Hyperthermia - an increase in human body temperature above 37.5 ° C. The normal human body temperature is 36.6 ° C. The measurement of body temperature can be made in the mouth, groin, armpit or rectum of the patient.
Hyperthermia is accompanied by an increase and qualitative metabolic disorders, loss of water and salts, impaired blood circulation and oxygen delivery to the brain, causing excitement, sometimes convulsions and fainting. High temperature with hyperthermia is more difficult to tolerate than with many febrile diseases.
Hyperthermic syndrome... Hyperthermia syndrome is understood as an increase in body temperature above 39 ° C, accompanied by a violation of hemodynamics and the central nervous system. Most often, hyperthermic syndrome occurs in neurotoxicosis associated with acute infections, and can also be in acute surgical diseases (appendicitis, peritonitis, osteomyelitis, etc.). A decisive role in the pathogenesis of hyperthermic syndrome is played by irritation of the hypothalamic region as the center of thermoregulation of the body.
Heatstroke... A kind of clinical syndrome of hyperthermia. Distinguish between load and non-load thermal shock. The first type is usually found in young people with great physical exertion in conditions when the outflow of heat is difficult for one reason or another (hot weather, stuffy room, etc.). The non-load variant of heatstroke usually occurs in the elderly or sick at a high ambient temperature: 27-32 C. The reason for heatstroke in such cases is a defect in the thermoregulation system. The usual clinical picture in both cases is stupor or coma. With a delay in the provision of care, mortality can reach 5%.
Symptoms... Feeling of heaviness in the head, nausea, vomiting, convulsions. Confusion of consciousness quickly sets in, then loss of it. There is an increase in heart rate and respiration. In most patients, a decrease in blood pressure is observed, but its increase is also possible; multiple hemorrhages appear on the mucous membranes.
Hyperthermia, malignant... A kind of clinical syndrome of hyperthermia. It occurs approximately 1 time per 100 thousand anesthesia when using depolarizing muscle relaxants (ditilin, listenone, myorelaxin, etc.) and inhalation anesthetics from the group of halogen-substituted hydrocarbons (fluoroghane, halothane, methoxyflurane, etc.). Hyperthermia occurs in patients with hypersensitivity to these drugs, which is associated with impaired calcium metabolism in the muscles. The consequence of this is generalized muscle twitching, and sometimes widespread muscle contracture, as a result of which a large amount of heat is generated and the body temperature quickly reaches 42 ° C at an average rate of 1 C / min. Mortality even in recognized cases reaches 20-30%.
Therapeutic hyperthermia... Therapeutic hyperthermia is one of the methods of therapy for malignant neoplasms. It is based on the fact that the entire body of the patient or its local areas are exposed to high temperatures, which ultimately increases the effectiveness of radiation or chemotherapy. The method of therapeutic hyperthermia is based on the fact that high temperatures are more destructive for actively dividing cancer cells than for healthy ones. Currently, therapeutic hyperthermia is used to a limited extent. This is explained not only by technical complexity, but also by the fact that it has not been fully studied.
Fevers also differ in type:
- Pink hyperthermia, at which heat production is equal to heat transfer and the general state is not changed.
- White hyperthermia, at which heat production exceeds heat transfer, as there is a spasm of peripheral vessels. With this type of hyperthermia, there is a cooling of the extremities, chills, pallor of the skin, a cyanotic shade of the lips, nail phalanges.
Types of hyperthermia
Exogenous or physical hyperthermia... The exogenous type of hyperthermia occurs when a person is staying for a long time in conditions of high humidity and high temperatures. This leads to overheating of the body and the development of heatstroke. The main link in the pathogenesis of hyperthermia in this case is a disorder of the normal water and electrolyte balance.
Endogenous or toxic hyperthermia... With a toxic type of hyperthermia, excess heat is produced by the body itself, and it does not have time to remove it outside. Most often, this pathological condition develops against the background of certain infectious diseases. The pathogenesis of endogenous hyperthermia is that microbial toxins are able to increase the synthesis of ATP and ADP by cells. During the breakdown of these high-energy substances, a significant amount of heat is released.
Pale hyperthermia
This type of hyperthermia occurs as a result of significant irritation of the sympathoadrenal structures, which causes a sharp spasm of the blood vessels.
Pale hyperthermia or hyperthermic syndrome occurs as a result of the pathological activity of the thermoregulation center. The causes of development can be some infectious diseases, as well as the introduction of drugs that have an exciting effect on the sympathetic part of the nervous system or have an adrenergic effect. In addition, the causes of pallid hyperthermia are general anesthesia with the use of muscle relaxants, craniocerebral trauma, stroke, brain tumors, that is, all those conditions in which the functions of the hypothalamic center of temperature regulation may be impaired.
The pathogenesis of pallid hyperthermia consists in a sharp spasm of the skin capillaries, which leads to a significant decrease in heat transfer and, as a result, increases body temperature.
With pallid hyperthermia, the body temperature quickly reaches life-threatening values - 42 - 43 degrees C. In 70% of cases, the disease ends in death.
Symptoms of physical and toxic hyperthermia
The symptoms and stages of endogenous and exogenous hyperthermia, as well as their clinical picture, are similar. The first stage is called adaptive. It is characterized by the fact that at this moment the body is still trying to regulate the temperature by:
- Tachycardia;
- Increased sweating;
- Tachypnea;
- Expansion of skin capillaries.
Patients complain of headache and muscle pain, weakness, and nausea. If he does not receive emergency care, then the disease goes into the second stage.
This is called the arousal stage. Body temperature rises to high values (39 - 40 degrees C). The patient is adynamic, stunned. Complains of nausea and severe headache. Sometimes there may be short-term episodes of loss of consciousness. Breathing and pulse are quickened. The skin is moist and hyperemic.
At the third stage of hyperthermia, paralysis of the vasomotor and respiratory centers develops, which can lead to the death of the patient.
Hypothermia of physical and toxic type is accompanied, as we have already said, by reddening of the skin and therefore it is called "pink".
Causes of hyperthermia
Hyperthermia occurs at the maximum stress of the physiological mechanisms of thermoregulation (sweating, dilation of skin vessels, etc.) and, if the causes that cause it are not eliminated in time, it steadily progresses, ending at a body temperature of about 41-42 ° C with heatstroke.
The development of hyperthermia is facilitated by an increase in heat production (for example, during muscular work), a violation of the mechanisms of thermoregulation (anesthesia, intoxication, some diseases), and their age-related weakness (in children of the first years of life). Artificial hyperthermia is used in the treatment of certain nervous and sluggishly current chronic diseases.
First emergency aid for hyperthermia
When the body is elevated, first of all, it is necessary to find out whether it is caused by fever or hyperthermia. This is due to the fact that in case of hyperthermia, measures should be taken immediately to reduce the elevated temperature. And with moderate fever, it is not worthwhile to urgently lower the temperature, on the contrary, since its increase has a protective effect on the body.
The methods used to lower the temperature are classified as internal and external. The former include, for example, lavage with ice water and extracorporeal cooling of blood, but they cannot be carried out on their own, and they can cause complications.
External cooling methods are easier to use, well tolerated and very effective.
- Conducted cooling techniques include applying hypothermic bags and ice water baths directly to the skin. Alternatively, ice can be applied to the neck, armpits, and groin.
- Convective cooling techniques include the use of fans and air conditioners, and the removal of excess clothing.
- A cooling technique is also often used, which works by evaporating moisture from the skin's surface. They take off their clothes, spray their skin with cool water, and use a fan for additional cooling or simply open a window.
Medication lowering the temperature
- In severe hyperthermia, provide supplemental oxygen, establish a continuous 12-line ECG to monitor cardiac activity and signs of arrhythmia.
- Use diazepam to relieve chills.
- In case of "red" hyperthermia: it is necessary to expose the patient as much as possible, to provide access to fresh air (avoiding drafts). Prescribe an abundant drink (0.5-1 liters more than the age norm of fluid per day). Use physical methods of cooling (blowing with a fan, cool wet bandage on the forehead, vodka-vinegar (9% table vinegar) rubdown - wipe with a damp swab). Assign orally or rectally paracetamol (Panadol, Calpol, Tylinol, Efferalgan, etc.) in a single dose of 10-15 mg / kg orally or in suppositories 15-20 mg / kg or ibuprofen in a single dose of 5-10 mg / kg (for children over 1 year old). If within 30-45 minutes the body temperature does not decrease, an antipyretic mixture is injected intramuscularly: 50% solution of analgin (children under 1 year old dose 0.01 ml / kg, over 1 year old dose 0.1 ml / year life), 2.5% solution of pi-polphene (diprazine) for children under one year old at a dose of 0.01 ml / kg, over 1 year old - 0.1-0.15 ml / year of life. A combination of drugs in one syringe is acceptable.
- With "white" hyperthermia: simultaneously with antipyretic drugs (see above) give vasodilators inside and intramuscularly: papaverine or noshpa at a dose of 1 mg / kg inside; 2% solution of papaverine for children under 1 year old - 0.1-0.2 ml, over 1 year old - 0.1-0.2 ml / year of life or solution of noshpa at a dose of OD ml / year of life or 1% solution of dibazol at a dose of 0.1 ml / year of life; you can also use a 0.25% solution of droperidol at a dose of 0.1-0.2 ml / kg intramuscularly.
Hyperthermia treatment
Treatment of hyperthermia consists in eliminating the causes that caused the hyperthermia of the body; cooling; if necessary, use dantrolene (2.5 mg / kg orally or intravenously every 6 hours).
What not to do with hyperthermia
- Wrap up the patient with a large number of warm things (blankets, clothes).
- Putting warming compresses for hyperthermia ─ they contribute to overheating.
- Give very hot drink.
Treatment of malignant hyperthermia
When establishing the fact of rapidly progressing hyperthermia, the above drugs should be discontinued. Of the anesthetic agents that do not lead to hyperthermia, tubocurarine, pancuronium, nitrous oxide and barbiturates should be noted. It is they who can be used if it is necessary to continue the anesthetic treatment. Due to the possibility of developing ventricular arrhythmia, prophylactic use of procainamide and phenobarbital in therapeutic doses is shown. It is necessary to provide for cooling procedures: placing containers with ice or cold water over large blood vessels. Oxygen inhalation should be immediately established, sodium bicarbonate (3% solution of 400 ml) IV should be injected. In severe cases, resuscitation is indicated. Hospitalization is required in the intensive care unit.
(Lecture No. XII).
1. Types, causes and pathogenesis of hyperthermia.
2. The difference between fever and hyperthermia.
3. The doctor's tactics when the body temperature rises.
4. Features of overheating in children.
Hyperthermia(hyperthermia) is a typical pathological process characterized by an increase in body temperature, the level of which depends on the environment. Unlike fever, this is a very dangerous condition because it is accompanied by a breakdown in thermoregulation mechanisms. Hyperthermia occurs under such conditions when the body does not have time to release an excess amount of heat (this depends on the ratio of heat production and heat transfer).
The amount of heat transfer is regulated by physiological mechanisms, the most important of which is vasomotor reaction... Due to a decrease in vascular tone, blood flow in human skin can increase from 1 to 100 ml / min per 100 cm3. Up to 60% of the heat production of the basal metabolism can be removed through the hands, although their area is equal to 6% of the total surface.
Another important mechanism is sweating- with intensive work of sweat glands, up to 1.5 liters of sweat are released per hour (0.58 kcal is spent on evaporation of 1 g of water) and only 870 kcal / hour is enough to maintain normal temperature during hard work under conditions of increasing ambient temperature.
Third - evaporation of water from the mucous membranes of the respiratory tract.
Classification of hyperthermia depending on the source of the formation of excess heat:
1) hyperthermia of exogenous origin (physical),
2) endogenous hyperthermia (toxic),
3) hyperthermia resulting from over-irritation of sympathoadrenal structures, which leads to vasospasm and a sharp decrease in heat transfer during normal heat production (so-called pallid hyperthermia).
Exogenous hyperthermia occurs with a prolonged and significant increase in the ambient temperature (when working in hot shops, in hot countries, etc.), with a large amount of heat from the environment (especially in high humidity conditions, which makes sweating difficult) - heatstroke. This is physical hyperthermia with normal thermoregulation.
Overheating is also possible as a result of direct exposure to sunlight on the head - sunstroke. According to the clinical and morphological picture, thermal and sunstrokes are so close that they should not be separated. Overheating of the body is accompanied by increased sweating with a significant loss of water and salts by the body, which leads to thickening of the blood, an increase in its viscosity, difficulty in blood circulation and oxygen starvation. The leading links in the pathogenesis of heatstroke are disorders of water and electrolyte balance due to impaired sweating and the activity of the hypothalamic center of thermoregulation.
Heat stroke is often accompanied by the development of collapse. Circulatory disorders are facilitated by the toxic effect on the myocardium of excess potassium in the blood, released from erythrocytes. Heatstroke also affects the regulation of respiration and renal function, and various types of metabolism.
In the central nervous system, with heatstroke, hyperemia and edema of the membranes and brain tissue, multiple hemorrhages are noted. As a rule, there is plethora of internal organs, small-point hemorrhages under the pleura, epicardium and pericardium, in the mucous membrane of the stomach, intestines, often pulmonary edema, dystrophic changes in the myocardium.
A severe form of heatstroke develops suddenly: changes in consciousness from mild to coma, convulsions of a clonic and tonic nature, periodic psychomotor agitation, often delirium, hallucinations. Breathing is shallow, rapid, incorrect. Pulse up to 120-140 / min is small, threadlike, deaf heart sounds. The skin is dry, hot, or clammy. Body temperature 41-42 degrees and above. On the ECG, there are signs of diffuse myocardial damage. There is a thickening of the blood with an increase in residual nitrogen, urea and a decrease in chlorides. There may be death from respiratory paralysis. Mortality is up to 20-30%.
Pathogenetic therapy - any simple cooling- the use of air conditioners, in hot shops - various panels.
Endogenous(toxic) hyperthermia arises as a result of a sharp increase in the formation of heat in the body, when it is not able to excrete this excess by sweating and through other mechanisms. The reason is the accumulation of toxins in the body (diphtheria, pyogenic microbes, in the experiment - thyroxine and a-dinitrophenol), under the influence of which a large number of high-energy compounds (ADP and ATP) are released, during the decomposition of which a large amount of heat is formed and released. If normally energy during the oxidation of nutrients is spent on the formation of heat and the synthesis of ATP, then in toxic hyperthermia, energy is used only for the formation of heat.
Stages of exogenous and endogenous hyperthermia and their clinical manifestation:
a) the adaptive stage is characterized by the fact that the body temperature has not yet increased due to a sharp increase in heat transfer by:
1.increased sweating,
2.tachycardia,
3.dilation of blood vessels of the skin,
4. rapid breathing.
The patient has a headache, weakness, nausea, pupils are dilated. With assistance, the symptoms of hyperthermia disappear.
b) excitement - characterized by an even greater sensation heat and an increase in heat transfer, but this is not enough and the temperature rises to 39-40 degrees. A sharp weakness, intense headache with nausea and vomiting, deafness, lack of confidence in movement, periodically short-term loss of consciousness develops. Pulse and breathing are quickened, the skin is hyperemic, moist, sweating is increased. With treatment, the body temperature decreases and the functions are normalized.
c) paralysis of the respiratory and vasomotor centers.
Pathogenetic therapy(since antipyretic substances do not help with exo- and endogenous hyperthermia, body temperature is lowered only by cooling the body in any way: airing the room, undressing, heating pads with ice on the limbs and liver, a cold towel on the head. It is very important to relieve sweating.
Help the victim: remove him from the overheating zone to a place protected from the sun and open to the wind, undress to the waist, moisten with cold water, an ice pack or cold towel on his head and neck. Oxygen inhalation. Intravenous or subcutaneous saline solution, glucose, if necessary - camphor, caffeine, strophanthin, lobelin, drop enemas. If necessary - chlorpromazine, diphenhydramine, anticonvulsants, if indicated - unloading spinal puncture.
Pale hyperthermia(hyperthermia as a result of pathological excitation of thermoregulation centers) - i.e. hyperthermic syndrome. Causes are severe infectious diseases or the administration of large doses of substances adrenergic actions, or substances that cause sharp excitement of sympathetic N.C... This leads to the excitation of sympathetic centers, vasospasm of the skin vessels and a sharp decrease in heat transfer and an increase in body temperature to 40 degrees or more. The causes of hyperthermic syndrome can be different: functional disorders or structural damage to hypothalamic thermoregulation centers, brain tumors, brain trauma, cerebral hemorrhages, infectious lesions, complications of anesthesia in combination with muscle relaxants.
Anesthesia and muscle relaxants aggravate the membrane defect and increase the release of cellular enzymes into the blood. This leads to disruption of metabolism in muscle tissue, stimulation of actin and myosin, persistent tonic muscle contraction, breakdown of ATP into ADP, an increase in K + and Ca2 + ions in the blood - a sympathoadrenal crisis occurs and sympathoadrenal hyperthermia.
Body temperature can reach 42-43 degrees and develop:
1) general muscle rigidity,
2) spasm of peripheral vessels,
3) increased blood pressure,
4) tachycardia,
5) increased breathing,
6) hypoxia,
7) a sense of fear.
Rapidly increasing metabolic acidosis, hyperkalemia, anuria, increased blood creatinine phosphatase, aldolase, myoglobin develop.
Pathogenetic therapy consists in inhibition of sympatho-adrenal mechanisms, a decrease in heat production and an increase in heat transfer. Applied: analgin, acetylsalicylic acid, which selectively reduce the sensitivity of the hypothalamic center of thermoregulation and increase heat transfer through increased sweating. A neuro-vegetative blockade is performed - chlorpromazine, droperidol. Antihistamines: diphenhydramine, diprazine. Ganglionic agents: pentamine, hygronium. Physical cooling, craniocerebral hypothermia. The mortality rate for this hyperthermia is up to 70%.
The difference between fever and hyperthermia:
1) various etiological factors,
2) different manifestations of the stage of temperature rise - with fever - chills and moderate stimulation of functions (by 1 degree increase in heart rate by 8-10 beats per minute and by 2-3 respiratory movements), and with hyperthermia, sudden sweating, a feeling of heat, a sharp increase in heart rate and breathing - by 10-15 respiratory movements with an increase in body temperature by 1 degree),
3) when the body is cooled with fever, the temperature will not change, with hyperthermia, it decreases; when warming up, the temperature will not change with fever and will increase with hyperthermia,
4) antipyretics reduce the temperature in fever and do not affect hyperthermia.
With fever, oxidative phospholation processes are activated, ATP synthesis increases, and protective reactions are accelerated. With hyperthermia, ATP synthesis is blocked and decomposed, a lot of heat is generated.
Doctor's tactics when the body temperature rises:
1) establish what it is: fever or hyperthermia. If there is hyperthermia - urgently cool, if there is a fever - it is impossible to immediately prescribe antipyretic drugs in a routine manner. If the fever is not accompanied by impaired breathing and blood circulation and is subfebrile in magnitude - or moderate - then it should not be reduced, because it has a protective meaning. If the temperature is very high and causes a disruption in the activity of vital systems: the central nervous system - severe headache, insomnia, delirium, loss of consciousness, the temperature is 39 degrees and increases - it is necessary to reduce antipyretic.
It should be borne in mind that infection is often a combination of fever and hyperthermia, in this case, cooling is necessary without changing body temperature by antipyretics. At high temperatures, especially with purulent infections, the room should be well ventilated and the condition of the patients should be relieved.
Overheating in children. Unlike adults, newborns and children under one year old are prone to overheating, which is associated with the peculiarities of their heat exchange and thermoregulation, which are gradually improving. In newborns, the reactions of chemical thermoregulation are quite developed, the reactions of physical thermoregulation are poorly represented, the fever is not very pronounced, and the rise in temperature is more often associated with overheating.
Overheating of the body in infants is facilitated by an increase in air temperature and excessive wrapping, in older children - a long stay in a hot, stuffy room, in the sun, prolonged physical stress.
Staying children 6-7 years old in a room with an air temperature of 29-31 degrees and walls 27-28 for 6-8 hours causes an increase in body temperature to 37.1 - 37.6 degrees. Solar overheating occurs with a predominance of primary disorders of the central nervous system, and an increase in body temperature is important, although not of primary importance.
In infants, overheating is manifested by lethargy, severe weakness, sleep disturbance, loss of appetite, regurgitation, and in some cases, digestive disorders. On examination - hyperemia of the skin, sweating, increased respiration and pulse rate, muffling of heart sounds and a decrease in blood pressure. Older children experience headache, dizziness, general weakness, drowsiness, fatigue, lethargy, vomiting, convulsions, and short-term loss of consciousness are possible.
Hyperthermia is a violation of the body's thermoregulation, accompanied by an increase in body temperature and arising in response to factors from the external environment or in case of failures in the mechanism of heat transfer in the body.
The following stages of hyperthermia are characteristic: compensation and decompensation of thermoregulation in the body, hyperthermic coma. The sooner medical care is provided, the less likely it is to develop complications.
The study of violations of heat transfer is the science of pathophysiology.
The standard for normal body temperature is 36.6 ° C. With the disease, its increase is observed above 37, 5 ° C. The skin is hot and moist. Perhaps a violation of consciousness (delusional state, hallucinations), breathing, the occurrence of tachycardia. Children have seizures, loss of consciousness.
There are 3 degrees of hyperthermia, each of which is characterized by the following symptoms:
Signs of hyperthermia
Signs of hyperthermia:
- increased sweating, hot skin;
- tachycardia;
- breathing disorder;
- nausea;
- violation of consciousness;
- unsure gait;
- frequent painful urination (more often in pregnant women);
- expansion of skin capillaries.
Hyperthermia should be distinguished from. Hypothermia has similar symptoms (tachycardia, respiratory failure, drowsiness, fever in the patient), but is characterized by a decrease in body temperature below 35 ° C.
Causes of the disease
The human body is homeothermal (does not depend on temperature fluctuations from the outside). Normally, thermoregulation occurs by the mechanisms of thermal radiation (heat is transferred to the external environment), thermal conduction (heat is transferred to other objects) and heat transfer (evaporation of heat during breathing through the lungs). In a pathological condition, a violation of heat exchange occurs, the body overheats.
External causes of hyperthermia:
- poor ventilation of the premises;
- prolonged exposure to heat;
- work under constant overheating conditions (hot shops);
- excessive presence in the bath, sauna;
- sports training, which are designed for increased muscle work, but minimal heat transfer (classes in special thermal clothing);
- high air humidity (the cooling mechanism turns off and heat removal becomes impossible);
- wearing clothes made of fabrics with poor heat dissipation.
Stages and types
The stages of the disease in children and adults are the same:
- compensation - the body's defense mechanisms are activated when overheating. Heat transfer increases, heat production decreases. The temperature rises within the upper limit of the normal range;
- decompensation - disruption of thermoregulation mechanisms. there is a loss of a large amount of fluid through sweat, exhaustion;
- hyperthermic coma (loss of consciousness and pain sensitivity).
Types of hyperthermia:
- Red is the most harmless, does not cause circulatory disorders. It arises due to the inclusion of thermoregulation mechanisms by the body during overheating. The patient's skin has a pinkish-red color, fever.
- Pale - characterized by impaired blood circulation, its centralization. The body begins to supply blood only to vital organs - heart, lungs, liver. The skin is pale, the patient complains of being cold. Possible pulmonary edema, cerebral edema, impaired consciousness, fever.
- Neurogenic - occurs due to brain injuries, hemorrhages, tumors.
- Exogenous - arises from external factors - overheating. There are no circulatory disorders, thermoregulation mechanisms. Symptoms are headache, weakness, nausea, loss of consciousness.
- Curative - a method of therapy that helps to cure cancer, is based on the destructive effect of high temperatures on cancer cells. It is used infrequently, since the method is poorly understood.
- Malignant is a pathological condition that occurs in response to the introduction of anesthetic drugs during surgery. Symptoms are noted: breathing and heart rate become more frequent, fever, muscles begin to contract frequently. If urgent help is not provided, the condition will be fatal.
More often than not, this condition is inherited. If relatives have had such a reaction to anesthesia, then the patient must be informed about this before the operation. Each operating room should contain medication for first aid in an attack.
First aid
| Type of hyperthermia | Urgent care |
| Red |
|
| Pale | Immediately call the ambulance team if there is a circulatory disorder. Before the arrival of the doctor:
|
| Malignant hyperthermia |
|
When providing assistance, you must not reduce the body temperature of the victim too sharply!
Treatment of other types of the disease is aimed at eliminating the factors that caused it. When exogenous, the victim should be provided with fresh air, give a cool drink. In neurogenic, care is directed towards treating brain injury.
A sharp fever in a child is dangerous, especially in children under one year old, with a history of febrile seizures, infants with lung and heart diseases, hereditary metabolic diseases. If the temperature rises above 38 ° C in young children, it is necessary to call a doctor, continue treatment in the hospital clinic.
Treatment methods
Treatment of hyperthermia is possible only on condition of preliminary diagnosis. It is necessary to collect anamnesis, take blood and urine tests, and take an X-ray.
The algorithm of therapy is as follows: take the victim out into fresh air, ventilate the room, and give an abundant drink. In case of fever over 38 ° C, taking medications (ibuprofen, paracetamol), with convulsions - no-spa and papaverine.
Possible complications and prevention
Prevention of complications consists in the timely and correct provision of first aid. You should not try to treat an increase in temperature with folk methods or alternative medicine, or rely on materials from Internet sites, be guided only by reviews. Treatment is possible after doctors determine the cause of the fever.
Possible complications of hyperthermia:
- paralysis of thermoregulatory centers
- heatstroke with prolonged failure to provide assistance;
- convulsions;
- paralysis of the respiratory, vasomotor centers;
- acute renal, heart failure;
- swelling of the brain;
- damage to the central nervous system;
- intoxication;
- coma;
- disseminated blood coagulation syndrome (DIC syndrome), in which hemorrhages into internal organs are possible;
- death.
Most often, hyperthermia appears in people with an inadequately developed mechanism of thermoregulation, these are children and the elderly. This category must be limited to visiting baths, rest in countries with hot climates.
Causes
Hyperthermia is understood as the accumulation of excess heat in the body due to an increase in body temperature due to impaired heat production and / or heat transfer. In the International Classification of Diseases (ICD-10), hyperthermia is found in various sections.
The causes of hyperthermia are quite numerous, and the first border separating them is the presence of signs indicating the physiological or pathological nature of the process.
Physiological hyperthermia must be distinguished from hyperthermia in case of illness, since an incorrect definition of the condition entails unreasonable therapy.
This is especially true for hyperthermia in children, since the likelihood of overdiagnosis of the infection is increased.
A healthy person's temperature rises:
- Overheating.
- With physical exertion.
- When overeating.
- When stressed.
Overheating is the main link in the pathogenesis of heat and sunstroke. It also occurs in situations when a person is warmly dressed in hot weather, drinks little, breathes hot and dry air, especially in a closed stuffy room. It can be manifested by hyperthermia of the skin - redness and a sensation of warmth when touching its surface.
Newborns are most often exposed to overheating, exacerbated by the inability for the child to communicate how they are feeling and the inexperience of supervising adults.
Physical activity, whether it be sports competitions or working in the backyard, increases body temperature. The same can be said for eating foods that contain significant amounts of fat. Emotional stress is more likely to cause a sharp increase in body temperature, which returns to normal in a calm state.
The pathological causes of hyperthermia are as follows:
- Infection.
The most common pathogens are viruses or bacteria. Also, hyperthermia is observed with helminthiasis. It accompanies both simple forms of infectious diseases and systemic inflammatory response syndrome, infectious toxic shock. Symptoms of hyperthermia are found in acute and chronic pathology. - Intoxication.
The entry into the blood of toxins of exogenous or endogenous origin causes an increase in temperature. Intoxication syndrome manifests itself in many diseases, including infectious ones. - Injury.
Tissue damage leads to an increase in body temperature, but hyperthermia is more often explained by the addition of infectious complications. The effect on the center of thermoregulation in the brain in traumatic brain injury, hemorrhage is considered separately. - Tumor.
In the diagnosis of hyperthermia, attention should be paid to signs of neoplasms: malignant histiocytosis, lymphomas, acute leukemia, kidney and liver damage. The tumor can also contribute to a rise in temperature if infection is observed, a secondary inflammatory process. - Metabolic disorders.
The most famous condition among endocrine pathologies accompanied by hyperthermia is thyrotoxicosis (excessive levels of thyroid hormones in the blood). In addition, increased body temperature is provoked by porphyria (violation of pigment metabolism), hypertriglyceridemia (high levels of triglycerides in the blood). - Immune disorders.
These are collagenoses (diseases characterized by damage to the connective tissue), drug fever (occurs when taking certain medications, as well as in response to pyrogens entering the blood with infusion fluids - substances that activate a hyperthermic reaction). - Vascular lesions.
High body temperature can be observed with heart attacks of various etiologies, including with the location of the pathological focus in the myocardium, brain.
Hyperthermia in therapy
Scientists have proven the protective role of high body temperature in many diseases, which explains the advisability of using hyperthermia in the treatment of oncology. In Moscow and other large cities, only private clinics are accepted for thermal therapy. The essence of the method is to artificially increase the body temperature to 41-45 ° C. In this case, tumor cells die.
Hyperthermia for the treatment of oncology is a relatively new and not fully understood method. It is contraindicated in some patients (especially in the case of diseases of the cardiovascular system), since high temperature has a pronounced adverse effect; the effectiveness of treatment may be less than the severity of complications following it.
Hyperthermia of malignant tumors with hot baths at home is a dangerous procedure, the end of which is unpredictable.
A detailed description of the method of treating hyperthermia in adults in the conditions of specialized hospital departments can be found in the presentations on the treatment of neoplasms.
Fever of unknown origin (LNG), isolated as a special type of hyperthermic state, is of great interest among researchers and at the same time significant difficulties in diagnosis. It is suggested on the basis of an increase in body temperature (as the initial criterion, a level of 38.3 ° C and higher is indicated) for 3 weeks or longer with a non-obvious diagnosis.
Also, hyperthermia of unknown origin is considered at least 4 cases of an increase in temperature in 2 weeks without clear symptoms of the disease. In this case, the patient should be examined by the usual general clinical methods, according to the results of which it was not possible to tell about the cause of hyperthermia. ICD-10 code - R50.
LNG is classified as:
When looking for the etiology of fever, one must remember about the possibility of aggravation and simulation, that is, exaggerating the significance of a symptom and creating the impression of its presence in the picture of pathology. People suffering from neuroses, psychopathies are prone to aggravation.
Hyperthermia syndrome
There is also a pathological variant of fever in children, the causes of hyperthermia are infections, trauma (especially during the childbirth process), dehydration. The body temperature rises sharply and quickly, while there is a violation of blood circulation in the microvasculature in combination with metabolic changes and irritation of the hypothalamus, which is the center of thermoregulation. Hyperthermic syndrome is characterized by a set of manifestations:
- weakness, lethargy;
- decreased motor and speech activity;
- pallor of the skin;
- lack of appetite;
- increased breathing and heart rate;
- chills.
In the pathophysiology of hyperthermia, the preservation of the possibility of heat transfer with excess heat production is of great importance. The regulation of body temperature is carried out through the release of sweat, followed by its evaporation.
In children, this mechanism is imperfect, which worsens the condition. In severe cases, fever is accompanied by vomiting, convulsions, hallucinations, a drop in blood pressure, severe anxiety, and motor agitation.
Diagnostics
Given the variety of symptoms accompanying an increase in body temperature, a comprehensive examination is required to identify the cause of the fever. Standard tests are carried out to 
detection of inflammatory changes, as well as signs of infection.
In case of fever of unknown origin, diagnosis begins with confirmation or exclusion of the inflammatory nature of hyperthermia.
The following methods are used:
- Collection of complaints, anamnesis, examination of the patient.
- Blood and urine tests.
- Chest x-ray, electrocardiography, echocardiography.
Further examination includes a targeted search for pathological changes - bacteriological, serological examination for infectious diseases, X-ray methods for purulent-inflammatory pathologies.
Until the end of the diagnostic search, especially in LNG, it is better to refrain from taking antibacterial drugs unless there are clear indications for the appointment.
Treatment
Eliminating hyperthermia does not mean curing the disease; moreover, in the case of acute infections, this is tantamount to depriving the body of its natural defense mechanism. Therefore, the fight against fever is carried out, taking into account the cause of its occurrence and the patient's condition. Standard activities are:
- plentiful drink (water, fruit drinks, fruit drinks, etc.);
- ventilation of the room and correction of temperature and humidity in case of excessively dry and hot air;
- refusal to wrap.
If hyperthermia is observed as a result of overheating in the sun, in a hot room, the patient should be taken out into the air, in a shaded place, given water to drink, and physical exertion should be excluded. On the area of large vessels, you can put ice, a container with cold water. In case of severe disturbance of the condition (respiratory distress, loss of consciousness, vomiting, convulsions), call emergency medical care.
Treatment of hyperthermia with antipyretic drugs (antipyretics) is carried out at a temperature above 38-38.5 ° C, while drugs such as paracetamol, ibuprofen are used. Acetylsalicylic acid in childhood is not used due to a possible complication, manifested in acute liver dysfunction.
You cannot alternate between different antipyretic substances, they should be taken at intervals of at least 4 hours, avoiding exceeding the permissible daily dose. If the temperature does not decrease after taking the medication, there is a progressive deterioration in the condition, you should seek medical help.
Hyperthermic syndrome is an indication for a doctor's examination and therapy. Emergency care for hyperthermia in children includes:
- Paracetamol (single dose 10-15 mg / kg), ibuprofen (single dose 5-10 mg / kg).
- If the type of fever is "red", with severe skin hyperemia, rubbing with a solution of alcohol at a concentration of 40% can be used, wrap the child in a wet diaper. In no case should you wrap it up, otherwise you can achieve the opposite effect - a sharp jump in temperature. For white fever, which is manifested by pallor of the skin, nicotinamide is used.
- Antispasmodics (drotaverine), glucocorticosteroids (hydrocortisone, prednisolone) are also used.
- As a method of cooling, an enema is carried out with water, the temperature of which is 18-20 ° C, cold is applied to the area of the liver and large vessels.
- For the relief of seizures, seduxen is indicated.
The target temperature level, after which it is necessary to stop anti-febrile measures, is 37.5 ° C.
With a prolonged increase in temperature, not caused by acute infections, it is necessary to look for the primary cause of hyperthermia. Unreasonable intake of antipyretics without a doctor's prescription can lead to a complication of the disease when side effects of the drug are realized or an overdose.
Is a condition characterized by acute hypermetabolism of skeletal muscle. It occurs under the influence of drugs for inhalation anesthesia, caffeine, succinylcholine, stressful situations. It manifests itself in the form of metabolic, cardiovascular, muscle disorders. DIC-syndrome, multiple organ failure develops later. Diagnosis is by clinical presentation, acid base balance analysis, and caffeine-halothane test data. Treatment involves the elimination of all possible triggers, the introduction of a solution of sodium bicarbonate, dantrolene. Physical methods are used to lower body temperature.
ICD-10
T88.3 Malignant hyperthermia induced by anesthesia
General information
Malignant hyperthermia (MH) is an acute pathological condition characterized by a significant increase in metabolic processes occurring in the striated skeletal muscles. Has a pharmacogenetic origin. The frequency of occurrence, according to information from different sources, varies within 1 case per 3-15 thousand general anesthesia. In adult patients, this figure is 1 case per 50-100 thousand anesthesia. In reality, there are more cases, however, it is not possible to track all abortive forms. In addition, medical practitioners do not always provide information on such complications. In men, pathology occurs 4 times more often than in women.
Causes
The main reason for the development of MH is the effect of drugs and products that have a triggering effect. The drugs that can provoke an attack include all inhalation anesthetics, curariform muscle relaxants, and caffeine. There are fragmentary data on the development of pathology in people who have undergone severe mental shock or physical stress. It is believed that this produces sympathoadrenal substances (adrenaline, norepinephrine), which lead to the development of a crisis in people predisposed to this.
People with a dominant mutation in the gene for the ryanodine receptor of chromosome 19 are considered more prone to developing MH. However, there are cases when, in the presence of obvious prerequisites for the occurrence of hypermetabolic muscle reactions, the gene responsible for the defective receptor was absent in the patient. A predisposition to the disease is usually traced in all blood relatives.
Pathogenesis
The pathogenesis is based on an increase in the duration of the opening of muscle calcium channels. This leads to an excessive accumulation of calcium ions in the sarcoplasm. The processes of polarization and depolarization are disrupted, which becomes the cause of generalized muscle contracture (rigidity). The reserves of ATP are depleted, the breakdown of which leads to increased consumption of oxygen by cells and the release of thermal energy. Tissue hypoxia develops, lactate accumulates in the muscles, and rhabdomyolysis occurs. In the blood plasma, the concentration of ions of potassium, calcium, magnesium, myoglobin and creatine phosphokinase increases.
The primary lesion affects only the skeletal muscles. However, the accumulation of toxic products of muscle tissue destruction within an hour leads to the formation of multiple organ failure, hemodynamic disturbances, and critical shifts in the acid-base balance. Edema of the lungs and brain may develop. A cascade of inflammatory reactions of the oxidative type is launched. DIC occurs, which leads to the development of latent internal and external bleeding.
Classification
Malignant hyperthermia can occur in several clinical variants, which differ in the rate of development of pathological processes and the time elapsed from the onset of the trigger to the manifestation of the crisis. In addition, there are differences in the severity and set of symptoms, the severity of the course. There are the following types of pathology:
- Classic... It occurs in 20% of cases. Differs in a detailed clinical picture, arises immediately after the administration of a drug with trigger activity. Pathology usually develops on the operating table in the presence of an anesthesiologist who has everything necessary to stop the hyperthermic reaction. The mortality rate is relatively low, the mortality rate does not exceed 5%.
- Abortive... It accounts for about 75% of all cases. Differs in a relatively mild course, an incomplete set of clinical symptoms. In many cases, there is no significant increase in body temperature. The mildest variants of the course sometimes go unnoticed or mistakenly refer to other pathological conditions. Mortality is 2-4%.
- Delayed... It occurs in 5% of cases, develops in a day or more after contact with a provoking factor. It flows relatively easily. The danger for the patient is that 24 hours after the operation, medical control over him weakens. Malignant hyperthermia at the initial stage of development often goes unnoticed or is misdiagnosed.
Symptoms of malignant hyperthermia
Signs of MH are divided into early and late. The early ones arise directly with the development of the crisis, the late ones - after 20 or more minutes. The first symptom is a spasm of the masticatory muscles, followed by generalized muscle contracture. Respiratory acidosis develops, CO2 at the end of expiration is more than 55 mm Hg. Art. Sweating increases, the skin becomes marbled. Oxygen consumption increases. As metabolic disorders worsen, changes occur in the work of the cardiovascular system: fluctuations in blood pressure, tachyarrhythmia.
The processes of myolysis and cleavage of ATP, developing in spasmodic muscles, lead to a sharp increase in body temperature. Usually this figure does not exceed 40 ° C. There are known cases of fever reaching 43-45 ° C, which became the cause of the death of the patient. Excessive accumulation of potassium exacerbates cardiac arrhythmias. The urine becomes dark, concentrated, and anuria may be noted. The condition is reversible if treatment measures were started on time. Otherwise, the patient develops complications.
Complications
Malignant hyperthermia can cause myocardial infarction, multiple organ failure, disseminated intravascular coagulation. A heart attack develops as a result of electrolyte disturbances and generalized muscle spasm. Bulky areas of myocardial necrosis lead to cardiogenic shock and asystole. Multiple organ failure is characterized by dysfunction of vital structures, which in 80% of cases leads to the death of the patient. With disseminated intravascular coagulation (DIC), microthrombi are formed in the vascular bed, which enhances multiple organ failure. In the future, the resource of the coagulation system is depleted, severe bleeding occurs.
Diagnostics
Diagnosis of already developed MH is carried out on the basis of the existing symptoms, as well as laboratory data. The predisposition to the occurrence of a crisis is determined by the results of specific testing methods. The patient examination algorithm includes:
- Taking anamnesis... It is possible to determine the presence of a predisposition to the disease in preparation for the operation. For this, a thorough survey of the patient and his relatives is carried out. They say about a high risk if among the patient's blood relatives there are people who have previously suffered a hyperthermic crisis, sudden death during anesthesia, and have episodes of unexplained seizures in the anamnesis.
- Laboratory diagnostics... With MH, signs of metabolic acidosis are found in the blood (pH less than 7.25, base deficiency more than 8 mmol / l), an increase in the concentration of CPK up to 20 thousand U / l and more, the concentration of potassium ions is more than 6 mmol / l. Pathological changes in plasma increase as the process develops. Normalization of indicators occurs within a day from the moment the crisis is stopped.
- Caffeine-halothane test... It is a specific analysis that reveals a tendency to develop muscle contracture. During the test, a muscle biopsy specimen is placed in a container filled with trigger solutions. In the presence of a predisposition to MH, muscle tissue contracts and contracture occurs. The test is carried out only for patients at risk, since the procedure for taking a biomaterial is traumatic.
- Genetic screening... Patients with a burdened history show a genetic study. It is aimed at identifying the gene responsible for the predisposition to the development of generalized muscle contractures. A study is considered positive, during which mutations in the RYR1 and CACNA1S genes are detected. Genetic analysis is not used as a general screening method due to the high cost and technical complexity of the work.
Genetically determined attacks of skeletal muscle rigidity should be differentiated with anaphylactic reactions, signs of insufficient analgesia, cerebral ischemia, thyroid crisis, neuroleptic malignant syndrome, and insufficient ventilation. A definite sign of MH is a decrease in the severity of symptoms soon after dantrolene administration.
Treatment of malignant hyperthermia
The effectiveness of treatment directly depends on the time elapsed from the development of the attack to the start of resuscitation measures. In the operating room, the patient is provided with assistance on the spot, interrupting the operation. If a crisis develops in the ward, the patient is urgently transported to the ICU. Leaving the patient in the general ward is unacceptable. Treatment consists in the use of non-specialized and etiotropic pharmacological methods, hardware, the use of physical methods of hypothermia. Key activities include:
- Terminating contact with a trigger... The supply of inhalation anesthesia is stopped, the contours of the anesthetic-respiratory device are purged with a clean breathing mixture. Replacement of the device, circuit, endotracheal tube is not performed. The method of hyperventilation with 100% oxygen is used. The minute breathing volume is 2-3 times higher than the norm. The duration of the procedure is 10-15 minutes.
- Etiotropic therapy. For patients diagnosed with malignant hyperthermia, administration of dantrolene, a relaxant with the ability to block ryanodine receptors, is indicated. The agent reduces the intracellular Ca concentration, inhibits the transmission of neuromuscular impulses, and leads to the rapid elimination of crisis symptoms. The drug is administered in dosage until the patient's condition is normalized.
- Symptomatic therapy... Depends on the available clinical picture. To maintain hemodynamics, titrated dopamine delivery through an injectomat can be used. Decrease in body temperature is carried out by imposing ice bubbles on the projection area of large vessels, introducing cold infusion solutions. To correct acid-base balance, a 4% solution of sodium bicarbonate is introduced. Removing excess electrolytes, toxins and maintaining kidney function requires loop diuretics.
Forecast and prevention
The prognosis is favorable if malignant hyperthermia was noticed and stopped in a timely manner. With a long stay of the patient in a state of metabolic acidosis and hypoxia, ischemic damage to the central and peripheral nervous system, disturbances in the work of the cardiovascular apparatus up to atrioventricular block, myocardial infarction, fibrillation are possible. With the abortive form, the chances of a successful outcome are much higher than with the classic one.
Specific prevention consists in a thorough preoperative examination aimed at establishing the fact of the patient's predisposition to muscle contractures. People with a confirmed genetic mutation are advised to give up coffee and caffeinated drinks, to minimize psychological stress in everyday life.
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