful procedures and diagnostic studies. To maintain anesthesia during combined general anesthesia. Applies only to semi-open systems without absorber using a special evaporator					Severe rapid breathing (tachypnea), arrhythmias, toxic damage to the liver and kidneys	Diseases of the lungs, liver, kidneys, as well as arrhythmias, anemia	Hermetically sealed dark bottles of 60 and 100 ml. Store in a dry, cool, dark place (sp. B)
Fluorotan	Colorless transparent liquid with a sweet smell. Relative density 1.865 - 1.870; t°K ip 49 - 51°. Vapors of halothane mixed with air, oxygen, nitrous oxide do not explode and do not ignite	In terms of narcotic activity, it is 3 times stronger than ether. The period of administration proceeds calmly and is not accompanied by a feeling of suffocation. After 1-2 min. after the start of inhalation, loss of consciousness occurs, and after 3-5 minutes. enters the surgical stage of anesthesia. The main amount of the drug is excreted by the lungs, up to 10-12% of halothane undergoes decomposition with the formation of trifluoroacetic acid and bromides, which are excreted by the kidneys. Rapid recovery from anesthesia	Inhalation anesthesia for all types of operations, especially on the organs of the chest cavity. For short-term operations in polyclinic conditions, in stomatol, practice. Applied in a semi-open, closed or semi-closed system with an adsorber using a specially calibrated evaporator located outside the circulation circle					Rapid onset of overdose and respiratory depression with deepening anesthesia. Causes a decrease in myocardial contractility, arrhythmias, bradycardia (up to cardiac arrest), hypotension, increased bleeding, impaired liver function, decreased uterine tone	Liver disease, pheochromocytoma, heart failure, hypotension, arrhythmias, severe hyperthyroidism	Hermetically sealed orange glass bottles of 50 ml. Store in a dry, cool, dark place (sp. B)
X loroform	Colorless transparent liquid with a sweet smell. Relative plot-	An active drug with a small breadth of therapeutic action, in terms of narcotic activity it exceeds ether by 4-5 times. Report-	As the main narcotic drug, it is used extremely rarely - only if there is an exact					Irritation of the mucous membrane of the respiratory tract, spasm of the larynx. Sensitizing	Liver disease, kidney disease, diabetes, respiratory disease	Hermetically sealed orange glass bottles of 50 ml (sp. B)
	density 1.474 -1.48 3; 2 °kip 5 9 - 6 2e. Vapors do not ignite or explode	the stages of anesthesia are clearly expressed. With a slow introduction to anesthesia, there is no excitation. The surgical stage of anesthesia develops in 5-7 minutes. after the start of inhalation. The exit from anesthesia occurs a few minutes after the cessation of inhalation. Post-drug depression disappears after 30 minutes. Provides good muscle relaxation	evaporator outside the circulation circle. It is used for induction anesthesia during ether anesthesia and to enhance the action of nitrous oxide during combined anesthesia. It is possible to use in an open system drip using a simple Esmarch mask and in a semi-closed or closed system using an anesthesia machine					no myocardium to adrenaline, causes arrhythmias (up to cardiac arrest), dystrophic changes in the myocardium, as well as toxic damage to the liver and kidneys, metabolic disorders, hyperglycemia, nausea and vomiting	levania, arrhythmias, hypertension, heart failure
Chloroethyl	Clear, colorless liquid with an ethereal odour. Relative density 0.919 - 0.923; Gkip 12 - 13°. Vapors mixed with air or oxygen are explosive	Active drug with a small breadth of therapeutic action. Anesthesia develops in 2-3 minutes. after the start of inhalation. Recovery from anesthesia is fast. The drug is excreted by the lungs in unchanged form. Has a local anesthetic and irritant effect	For short-term anesthesia (opening abscesses, extracting drains, etc.) or for induction anesthesia in children. For local surface anesthesia (cooling of the skin surface). Can be used in an open system drip and with oxygen through the evaporator of a conventional anesthesia machine					Due to the small breadth of the narcotic action, overdose and respiratory depression are possible, therefore its use is possible only in rare cases (for induction anesthesia). Due to toxicity, they are not used for basic anesthesia. Violates metabolic processes, circulatory disorders, headaches, nausea and vomiting may occur	Diseases of the respiratory tract, heart, lungs, liver	Ampoules of 30 ml. Store in a cool, dark place (sp. B)
Cyclopropane	A colorless gas with a sweet smell. Relative density 1.879. Forms explosive mixtures with air, oxygen and nitrous oxide	Strong general anesthetic. Introduction to anesthesia and removal from it is fast (2 - 3 minutes). It is excreted unchanged by the lungs within 10 minutes. May cause short-term hyperglycemia, increases the sensitivity of the myocardium to adrenaline. Stimulates the choline-reactive systems of the body	Inhalation anesthesia for all types of operations, especially in children during induction of anesthesia, as well as in the elderly and in patients with diabetes, with impaired liver function, with lung diseases. Used in combination with other general anesthetics. Can be used in a semi-open, semi-closed or closed system with significant reversal of inhaled gases					Increased salivation, spasm of the larynx, respiratory depression (apnea), hypercapnia, acidosis, arrhythmias, increased arterial and venous pressure; vomiting, intestinal paresis, acute psychosis, the so-called. cyclopropane shock in the postoperative period. All complications caused by cyclopropane are associated with its use in its pure form. There are no complications with its combined use.	Bronchial asthma, arrhythmias, pheochromocytoma, thyrotoxicosis	Metal orange cylinders with a capacity of 1 and 2 liters with liquid gas under pressure 5 atm
Ether for anesthesia (see Ethyl ether)	Colorless, transparent volatile liquid with a characteristic odor. Relative density 0.713-0.714; £°bp 34-35°. Ether vapors mixed with oxygen, air, nitrous oxide are explosive	It inhibits electrically excitable cell membranes, disrupts the process of the emergence of an action potential. The stages of anesthesia are clearly expressed depending on the concentration of the drug in the inhaled air and blood. It is allocated from an organism lungs (92%), skin, kidneys and through went. - kish. tract. The drug is strongly sorbed by tissues, and its complete elimination lasts for several days. Significantly does not depress breathing, activates the sympathetic-adrenal system, increases the stroke and minute volume of the heart, speeds up the pulse, moderately constricts peripheral vessels	Inhalation anesthesia for all types of operations. Applied in an open system by drip using a mask and in a semi-open, semi-closed or closed system using anesthesia machines					The long period of introduction to an anesthesia, during to-rogo the expressed excitement is observed. Irritation of the mucous membrane of the respiratory tract, increased secretion of bronchial glands, saliva and mucus, cough, laryngospasm, increased blood pressure, tachycardia, postoperative pneumonia	In some cases, with pulmonary tuberculosis, acute inflammatory diseases of the lungs and respiratory tract; cardiovascular diseases with increased blood pressure, severe forms of liver failure, diabetes mellitus, metabolic acidosis, myasthenia gravis, adrenal insufficiency	Hermetically sealed orange glass bottles of 100 and 150 ml. Store in a cool, dark place, away from fire (sp. B)

Table 2. BASIC CLINICAL AND PHARMACOLOGICAL INFORMATION ON NON-INHALATION ANESTHETICS

The name of the drug. Typed in italics are published as independent articles	Physico-chemical characteristic	pharmachologic effect	Main indications for use	Concentration and used doses of the drug	Side effects and complications	Contraindications	The main forms of release and methods of storage
Hexenal	White, slightly yellowish powder of bitter taste, soluble in alcohol and water. R-ry prepared ex tempore	Depending on the dose, it has a sedative, hypnotic and narcotic effect. With intravenous administration, the effect develops after 1 - Ix / 2 minutes. and lasts 15 - 30 minutes. The short duration of action is due to the rapid inactivation of the drug in the liver. Causes moderate relaxation of skeletal muscles, retrograde amnesia	Used intravenously, mainly for induction anesthesia in combination with inhalation anesthetics. Used for short-term operations, diagnostic procedures, for the relief of mental arousal	2-5% solution is used. In debilitated, debilitated, elderly patients, in children and in cardiovascular disorders, 1-2% solution is used. The maximum allowable dose is 1 g	Inhibition of the respiratory and vasomotor centers, motor and mental excitation upon recovery from anesthesia	Diseases of the liver, kidneys, sepsis, inflammatory diseases of the nasopharynx, febrile conditions, pronounced circulatory disorders, a sharp decrease in the level of metabolism, anemia, exhaustion	Hermetically sealed glass vials of 1 g. Store in a dry, cool, dark place (sp. B)
Ketamine (see Non-Inhalational Parkosis)	White crystalline powder, easily soluble in water; pH of the solution is 3.5 - 5.5. Official solutions for intramuscular injection contain 50 mg of the drug in 1 ml, solutions for intravenous administration contain 20 mg of the drug in 1 ml	It has a fast general anesthetic effect. With intravenous administration, the effect develops after 1-2 minutes. and lasts 10-15 minutes, with intramuscular injection - the effect develops after 6-8 minutes. and lasts 3 0 - 40 minutes. Has a wide range of therapeutic effects	For induction and main anesthesia in combination with nitrous oxide and oxygen. It is used during operations and manipulations that do not require muscle relaxation, with preserved spontaneous ventilation of the lungs or in combination with muscle relaxants and other drugs for anesthesia while providing artificial ventilation of the lungs.	For intravenous general anesthesia, a dose of 2 mg / kg of weight (mass) is used, for intramuscular anesthesia - 6 mg / kg of weight	Increases salivation, causes an increase in blood pressure, increases heart rate and cardiac output, causes muscle rigidity. Psychomotor agitation, hallucinations are possible when coming out of anesthesia.	Cerebral circulation disorders, severe hypertension, circulatory decompensation, eclampsia, preeclampsia	Vials of 20 and 10 ml (sp. A)
Sodium oxybutyrate propanidide	White with a creamy tint crystalline powder, highly soluble in water; pH of the solution 7.7 - 8.7 Light yellow oily liquid, insoluble in water	According to chem. to a structure and pharmakol, to properties it is close to gamma-aminobutyric to - those participating in regulation of brake processes in c. n. with. Depending on the dose, it has a sedative, hypnotic and narcotic effect. It reduces motor activity, increases the resistance of brain and heart tissues to hypoxia, slightly reduces blood pressure and slows down the pulse. With intravenous administration, the effect develops after 5-10 minutes. and lasts up to 4 hours, but the drug causes insufficient analgesia It has an ultra-short narcotic effect. The effect develops after 20-40 seconds. and lasts 4-6 minutes. Post-narcotic depression disappears in 20-30 minutes. The short duration of action is due to rapid inactivation by enzymatic cleavage	For induction and main anesthesia; for mononarcosis during low-traumatic operations with the preservation of spontaneous breathing, as a hypnotic in violation of falling asleep; to relieve mental arousal; for the prevention and treatment of hypoxic cerebral edema Used intravenously for mononarcosis during short-term operations in clinical and outpatient settings (biopsy, reduction of dislocations, etc.) and for induction anesthesia	An official 20% solution is used at the rate of 70-120 mg/kg of body weight intravenously and 100-150 mg/kg of body weight orally The average narcotic dose is 8-10 mg/kg of body weight. In debilitated patients and children, 2.5% solution is used. Re-introduction (in case of insufficient dose) no more than 2 times in doses constituting 2/3 and 3/4 of the initial	Low toxicity. With a quick introduction, motor excitation, convulsive twitching of the limbs and tongue is possible. When exiting anesthesia - motor and speech excitation Hyperventilation, apnea, tachycardia, nausea, hiccups, muscle twitching, sweating, salivation, sometimes pain along the veins, phlebitis, increased pressure in the pulmonary artery	Hypokalemia, myasthenia gravis. Limited use for toxicosis of pregnancy with hypertensive syndrome Shock, hemolytic jaundice, renal failure, tendency to convulsions. Limited use for violations of coronary blood flow, hypertension, allergies	Powder and 10 ml ampoules with 20% solution. Store in tightly sealed dark glass jars, solutions - in sealed ampoules (sp. B) Ampoules of 10 ml with 5% solution (sp. B)
	White crystalline powder, highly soluble in water; pH of the solution is 7.8-10.2. R-ry prepared ex tempore	A steroid drug devoid of active hormonal properties. It has a significant breadth of therapeutic action (three times more than that of barbiturates). The effect develops in 3-5 minutes. and lasts 30-60 minutes. dose dependent. There is a secondary dream. Well relaxes muscles, inhibits reflexes from the trachea and bronchi	Used intravenously for induction and main anesthesia in combination with inhalation anesthetics and for mononarcosis	2.5% solution is injected quickly in an amount of 0.5 - 1 g. The surgical stage of anesthesia occurs with the introduction of 15-20 mg / kg of body weight	Pain along the veins, phlebitis. With rapid administration - a decrease in blood pressure, arrhythmias	Thrombophlebitis	Hermetically sealed bottles of 0.5 g. Store in a place protected from light (sp. B)
Thiopental-sodium	The crystalline mass is slightly greenish in color, highly soluble in water; pH of the solution is 10.5. R-ry prepared ex tempore	It acts like hexenal, has a hypnotic effect in small doses, and a narcotic effect in large doses. The effect develops faster than that of hexenal, and is more pronounced. Relaxes skeletal muscles more than hexenal. The recovery period is shorter. The short duration of action is due to the redistribution of the drug in the fat depot.	Used intravenously for induction and main anesthesia in combination with inhalation anesthetics	Apply 2-2.5% solution. In children, the elderly and debilitated patients, 1% solution is used. For induction anesthesia, 400-600 mg is sufficient. Can be used as a 5% solution orally and in suppositories (eg in children). The highest single dose for adults with intravenous administration of 1 g	Slight depression of the respiratory and vasomotor centers, laryngospasm, profuse salivation, cough and other signs of vagotonia. Causes severe irritation if injected into the artery and under the skin	Diseases of the liver, kidneys, diabetes, cachexia, collapse, bronchial asthma, inflammatory diseases of the nasopharynx, fever, shock, anabolic acidosis, Addison's disease	Hermetically sealed glass vials of 0, 5 and 1 g. Store in a dry, cool, dark place (sp. B)

Bibliography: Bunyatyan A. A., Ryabov G. A. and Manevich A. 3. Anesthesiology and resuscitation, M., 1977; Vishnevsky A. A. and Shraiber M. I. Military field surgery, M., 1975; Darbinyan T. M. and Golovchinsky V. B. Mechanisms of anesthesia, M., 1972; Zhorov I. S. General anesthesia, M., 1964; Manevich A. 3. Pediatric anesthesiology with elements of resuscitation and intensive care, M., 1970; The experience of Soviet medicine in the Great Patriotic War of 1941-1945, vol. 3, part 1, p. 492, M., 1953; Guide to anesthesiology, ed. T. M. Darbinyan. Moscow, 1973. Uvarov B.S. Anesthetic care in the conditions of modern warfare, Voyen.-med. journal, no. 10, p. 25, 1966; Atkinson R. S. a. Lee J. A. Synopsis der Anasthe-sie, B., 1978; Emergency war surgery, Washington, 1975; Kinderanasthesie, hrsg. v. W. Dick u. F. W. Ahnefeld, B. u. a., 1978, Bibliogr.; A practice of anaesthesia, ed. by W. D. Wylie a. H. C. Churchill-Davidson, L., 1972; Stephens K. F. Some aspects of anaesthesia in war, Med. Bull. US Army Europe v. 20, p. 170, 1963.

G. A. Ryabov; V. A. Mikhelson (det.), B. S. Uvarov (military).

All types of anesthesia divided into 2 groups:

one). General anesthesia (narcosis).

2). Local anesthesia.

Narcosis is an artificially induced reversible inhibition of the central nervous system, caused by the introduction of narcotic drugs, accompanied by a loss of consciousness, all types of sensitivity, muscle tone, all conditioned and some unconditioned reflexes.

From the history of anesthesia:

In 1844, H. Wells used nitrous oxide inhalation during tooth extraction. In the same year, Ya.A. Chistovich used ether anesthesia for amputation of the thigh. The first public demonstration of the use of anesthesia during surgery took place in Boston (USA) in 1846: the dentist W. Morton gave ether anesthesia to the patient. Soon W. Squire designed an apparatus for ether anesthesia. In Russia, ether was first used in 1847 by F.I. Inozemtsev.

• 1857 - C. Bernard demonstrated the effect of curare on the neuromuscular synapse.
• 1909 - intravenous anesthesia with hedonal was used for the first time (N.P. Kravkov, S.P. Fedorov).
• 1910 - tracheal intubation is used for the first time.
• 1920 - Description of the signs of anesthesia (Guedel).
• 1933 - Sodium thiopental introduced into clinical practice.
• 1951 - Suckling synthesized halothane. In 1956, it was first used in the clinic.
• 1966 - First use of enflurane.

Theories of anesthesia

one). coagulation theory(Kuhn, 1864): narcotic substances cause intracellular protein folding in neurons, which leads to impaired function.

2). lipid theory(Hermann, 1866, Meyer, 1899): most narcotic substances are lipotropic, as a result of which they block the membranes of neurons, disrupting their metabolism.

3). Surface Tension Theory(adsorption theory, Traube, 1904): an anesthetic reduces the force of surface tension at the level of neuronal membranes.

4). Redox theory(Verworn, 1912): narcotic substances inhibit redox processes in neurons.

5). Hypoxic theory(1920): Anesthetics cause CNS hypoxia.

6). Theory of water microcrystals(Pauling, 1961): narcotic substances in aqueous solution form microcrystals that prevent the formation and propagation of an action potential along nerve fibers.

7). Membrane theory(Hober, 1907, Winterstein, 1916): narcotic substances cause a violation of the transport of ions across the membrane of neurons, thereby blocking the occurrence of an action potential.

None of the proposed theories fully explains the mechanism of anesthesia.

Modern views : at present, most scientists, based on the teachings of N.E. Vvedensky, A.A. Ukhtomsky and I.P. Pavlov, believe that anesthesia is a kind of functional inhibition of the central nervous system ( physiological theory of CNS inhibition- V.S. Galkin). According to P.A. Anokhin, the reticular formation of the brain is most sensitive to the effects of narcotic substances, which leads to a decrease in its upward influence on the cerebral cortex.

Classification of anesthesia

one). Factors affecting the CNS:

• Pharmacodynamic anesthesia- the effect of narcotic substances.
• Electronarcosis- the action of the electric field.
• Hypnonarcosis- effect of hypnosis.

2). According to the method of administration of the drug into the body:

• Inhalation:

Mask.

Endotracheal (ETN).

Endobronchial.

• Non-inhalation:

Intravenous.

Intramuscular (rarely used).

Rectal (usually only in children).

3). By number of narcotic drugs:

• Mononarcosis- 1 drug is used.
• Mixed anesthesia- Several drugs are used at the same time.
• Combined anesthesia- the use of various drugs at different stages of the operation; or a combination of drugs with drugs that selectively act on other body functions (muscle relaxants, ganglioblockers, analgesics, etc.).

4). Depending on the stage of the operation:

• Introductory anesthesia- short-term, occurs without a phase of excitation. Used for rapid induction into anesthesia.
• Maintenance anesthesia- used throughout the operation.
• Basic anesthesia- this is, as it were, the background against which the main anesthesia is carried out. The action of basic anesthesia begins shortly before the operation and lasts for some time after its completion.
• Additional anesthesia- against the background of maintenance anesthesia, other drugs are administered to reduce the dose of the main anesthetic.

Inhalation anesthesia

Preparations for inhalation anesthesia

one). Liquid anesthetics- evaporating, have a narcotic effect:

• Fluorotan (narcotan, halothane) - is used in most domestic devices.
• Enflurane (etran), methoxyflurane (ingalan, pentran) are used less frequently.
• Isoflurane, sevoflurane, desflurane are new modern anesthetics (used abroad).

Modern anesthetics have a strong narcotic, antisecretory, bronchodilatory, ganglion blocking and muscle relaxant effect, rapid induction into anesthesia with a short excitation phase and rapid awakening. Do not irritate the mucous membrane of the respiratory tract.

Side effects halothane: the possibility of oppression of the respiratory system, a drop in blood pressure, bradycardia, hepatotoxicity, increases the sensitivity of the myocardium to adrenaline (therefore, these drugs should not be used with halothane anesthesia).

Ether, chloroform and trichlorethylene are not currently used.

2). Gaseous anesthetics:

The most common is nitrous oxide, because it causes a rapid induction into anesthesia with practically no excitation phase and a rapid awakening. Used only in combination with oxygen: 1:1, 2:1, 3:1 and 4:1. It is impossible to reduce the oxygen content in the mixture below 20% due to the development of severe hypoxia.

disadvantage is that it causes superficial anesthesia, weakly inhibits reflexes and causes insufficient muscle relaxation. Therefore, it is used only for short-term operations that do not penetrate into the cavities of the body, as well as induction anesthesia for major operations. It is possible to use nitrous oxide for maintenance anesthesia (in combination with other drugs).

Cyclopropane is currently practically not used due to the possibility of respiratory depression and cardiac activity.

The principle of the device of anesthesia machines

Any anesthesia machine contains the main components:

one). Dosimeter - serves for accurate dosing of narcotic substances. Rotary dosimeters of the float type are more commonly used (the displacement of the float indicates the gas flow rate in liters per minute).

2). Vaporizer - serves to convert liquid narcotic substances into vapor and is a container into which an anesthetic is poured.

3). Cylinders for gaseous substances- oxygen (blue cylinders), nitrous oxide (gray cylinders), etc.

4). Respiratory block- consists of several parts:

• breathing bag- used for manual ventilation, as well as a reservoir for the accumulation of excess narcotic substances.
• Adsorber- serves to absorb excess carbon dioxide from the exhaled air. Requires replacement every 40-60 minutes of operation.
• valves- serve for one-way movement of a narcotic substance: an inhalation valve, an exhalation valve, a safety valve (for dumping excess narcotic substances into the external environment) and a non-reversing valve (for separating the flows of inhaled and exhaled narcotic substances)
  At least 8-10 liters of air should flow to the patient per minute (of which at least 20% is oxygen).

Depending on the principle of operation of the respiratory unit, there are 4 breathing circuits:

one). Open loop:

Inhalation - from atmospheric air through the evaporator.

Exhale - to the external environment.

2). Semi-open circuit:

Inhale - from the apparatus.

Exhale - to the external environment.

Disadvantages of open and semi-open circuits are operating room air pollution and a high consumption of narcotic substances.

3). Semi-closed contour:

Inhale - from the apparatus.

Exhalation - partly into the external environment, partly - back into the apparatus.

4). Closed Loop:

Inhale - from the apparatus.

Exhale - into the apparatus.

When using semi-closed and closed circuits, the air, having passed through the adsorber, is released from excess carbon dioxide and again enters the patient. the only disadvantage of these two circuits is the possibility of developing hypercapnia due to the failure of the adsorber. Its performance must be regularly monitored (a sign of its operation is some heating, since the process of absorbing carbon dioxide goes with the release of heat).

Currently in use anesthesia machines Polinarkon-2, -4 and -5, which provide the possibility of breathing through any of the 4 circuits. Modern anesthesia rooms are combined with ventilators (RO-5, RO-6, PHASE-5). They allow you to control:

• Respiratory and minute volume of the lungs.
• The concentration of gases in the inhaled and exhaled air.
• Ratio of inspiratory to expiratory time.
• outlet pressure.

Of the imported devices, the most popular are Omega, Draeger and others.

Stages of anesthesia(Guedel, 1920):

one). Stage of analgesia(lasts 3-8 minutes): gradual depression of consciousness, a sharp decrease in pain sensitivity; however, thoracic reflexes, as well as temperature and tactile sensitivity, are preserved. Respiration and hemodynamic parameters (pulse, blood pressure) are normal.

In the stage of analgesia, 3 phases are distinguished (Artusio, 1954):

• Initial phase- analgesia and amnesia yet.
• Phase of complete analgesia and partial amnesia.
• Phase of complete analgesia and complete amnesia.

2). Excitation stage(lasts 1-5 minutes): was especially pronounced during the use of ether anesthesia. Immediately after the loss of consciousness, motor and speech excitation begins, which is associated with the excitation of the subcortex. Breathing quickens, blood pressure rises slightly, tachycardia develops.

3). Narcotic sleep stage (surgical stage):

It has 4 levels:

I - U level of eyeball movement: eyeballs make smooth movements. The pupils are constricted, the reaction to light is preserved. Reflexes and muscle tone are preserved. Hemodynamic parameters and respiration are normal.

II - Lack of corneal reflex: eyeballs are immobile. The pupils are constricted, the reaction to light is preserved. Reflexes (including corneal) are absent. Muscle tone begins to decline. Breathing is slow. Hemodynamic parameters are normal.

III - Pupil dilation level: pupils are dilated, their reaction to light is weak. A sharp decrease in muscle tone, the root of the tongue can fall back and block the airways. The pulse is quickened, the pressure is reduced. Shortness of breath up to 30 per minute (diaphragmatic breathing begins to predominate over costal breathing, exhalation is longer than inhalation).

IV- Diaphragmatic breathing level: pupils are dilated, there is no reaction to light. The pulse is frequent, thready, the pressure is sharply reduced. Breathing is shallow, arrhythmic, completely diaphragmatic. In the future, paralysis of the respiratory and vasomotor centers of the brain occurs. Thus, the fourth level is a sign of an overdose of narcotic substances and often leads to death.

Depth of anesthesia when using inhalation mononarcosis, it should not exceed the I-II level of the surgical stage, only for a short time it can be deepened to level III. When using combined anesthesia, its depth usually does not exceed 1 level of the surgical stage. It is proposed to operate at the stage of anesthesia (raush anesthesia): short-term superficial interventions can be performed, and with the addition of muscle relaxants, almost any operation can be performed.

4). Awakening stage(lasts from several minutes to several hours, depending on the dose received and the patient's condition): occurs after the cessation of the supply of the narcotic substance and is characterized by a gradual restoration of consciousness of other body functions in reverse order.

This classification is rarely used in intravenous anesthesia, since the surgical stage is reached very quickly, and premedication with narcotic analgesics or atropine can significantly change the reaction of the pupils.

Mask anesthesia

Mask anesthesia is used:

• For short operations.
• If it is impossible to carry out tracheal intubation (anatomical features of the patient, trauma).
• When administered under anesthesia.
• Before tracheal intubation.

Technique:

one). The patient's head is thrown back (this is necessary to ensure greater patency of the upper respiratory tract).

2). Apply a mask so that it covers the mouth and nose. The anesthetist must maintain the mask during the entire anesthesia.

3). The patient is allowed to take a few breaths through the mask, then pure oxygen is connected, and only after that the supply of the narcotic substance begins (gradually increasing the dose).

4). After anesthesia enters the surgical stage (level 1-2), the dose of the drug is no longer increased and kept at the individual level for each person. When anesthesia deepens to the 3rd level of the surgical stage, the anesthesiologist must bring the patient's lower jaw forward and hold it in this position (to prevent tongue retraction).

Endotracheal anesthesia

It is used more often than others, mainly for long-term abdominal operations, as well as for operations on the organs of the neck. Intubation anesthesia was first used in the experiment by N.I. Pirogov in 1847, during operations - by K.A. Rauhfuss in 1890

The advantages of ETN over others are:

• Accurate dosing of narcotic substances.
• Reliable patency of the upper respiratory tract.
• Aspiration is practically excluded.

Tracheal intubation technique:

Mandatory conditions for the start of intubation are: lack of consciousness, sufficient muscle relaxation.

one). Produce maximum extension of the patient's head. The lower jaw is brought forward.

2). A laryngoscope (with a straight or curved blade) is inserted into the patient's mouth, on the side of the tongue, with which the epiglottis is lifted. They examine: if the vocal cords move, then intubation cannot be performed, because. you can hurt them.

3). Under the control of a laryngoscope, an endotracheal tube of the required diameter is inserted into the larynx, and then into the trachea (for adults, usually No. Inflating the cuff too much can lead to pressure ulcers in the tracheal wall, and too little will break the seal.

4). After that, it is necessary to listen to breathing over both lungs with the help of a phonendoscope. If intubated too deep, the tube may enter the thicker right bronchus. In this case, breathing on the left will be weakened. If the tube rests against the bifurcation of the trachea, there will be no breath sounds anywhere. If the tube enters the stomach, against the background of the absence of respiratory sounds, the epigastrium begins to swell.

Recently, more and more often laryngeal mask. This is a special tube with a device for bringing the respiratory mixture to the entrance to the larynx. Its main advantage is ease of use.

Endobronchial anesthesia

used in lung operations when only one lung needs to be ventilated; or both lungs, but in different modes. Intubation of both one and both main bronchi is used.

Indications :

one). Absolute (anesthetic):

• The threat of infection of the respiratory tract from bronchiectasis, lung abscesses or empyema.
• Gas leak. It can occur when a bronchus ruptures.

2). Relative (surgical): improvement of surgical access to the lung, esophagus, anterior surface of the spine and large vessels.

Collapse of the lung on the side of surgery, it improves surgical access, reduces trauma to the lung tissue, allows the surgeon to work on the bronchi without air leakage, and limits the spread of infection with blood and sputum to the opposite lung.

For endobronchial anesthesia are used:

• Endobronchial obturators
• Double lumen tubes (right and left).

Flattening a collapsed lung after surgery:

The bronchi of the collapsed lung should be cleared of sputum by the end of the operation. Even with an open pleural cavity at the end of the operation, it is necessary to inflate the collapsed lung under visual control using manual ventilation. Physiotherapy and oxygen therapy are prescribed for the postoperative period.

The concept of the adequacy of anesthesia

The main criteria for the adequacy of anesthesia are:

• Complete loss of consciousness.
• The skin is dry, normal color.
• Stable hemodynamics (pulse and pressure).
• Diuresis is not lower than 30-50 ml/hour.
• Absence of pathological changes on the ECG (if monitored).
• Normal volume indicators of ventilation of the lungs (determined using an anesthesia machine).
• Normal levels of oxygen and carbon dioxide in the blood (determined using a pulse oximeter, which is worn on the patient's finger).

Premedication

This is the introduction of drugs before surgery in order to reduce the likelihood of intraoperative and postoperative complications.

Tasks of premedication:

one). Decreased emotional arousal, feelings of fear before the operation. Sleeping pills (phenobarbital) and tranquilizers (diazepan, phenazepam) are used.

2). Stabilization of the autonomic nervous system. Antipsychotics (chlorpromazine, droperidol) are used.

3). Prevention of allergic reactions. Antihistamines are used (diphenhydramine, suprastin, pipolfen).

4). Decreased secretion of glands. Anticholinergics (atropine, metacin) are used.

5). Strengthening the action of anesthetics. Narcotic analgesics are used (promedol, omnopon, fentanyl).

Numerous premedication schemes have been proposed.

Scheme of premedication before emergency surgery:

• Promedol 2% - 1 ml / m.
• Atropine - 0.01 mg/kg s.c.
• Diphenhydramine 1% - 1-2 ml / m or (according to indications) droperidol.

Scheme of premedication before a planned operation:

one). The night before, before going to bed - sleeping pills (phenobarbital) or a tranquilizer (phenazepam).

2). In the morning, 2-3 hours before the operation - an antipsychotic (droperidol) and a tranquilizer (phenazepam).

3). 30 minutes before surgery:

• Promedol 2% - 1 ml / m.
• Atropine - 0.01 mg/kg s.c.
• Diphenhydramine 1% - 1-2 ml / m.

Intravenous anesthesia

This is anesthesia caused by intravenous administration of narcotic drugs.

Main advantages intravenous anesthesia are:

one). Rapid induction into anesthesia, pleasant for the patient, with virtually no stage of excitation.

2). Technical ease of implementation.

3). Possibility of strict accounting of narcotic substances.

4). Reliability.

However, the method is not without shortcomings:

one). It lasts for a short time (usually 10-20 minutes).

2). Does not give complete relaxation of the muscles.

3). More likely to overdose compared to inhalation anesthesia.

Therefore, intravenous anesthesia is rarely used alone (in the form of mononarcosis).

The mechanism of action of almost all drugs for intravenous anesthesia is to turn off consciousness and deep inhibition of the central nervous system, while the suppression of sensitivity occurs a second time. An exception is ketamine, the action of which is characterized by sufficient pain relief with partially or fully preserved consciousness.

The main drugs used for intravenous anesthesia

one). Barbiturates:

• Sodium thiopental is the main drug.
• Geksenal, thiaminal - are used less often.

Are used for induction anesthesia and for short-term anesthesia for minor operations. The mechanism of action is explained by the inhibitory effect on the reticular formation of the brain.

The solution is prepared before the operation: 1 vial (1 gram) is dissolved in 100 ml of saline (1% solution is obtained) and injected intravenously at a rate of approximately 5 ml per minute. 1-2 minutes after the start of administration, unexpressed speech excitation usually occurs (disinhibition of subcortical structures). Motor excitation is not typical. After another 1 minute, consciousness is completely turned off and the patient enters the surgical stage of anesthesia, which lasts 10-15 minutes. A long duration of anesthesia is achieved by fractional administration of 0.1-0.2 g of the drug (i.e. 10-20 ml of solution). The total dose of the drug is not more than 1 g.

Possible side effects: respiratory depression and cardiac activity, a drop in blood pressure. Barbiturates are contraindicated in acute liver failure.

2). Ketamine (ketalar, calypsol).

used for short-term anesthesia, as well as a component in combined anesthesia (in the maintenance phase of anesthesia) and ataralgesia (together with tranquilizers).

Mechanism of action This drug is based on the temporary disconnection of nerve connections between different parts of the brain. It has low toxicity. It can be administered both intravenously and intramuscularly. The total dose is 1-2 mg/kg (intravenously) or 10 mg/kg (intramuscularly).

After 1-2 minutes after the injection, analgesia occurs, however, consciousness is preserved and it is possible to talk with the patient. After the operation, the patient does not remember anything due to the development of retrograde amnesia.

This is the only anesthetic that stimulates the cardiovascular system, so it can be used in patients with heart failure and hypovolemia; contraindicated in patients with hypertension.

Possible side effects: increased blood pressure, tachycardia, increased sensitivity of the heart to catecholamines, nausea and vomiting. Characterized by frightening hallucinations (especially upon awakening). For their prevention in the preoperative period, tranquilizers are administered.

Ketamine is contraindicated in patients with increased ICP, hypertension, angina pectoris, and glaucoma.

3). Deprivan (propofol). Ampoules 20 ml 1% solution.

One of the most modern drugs. It is short acting and therefore usually requires combination with other drugs. It is the drug of choice for induction anesthesia, but can also be used for long-term anesthesia. A single dose - 2-2.5 mg / kg, after the introduction of anesthesia lasts 5-7 minutes.

Possible side effects are very rare: short-term apnea (up to 20 seconds), bradycardia, allergic reactions.

4). Sodium oxybutyrate(GHB - gamma-hydroxybutyric acid).

Used for induction of anesthesia. The drug has low toxicity, therefore it is the drug of choice in debilitated and elderly patients. In addition, GHB also has an antihypoxic effect on the brain. The drug must be administered very slowly. The general dose is 100-150 mg/kg.

Its disadvantage is only that it does not cause complete analgesia and muscle relaxation, which makes it necessary to combine it with other drugs.

5). Etomidat - is used mainly for induction into anesthesia and for short-term anesthesia. A single dose (it lasts for 5 minutes) is 0.2-0.3 mg / kg (you can re-enter no more than 2 times). The advantage of this drug is that it does not affect the cardiovascular system.

Side effects: nausea and vomiting in 30% of adults and involuntary movements immediately after administration of the drug.

6). Propanidide (epontol, sombrevin).

It is used mainly for induction into anesthesia, as well as for short-term operations. Anesthesia comes "at the end of the needle", awakening - very quickly (after 5 minutes).

7). Viadryl (predion).

It is used in combination with nitrous oxide - for induction into anesthesia, as well as during endoscopic examinations.

Propanidide and Viadryl have been practically not used in the last few years.

Muscle relaxants

There are 2 groups of muscle relaxants:

one). Antidepolarizing(long-acting - 40-60 minutes): diplacin, anatruxonium, dioxonium, arduan. The mechanism of their action is the blockade of cholinergic receptors, as a result of which depolarization does not occur and the muscles do not contract. The antagonist of these drugs is cholinesterase inhibitors (prozerin), tk. cholinesterase stops destroying acetylcholine, which accumulates in the amount necessary to overcome the blockade.

2). Depolarizing(short-acting - 5-7 minutes): ditilin (listenone, myorelaxin). At a dose of 20-30 mg it causes muscle relaxation, at a dose of 40-60 mg it turns off breathing.

The mechanism of action is similar to acetylcholine, i.e. they cause long-term persistent depolarization of the membranes, preventing repolarization. The antagonist is pseudocholinesterase (found in freshly citrated blood). Prozerin cannot be used, because. due to the inhibition of cholinesterase, it enhances the action of dithylin.

If both groups of muscle relaxants are used simultaneously, then a “double block” is possible - dithylin appears the properties of drugs of the first group, resulting in a prolonged respiratory arrest.

Narcotic analgesics

reduce the excitability of pain receptors, cause euphoria, anti-shock, hypnotic, antiemetic effects, reduce the secretion of the gastrointestinal tract.

Side effects:

oppression of the respiratory center, decreased peristalsis and secretion of the gastrointestinal tract, nausea and vomiting. Addiction quickly sets in. To reduce side effects, they are combined with anticholinergics (atropine, metacin).

Are used for premedication, in the postoperative period, and also as a component of combined anesthesia.

Contraindications: general exhaustion, insufficiency of the respiratory center. For anesthesia of childbirth is not used.

one). Omnopon (Pantopon) - a mixture of opium alkaloids (contains up to 50% morphine).

2). Promedol - compared with morphine and omnopon has fewer side effects and therefore is the drug of choice for premedication and central analgesia. The analgesic effect lasts 3-4 hours.

3). Fentanyl - has a strong, but short-term (15-30 minutes) effect, therefore it is the drug of choice for neuroleptanalgesia.

With an overdose of narcotic analgesics, naloxone (an opiate antagonist) is used.

Classification of intravenous anesthesia

one). Central analgesia.

2). Neuroleptanalgesia.

3). Ataralgesia.

Central analgesia

Due to the introduction of narcotic analgesics (promedol, omnopon, fentanyl), pronounced analgesia is achieved, which plays the main role. Narcotic analgesics are usually combined with muscle relaxants and other drugs (deprivan, ketamine).

However, high doses of drugs can lead to respiratory depression, which often forces a switch to a ventilator.

Neuroleptanalgesia (NLA)

The method is based on the combined application:

one). Narcotic analgesics (fentanyl), which provide pain relief.

2). Antipsychotics (droperidol), which suppress autonomic reactions and cause a feeling of indifference in the patient.

A combined preparation containing both substances (thalamonal) is also used.

Advantages of the method is the rapid onset of indifference to everything around; reduction of vegetative and metabolic changes caused by the operation.

Most often, NLA is used in combination with local anesthesia, and also as a component of combined anesthesia (fentanyl with droperidol is administered against the background of anesthesia with nitrous oxide). In the latter case, the drugs are administered fractionally every 15-20 minutes: fentanyl - with an increase in heart rate, droperidol - with an increase in blood pressure.

Ataralgesia

This is a method that uses a combination of drugs of 2 groups:

one). Tranquilizers and sedatives.

2). Narcotic analgesics (promedol, fentanyl).

The result is a state of ataraxia (“desouling”).

Ataralgesia is usually used for minor superficial operations, and also as a component of combined anesthesia. In the latter case, add to the above drugs:

• Ketamine - for potentiation of narcotic action.
• Antipsychotics (droperidol) - for neurovegetative protection.
• Muscle relaxants - to reduce muscle tone.
• Nitrous oxide - to deepen anesthesia.

The concept of combined anesthesia

Combined intubation anesthesia is currently the most reliable, manageable and versatile method of anesthesia. The use of several drugs allows you to reduce the dose of each of them and thereby reduce the likelihood of complications. Therefore, it is the method of choice for extensive traumatic operations.

Benefits of combined anesthesia:

• Rapid induction into anesthesia with virtually no excitation phase.
• Decreased drug toxicity.
• Connection of muscle relaxants and neuroleptics allows operating at the 1st level of the surgical stage of anesthesia, and sometimes even at the stage of analgesia. This reduces the dose of the main anesthetic and thereby reduces the risk of complications of anesthesia.
• Endotrachelal administration of breathing mixture also has its advantages: rapid management of anesthesia, good airway patency, prevention of aspiration complications, and the possibility of airway sanitation.

Stages of combined anesthesia:

one). Introductory anesthesia:

One of the following drugs is commonly used:

• Barbiturates (sodium thiopental);
• Sodium oxybutyrate.
• Deprivan.
• Propanidide in combination with a narcotic analgesic (fentanyl, promedol) is rarely used.

At the end of the induction of anesthesia, respiratory depression may occur. In this case, it is necessary to start ventilation with a mask.

2). Tracheal intubation:

Before intubation, short-acting muscle relaxants (ditilin) ​​are administered intravenously, while continuing mechanical ventilation through a mask for 1-2 minutes with pure oxygen. Then intubation is performed, stopping ventilation for this time (there is no breathing, so intubation should not take more than 30-40 seconds).

3). Main (maintenance) anesthesia:

Basic anesthesia is carried out in 2 main ways:

• Apply inhalation anesthetics (halothane; or nitrous oxide in combination with oxygen).
• Neuroleptanalgesia (fentanyl with droperidol) is also used, alone or in combination with nitrous oxide.

Anesthesia is maintained at the 1-2 level of the surgical stage. To relax the muscles, anesthesia is not deepened to level 3, but short-acting muscle relaxants (ditilin) ​​or long-acting (arduan) are injected. However, muscle relaxants cause paresis of all muscles, including respiratory ones, therefore, after their administration, they always switch to mechanical ventilation.

To reduce the dose of the main anesthetic, neuroleptics and sodium hydroxybutyrate are additionally used.

4). Withdrawal from anesthesia:

By the end of the operation, the introduction of narcotic drugs is gradually stopped. The patient begins to breathe on his own (in this case, the anesthesiologist removes the endotracheal tube) and regains consciousness; all functions are gradually restored. If spontaneous breathing is not restored for a long time (for example, after using long-acting muscle relaxants), then decurarization is carried out using antagonists - cholinesterase inhibitors (prozerin). To stimulate the respiratory and vasomotor centers, analeptics (cordiamin, bemegrid, lobelin) are administered.

Control over the administration of anesthesia

During anesthesia, the anesthesiologist constantly monitors the following parameters:

one). Every 10-15 minutes measure blood pressure and pulse rate. It is desirable to control and CVP.

2). In persons with heart disease, ECG monitoring is performed.

3). The parameters of mechanical ventilation (tidal volume, minute volume of breathing, etc.) are controlled, as well as the partial tension of oxygen and carbon dioxide in the inhaled, exhaled air and in the blood.

4). Control indicators of the acid-base state.

5). Every 15-20 minutes, the anesthesiologist performs auscultation of the lungs (to control the position of the endotracheal tube), and also checks the patency of the tube with a special catheter. In case of violation of the tightness of the tube to the trachea (as a result of relaxation of the muscles of the trachea), it is necessary to pump air into the cuff.

The anesthetic nurse maintains an anesthetic card, in which all the listed parameters are noted, as well as narcotic drugs and their doses (taking into account the stage of anesthesia they were introduced into). The anesthesia card is inserted into the patient's medical history.

The mechanism of anesthesia has been of interest to researchers since the discovery of ether anesthesia, but the first theories based on the study of changes in brain cells appeared at the beginning of the 20th century.

The most common of them explain anesthesia in terms of the physical and chemical properties of the drug. With the development of the physiology of the central nervous system and higher nervous activity, the emphasis in the search for an acceptable hypothesis was placed on changes in the physiological state of different parts of the brain. As it turned out, the mechanisms of cellular anesthesia and anesthesia in a highly organized organism are fundamentally different.

More G1.M. Sechenov believed that in a state of anesthesia, a purposeful inhibition of the brain occurs, which extends to the lower sections and the spinal cord. NOT. Vvedensky (1903) showed that inhibition develops under conditions of prolonged exposure to superstrong stimuli, and stimuli that exceed the limit of functional mobility (lability) of the cell are excessive. The narcotic substance sharply reduces the lability of neurons, and narcotic inhibition develops in them.

B.C. Galkin (1953) developed a theory according to which the effect of a drug on the central nervous system is expressed in sequentially advancing inhibition of the cortex, and then subcortical formations. In his opinion, at the first stage, active inhibition occurs in the cerebral cortex, at the second - inhibition of the cortex with the release of the subcortex with its possible positive induction, which is manifested by the stage of excitation, at the third - inhibition of both the cortex and the subcortex - the phase of narcotic sleep.

CHAPTER XI. ANESTHESIA

PC. Anokhin connected the mechanism of anesthesia with the reticular formation of the brain stem. The hypothesis proposed by him is based on the unequal sensitivity of different parts of the brain to a narcotic substance, where the most sensitive is the reticular formation. The reticular formation is associated with many centers of the cerebral cortex and supracortical structures. Under the influence of the drug, its activating effect on the cortex and subcortical structures decreases; narcotic sleep occurs.

2.2. STAGES OF ONE-COMPONENT ANESTHESIA

In the clinical course of single-component anesthesia (using ether as an example), four stages are distinguished.

/ stage(analgesia) occurs gradually after 3-5 minutes from the onset of anesthesia. Consciousness fades away until it is turned off. At this stage, the highest nervous activity is subjected to the greatest test, the subjective attitude of patients to anesthesia is created.

All parameters look the same as before the onset of anesthesia: the color of the skin is normal, hemodynamic and respiratory parameters are at the initial level. Reflexes are usually elevated. The patient reacts to any irritation more sharply than usual. All complications during this period are reflex in nature: bronchospasm, laryngospasm, reflex respiratory arrest, heart failure. As the patient falls asleep, the feeling of pain is progressively suppressed and complete analgesia occurs. This is the stage of roush anesthesia (stunning), which is used as an independent anesthetic aid for short-term interventions (reduction of dislocations, opening of an abscess, tooth extraction).

// stage(excitation) occurs from the moment of loss of consciousness, for ether usually after 6-8 minutes. This stage is characterized by pronounced motor excitation, rapid breathing, tachycardia, increased blood pressure, hyperemia of the skin. The pupils are dilated and do not react to light. Could be vomiting. Any irritation (operation) during the log period is undesirable, as it causes uncontrolled actions on the part of the patient.

III stage(surgical) allows you to perform surgical interventions and is the task of general anesthesia. Classical is the division of the surgical stage of anesthesia into four levels (Gwedel, 1937). All sublevels of stage III anesthesia in their pure form are peculiar and differ from one another in the state of respiration, cardiovascular activity, degree of relaxation of skeletal muscles and reflexes.

CHAPTER XI. ANESTHESIA

Since H.II. Pirogov, the levels of the surgical stage of anesthesia are most conveniently determined by eye reflexes. These include involuntary mobility of the eyeballs, corneal reflex, pupillary reaction to light. Egp reflexes are associated with the oculomotor center of the medulla oblongata, located near the centers of respiration and blood circulation, therefore, with their help, one can indirectly judge the degree of respiratory depression and cardiac activity.

The 1st level of anesthesia is called the level of movement of the eyeballs (by the end of this level, the involuntary movement of the eyeballs stops and they occupy a central position); 2nd - the level of the corneal reflex (the end of this level is marked by the disappearance of the corneal reflex); 3rd - pupil dilation level; and, finally, the 4th - paralysis of eye reflexes, in which there is also complete inhibition of diaphragmatic breathing. With the deepening of anesthesia, paralysis of the respiratory and vasomotor center and death occur.

IV stage- awakening. Exit from ether anesthesia occurs in the reverse order of introduction into anesthesia. However, the awakening process is longer.

2.3. PREPARATION OF THE PATIENT FOR ANESTHESIA

Special attention should be paid to the preparation of patients for anesthesia. It begins with the personal contact of the anesthesiologist with the patient. Beforehand, the anesthesiologist needs to familiarize himself with the medical history and clarify the indications for surgery, and he must personally find out all the questions of interest to him

With planned operations, the anesthesiologist begins the examination and acquaintance with the patient a few days before the operation. In cases of emergency interventions, an examination is carried out immediately before the operation.

The anesthesiologist is obliged to know the patient's occupation, whether his "food activity is associated with harmful production (nuclear energy, chemical industry, etc.). The patient's life history is of great importance: previous diseases (diabetes, coronary artery disease and myocardial infarction, hypertension) , regularly taken medications (glucocorticoid yurmons, insulin, antihypertensive drugs).It is especially necessary to find out the tolerability of drugs (allergic history).

The doctor conducting anesthesia should be well aware of the state of the cardiovascular system, lungs, and liver. Among the mandatory

CHAPTER XI. ANESTHESIA

Other methods of examining the patient before surgery include: blood and urine marijuana, biochemical analysis of blood, blood coagulation (coagulo-c\shma). Blood type and Rh-affiliation must be determined without fail. They also perform electrocardiography. The use of inhalation anesthesia forces to pay special attention to the study of the functional state of the respiratory system, spirography is performed, I determine! Stange and Compliance tests: the time for which the patient can hold his breath while inhaling and exhaling. In the preoperative period during elective operations, if possible, correction of existing homeostasis disorders should be carried out. In emergencies, training is limited.

After assessing the patient's condition, the anesthesiologist determines the degree of operational risk and chooses the method of anesthesia. The best known is the risk assessment proposed by N.N. Malinovsky (1973). It is based on the scoring principle for assessing the scope of the proposed intervention, surgical pathology, concomitant diseases and age. In accordance with the number of points, there are small degrees of risk (I-I1), moderate risk (III) degree and high risk (IV-V degree).

The person who is going to have the operation is naturally worried, therefore, a sympathetic attitude towards him is necessary, an explanation of the need for the operation. Such a conversation can be more effective than the action of sedatives. However, not all anesthesiologists can communicate with patients equally convincingly. The state of anxiety in a patient before surgery is accompanied by a release of adrenaline from the adrenal medulla, an increase in metabolism, which makes anesthesia difficult and increases the risk of developing cardiac arrhythmias. Therefore, premedication is prescribed for all patients before surgery. It is carried out taking into account the psycho-emotional state of the patient, his reaction to the disease and the upcoming operation, the characteristics of the operation itself and its duration, as well as age, constitution and anamnesis of life.

Premedication for a planned operation begins a few days before the operation with oral administration of tranquilizers or barbiturates. In case of an emergency operation, it is advisable to carry out premedication directly on the operating table under the supervision of an anesthesiologist. On the day of the operation, the patient is not fed. Before surgery, empty the stomach, intestines, and bladder. In emergency cases, this is done using a gastric tube, urinary catheter. If the patient has dentures, they must be removed

GPAVACH1. ANESTHESIA

Before anesthesia, a single dose of an ashacid substance can be administered to prevent aspiration of gastric contents. To reduce the volume of gastric secretion and acidity, instead of antacids, you can use a blocker of H 2 -histamine receptors of the stomach. (tsgshetidi,

ranshgshbii) or hydrogen pump (omsprazol, amez etc.).

Immediately before the operation, a direct premedication is prescribed. She aims to:

Sedation and amnesia - effective premedication suppresses the increase in cortisone in the blood during stress. Most versatile morphine and its derivatives (diazepill. tazepam etc.), neuroleptics (droperidot).

Analgesia - it is especially important in the case of pain before surgery. Narcotic analgesics are used.

Inhibition of the parasympathetic nervous system - prevention of vagal cardiac arrest. It is achieved by using atropine. In patients with glaucoma, atropine is replaced metaci-iom.

Premedication should include antihistamines (diphenhydramine, tiyulfen, passionate) taking into account the fact that any operation and violation of the integrity of tissues cause the release of histampon, and this can lead to undesirable reactions (bronchospasm, tachycardia, lowering blood pressure). The sedative effect of antignathamine drugs is used to potentiate anesthesia.

The drugs are administered, as a rule, intramuscularly 30-60 minutes before the anestezin is administered.

All patients who underwent premedication are delivered to the operating room on a gurney, accompanied by medical staff.

2.4. INHALATION N\RCOS

Inhalation anesthesia basic on the introduction of general anesthetics in the form of vapor or laza through the respiratory tract, followed by diffusion of n \\ from the alveoli into the blood. The saturation of the body with an inhalation anesthetic and the release of the latter depend on the drug, its concentration in the inhaled mixture, solubility in the blood and tissues, as well as on the state of the patient's breathing and circulation.

Distinguish mask and pntubatsponny methods of inhalation anesthesia. The mask method can be applied both with a simple Esmarch mask and with special anesthesia equipment. He came-

CHAPTER XI. ANESTHESIA

changes during short operations and manipulations that do not require controlled breathing and muscle relaxation

Nitrous oxide and cyclopropane are used as gaseous anesthetics; The most commonly used liquid volatile anesthetics are ether, fluorogan, trpchlorethylene (trilene).

Ether It is a clear, colorless liquid with a specific pungent odor. It decomposes under the action of light and air, so it is stored in dark bottles with a ground-in lid. Ether vapors mixed with oxygen are explosive. The positive properties of the ether include its large therapeutic sprat - the difference between the dose that causes the chronic stage of anesthesia and the toxic dose, as well as the ability to use it in poorly adapted conditions. Negative properties: lulling with ether is long and poorly tolerated by patients; the stage of excitation is very pronounced; ether causes irritation of the upper respiratory tract, excites the sympathoadrenal system; the awakening stage is also very long.

Ftorotai - clear liquid with a sweet smell. Not explosive. It is much stronger than ether, therefore it requires special equipment for its use. It has a small therapeutic breadth, an overdose of halothane is manifested by bradycardia, a decrease in blood pressure. Being more of an anesthetic than an analgesic, it is often used as an element of mixed (with nitrous oxide and oxygen) and combined anesthesia.

Nitrous oxide It is a colorless inert gas with a pleasant sweet smell. It does not ignite, however, in combination with ether and oxygen, it supports combustion, and in a mixture with chlorethnl, ether, cyclopropane in certain concentrations, it is explosive. The negative properties of nitrous oxide include low narcotic power, so it is more often used as a component of mixed or combined general anesthesia. To avoid hypoxia, the content of nitrous oxide in the inhaled mixture should not exceed 80 ° o. Nitrous oxide in commonly accepted concentrations does not have a toxic effect. There are no contraindications to anesthesia with nitrous oxide.

Trpchlorethylene has a pronounced analgesic effect. Change of stages of anesthesia occurs quickly. Does not irritate the mucous membrane of the respiratory tract. It has a large anesthetic power and easy controllability of the level of anesthesia.

In its pure form, it is not used for long-term operations, since in large doses it causes arrhythmia, respiratory depression and cardiac activity. Trpchlorethylene is used only in open and semi-open

CHAPTER XI. PAIN RELIEF

to the contours, since in contact with soda lime it decomposes with the formation of carbon monoxide and phosgene.

Cyclopropane - colorless gas with a characteristic odor. With anesthesia with cyclopropane, anesthesia occurs quickly and without excitation, there is no adverse effect on hemodynamics. Recovery from anesthesia lasts 5-7 minutes. Widespread use of cyclopropane in the clinic is limited by its explosiveness and high cost.

The combination of cyclopropane with nitrous oxide and oxygen is called the Shepna-Ashmaia mixture.

Equipment and methods of inhalation anesthesia. The main purpose of devices for inhalation anesthesia is to deliver to dy- narcotic drugs in the gas or vapor phase as part of a gas mixture containing at least 20% oxygen and practically devoid of CO 2 - The load on the patient's respiratory system should be minimal. The current level of development of anesthesiology and international standards impose additional requirements on the equipment: the presence of a backup source of oxygen, an alarm about a decrease in oxygen pressure, blocking the supply of nitrous oxide when oxygen pressure decreases, ensuring the disassembly of the respiratory circuit for subsequent disinfection and sterilization, increasing the safety of the device for patients and attendants personnel.

A modern anesthesia machine consists of four parts: 1 - high pressure systems (cylinders with reducers); 2 - systems of dosimeters For gaseous substances; 3 - evaporators for volatile liquid anesthetics; 4 - breathing circuit.

The cylinders contain gases used for anesthesia: oxygen - at a pressure of 150 atm, nitrous oxide - 50 atm and cyclopropane - 6 atm. For safety reasons, the cylinders are painted in different colors: for oxygen - blue, for nitrous oxide - gray, for cyclopropane - red. In foreign countries, a different color of cylinders is adopted.

Reducers reduce the pressure of the gas supplied to the anesthesia machine. Up to 3-4 atm. They are equipped with pressure gauges showing the pressure in the oallop. The amount of oxygen in the cylinder can be determined by reading the pressure gauge on the reducer. To do this, it is enough to multiply the volume of the cylinder (usually 40 or 10 liters) by the pressure. The result corresponds to the number of liters of oxygen gas. Since the nitrous oxide in the cylinder is contained in liquid form, the readings of the pressure gauge on the cylinder do not depend on its "shshchestig * - To determine the amount of nitrous oxide in the cylinder, it must be weighed

CHAPTER 1. ANESTHESIA

Dosimeters are included in the inhalation circuit of the anesthesia machine. The gaseous substance through the systems) "of hoses and reducers enters the dosimeter, which allows me to supply a given volume of narcotic gas to the patient. Usually, float dosimeters are used, designed for a flow of uiu or 1 to 10 liters per minute) (for nitrous oxide and oxygen). Dosed according to -1ECT1 of liquid narcotic substances is carried out with the help of vaporizers in which these substances evaporate and are already inhaled in the form of vapors by patients.The simplest vaporizers allow the drug (usually h)\u003e ir) to be administered only in approximate concentrations.The actual concentration of bu-ici depends on the air temperature, drop in the temperature of the evaporating drug, the amount of drug poured, the magnitude of the gas flow and other parameters. Temperature-compensated evaporators, along with dosing taps, have thermal water tanks or automatic devices that control the influence of external conditions on the concentration of anesthetic in the 1-drug mixture. These evaporators are used for such powerful narcotic substances like fgorotan .

The respiratory circuit includes corrugated hoses, valves, a breathing bag (fur) and a mask or ingubation tube. There are four methods (circuits) for conducting inhalation anesthesia: open, semi-open, semi-closed and closed.

At open method the patient inhales the anesthetic along with the air and breathes it into the surrounding atmosphere. The simplest method of anesthesia by open konguru is anesthesia with ether using the Es-March mask. Anesthesia by o [covered circuit is used in the absence of oxygen cylinders (Fig. 1)

At semi-open method the patient inhales the anesthetic from the apparatus, the iso-narcotic mixture is isolated from the surrounding air, and the exhaled gas is completely emitted into the surrounding atmosphere (Fig. 2)

Semi-Closed Method provides that the patient inhales the narcotic mixture from a closed space, and the exhaled air with the narcotic drug is partly discharged into the atmosphere, partly reused when inhaling. This allows a significant reduction in the amount of drug and oxygen used*. Another advantage is the minimal loss of heat and moisture to patients (Fig. 3).

closed source provides for both inhalation and exhalation in a closed space - the method requires the most careful control over the gas composition of the inhaled mixture. Attractive is its cost-effectiveness (Fig. 4).

When anesthesia is carried out by the method with gas reversion (semi-closed or closed circuits), an adsorbent is included in the respiratory circuit - us-

CHAPTER XI. ANESTHESIA

------ -^

Rice. 1. Schematic diagram of an open system: / - mask; 2 - exhalation valve; 3 shnt; 4 - inhalation valve; 5 - evaporator

tristvo for absorption of excess CO 2 . Soda lime is used as a chemical absorber (Fig. 5).

Modern domestic anesthesiologists use devices for inhalation anesthesia of the third (“Polinarcon-2”, “Polinarcon-2P”) and the fourth (“Polinarcon-2P”).

con-4" and "Polynarcon-5") rest, v at

Lenin (Fig. 6). In addition to inhalation - \ F ^, *rt

NO

mask anesthesia, they make it possible to carry out ventilation manually (fur or breathing bag) or automatically by connecting a domestic or foreign ventilator. There are also: a portable apparatus for giving anesthesia and carrying out mechanical ventilation with a breathing bag in any medical institutions, in military field conditions and in ambulance stations - p> 1C 2. Schematic diagram of the half-open Narcon-2; intermittent system devices / dosimeter; 2- evaporator; 01 ohm flow applied in 3 safety clips; valve of dentistry and gynecology, - inhalation; 5- hose; b gas valve, / ma-PAPP-2, NLPP-4; Portuguese; L" breathing bag

CHAPTER XI. ANESTHESIA

ilj_a_No

new apparatus with self-contained power supply - AN-2; anesthetic inhalers for spontaneous breathing - Tringal and Trilan.

Respiratory equipment. Modern breathing apparatus has:

Compressor for IVL.

Injector vacuum suction.

Rotameter-dispenser of gases. Respiratory capabilities

monitoring: pressure in the breathing circuit, oxygen content in the inhaled air and carbon dioxide in the exhaled air, real tidal volume and minute breathing volume. Additionally, it is possible to carry out pulse oximetry (determination of the partial pressure of oxygen in the blood) and control of the concentration of the anesthetic on inspiration.

Old respirators of the RO type had a fur pneumospstem. In second-generation pneumatic systems, the gas flow is interrupted in accordance with the specified parameters (“Phase” type). Modern equipment has a third-generation pneumosystem, in which there are stepper electric motors and the mixture is supplied under a predetermined pressure.

The built-in microprocessor allows you to adjust the distribution of the gas mixture in the lungs, determining the compliance of the lungs (“complasgaps”) and the resistance of the sneezing tract (“resins-eps”). The scrap class includes P-pirptor firms "Drster", "Kgsgrem", "Benket", "Hprapa".

1*1 N**-b"H&"

Rice. 6. Apparatus for carrying out the park "I 1olpnGfKoi-4"

CHAPTER XI. ANESTHESIA

Incubation method of anesthesia. The method is based on the introduction of an anesthetic substance, depending on the design of the puncture tube, directly into the trachea (endotracheal) or bronchi (endobronchial).

The NN tubation method of conducting anesthesia has a number of advantages over other methods of inhalation anesthesia. It ensures the patency of the respiratory tract, preventing the retraction of the tongue, excludes the ingress and aspiration of gastric contents, blood into the trachea, allows suction of the contents from the trachea and bronchi; creates optimal conditions for mechanical ventilation, reduces the volume of anatomical "dead space" (respiratory tract, where there is no gas exchange between atmospheric air and blood); opens up the possibility of using muscle relaxants, reduces the amount of anesthetic used, and anesthesia can be carried out at a more superficial and safe level, makes anesthesia more manageable in terms of controlling vital body functions (respiration, blood circulation, homeostasis).

Indications for the intubation method of anesthesia are: 1) operations in which there is a high probability of impaired airway patency - maxillofacial surgery; 2) operations requiring the use of muscle relaxants - abdominal surgery, traumatology; 3) operations on the opened chest - cardiopulmonary surgery; 4) the expected high invasiveness of the operation, its duration. Tracheal intubation allows mechanical ventilation in the postoperative period (extended mechanical ventilation); 5) senile age of patients, severe concomitant pathology, i.e. those situations when careful control over vital functions is necessary.

There are no absolute contraindications to intubation anesthesia. Relative contraindications can be recognized as significant difficulties during tracheal intubation associated with the anatomical features of the patient: stiffness of the cervical spine, narrowing of the trachea, larynx

Endotracheal anesthesia, as a rule, is combined.

Tracheal intubation technique. Tracheal intubation is performed under induction anesthesia or, much less often, under local anesthesia - after oro-shshsh of the pharynx, epiglottis and vocal cord area with a local anesthetic, such as lidocaine or dicaip

For intubation, you need: a laryngoscope with a set of blades - straight and curved (Fig. 7), ptubation tubes (usually with an inflatable cuff) of different diameters, a rigid conductor for sagging

Modern surgical intervention is impossible to imagine without adequate anesthesia. The painlessness of surgical operations is currently provided by a whole branch of medical science called anesthesiology. This science deals not only with the methods of anesthesia, but also with the methods of controlling the functions of the body in a critical state, which is modern anesthesia. In the arsenal of a modern anesthesiologist who comes to the aid of a surgeon, a large number of techniques - from relatively simple (local anesthesia) to the most complex methods of controlling body functions (hypothermia, controlled hypotension, cardiopulmonary bypass).

But it was not always so. For several centuries, stupefying tinctures were offered as a means of combating pain, patients were stunned or even strangled, and nerve trunks were pulled with tourniquets. Another way was to reduce the duration of surgery (for example, N. I. Pirogov removed stones from the bladder in less than 2 minutes). But before the discovery of anesthesia, abdominal operations were inaccessible to surgeons.

The era of modern surgery began in 1846, when the anesthetic properties of ether vapor were discovered by chemist C. T. Jackson and dentist W. T. G. Morton and the first extraction of a tooth under general anesthesia was performed. Somewhat later, surgeon M. Warren performed the world's first operation (removal of a neck tumor) under inhalation anesthesia using ether. In Russia, the introduction of anesthesia techniques was facilitated by the work of F. I. Inozemtsev and N. I. Pirogov. The works of the latter (he made about 10 thousand anesthesias during the Crimean War) played an exceptionally large role. Since that time, the technique of anesthesia has become much more complicated and improved, opening up opportunities for the surgeon to perform unusually complex interventions. But the question of what is anesthesia sleep and what are the mechanisms of its occurrence still remains open.

A large number of theories have been put forward to explain the phenomenon of anesthesia, many of which have not stood the test of time and are of purely historical interest. These are, for example:

1) Bernard's coagulation theory(according to his ideas, the drugs used for induction into anesthesia caused coagulation of the protoplasm of neurons and a change in their metabolism);

2) lipoid theory(according to her ideas, narcotics dissolve the lipid substances of the membranes of nerve cells and, penetrating inside, cause a change in their metabolism);

3) protein theory(narcotic substances bind to enzyme proteins of nerve cells and cause a violation of oxidative processes in them);

4) adsorption theory(in the light of this theory, drug molecules are adsorbed on the surface of cells and cause a change in the properties of membranes and, consequently, the physiology of the nervous tissue);

5) theory of inert gases;

6) neurophysiological theory(most fully answers all the questions of researchers, explains the development of anesthesia under the influence of certain drugs by phase changes in the activity of the reticular formation, which leads to inhibition of the central nervous system).

In parallel, studies were conducted to improve the methods of local anesthesia. The founder and main promoter of this method of anesthesia was A. V. Vishnevsky, whose fundamental works on this issue are still unsurpassed.

2. Anesthesia. Its components and types

anesthesia- this is an artificially induced deep sleep with the exclusion of consciousness, analgesia, inhibition of reflexes and muscle relaxation. It becomes clear that modern anesthetic management of surgical intervention, or anesthesia, is the most complex multicomponent procedure, which includes:

1) narcotic sleep (caused by drugs for anesthesia). Includes:

a) turning off consciousness - complete retrograde amnesia (events that happened to the patient during anesthesia are recorded in the memory);

b) decrease in sensitivity (paresthesia, hypesthesia, anesthesia);

c) proper analgesia;

2) neurovegetative blockade. It is necessary to stabilize the reactions of the autonomic nervous system to surgical intervention, since the autonomics are not largely controlled by the central nervous system and are not regulated by anesthetic drugs. Therefore, this component of anesthesia is carried out by using peripheral effectors of the autonomic nervous system - anticholinergics, adrenoblockers, ganglionic blockers;

3) muscle relaxation. Its use is applicable only for endotracheal anesthesia with controlled breathing, but it is necessary for operations on the gastrointestinal tract and major traumatic interventions;

4) maintaining an adequate state of vital functions: gas exchange (achieved by an accurate calculation of the ratio of the gas mixture inhaled by the patient), blood circulation, normal systemic and organ blood flow. You can monitor the state of blood flow by the value of blood pressure, as well as (indirectly) by the amount of urine excreted per hour (urine debit-hour). It should not be lower than 50 ml/h. Maintaining blood flow at an adequate level is achieved by blood dilution - hemodilution - by constant intravenous infusion of saline solutions under the control of central venous pressure (normal value is 60 mm of water column);

5) maintaining metabolic processes at the proper level. It is necessary to take into account how much heat the patient loses during the operation, and to conduct adequate warming or, conversely, cooling the patient.

Indications for surgical intervention under general anesthesia determined by the severity of the planned intervention and the patient's condition. The more severe the patient's condition and the more extensive the intervention, the more indications for anesthesia. Minor interventions in a relatively satisfactory condition of the patient are carried out under local anesthesia.

Classification of anesthesia along the route of drug administration into the body.

1. Inhalation (narcotic substance in vapor form is supplied to the patient's respiratory system and diffuses through the alveoli into the blood):

1) mask;

2) endotracheal.

2. Intravenous.

3. Combined (as a rule, induction anesthesia with an intravenously administered drug, followed by the connection of inhalation anesthesia).

3. Stages of ether anesthesia

First stage

Analgesia (hypnotic phase, round anesthesia). Clinically, this stage is manifested by a gradual depression of the patient's consciousness, which, however, does not completely disappear in this phase. The patient's speech gradually becomes incoherent. The patient's skin turns red. Pulse and respiration slightly increased. The pupils are the same size as before the operation, they react to light. The most important change in this stage concerns pain sensitivity, which practically disappears. The remaining types of sensitivity are preserved. In this stage, surgical interventions, as a rule, are not performed, but small superficial incisions and reduction of dislocations can be performed.

Second stage

Excitation stage. In this stage, the patient loses consciousness, but there is an increase in motor and autonomic activity. The patient is not accountable for his actions. His behavior can be compared with the behavior of a person who is in a state of extreme intoxication. The patient's face turns red, all muscles tense up, neck veins swell. On the part of the respiratory system, there is a sharp increase in breathing, there may be a short-term stop due to hyperventilation. Increased secretion of the salivary and bronchial glands. Blood pressure and pulse rate rise. Due to the increased gag reflex, vomiting may occur.

Often, patients experience involuntary urination. Pupils in this stage dilate, their reaction to light is preserved. The duration of this stage during ether anesthesia can reach 12 minutes, with the most pronounced excitation in patients who have been abusing alcohol for a long time and drug addicts. These categories of patients need fixation. In children and women, this stage is practically not expressed. With the deepening of anesthesia, the patient gradually calms down, the next stage of anesthesia begins.

Third stage

Anesthesia sleep stage (surgical). It is at this stage that all surgical interventions are carried out. Depending on the depth of anesthesia, there are several levels of anesthesia sleep. All of them completely lack consciousness, but the systemic reactions of the body have differences. In connection with the special importance of this stage of anesthesia for surgery, it is advisable to know all its levels.

signs first level, or stages of preserved reflexes.

1. Only superficial reflexes are absent, laryngeal and corneal reflexes are preserved.

2. Breathing is calm.

4. The pupils are somewhat narrowed, the reaction to light is lively.

5. Eyeballs move smoothly.

6. Skeletal muscles are in good shape, therefore, in the absence of muscle relaxants, operations in the abdominal cavity at this level are not performed.

Second level characterized by the following manifestations.

1. Weaken and then completely disappear reflexes (laryngeal-pharyngeal and corneal).

2. Breathing is calm.

3. Pulse and blood pressure at the preanesthetic level.

4. Pupils gradually dilate, in parallel with this, their reaction to light weakens.

5. There is no movement of the eyeballs, the pupils are set centrally.

6. Relaxation of skeletal muscles begins.

Third level has the following clinical features.

1. There are no reflexes.

2. Breathing is carried out only due to movements of the diaphragm, therefore shallow and rapid.

3. Blood pressure decreases, pulse rate increases.

4. The pupils dilate, and their reaction to the usual light stimulus is practically absent.

5. Skeletal muscles (including intercostal) are completely relaxed. As a result of this, the jaw often droops, the retraction of the tongue and respiratory arrest can pass, so the anesthesiologist always brings the jaw forward in this period.

6. The transition of the patient to this level of anesthesia is dangerous for his life, therefore, if such a situation arises, it is necessary to adjust the dose of the anesthetic.

Fourth level previously called agonal, since the state of the organism at this level is, in fact, critical. At any moment, due to paralysis of breathing or cessation of blood circulation, death can occur. The patient needs a complex of resuscitation measures. The deepening of anesthesia at this stage is an indicator of the low qualification of the anesthesiologist.

1. All reflexes are absent, there is no pupil reaction to light.

2. The pupils are maximally dilated.

3. Breathing is superficial, sharply accelerated.

4. Tachycardia, thready pulse, blood pressure is significantly reduced, may not be detected.

5. There is no muscle tone.

Fourth stage

Occurs after the cessation of the drug supply. The clinical manifestations of this stage correspond to the reverse development of those during immersion in anesthesia. But they, as a rule, proceed more quickly and are not so pronounced.

4. Certain types of anesthesia

Mask anesthesia. In this type of anesthesia, the anesthetic in the gaseous state is supplied to the patient's respiratory tract through a mask of a special design. The patient can breathe on his own, or the gas mixture is supplied under pressure. When carrying out inhalation mask anesthesia, it is necessary to take care of the constant airway patency. For this, there are several methods.

2. Removal of the lower jaw forward (prevents the retraction of the tongue).

3. Establishment of the oropharyngeal or nasopharyngeal duct.

Mask anesthesia is quite difficult to tolerate by patients, so it is not used so often - for minor surgical interventions that do not require muscle relaxation.

Advantages endotracheal anesthesia. This is to ensure constant stable ventilation of the lungs and the prevention of obstruction of the airways by aspirate. The disadvantage is the higher complexity of this procedure (in the presence of an experienced anesthesiologist, this factor does not really matter).

These qualities of endotracheal anesthesia determine the scope of its application.

1. Operations with an increased risk of aspiration.

2. Operations with the use of muscle relaxants, especially thoracic ones, in which there may often be a need for separate ventilation of the lungs, which is achieved by using double-lumen endotracheal tubes.

3. Operations on the head and neck.

4. Operations with turning the body on its side or stomach (urological, etc.), in which spontaneous breathing becomes very difficult.

5. Long-term surgical interventions.

In modern surgery, it is difficult to do without the use of muscle relaxants.

These drugs are used for anesthesia during intubated trachea, abdominal operations, especially during surgical interventions on the lungs (tracheal intubation with a double-lumen tube allows ventilation of only one lung). They have the ability to potentiate the action of other components of anesthesia, so when they are used together, the concentration of the anesthetic can be reduced. In addition to anesthesia, they are used in the treatment of tetanus, emergency therapy for laryngospasm.

For combined anesthesia, several drugs are used simultaneously. This is either several drugs for inhalation anesthesia, or a combination of intravenous and inhalation anesthesia, or the use of an anesthetic and a muscle relaxant (when reducing dislocations).

In combination with anesthesia, special methods of influencing the body are also used - controlled hypotension and controlled hypothermia. With the help of controlled hypotension, a decrease in tissue perfusion is achieved, including in the area of ​​surgical intervention, which leads to minimization of blood loss. Controlled hypothermia or lowering the temperature of either the whole body or part of it leads to a decrease in tissue oxygen demand, which allows for long-term interventions with limited or switched off blood supply.

5. Complications of anesthesia. Special forms of anesthesia

Special forms of anesthesia are neuroleptanalgesia- the use of a combination of an antipsychotic (droperidol) and an anesthetic drug (fentanyl) for pain relief - and ataralgesia - the use of a tranquilizer and an anesthetic drug for pain relief. These methods can be used for small interventions.

Electroanalgesia- a special effect on the cerebral cortex with an electric current, which leads to synchronization of the electrical activity of the cortex in ? -rhythm, which is also formed during anesthesia.

Anesthesia requires the presence of a specialist anesthesiologist. This is a complex procedure and a very serious interference in the functioning of the body. Properly performed anesthesia, as a rule, is not accompanied by complications, but they still happen even with experienced anesthesiologists.

Quantity anesthesia complications extremely large.

1. Laryngitis, tracheobronchitis.

2. Obstruction of the respiratory tract - retraction of the tongue, entry of teeth, prostheses into the respiratory tract.

3. Lung atelectasis.

4. Pneumonia.

5. Violations in the activity of the cardiovascular system: collapse, tachycardia, other cardiac arrhythmias up to fibrillation and circulatory arrest.

6. Traumatic complications during intubation (wounds of the larynx, pharynx, trachea).

7. Violations of the motor activity of the gastrointestinal tract: nausea, vomiting, regurgitation, aspiration, intestinal paresis.

8. Urinary retention.

9. Hypothermia.

Clinical manifestations of the action of general anesthetics have been known for a long time, but the mechanism of their influence remained unclear for a long time, and it is not completely clear at the present time. There are several historically significant theories of anesthesia:

Kuhn's Coagulation Theory (1864)

Anesthetics cause a kind of folding of the intracellular protein, which leads to dysfunction of nerve cells.

Hermann's Lipoid Theory (1866)

Anesthetics have a tropism for lipoids, which are abundant in nerve cells. Therefore, a rich saturation of the membranes of nerve cells with anesthetics leads to a blockade of metabolism in cells. At the same time, the greater the affinity for lipoid tissue, the stronger the anesthetic.

Traube's theory of surface tension (1904-1913)

Anesthetics with high lipoidotropy have the ability to reduce the surface tension at the border of the lipoid sheath of nerve cells and the surrounding fluid. Therefore, the membrane becomes easily permeable to anesthetic molecules.

The redox theory of Warburg (1911) and Verworn (1912)

The narcotic effect of anesthetics is associated with their inhibitory effect on enzyme complexes that play a key role in providing redox processes in the cell.

Hypoxic theory (30s of the XX century)

Anesthetics lead to inhibition of the central nervous system as a result of cell energy.

Pauling's theory of aqueous microcrystals (1961)

Anesthetics in an aqueous solution form a kind of crystals that prevent the movement of cations through the cell membrane, and thereby block the process of depolarization and the formation of the action process.

The membrane theory of Hober (1907) and Winterstein (1916)

Anesthetics cause changes in the physicochemical properties of cell membranes, which disrupts the transport of Na + , K + and Ca ++ ions, and thus affect the formation and conduction of the action potential.

None of the presented theories fully explains the mechanism of anesthesia.

Modern views

The influence of anesthetics, first of all, occurs at the level of formation and propagation of the action potential in the neurons themselves, and especially in interneuronal contacts. The subtle mechanism of the effect of anesthetics is still unknown. Some scientists believe that by fixing on the cell membrane, anesthetics prevent the process of depolarization, others believe that anesthetics close sodium and potassium channels in cells..

With all the value of information about the subtle mechanisms of the interaction of anesthetics with cellular structures, anesthesia is presented as a kind of functional state of the central nervous system. A great contribution to the development of this concept was made by N. E. Vvedensky, A. A. Ukhtomsky and V. S. Galkin. In accordance with the theory of parabiosis (N. E. Vvedensky), anesthetics act on the nervous system as strong stimuli, subsequently causing a decrease in the physiological lability of individual neurons and the nervous system as a whole. Recently, many experts support the reticular theory of anesthesia, according to which the inhibitory effect of anesthetics has a greater effect on the reticular formation of the brain, which leads to a decrease in its ascending activating effect on the overlying parts of the brain.