Capillary blood acid level. Indicators of the acid-base state (ABS) of the blood. How the systems work

In the article we will consider the norm of blood acid base.

Analysis of the acid-base state of blood and its gases is of no small importance in the diagnosis of diseases in surgery, anesthesiology and resuscitation, and also plays an equally important role in treatment. In each modern laboratory there is a special blood. If you want to monitor key indicators in the blood, an electrolyte analyzer can provide data on them.

Any changes in the acid-base state of the blood indicate the development of a certain pathological process. Blood gas tests are usually used when a person is suspected of having respiratory diseases or in case of violations metabolic processes. The results of repeated studies make it possible to track the dynamics and evaluate the effectiveness of the prescribed treatment.

But for this you need to know the norm of acid-basic acid.

What does this study show?

Blood is one of the main substances human body. It constantly circulates through it, supplying oxygen to all tissues and cells. In addition, it is directly involved in removing toxins and harmful compounds from the body. Blood renewal is also a continuous process. It is important to understand that a blood test for acid-base balance is an analysis based on the results of which a specialist can evaluate the functioning of the body as a whole.

Most clinically significant indicator is the pH level. This value must be stable. If it deviates to a lesser or greater extent, a specialist may suspect violations in the processes that are responsible for the formation of such an indicator.

The norm of acid-base balance in adults differs from this indicator in children.

When the acid-base balance is disturbed, a person experiences very rapid aging. Along with this, a significant weakening of the body’s protective barriers occurs, as a result of which various diseases develop. If treatment is not timely, there may be serious pathologies which often cannot be treated.

Indicators

In addition to pH, the main indicators of blood acid base are:

рСО2 - this value characterizes the partial voltage carbon dioxide in blood. It is determined in conditions of lack of air access. Based on this indicator, we can talk about the degree of functioning respiratory organs.
PaO2 is a value that characterizes the partial pressure of oxygen that is present in a gaseous environment balanced with blood.
PAO2 - which is present in the alveolar air.
TCO2 is an indicator that characterizes the overall level of carbon dioxide, that is, all its forms and states.
AB is an indicator of true bicarbonate. A deviation of this value in one direction or another is observed with respiratory disorders.
SB is an indicator of standard bicarbonate. Allows you to assess the severity of disturbances in metabolic processes.
BE is an indicator of excess or deficiency of non-carboxylic acids. This value shows the volume of a strong base that is necessary to normalize pH values.
BE-ecf is the value of base excess or deficiency, which is calculated for extracellular fluid.
BB is the total indicator of bicarbonate ions and protein anions.
CaO2 is the level of oxygen capacity of the blood.
CtO2 is a value reflecting the actual oxygen content in the blood.
DA-aO2 is a value based on which the diffusion capacity of the lungs and the volume of shunt blood flow can be assessed.
SpO2 is an indicator that characterizes the ratio of the total and oxygenated fractions of hemoglobin.

If you suspect the occurrence of certain pathological processes in the body, the doctor prescribes a laboratory test for examination acid-base balance.

Indications for prescribing the study

A doctor should be contacted if certain alarming symptoms appear that indicate organ dysfunction digestive system, liver, kidneys and lungs, as well as frequent conditions exacerbation of existing chronic diseases. Especially if a person experiences rapid aging, which externally manifests itself in the form of the appearance of early wrinkles and sagging skin, this indicates deviations from the normal blood acid-base level.

Goals of the analysis

The study of gas composition is prescribed for the following purposes:

Detection of various pathologies at the most early stages their development.
Evaluation of the effectiveness of a previously established therapeutic regimen.

When assessing the results of the study, the specialist can also judge the general condition of the patient’s body.

Preparing for the study

When prescribing an acid base analysis, the specialist explains to the patient some rules that must be followed before donating biological material. The doctor must inform the patient that when performing this analysis, in most cases, puncture of the artery is performed. The patient should be prepared for the appearance of discomfort or painful sensations in the puncture area blood vessel. Before collecting biomaterial, the patient is recommended to rest for 30 minutes. A stable physical condition is the key to obtaining the most informative results, especially for people suffering from severe respiratory failure. No adjustments to diet or nutrition are required before the study.

Rules for collecting biomaterial

To study the acid-base balance, blood is needed:

Venous. KSH norms venous blood Ph 7.26-7.36.
Lymph - 7.35-7.40.
Arterial. The norms of arterial blood acid base pH are 7.35-7.45.
Intercellular fluid - 7.26-7.38.
Capillary. Norms for capillary blood acid base pH are 7.35-7.44.
Intra-articular fluid - 7.3.

Arterial blood is the most suitable biological material for studying gas composition. This is explained by the fact that its study allows us to fully assess the degree of functioning of organs respiratory system.

Types of receipt:

Radial artery puncture. This technique considered the simplest. After its implementation, the probability of hematoma formation is less than 2%. Puncture of the radial artery cannot be performed if there is severe atherosclerosis in this area, as well as if a negative Allen test is obtained. The latter is done as follows: the patient needs to squeeze and unclench the hand several times until it turns pale. skin, after which the vessel is clamped. If normal skin color is restored in less than 5 seconds, this can be considered normal. A longer process of restoration of shade indicates blood flow disturbances.
Puncture femoral artery. The disadvantages of this technique are high risk blood loss, thrombosis, blood vessel occlusion, arm ischemia, various complications infectious nature. Biomaterial is not taken if there is vascular prosthesis in this area, taking anticoagulants, with aneurysms and local thrombosis. The complexity of this method of conducting research lies in the fact that it is not always possible to puncture the artery on the first try.

The level of carbon dioxide, which is the end product of metabolic processes in tissues, is slightly higher in venous blood than in arterial blood. In this case, the volume of oxygen, on the contrary, is lower. If you conduct a study of the acid base level of venous blood, it is possible to assess the indicators of systemic metabolism. Biological material is extremely rarely taken from peripheral vessels, since the result of such a study is not considered clinically significant.

In most cases, such analysis is carried out by puncture pulmonary artery. When taking blood, if it is taken from a vessel of a limb, a tourniquet, as a rule, is not applied. This is due to the fact that against the background of changes in local blood circulation, the results of the study are significantly distorted and become uninformative. If biomaterial is taken using a catheter installed in central vein, the practitioner should avoid the channel through which glucose and electrolytes are administered. Blood acid base in in this case may also be considered uninformative due to falsely elevated indicators.

In terms of gas content, capillary connective liquid tissue is close to arterial tissue. However, clinicians consider her study to be the least informative. Capillary blood is collected, as a rule, in cases where it is necessary to evaluate the main indicators of the acid-base balance of the blood in newborn babies.

So, what is the norm of acid-basic acid?

Interpretation of results

The norm of blood acid base is of interest to many. First of all, experts analyze the pH level. This is explained by the fact that this value is the main one among all clinically significant ones. Doctors such as hematologists and therapists are involved in deciphering the normal blood acid base level in adults. Normal result it is considered if this indicator is in the range of 7.37-7.44. With a slight deviation to a smaller or larger direction, it is customary to talk about certain disturbances in the functioning of the body. If this indicator significantly increases or decreases, the person usually experiences death.

In children, the interpretation of blood acid base level is carried out by a pediatrician and a hematologist. The result of the norm for children is values from 7.30 to 7.37.

The norms of acid-base balance in newborns are presented in the table.

In addition, diagnostic important indicators are:

Partial tension of carbon dioxide. In this case, arterial blood is most often taken. The normal acid-base balance for children can be considered from 27 to 39 mm Hg. Art., for women - from 31 to 44 mm Hg. Art., for men - from 34 to 49 mm Hg. Art. If the biological material was venous blood, such indicators will be higher by 5-6 units, which is not a deviation.
Standard bicarbonates. The normal acid-basic acid level for whole arterial blood is from 17 to 24 mmol/l, for venous plasma - from 21 to 30 mmol/l. When these indicators decrease, it is customary to talk about the development of acidosis, and when they increase, alkalosis occurs.

Now it’s clear what acid-base balance is. The meaning of the norm is described above.

Factors that have a negative impact on acid-base balance

If, in the process of interpreting a blood test for acid-base balance, a specialist discovers certain deviations, he is obliged to clarify whether the patient donated biological material in a calm state, and also to determine what other factors could have caused the distortion of the results.

Negative Impact on key indicators this study can provide:

unbalanced diet, overuse fast food;
living in areas with unfavorable environmental conditions;
frequent use alcoholic drinks;
prolonged state of stress;
smoking;
wrong mode day.

If such factors are present, the specialist may prescribe a repeat study of blood acid base in children and adults.

Determining the acid-base status yourself

It is extremely important to understand that the information content of research in a specialized laboratory is as high as possible. It is carried out using modern automated analyzers of blood gases, electrolytes, glucose and acid-base balance. If, for certain reasons, a patient needs to frequently donate biological material, he can purchase a special device and use it to regularly evaluate pH values.

Operating principle of this device is as follows: the device has two electrodes that are placed in a drop of blood. In this case, an electromotive force arises. After analyzing the pH meter (within one minute), the device displays accurate results. Such a device can be digital or analog. Analog models are considered outdated, so they are extremely rarely used by patients in practice. Digital pH meters are the most modern devices, having a user-friendly interface, built-in memory and a prompt system, so there is no need to record the results of the study on paper every time.

Portable and stationary devices can be purchased at pharmacies and medical equipment stores. Thus, a person can install a pH meter at home. There are mobile versions of this device.

It is not difficult to decipher the normal blood acid base level.

Alkalosis and acidosis

It is customary to talk about such conditions in cases where, when deciphering the acid-base balance, the doctor discovers deviations. Alkalosis is a disease that is characterized by an increase in the levels of basic indicators. This condition leads to the following consequences:

disruption of food digestion processes;
deficit minerals;
the entry into the blood of a large volume of toxic compounds.

Over time given pathological process begins to progress. Lack of treatment leads to organ pathologies digestive tract, heavy allergic reactions, dermatological problems. In addition, if a person has chronic diseases, against the background of alkalosis, they begin to rapidly become more complicated. The reasons for the increase in pH are:

disruptions in the functioning of the heart and blood vessels;
long-term stressful situations;
diseases in which frequent episodes of vomiting are observed;
overweight;
unbalanced diet.

If during the study of acid-base balance a deviation of the indicators is revealed in a smaller direction, this indicates acidosis. This condition is considered very life-threatening, and this threat lies in the fact that initial stages the disease is not accompanied alarming symptoms. As it progresses, the following phenomena occur:

increased blood sugar;
episodes of shortness of breath;
nausea;
state of shock.

If the analysis indicators are significantly reduced, the blood becomes acidic. At untimely treatment death is inevitable.

We looked at the decoding and norms of blood acid base in children and adults.

Prices for Acid-Base State

Testing the level of carboxyhemoglobin in the blood RUB 500.
Testing the level of methemoglobin in the blood RUB 500.
KSH 1100 rub.

Study of acid-base state (ABC) or acid-base status (ABS) is important in the diagnosis and treatment of various emergency conditions, including surgical ones.

Acidity and alkalinity mean the concentration of free hydrogen ions (H +) in a solution, i.e. Blood pH. For the efficient functioning of vital processes, the concentration of free hydrogen ions (H +) must be within strict limits. In fact, the study of acid-base balance includes, along with measuring pH, the determination of physiologically important gases present in the blood (oxygen - O 2 and carbon dioxide - CO 2) and about 20 other parameters. All these indicators and their values are closely interrelated with each other.

Patients in the intensive care unit and operating room may experience significant changes in these indicators over short periods of time. Research on acid-basic acid, unlike all other types laboratory tests, performed on arterial blood samples.

For normal functioning All cells of the body require oxygen (O 2). The decisive role in the transport of oxygen to tissues belongs to the hemoglobin contained in red blood cells. The term “hemoglobin” refers to several forms of hemoglobin that are present in human blood, both normally and in pathology. More than 98% of the oxygen absorbed by the lungs from the inhaled air is transferred to the body's cells in the blood in the form of oxyhemoglobin. Normally, small quantities of hemoglobin fractions are present in the blood that are not capable of carrying O2 - dishemoglobins (sulfhemoglobin, methemoglobin, carboxyhemoglobin).

Methemoglobin is constantly formed as a result of normal metabolism of body cells. Methemoglobin contains ferric iron and is not capable of transporting oxygen! When significant amounts of methemoglobin are formed, the transport function of the blood is sharply disrupted. The body has a mechanism for regulating the level of methemoglobin in the blood, which maintains the proportion of this fraction not higher than 1.0 - 1.5% of total hemoglobin.

Carboxyhemoglobin- a strong compound of hemoglobin (Hb) and carbon monoxide (CO). Carboxyhemoglobin is formed very quickly, since the ability of carbon monoxide to attach to hemoglobin is approximately 200 times higher than that of oxygen. Carboxyhemoglobin is not capable of carrying oxygen to the tissues of the body, therefore, in case of carbon monoxide poisoning, death can quickly occur in a person. Carboxyhemoglobin is formed in large quantities during poisoning carbon monoxide, and in small ones it is always present in the blood of all smokers and residents of large cities.

Indications:

ABL analysis is required

· To make a diagnosis Blood gas analysis is an integral part of diagnosing respiratory failure and primary hyperventilation. It also detects metabolic acidosis and alkalosis.

· To assess the severity of the disease

· To monitor the effectiveness of treatment Such analysis is very important for selecting oxygen (O2) therapy for patients with chronic respiratory failure type 2 and for optimizing ventilator settings.

An increase in methemoglobin (FMetHb) in the blood develops when:

· poisoning with nitrites, nitrates, nitroso compounds, aniline, sulfonamides, acetanilide, chlorides, bromides, etc.

hereditary deficiency of NADH-methemoglobin reductase: low enzyme activity manifests itself in early childhood. As a rule, this disease has no clinical consequences, manifesting itself as a minor cosmetic defect.

presence of abnormal variants of hemoglobin, designated hemoglobin M

An increase in carboxyhemoglobin (FCOHb) in the blood develops when:

· carbon monoxide poisoning. When FСOHb levels are above 30%, severe headaches are observed, general weakness, vomiting, shortness of breath, tachycardia, and at a level of 50% - convulsions, coma; above 70% occurs respiratory failure and possible death.

Methodology:

Determination of blood gases, acid-base status, oximetry parameters are carried out on the ABL 800 FLEX analyzer from RADIOMETR, Denmark, determination of up to 50 parameters.

A decrease or increase in one indicator - blood pH - indicates acidosis or alkalosis, but does not provide a comprehensive answer to the question of which component of the acid base is disturbed: respiratory or metabolic.

If two indicators are interpreted (pH and pCO2), then determining the primacy of the acid-base balance disorder becomes possible (Table 1).

Table 1. Determination of the primacy of the acid-base balance disorder

Arterial blood pH (norm 7.35 - 7.45)	рС0 2 (normal 35 -45 mm Hg)	Primary violation
Reduced	Increased	Respiratory acidosis
Reduced	Normal or reduced	Metabolic acidosis
Promoted	Increased or normal	Metabolic alkalosis
Increased	Reduced	Respiratory alkalosis
Norm	Downgraded	Mixed form respiratory alkalosis and metabolic acidosis
Norm	Increased	Mixed form respiratory acidosis and metabolic alkalosis

Acid-base homeostasis of the blood is characterized by the following indicators:

pH is an indicator of the active reaction of the blood; summarily reflects functional state respiratory and metabolic components and changes if the capabilities of all are exceeded buffer systems(normally 7.35 - 7.45).

pCO 2 (mm Hg) - carbon dioxide tension in the blood; the only respiratory indicator of COG, reflecting the functional state of the respiratory system, changing with its pathology and as a result of compensatory reactions during metabolic changes (normally 35-45 mm Hg in arterial blood).

AB (mmol/l) - true blood bicarbonates (aktual bicarbonate); concentration of carbonic acid ions, HC0 3 - at physical condition blood in the bloodstream, i.e. determined without contact with air at a temperature of 38 ° C (normally 21.8-27.2 mmol/l).

SВ (mmol/l) - standard bicarbonate (standard bikar-bonate); concentration of bicarbonate ions (HC0 3 -, measured under standard conditions: рС0 2 - 5.3 kPa (40 mm Hg), at a temperature of 38 ° C and complete saturation of hemoglobin with oxygen. Characterizes the displacement of ions of the bicarbonate system.

This indicator is considered more valuable diagnostically than true bicarbonate, since it reflects only metabolic changes (normally 21.6-26.9 mmol/l).

BB (mmol/l) - buffer bases of blood (buffer base); total concentration of buffer ions bicarbonates, proteins, hemoglobin in fully oxygenated blood. The diagnostic value of this indicator is small, because it varies depending on pC0 2, hemoglobin concentration (normally 43.7-53.5 mmol/l).

BE (mmol/l) - excess or lack of buffer bases (base excess). Characterizes the shift of ions of all buffer systems and indicates the nature of disturbances in acid-base homeostasis. A negative BE value reflects a base deficiency or an acid excess. With metabolic shifts in blood COG, the BE shift will be more pronounced than with respiratory disorders (normally BE = -3 - + 3 mmol/l).

AP - anion difference. The clinical use of the AR indicator is based on the assumption that any solution, including plasma, must be electrically neutral, i.e. the sum of cations is equal to the sum of anions. The plasma contains one main measurable cation Na+ and two main measurable anions CI - and HCO 3 - . The contribution of other unmeasured anions (NA) and cations (NC) is small (Table 2). It follows from this that the sum of measured and unmeasured anions is equal to the sum of measured and unmeasured cations:

HA + (CI - + NSO h -) = NK + Na +

Table 2.

Using the table data, you can calculate AR:

AR = NA - NK = 23 - 11 = 12 meq/l

AR = NA - NK = Na+ - (CI - + HCO3 -)

In cases of increasing H +, the disparity between the measured plasma concentrations of cations and anions will exceed the normal range of 9 - 13 mEq/L.

The AP value may be useful in identifying the etiology of metabolic acidosis.

As a rule, the higher the AR, the easier it is to determine the cause of acidosis.

High AR is characteristic of lactic acidosis caused by anaerobic glycolysis. Diabetic ketoacidosis and uremia are also accompanied by an increase in AR. If lactate, ketone and creatinine levels are normal with high AR, the most likely cause of acidosis is toxic intake (methanol, paraldehyde, ethanol, ethylene glycol, medicines). High level salicylates in plasma is accompanied by a significant increase in AR.

Classification of acid-base balance violations

1. Simple violations:

Acidosis:
- metabolic
- respiratory
Alkalosis:
- metabolic
- respiratory

2. Mixed violations:

2.1 Unidirectional: metabolic and respiratory acidosis and alkalosis
2.2 Multidirectional:

Metabolic acidosis and respiratory alkalosis
- metabolic alkalosis and respiratory acidosis

By degree of compensation:

1. Compensated.

pH values remain within normal limits (pH = 7.35 - 7.45), the content of bicarbonates and CO 2 changes depending on the direction of metabolic and respiratory changes.

2. Subcompensated.

In addition to changes in the content of bicarbonates and CO 2, pH also changes, but within insignificant limits + 0.04 (pH = 7.31 - 7.49)

3. Uncompensated.

RN< 7,30 - некомпенсированный ацидоз;

pH > 7.50 - uncompensated alkalosis.

Metabolic acidosis

Metabolic acidosis occurs due to a significant decrease in bicarbonate levels in the body.

Causes:

1. Increased production of non-volatile acids.

Enhanced production of acidic metabolites (so-called keto acids - (3-hydroxybutyrate and acetoacetate) is one of characteristic features uncontrolled or poorly controlled insulin-dependent diabetes. In this condition, called diabetic ketoacidosis, the amount of bicarbonate in the blood is significantly reduced due to its use to neutralize excess acids.

In cells that are largely deprived of oxygen and therefore cannot metabolize (oxidize) glucose, lactate accumulates. This significant accumulation of lactate in the blood in quantities sufficient to cause metabolic acidosis occurs if the tissues are inadequately perfused with blood and therefore insufficiently oxygenated.

The most obvious cause of lactic acidosis when tissue perfusion is impaired is hypovolemic shock. In addition, lactic acidosis can occur with renal or liver failure, diabetes, sepsis and leukemia.

2. Increased base loss.

Bicarbonate is secreted into the cavity small intestine for digestion and is absorbed in the lower sections gastrointestinal tract. If reabsorption does not occur, it is lost in the feces.

Any illness of the digestive tract (for example, severe diarrhea) can lead to the loss of bicarbonate from the body in quantities sufficient to develop metabolic acidosis.

Also, loss of bicarbonate may be associated with renal failure (proximal tubular acidosis - renal acidosis type II). Deterioration of Na+ reabsorption leads to the appearance alkaline reaction urine. In addition, proximal tubular acidosis is characterized by a decrease in urate, phosphate and potassium in the blood serum, glucosuria and aminoaciduria.

Using the AR value, it is possible to distinguish losses of HCO3 - during diarrhea from losses of HCO3 - caused by renal tubular acidosis. 3.

Table 3. Anion difference according to (P. Marino, 1998)

3. Increased intake of acids into the body from outside.

Abuse of acidic foods, ingestion of hydrochloric acid, injection of large quantities of old canned blood

4.Reduced excretion of H + ions through the kidneys.

Under normal conditions, the kidneys excrete H+ in the form of titratable acid (phosphates, sulfates) and ammonia. This mechanism may be impaired in kidney disease, adrenal insufficiency, distal renal tubular acidosis, and hyperaldosteronism. In case of renal failure, a decrease in the number of functioning nephrons, adequate filtration and excretion of H + are absent.

In type I renal acidosis (distal tubular acidosis), H+ secretion in the distal tubules is impaired. Since H + excretion in the distal tubules depends on Na + exchange, a decrease in fluid volume contributes to an increase in acidosis. Through the same mechanism associated with a decrease in the supply of Na + to the renal tubules, adrenal insufficiency and selective hypoaldosteronism also lead to a deterioration in H + excretion. In this case, metabolic acidosis is combined with other forms of electrolyte metabolism disorders: hyperkalemia, hyponatremia, hypercalcemia.

Compensatory reactions

The decrease in the level of HCO 3 - in the blood plasma (metabolic acidosis), which occurs primarily, is compensated by an increase in pulmonary ventilation and a decrease in pC0 2, while the ratio of pC0 2 /HCO 3 - remains unchanged.

The increase in acid content is buffered by a bicarbonate buffer:

HC1 + H 2 C0 3 /NаHC0 3 ↔ Na Сl+ H 2 C0 3

C0 2 + H 2 O

Diagnostic criteria:

1. With a reduced pH, normal or reduced level pCO 2 indicates primary metabolic acidosis;

2. At a normal pH value, a reduced level of pCO 2 indicates a mixed form of respiratory alkalosis and metabolic acidosis;

3. At normal pH normal level pCO 2 may indicate that acid-basic acid levels are within normal limits, but the possibility of mixed metabolic alkalosis/acidosis cannot be ruled out.

In these cases, AR is determined and changes in acid-base balance are judged by this indicator.

4. Base deficiency - AB, BE, BB, SV.

Clinical forms acidosis

Lactate - acidosis

Etiopathogenesis.

1. Reduced tissue oxygenation - tissue hypoxia. Highest value cause circulatory disorders (cardiogenic, septic, hypovolemic shock). The presence of all forms of hypoxia theoretically contributes to the development of lactic acidosis. Cardiac arrest is accompanied by anaerobic metabolism and lactic acidosis;

2. Impaired liver function reduces its ability to convert lactic acid into glucose and glycogen.

3. Lack of thiamine (vitamin B1) in patients who abuse alcohol leads to inhibition of pyruvate oxidation in mitochondria and promotes the accumulation of lactic acid.

4. Increased dextrorotatory isomer of lactic acid (D-lactic acidosis), undetectable by standard laboratory methods. This isomer is formed as a result of the action of microorganisms that break down glucose in the intestines. Most often occurs in patients after extensive operations on the intestines, with dysbacteriosis, gastrointestinal dysfunction. Apparently, this is the most common violation of the acid-base balance, but it is often not diagnosed (P. Marino, 1998);

5. The possibility of lactic acidosis with long-term infusions of adrenaline and other vasoconstrictors cannot be ruled out.

6. Lactic acidosis can develop in cases of using sodium nitroprusside, the metabolism of which produces cyanides that can disrupt the processes of oxidative phosphorylation.

Diagnosis of lactic acidosis:

The presence of metabolic acidosis associated with increased AR;

Marked base deficiency;

AP>30 mEq/L, while other causes of acidosis (ketoacidosis, renal failure, introduction of toxic substances), absent;

The level of lactic acid in venous blood exceeds 2 mEq/L. This indicator reflects the intensity of lactate formation in tissues.

Treatment:

Eliminating the cause of lactic acidosis.

Administration of sodium bicarbonate is indicated at pH<7,2, содержании НСОз - <15 ммоль/л. Расчет примерной дозы натрия бикарбоната можно провести по следующей формуле:

HCO3 deficiency - (mmol) = 0.3 * body weight (kg) * BE = ml 8.5% soda solution

For 3% soda: BE*0.8*body weight

For 4% soda: BE*0.6*body weight

For 5% soda: BE*0.5*body weight

First, half of the identified HCO3 deficiency is eliminated by intravenous administration of the solution for 30 minutes. Then, under the control of the HCO3 content in the blood serum, the correction is continued for 4 to 6 hours.

In this case, the pH is below normal - referred to as uncompensated acidosis. Next, we evaluate the gas composition of the blood: the level of pO 2 for arterial blood is slightly increased, but pCO 2 is reduced. Considering the base deficiency and increased lactate, we can conclude that this is metabolic lactic acidosis, in which immediate compensation is included in the form of hyperventilation.

Ketoacidosis.

Etiopathogenesis

In conditions of severe insulin deficiency, the supply of glucose to muscles and adipose tissue is blocked, the level of glucose in cells decreases, and the tissues experience “energy starvation.” This leads to hypersecretion of contrainsular hormones - somatotropin, glucagon, cortisol, adrenaline. Under the influence of these hormones, glycogenolysis, gluconeogenesis and lipolysis are stimulated. As a result of lipolysis, fats are broken down into free fatty acids, which become a source of energy and ketone bodies. In conditions of insulin deficiency, excessive formation of ketone bodies occurs and ketoacidosis develops.

Diagnostics

Clinical symptoms:

Weakness, thirst, nausea;

Diabetic precoma;

Diabetic coma.

Laboratory data:

Hyperglycemia

Glucosuria

Metabolic acidosis (decrease in pH, HCO3, pCO 2, severe base deficiency)

Acetone in plasma

Acetonuria

Plasma hyperosmolarity > 300 mOsm/L

Treatment

The initial dose of insulin is 10 units IV. Subsequent infusion of insulin in isotonic sodium chloride solution or 5% glucose solution is carried out at a rate of 0.1 U/kg/hour.

The deficiency of extracellular and intracellular fluid in ketoacidosis can reach 10% of body weight. Treatment should begin with the administration of isotonic solutions containing Na + and CI -. The danger of overadministration of crystalloids lies not only in volume overload, but also in imbalance of sodium and glucose concentrations. Therefore, dynamic monitoring of these substances and, if necessary, timely correction are necessary.

K+ losses during ketoacidosis reach 200 - 700 mmol and continue as the acidosis resolves. When correcting hypokalemia, it is necessary to take into account not only the deficiency, but also the need. The formula for calculating the K+ deficiency is presented:

Potassium deficiency (mmol) = patient weight (kg) x 0.2 x (4.5 - K + plasma)

It is recommended to administer sodium bicarbonate when the pH decreases.< 7,2 и снижении АД сист ниже 90 мм рт.ст., для предупреждения дальнейших электролитных нарушений и гемолиза. Но введение раствора соды должно быть более осторожным, чем при лактат-ацидозе, рекомендуется вводить 1/2 расчетной дозы.

Alcoholic ketoacidosis

Causes:

Conversion of ethanol during metabolism in the liver into acetaldehyde with the formation of NAD-H, which promotes the production of ketone bodies;

Concomitant fasting, accompanied by increased ketogenesis and ketonemia;

Dehydration leading to oliguria and decreased urinary excretion of ketone bodies.

Diagnostics.

Alcoholic ketoacidosis usually develops 1 to 3 days after excessive drinking. As a rule, the level of glucose and ketone bodies does not increase very much.

Treatment.

Intravenous administration of isotonic sodium chloride solution and 5% glucose is indicated.

Glucose inhibits the formation of ketone bodies in the liver, and saline solutions increase their excretion in the urine. Potassium correction is carried out according to its content in the blood serum. sodium bicarbonate is only applicable if the pH< 7,2 и снижении АД сист ниже 90 мм рт.ст..

Interpretation of the analysis begins with pH. In this case, the pH is below normal and is designated as uncompensated acidosis. Next, we evaluate the gas composition of the blood: the level of pO 2 for venous blood is normal, but it is impossible to draw a conclusion about the presence of hypoxemia; for this it is necessary to determine pO 2 in arterial blood. But taking into account the normal lactate level, we can conclude that there is no O 2 deficiency, aerobic glycolysis is in progress. The genesis of acidosis is metabolic and this conclusion can be made based on the level of base deficiency.

A decrease in bicarbonate levels may be associated with metabolic acidosis or developed renal failure, this can be said taking into account anamnestic and clinical data.

Metabolic alkalosis

Causes:

Loss of non-volatile acids

Severe and prolonged vomiting of gastric juice (it is acidic) leads to the loss of HCI from the body. These are the causes of metabolic alkalosis associated with pyloric stenosis, a condition in which it is difficult for gastric contents to move into the small intestine.

Loss of H+ ions

Hypokalemia increases proximal tubular reabsorption of HCO3 and increases distal tubular H+ secretion. Increasing albdosterone levels increases H+ secretion.

Excessive administration of sodium bicarbonate.

In this case, alkalosis develops with uncontrolled administration of bicarbonate, citrate, lactate or acetate.

Compensatory mechanisms:

Increased HCO3 content in the blood plasma (metabolic alkalosis), occurring primarily, is compensated by a decrease in pulmonary ventilation andan increase in pCO 2. As a rule, severe respiratory acidosis is not develops. However, with severe metabolic alkalosis, there is a risk of hypoventilation and hypercapnia.

NaOH + H 2 C0 3 /NaHC0 3 ↔ 2NaHC0 3 + H 2 O

Diagnostics.

NSOz in arterial blood is more than 25 mmol/l, in venous blood - more than 30 mmol/l;

pH is higher than normal;

PCO2 is normal or increased, in the most severe cases it may be decreased;

In hypochloremic alkalosis - CI less than 100 mmol/l;

Hypokalemia is common.

Treatment.

1. Elimination of the main cause of alkalosis;

2. Replenishment of the deficiency: CI deficiency (mol/l) = 0.27 * body weight (kg) * (100 - actual CI content)

The required volume of isotonic sodium chloride solution can be determined by the formula: NaСI (l) = CI deficiency / 154, where 154 is the content of CI (mol/l) in 1 liter of 0.9% sodium chloride solution;

3.If HCI is lost, an IV solution of HCI is required. A prerequisite for its use is normal fluid content in the body and normal concentration of K+ in the blood serum. Hydrogen deficiency is determined by the following formula:

H+ deficiency = 0.5 * body weight (kg) *
(actual HC0 3 content - desired HC0 3 content)

1 liter of 0.1 normal HC0 3 solution contains 100 mmol H+. the rate of administration of the HCI solution is 0.2 mmol/kg/hour.

The maximum daily dose of HCI solution = 100 mmol.

Ph blood, its norm for a healthy person is clearly indicated, is an important laboratory test. Ph is the level of acid-base balance and is an important indicator of human blood health. This is the concentration of hydrogen in the body. If its content does not exceed the norm, then all systems and organs operate in the required mode. When the balance is disturbed, a failure occurs: it can lead to the development of serious pathological processes that can even threaten life. When the acid-base balance may be disturbed, what consequences can this have?

What is Ph level and its norm

This indicator indicates the health of the body and normal immunity. Therefore, it is advisable to maintain the acid-base balance and regularly undergo analysis of its level. Only if the body has a sufficient amount of vitamins and minerals will it not quickly age and get sick.

These indicators may be negatively affected by:

poor nutrition;
unfavorable environmental situation;
alcohol abuse, smoking;
constant stress;
incorrect daily routine.

These factors lead to a blood test showing low Ph. Some of them can be influenced by humans. For example, you can balance your diet and monitor the quality of food.

If the acid-base balance is disturbed, problems such as:

disruption of the digestive system;
deterioration in the functioning of the lungs and kidneys, which purify the air and substances entering the body;
the main regulatory organ - the liver - begins to work poorly;
chronic pathologies develop.

All this negatively affects a person’s appearance. He is starting to age quickly.

If hydrogen ions are in the body in normal quantities, then the body is fine. The lungs, liver and kidneys are responsible for the acid-base state. These organs remove toxic substances and maintain the required concentration of acids and alkalis. It is very important to monitor its level in order to notice the development of serious diseases in time.

How is human blood pH and deviations determined?

During a preventive examination, doctors usually recommend that the patient determine the acidity of the blood. This will help the specialist assess the person’s health status and identify pathology. Hydrogen content is also determined at home. Anyone can buy a special device for this.

Laboratory research is carried out using the electrometric method. Capillary blood is used for the study. It contains a stable acid-base environment. Therefore, you can get accurate information without errors. The amount of hydrogen is determined by special glass electrodes. At the same time, they also take into account how much carbon dioxide is in the blood cells.

Determining Ph in laboratory conditions will provide more information, and specialists can decipher the result. If it is not possible to visit the hospital, you can buy a special device at the pharmacy that will show the condition of the blood.

Alkalosis

This condition leads to disruption of metabolic processes in the body.

Its reasons are:

prolonged vomiting, which releases stomach acid;

abuse of foods high in alkaline compounds;
constant stress;
excess body weight;
pathologies of the cardiovascular system.

You can get rid of the problem only by eliminating the causes that affected Ph.

Usually, breathing exercises and various solutions are prescribed to increase the level. You cannot treat yourself; drugs and their dosage should only be prescribed by a doctor.

Acidosis

A mild form of acidosis in adults can only be detected after testing.

A progressive problem can make itself felt:

signs of diabetes;
lack of oxygen in the body and the resulting consequences;
constant nausea and vomiting;
breathing problems;
shock state in the presence of other chronic pathologies.

Severe acidosis requires immediate medical attention, as this condition can be life-threatening. You can eliminate the symptoms of the disease by drinking a glass of water with soda.

How to normalize acidity

You can control your acid-base environment using the following rules:

Adhere to the principles of proper nutrition. There are certain products that will help maintain normal levels of acids and alkalis. These are vegetables, fruits, some cereals, nuts, dried fruits, and mineral water.

Garlic, potato juice and some types of medicinal herbs (chamomile, mint) help normalize Ph.
It is necessary to give up fatty, fried and smoked foods, drink less caffeine- and alcohol-containing liquids, and stop smoking. All this leads to the accumulation of substances harmful to the body and their deposition on the walls of blood vessels.
To eliminate Negative influence These products are necessary to cleanse the body.

It is useful to drink special alkaline water, which enriches the body with ions, helps strengthen the immune system and removes waste and toxins from the body. You can make tea from this water or use it in preparing first courses. If medications are prescribed to increase the acid-base environment, then a break of several hours must be taken between taking them and drinking water.

In addition, it is worth leading a healthy lifestyle, normalizing physical activity, and not forgetting about adequate periods of sleep and rest.

The acid-base balance or pH of the blood has an important function in the body. If deviations from the norm are observed in one direction or another, this will have serious consequences for human health. The pH of human blood is called the hydrogen index, as it is translated from Latin as “the power of hydrogen.”

If we talk about the normal pH in the blood, it varies depending on the vessels. For veins it can range from 7.32-7.42, if we talk about arteries, here it varies from 7.376-7.43.

In medical practice, conditions when the blood pH is below 6.8 or above 7.8 are considered fatal to humans.

If this indicator is normal, then the required amount of hydrogen ions is in the blood. Then all body systems, such as the respiratory and urinary systems, work normally and help remove waste products from the body.

Signs of a serious deviation of blood pH from normal are:

Disturbances in the gastrointestinal tract.
Pathologies in the functioning of the respiratory organs (respiratory arrhythmia, etc.), kidneys.
Liver hemangioma and other anomalies.

In this case, a person may be diagnosed with a chronic disease and his appearance will worsen.

Effects of pH on Health

This procedure is prescribed for patients who have certain abnormalities. How is a blood pH test done? It is preferable to use arterial blood for the procedure, which is considered pure and gives the most accurate result. A blood pH test involves identifying the level of hydrogen and general acidity in the body.

This test for acid-base balance is carried out on an empty stomach, and blood is taken from the capillaries. The laboratory analysis procedure is carried out using the electrometric method. This requires glass pH electrodes. The level of carbon dioxide in the blood is measured, as well as the amount of hydrogen ions.

The interpretation of the blood pH test is carried out by a laboratory assistant who is an expert in his field.

Using this procedure, the following can be said about human health:

A result of 7.4 indicates that the balance is slightly alkaline and the person’s condition is normal.
If the pH in the blood is high, then there is a lot of alkali in the body, which leads to a condition called alkalosis.
If the level is much lower than normal, then this condition is called “acid blood” and indicates an increase in acidity. In medical terms, this pathology is called acidosis.

Any abnormality should be carefully treated. Both oxidation and alkalization of blood have a bad effect on the human body. Therefore, it is necessary to take special medications that restore normal balance in the blood.

The most common causes of alkalosis are:

With stress and depression, alkalosis can develop.
May appear as a result of heart and vascular diseases.
If the patient is obese.
If the patient has previously had prolonged vomiting, as a result of which he has lost a lot of acid.
If a person often eats dairy, as well as some vegetables and fruits.

Stress is one of the causes of alkalosis

With alkalosis, metabolic function is impaired, as a result of which the digestion of food is significantly impaired and toxins enter the blood.

As a result, the patient experiences the following anomalies:

Allergy, allergic vasculitis.
Various skin diseases may occur.
Diseases of the stomach and intestines.
Various pathological conditions of the liver.

Such diseases most often become chronic and often experience periods of exacerbation.

This disease is observed more often than alkalosis. Acidosis can be caused by alcoholism or complications of diabetes.

Usually this disease does not have pronounced symptoms. But in some cases you can observe:

Constant heartburn.
Regular nausea.
And in some cases, vomiting.
All symptoms of diabetes.
Increased fatigue and weakness.
Problems with the respiratory system and a noticeable lack of oxygen.

As a result of the fact that oxygen is supplied in insufficient quantities to tissues and organs, a lack of microelements such as magnesium, potassium in the blood and sodium may develop, which will lead to abnormal conditions:

Obesity.
Tumor formations.
Weaknesses of the body.
Diseases of the cardiovascular system.
Kidney and liver problems.
Bones become brittle.
Diabetes may develop.
Pain in veins, joints, muscles.
Immunity decreases.

Many patients have a question: how to determine blood pH at home? To do this, a special device is purchased at the pharmacy, with which a puncture is made and the required amount of blood is taken. This device analyzes data using a microprocessor and displays the result digitally on the display.

PH meter for blood

But in any case, you cannot diagnose yourself, so you need to contact any medical institution in order to carry out this procedure in a special laboratory.

The body's acid-base balance may be abnormal depending on several factors:

If the city has a bad environment.
Human exposure to stress.
Irregular and unhealthy diet.
Tobacco smoking.
Frequent drinking of alcohol.
Work and rest schedules do not coincide.

Acid-base balance is a very important indicator of human health. If even minor deviations in blood pH from the norm are detected, this can lead to the destruction of cells in the body, enzymes lose their basic functions, which can even result in death. Therefore, it is important to prevent this pathology in time. The pH of a person’s blood is a very important indicator for his life, so you always need to be aware of what it is, because the slightest deviation from the norm can lead to death.

Have questions? Ask them to us on VKontakte

Share your experience in this matter Cancel reply

If you find an error in the text, select it and press Shift + Enter or click here and we will try to quickly correct the error.

Sign up to our newsletter

Thank you for your message. We will fix the error soon.

Indicators of ABS - acid-base state - reflect the close relationship between acid-base, oxygen and water-electrolyte metabolism. An imbalance in one of them always entails sharp disturbances in the other two and in the normal course of physiological reactions of homeostasis in general.

In order to understand the significance of CBS regulation, let's consider a simple example.

Hypoxia is accompanied by disturbances in the CBS and water-electrolyte balance of the following nature: - the main cation of the extracellular fluid enters in excessive quantities into the cells and with each mmol of Na, 6 ml of H2O is introduced into the cell, which entails cell swelling and, at the same time, artificial hypovolemia . This, in turn, causes an increase in plasma osmolality and leads to an increase in secretion with a decrease in urine output.

A decrease in circulating blood volume is accompanied by increased secretion and retention of Na and fluid in the body. That is, the body’s compensatory mechanisms, destabilized by hypoxia, not only fail to cope, but also prevent the removal of excess fluid from the body. As a result of the redistribution of water in the body, a false “hypoxic hypovolemia” occurs due to cell outflow. Therapeutic measures of clinicians in this case are aimed at eliminating hypoxia. Transfusion of fluids to a patient to replenish the volume of circulating blood against the background of severe hypoxia can only aggravate the patient’s condition due to increased cellular and intraorgan edema.

blood pH

Provides information about the content of H+ ions in the blood.

Normally: in arterial blood pH = 7.36-7.42, in venous blood pH = 7.26-7.36, in capillary blood pH = 7.35-7.44. It should be borne in mind that a normal pH value does not always indicate the absence of violations of the CBS, since in this case it is impossible to exclude compensated acidosis or.

Whole blood PCO2

Partial pressure of carbon dioxide in the blood.

Normal: in arterial blood 35-45 mm Hg. Art., in venous blood - 46-58 mm Hg. Art. An increase or decrease in pCO2 compared to the normal level is a sign of respiratory impairment of the respiratory system.

Whole blood buffer bases (WB)

This is the sum of the anions of all weak acids, the main of which are bicarbonates and protein anions in blood completely saturated with O2. Normal levels are 42-52 mmol/l. This indicator does not change with changes in pCO2. Therefore, by the value of explosives one can judge the presence of non-respiratory disorders of the respiratory system associated with changes in the content of non-volatile acids in the blood.

Normal Buffer Bases (NBB)

Normal buffer bases (NBB) - the sum of all basic (anionic) buffers in the patient’s blood, but reduced to standard conditions (pH = 7.38; pCO2 = 40 mm Hg; 38 °C; HbO2 = 100%).

Buffer Base Offset

Shift of buffer bases (BE - base excess) in relation to standard conditions.

BE = BB - NBB.

The permissible bias limit is ±2.0 mmol/L. The indicator changes with non-respiratory disorders of CBS. In this case, there is a deficiency of buffer bases due to their binding with non-volatile acids - negative BE. In alkalosis, buffer bases increase due to a decrease in non-volatile acids - positive BE.

Current blood bicarbonate

Actual blood bicarbonate (AB - Actual bicarbonate) reflects the concentration of bicarbonates (HCO3-) in blood plasma under physiological conditions. Normally it is 21-26 mmol/l.

Standard bicarbonate

Standard bicarbonate (SB - Standard bicarbonate) - the concentration of bicarbonate in blood plasma, reduced to standard conditions. Normally it is 20-26 mmol/l. By the difference between standard and actual bicarbonates, as well as by pCO2, one can judge the presence of respiratory disorders of the CBS by the fact that the main part of HCO3- ions is transported in the form of carbon dioxide. Moreover, if SB = AB - there are no violations; if SB > AB - ; if SB< АВ - .

Total CO2 content

Normally it is 52-73% or 23-53 mmol/l.

PO2 - partial pressure of oxygen

It is an indicator of oxygen supply to tissues. Normally it is 38-40 mmHg in venous blood. Art., in arterial blood - 80-108 mm Hg. Art. A decrease in this indicator indicates a deficiency of oxygen in the tissues - hypoxia. However, cases have been described when pO2 remained within normal limits or was above normal for a number of pathological conditions organism (pronounced).

Used as an indicator of the presence or absence of hypoxia in patients. Lactate is a breakdown intermediate product. Its complete oxidation occurs when the body is sufficiently saturated with oxygen through conversion to pyruvate and subsequently, through resynthesis of glycogen in the liver or breakdown to CO2 and H20. Normally, the lactate content in arterial blood does not exceed 1 mmol/l, and in venous blood - no more than 2 mmol/l. If the patient does not have severe diabetes, an increase in lactate in the blood - hyperlactic acidemia, is interpreted as an indicator of oxygen deficiency in the body.

Content of residual (residual - R) anions in the blood

This indicator is informative for assessing the violation of CBS caused by the accumulation of under-oxidized metabolic products in the body. Residual anions include anions of non-volatile (organic and inorganic) acids.

The normal concentration of R-anions is on average 12 mmol/l. A significant correlation was noted between lactate and R-anions in the blood. Therefore, if it is impossible to determine lactic acid in the laboratory, R-anions can serve as a reliable criterion for assessing lactate content. An increase in R-anions corresponds to an increase in lactate content in the blood and, in combination with other indicators of CBS, allows us to confirm hypoxia as the cause of metabolic disorders.

Laboratory indicators of the acid-base state of the blood was last modified: October 23rd, 2017 by Maria Saletskaya