Infusion therapy in animals. Infusion-hemotransfusion therapy and parenteral nutrition. Increased loss of potassium ions in urine

Infusion therapy(from Latin infusio - infusion, injection; and other Greek θεραπεία - treatment) is a treatment method based on restoring the volume and composition of extracellular and intracellular fluids with the help parenteral administration medicinal solutions.

Infusion pump

Fluid and electrolyte balance is very important for every body. IN healthy body fluid intake and excretion are in balance, which ensures the functioning of cells and maintains a normal level of hydration. During illness, due to fluid loss or insufficient intake, the balance is disturbed, which aggravates the course of the disease and increases the duration of recovery. Therefore the main goal infusion therapy is the restoration of volume and electrolyte composition body of water body.

Every day, warm-blooded animals should consume up to 50 ml/kg of water weight. This includes both the liquid you drink and the water contained in your food. In many diseases, the body develops a deficiency of water and electrolytes. This occurs in conditions such as:

• increased loss of fluid and salts due to vomiting, diarrhea, high temperature, increased volume of urination. This is observed in cases of poisoning, infectious diseases, diseases of the gastrointestinal tract, chronic diseases in the acute stage, etc.;
• diseases leading to the accumulation of toxic products in the body, such as chronic renal failure, hepatitis, poisoning;
• shock caused by any reason (car injury, fall from a height, extensive blood loss, pyometra) causes a large amount of fluid to leave the vascular bed and leads to a decrease in circulating blood volume;
• carrying out surgical interventions. On the day of surgery, the animal is usually deprived of food and water, and the surgery is accompanied by blood loss.
• inability of the animal to independently take food and water (postoperative period, general serious condition). In this case, parenteral nutrition is prescribed, that is, the introduction of substances necessary for the body intravenously.
• administration of medications that cannot be administered in any other way.

Goals of fluid therapy:

1. Replenishment of circulating blood volume.
2. Restoration of water-electrolyte and acid-base balance.
3. Improving the rheological properties of blood (“viscosity”).
4. Detoxification.
5. Parenteral or intravenous nutrition.

To achieve these purposes, three types of solutions are used:

• crystalloids (solutions of salts and glucose),
• colloids (reopolyglucin, polyglucin, hydroxyethyl starch solutions),
• blood products (whole blood, fresh frozen plasma).

With moderate dehydration and the general stable condition of the animal, fluids are administered subcutaneously. If the patient's condition is severe, a peripheral intravenous catheter is installed. This is a flexible plastic tube, fixed with a patch on the paw, with which the animal can walk for 5 days.

If the patient's condition is stable, then infusion therapy is carried out on an outpatient basis. If the animal's condition is serious, hospital treatment is recommended.

You can perform this procedure in our clinic. If very slow administration of drugs is required, then we use an infusion pump - a special device for dosed administration of solutions.

The plan for infusion therapy in animals includes the choice of fluid, the volume and speed of its administration.

Fluid therapy in animals is used to correct life-threatening abnormalities in volume, electrolyte composition, and acid-base balance. The primary goal is to provide the smallest volume of fluid needed to complete resuscitation more quickly. The achievement of the final result of resuscitation is judged by clinical markers. Those elements of the initial examination that indicated shock are used as markers and include the following: change in consciousness; long time capillary filling; weak and thready pulse/hypotension; tachycardia/bradycardia, tachypnea, cold extremities; weakness, decreased diuresis; and pale mucous membranes.

Fluid therapy in animals is usually divided into a resuscitation phase (correction of perfusion deficits), a rehydration phase (correction of interstitial deficits) and a maintenance phase. The requirements for maintaining the condition are higher in rodents due to their high metabolic rate and, as a rule, twice as high as in cats and dogs.

Types of liquids:The characteristics of the solutions affect the type of administration and the required volume of liquid. During the resuscitation phase, isotonic crystalloid solutions are usually used together with colloids. The four main groups of fluids include: crystalloids, synthetic colloids, hemoglobin-based oxygen-carrying solutions, and blood products, which are commonly used for shock, rehydration, and supportive care. Oxyglobin is a colloid similar to hydroxyethyl starch, but the latter has the added benefit of transporting oxygen.

Infusion therapy in rodents: From the experience of veterinarians, hypovolemia in rodents appears at the beginning of the decompensatory stage of shock, which is similar to cats and small mammals. The preceding compensatory stages of shock, often found in dogs and birds, are not observed in rodents (or in cats or small mammals). Signs of early decompensatory shock in rodents (as well as in cats and small mammals) include bradycardia, hypothermia and hypotension. In cases of intravascular volume deficiency that leads to deterioration of perfusion, rapid administration of crystalloid solutions in a volume equivalent to the animal's blood volume has previously been recommended. However, resuscitation using crystalloid solutions alone may result in fluid accumulation in the lungs and pleural cavity. Hypoxemia occurs, which contributes to the pathophysiological progression of shock. Rodents are difficult to resuscitate in hypotensive conditions, and early aggressive therapy with intravenous or intraosseous infusion is recommended.

It has been found that in rabbits, when baroreceptors detect inadequate arterial distension, the vagus nerve fibers are stimulated simultaneously with the sympathetic fibers. As a result, the heart rate may be normal or slow rather than showing the typical tachycardia seen in dogs in the compensatory stage of shock. This baroreceptor response may be similar in rodents. The normal heart rate in rodents is 180 to 350 beats per minute (bpm), and systolic blood pressure is 90 to 120 mmHg. Art., and a body temperature between 36 and 38.8 °C (97-102 °F) (see also Chapter 1). Most animals with hypovolemic shock have a heart rate less than 200 beats/min. hypotension (systolic blood pressure less than 90 mmHg) and hypothermia (temperature<36 °С). Эти признаки являются классическими признаками декомпенсаторной стадии шока. Брадикардия и слабый сердечный выброс приводят к гипотермии, а гипотермия усугубляет брадикардию. Так как сердечный выброс зависит от сократимости миокарда и скорости кровотока, компенсаторный ответ на шок, обычно наблюдаемый у собак и птиц, скорее всего, притупляется у грызунов, мелких млекопитающих и кошек, таким образом гипердинамические признаки шока, видимые у собак и птиц, чаще всего не заметны у грызунов.

Resuscitation and infusion therapy in animals with hypovolemic shock can be safely performed using crystalloid and colloid solutions and warming. For rodents with hypovolemia, infusions of isotonic crystalloids at a dose of 10-15 ml/kg are recommended. Hydroxyethyl starch (HES) is administered intravenously or intraosseously at a dose of 5 ml/kg for 5-10 minutes. Blood pressure is measured; when systolic is above 40 mm Hg. Art., only an isotonic crystalloid solution is administered, and the patient is intensively warmed. Warming is carried out for 1-2 hours using a bottle of warm water, a warm blanket and intravenous administration of warm solutions. Warm intravenous fluids (or running the IV fluid line through a container of hot water) help raise your core body temperature. When rectal temperature reaches 36.6°C, adrenergic receptors begin to respond to catecholamines and fluid therapy. All rodents should have their temperature taken frequently during the rewarming process to prevent hyperthermia. Blood pressure is measured again when the temperature becomes > 36.6°C, and administration of isotonic crystalloid solution (10 ml/kg) with HES at a dose of 5 ml/kg can be repeated for 15 minutes until systolic blood pressure rises above 90 mmHg Art. Rectal temperature should be kept at the proper level by a warm incubator or warm infusions. When systolic pressure blood will be >90 mm Hg. Art., the rehydration phase begins. During the rehydration phase (eg, perfusion deficiency persists or there are signs of hypoproteinemia), a constant rate of HES infusion is maintained at a dose of 0.8 ml/kg/h.

If during infusion therapy in animals it is not possible to achieve the expected result (normal blood pressure, heart rate, color of mucous membranes, colorectal temperature), the animal is re-examined and the search for the causes of uncontrolled shock (excessive vasodilation or vasoconstriction, hypoglycemia, electrolyte or acid-base imbalance) is continued. imbalance, cardiac dysfunction, hypoxemia) and begin corrective therapy.

If cardiac function is normal and abnormalities related to blood glucose, acid-base and electrolyte imbalances have been normalized, treatment for shock should be continued. Oxyglobin has not been approved for use in cats, small mammals or rodents, but has been used successfully by the authors in small volumes (2 ml/kg) for 10-15 minutes until established normal heart rate and blood pressure (systolic blood pressure above 90 mm Hg). This occurs after continuous infusion of Oxyglobin at a dose of 0.2-0.4 ml/kg/hour. If Oxyglobin is not available for the treatment of persistent hypotension, the authors used 7.5% hypertonic saline at a dose of 2-3 ml/kg bolus with HES at a dose of 3 ml/kg bolus slowly over 10-15 minutes. Vasopressors such as dopamine or norepinephrine may also be used to treat persistent hypotension.

Dehydration deficiency is assessed when perfusion parameters are normal. Replacement therapy involves the use of isotonic crystalloid solutions. This issue will be discussed in the section below.

Summary of principles for the use of infusion therapy in animals with hypovolemia:

1. Carrying out intravenous or intraosseous catheterization.
2. Warming in case of hypovolemia.
3. Measurement of indirect systolic pressure.
4. Infusion of warm solutions of isotonic crystalloids at a dose of 10-15 ml/kg and hydroxyethyl starch (6%) at a dose of 5 ml/kg over 5-10 minutes until the Doppler sensor shows a systolic pressure of more than 40 mm Hg. Art.
5. Continue external and internal warming of the body until the rectal temperature exceeds 36.6 °C.
6. Bolus fluid therapy in animals (10-15 ml/kg) and colloids such as hydroxyethyl starch (5 ml/kg) until Doppler systolic blood pressure is greater than 90 mmHg. Art.

ETC. Pulnyashenko, R.S. Koziy, V.N. Fedorov
Veterinary hospital "Fauna Service".

Infusion therapy (IT) is one of the most important components of the complex of resuscitation measures, the introduction of any fluids into the body by parenteral route. It is used for the prevention and correction of dysfunctions and body systems (cardiovascular, volemic, respiratory, metabolic, etc.) caused by the underlying disease, or surgery and anesthesia. IT in case of shock of any etiology, it is aimed at correcting the disorders caused by it along with other measures of anti-shock therapy. Elimination of circulatory disorders, CBS, electrolyte disturbances, restoration of diuresis, prevention and treatment of microthrombosis are the most important tasks IT in shock. For peritonitis and intestinal obstruction IT begin in the preoperative period to eliminate dehydration and hypovolemic acidotic (alkalotic) shock, restore impaired water-salt metabolism. The tasks of IT in case of blood loss are: elimination of BCC deficiency, peripheral vascular spasm, acidosis, etc.

PARENTERAL (INTRAVENOUS) NUTRITION (PN) is included in the IT complex along with other treatment methods only if enteral or tube nutrition is impossible or undesirable. PN, like regular nutrition, fully provides the body with all nutrients (carbohydrates, proteins, fats, water, vitamins, microelements) and, when carried out correctly, maintains the nitrogen balance and body weight of the patient. PN is successfully used in surgery in weakened animals for preoperative preparation during operations on the gastrointestinal tract and in the complicated postoperative period (peritonitis, intestinal fistulas, etc.), PN can be complete when all nutrition is carried out exclusively intravenously (the patient does not even drink water), and combined (a combination of intravenous and oral nutrition). PP contains sources of nitrogen and energy, water, vitamins and electrolytes. The optimal ratio of carbohydrates, fats and proteins in the total calorie content of mixtures for complete PP is 50, 40 and 10%, respectively. Total requirement for energy and other ingredients.

During PN, glucose, amino acids, protein hydrolysates and fat emulsions directly, without intermediate breakdown, enter into metabolic processes with tissue cells. The role of glucose in PP is to provide basic energy needs, prevent protein breakdown and have a nitrogen-protective effect. Fat emulsions, in addition to supplying the body with fatty acids, allow you to introduce a large amount of energy in a small volume.

In the complex of measures during infusion therapy, blood transfusion has important. IN clinical practice blood transfusions are used for replacement purposes (transfused red blood cells remain in the recipient’s blood for 30-120 days); stimulating purpose (acts on various functions animal organism); in order to improve hemodynamics (increase in blood volume, increased heart function, increased cardiac output); hemostatic purpose (blood transfusion has a stimulating effect on the recipient’s hemostasis system, causing moderate hypercoagulation due to an increase in thromboplastic and a decrease in the anticoagulant function of the blood).

Dogs have seven blood groups, determined by antigen: A, B, C, D, E, F and G. Factor A in animals has the same importance as the Rh factor in humans. This factor is present in approximately 60-65% of animals. Repeated blood transfusion to an animal that does not have this factor can lead to severe blood transfusion consequences - blood hemolysis and death of the animal. To avoid these complications, it is necessary to conduct tests on group and individual compatibility. To do this, it is necessary to add 0.1 ml of donor erythrocytes to 1 ml of recipient serum. The reaction is carried out on glass at a temperature of +22-25? C. Accounting is carried out in 5 minutes. If there is no agglutination reaction, you can proceed to the biological compatibility test.

A biological test for individual compatibility is carried out by transfusion of 10-15 ml of blood large breeds dogs and 3-5 ml-small. The test is carried out three times. In this case, if possible, the animal’s blood pressure, pulse rate, and number of respirations are measured before the transfusion and after 10-15 minutes. After a jet infusion of blood. Anxiety of the animal, shortness of breath, tachycardia or arrhythmia, drop in pressure, vomiting, and pain indicate incompatibility of the transfused blood.

When transfusing blood, it should be taken into account that the most suitable blood transfusion is fresh donor blood. When transfusing pre-prepared blood, it must be heated in a water bath to a temperature of +37°C, because cold blood causes myocardial hypothermia, peripheral vascular spasm and acidosis, and easily goes into the blood depot. For every 200-250 ml of citrated blood, 5 ml of a 10% solution is injected calcium chloride, 50 ml 40% glucose with 4 units. insulin and 20-30 ml of 3% soda.

Blood is collected from the animal by venipuncture with a thick needle and poured into a bottle with a prepared preservative. To prevent blood coagulation in the system, the latter must first be washed with a heparin solution or glugitsir

Without harming the health of the animal, blood can be taken at a rate of 10 ml/kg. Blood is transfused dropwise at a rate of 40-60 drops/min. At the rate of 5-18 ml/kg per hour. Repeated blood sampling can be done after 1.5-2 months.

Fluid in the body

INTRAVASCULAR PART: 7-9% OF BODY WEIGHT

• arterial system: 18% venous system: 70%
• heart: 7%. capillaries: 5%

EXTRAVASCULAR PART: 53% WEIGHTS TEPA .

• intracellular: 33% body weight
• interstitial: 20% body weight

Substances dissolved in water are in ionized and non-ionized forms. The number of cations and anions are in balance, ensuring electrical neutrality of the environment. The composition of water spaces is constantly changing, providing chemical, physical, neurohumoral regulatory mechanisms and metabolic processes. At the same time, it is in constant balance due to the exchange of fluid between the body and the external environment. This occurs when there is a correspondence between the intake and excretion of fluid. In healthy animals, daily fluid loss is 40 ml/kg per day. of them 50% accounts for undetectable losses (salivation, perspiration, excretion from the surface of the body, during internal water exchange, etc.) and 50% (about 20 ml/kg per day) is excreted in the form of urine and feces. Any pathological process, accompanied by fluid loss (bleeding, shortness of breath, increased body temperature) leads to the loss of a large amount of water. Thus, an increase in body temperature by 1C° increases water loss by 4-8 ml/kg. Normally, imbalance of water spaces is regulated by thirst. Increased thirst observed in animals with peritonitis, intestinal obstruction and other pathological conditions. accompanied by increased body temperature and shortness of breath. A change in the volume of water spaces can lead to changes in electrolyte metabolism.

ELECTROLYTE EXCHANGE

Sodium– the main cation of the extracellular space, where 98% of the sodium of the whole organism is located; 2% of sodium is found in the intracellular space. IN bone tissue sodium is in bound form and normally does not participate in metabolism. Sodium plays main role in maintaining osmotic pressure, in the exchange of fluid between spaces and is important in acid-base balance.

Physiological sodium concentration is 135 --145 mmol/l. Sodium is excreted mainly in the urine (120-220 mmol/day). to a lesser extent - with feces (10 mmol/day). In the renal regulation of sodium content, glomerular filtration plays a role, and in mineralocorticoid filtration, reabsorption in the tubules plays a role.

Determination of sodium in blood serum above 150 mmol/l) does not mean an increase in sodium content in the entire body.

Hypernatremia - possible with hypertonic dehydration (lack of electrolyte-free water) and hypertonic hyperhydration (excess sodium).

Hyponatremia- sodium content in blood serum is below 135 mmol/l. With hyponatremia, sodium excretion in the urine decreases. When regulatory mechanisms are depleted, obvious hyponatremia develops. In severe cases, the total sodium content of the body also decreases. Hyponatremia is simultaneously accompanied by hypochloremia, which causes alkalosis (increased levels of bases or loss of acids). The level of sodium in the blood serum decreases both with hypotonic dehydration and with hypotonic overhydration. In the differential diagnosis of these conditions, it is of great importance to identify the root cause of the disturbance of water-electrolyte metabolism and the disturbance of which metabolism - water or electrolyte - predominates.

Potassium is the main cation of the intracellular space. The level of potassium in the blood serum is 4-4.5 mmol/l, the total amount of potassium in the body is 51 mmol/kg body weight. 98% of potassium is found in cells, and 2% is in the extracellular space. Of the total amount of potassium, 10% is associated with proteins, glycogen, and phosphates. active potassium is The daily potassium requirement is 0.7-1.0 mmol/kg. Potassium is absorbed in the upper parts of the small intestine, excreted mainly in the urine, 10% in feces. Potassium is filtered by the glomeruli of the kidneys, in the proximal tubules it is absorbed back, and in the distal tubules it is released through Na+-K+ ion exchange.

A disturbance in potassium metabolism is observed primarily when there is a disturbance in the supply of potassium, its penetration into the cell, a disturbance in excretion through the kidneys, and only sometimes due to its pathological distribution in the body. In the extracellular space, the normal level of potassium fluctuates within small limits, and even a slight decrease or increase in it leads to the development of pathological conditions.

In the intracellular space, potassium in the cell determines electrical neutrality, osmotic concentration and enzymatic activity; in the extracellular - muscle contractility and nervous excitability

A normal level of potassium in the blood serum is a prerequisite for cell integrity. When cell function is damaged, the function of the sodium-potassium pump is disrupted, as a result of which potassium enters the extracellular space, and sodium and hydrogen ions take its place.

The level of potassium in the extracellular space does not reflect the potassium content in the cells, but practically, to determine the degree of imbalance, the amount of potassium in the blood serum provides satisfactory information, especially if the direction of potassium migration is known for a given pathology of saturation of the body with water and exact daily urinary potassium losses. A disturbance in the metabolism of potassium is observed when there is insufficient intake of it into the body, or when there is a violation of its entry into the cell and its excretion.

Hyperkalemia- serum potassium level above 5 mmol/l. With healthy kidneys, potassium excretion corresponds to intake, and with kidney failure, oligo- or anuria, potassium excretion in the tubules is disrupted and its level in the blood serum increases. .

Hyperkalemia is observed in conditions associated with tissue crushing, burns, injuries, necrosis of parenchymal organs, intravascular hemolysis, transfusion of large quantities of preserved blood, increased cellular metabolism, metabolic acidosis. Dangerous hyperkalemia is caused by rapid administration of potassium solutions (over 20-40 mmol/g). Chronic hyperkalemia is observed upon administration medicines, causing delay his.

The clinical picture does not always correspond to the degree of increase in the level of potassium in the blood serum, since metabolic acidosis and disturbances in the metabolism of sodium and chlorine are simultaneously observed. Characteristic symptoms are: inhibition of neuromuscular excitability, general muscle weakness, sensory disturbances, heart enlargement, cardiac arrhythmia. The ECG shows a high tent. prong T, expansion of the complex QRS interval shortening Q-T, outlining of the leg block, flattening of the tooth R. If the level of potassium in the blood serum exceeds 7-10 mmol/l, ventricular fibrillation or cardiac arrest in diastole is possible.

Hypokalemia(serum potassium level below 3.5 mmol/l) is observed with insufficient intake of potassium into the body and increased excretion. A change in K+ concentration in the blood serum does not always correspond to a change in the level of potassium in the cell.

In severe hypokalemia, the level of potassium in the cells also decreases. The most common causes of hypokalemia are acute and chronic inflammatory diseases kidneys, stage of polyuria with diabetes mellitus, hypersecretion of the stomach and intestines. Hypokalemia is possible with uncontrolled use of diuretics, corticosteroids and laxatives - without replenishing potassium losses. The pathogenesis of potassium loss by the kidneys, when the reabsorption of potassium by the renal tubules sharply decreases, is the same as with an enzyme disorder. Hypokalemia is caused by the accumulation of acidic metabolic products, since part of the H+ binds to K+ and is excreted. Glycogen formation and protein anabolism lead to transient hypokalemia, since both processes require the consumption of potassium in large quantities. The use of saline solutions and glucose solutions without potassium content leads to the loss of intracellular potassium, which is excreted in the urine, while sodium enters the cells.

Clinical symptoms that appear with hypokalemia: weakening of reflexes until they disappear, muscle weakness, asthenia. Muscle activity decreases sharply, and paralysis of the respiratory muscles is possible. Impaired function of non-striated (smooth) muscles leads to atony of the stomach and intestines. Weakness of the respiratory muscles makes breathing and sputum production difficult. Myocardial dysfunction is clearly visible on the ECG: cardiac arrhythmia, tooth flattening T and merging it with the tooth U, decline in segment S-T, interval extension Q-T. Severe hypokalemia can lead to cardiac arrest. The metabolic alkalosis accompanying hypokalemia causes the loss of H+ and Cl?. With hypokalemia, the excretion of potassium by the kidneys decreases, but does not stop, but the role of the kidneys in saving potassium is negligible. Intense losses of potassium are observed in diabetic acidosis, with certain kidney diseases, and with the use of diuretics and steroid hormones.

Potassium excretion decreases with oligo- and anuria, hypokalemia. 5 mmol/day of potassium is excreted in feces.

Calcium

99% is contained in bone tissue. There is 0.3 g of calcium in the extracellular space. Calcium metabolism is regulated by the parathyroid glands. There is 4.5-5 mmol/l calcium in the blood plasma, 2/3 in an ionized state. The clinical picture is determined by the level of calcium in the blood plasma. Calcium supplied with food is absorbed in the small intestine. Absorption is regulated by ergocalciferol (vitamin D2) and the chemical composition of the contents of the small intestine. Calcium plays a major role in the blood clotting mechanism, in the regulation of neuromuscular excitability and cell membrane permeability.

Reason gunercalcium More often there is an overdose of calcium salts and ergocalciferol, as well as increased function of the parathyroid glands. Hypercalcemia is observed in multiple myeloma, sarcoidosis, chronic glomerulonephritis, bone fractures, tumor metastases to bone, and in some cases of respiratory alkalosis.

Clinical symptoms: weakness, thirst, lack of appetite, vomiting, hiccups, polyuria. Characterized by a decrease in neuromuscular excitability, increased contractility of the heart, cardiac arrhythmia, in particular ventricular extrasystole leads to systolic cardiac arrest and hypercalcemic coma.

Gonocalcemia caused by insufficient intake of calcium from food, impaired absorption and increased secretion it from the body. The causes of hypocalcemia are hypofunction of the parathyroid glands or their removal, as well as a lack of ergocalciferol in the body. Hypocalcemia is possible with massive blood transfusion of canned blood (citrate binds calcium). Hypocalcemia is accompanied by an increase in the level of phosphorus in the blood.

The clinical picture is characterized by an increase in neuromuscular excitability, which causes tetanic convulsions, intestinal colic, diplopia, stridor, and dyspnea. The ECG is characterized by impaired cardiac contractility, prolongation of the interval Q-T and interval S-T. The excretion of calcium in the urine depends on its entry into the body. Normally, about 100-300 mg of calcium is released per day. 50-150 mg/day of calcium is excreted in feces. With hypercalcemia, urinary calcium excretion is increased, and with hypocalcemia, it is decreased.

Magnesium. The body contains 7-12 mmol/kg magnesium, 50% of it is in an undissolved state in bone tissue. The extracellular space contains 1.2-2.5 mmol/l magnesium. Magnesium, like potassium, is the most important intracellular cation. Magnesium is involved in the activation of the body's enzymatic systems and in the processes of muscle contraction.

Large amounts of magnesium are lost during profuse diarrhea and polyuria.

Clinical picture: increased excitability of the nervous system, athetosis. Myocardial damage is characterized by tachycardia and rhythm disturbance.

2-24 mmol of magnesium per day is excreted in urine, and 80-90% of administered magnesium is excreted in feces.

The release of magnesium increases with increased physical activity and the administration of diuretics.

Chlorine is the main anion of the extracellular space. The body contains 30 mmol/kg of chlorine, and the blood serum contains 100 mmol/l. The introduction of Cl- depends mainly on the introduction of NaCl with food. Chlorine is absorbed in the small intestine and excreted in urine and sweat. Chlorine, like sodium, is involved in maintaining osmotic concentration. The normal content of chlorides in urine is 120-240 mmol/day. The release of chlorides increases with the administration of diuretics and with kidney disease, hypokalemia, and decreases with treatment with steroids, with hypersecretion of the glands of the alimentary canal, with a salt-free diet. 2 mmol/day of chlorine is excreted in feces. With diarrhea, the loss of chlorine increases to 60-500 mmol/day.

Causes hyperchlorem the same as for hypernatremia. With increased administration of sodium chloride, hyperchloremia with interstitial edema and pulmonary edema is possible (with the administration of hypertonic solutions). To maintain electrical neutrality, the kidneys during hyperchloremia intensify the secretion of bicarbonates, which can lead to metabolic acidosis.

IN clinical picture symptoms of metabolic acidosis dominate.

Hypochloremia develops with vomiting caused by pyloric stenosis, small intestinal obstruction and prolonged duodenal suction. Hypochloremia is accompanied by hyponatremia, but the proportions may be disturbed. The body compensates for the loss of chlorine by increasing the level of hydrocarbonates in the plasma to maintain electrical neutrality. As a result, metabolic alkalosis develops. The clinical picture of hypochloremia is manifested by symptoms of alkalosis.

The body's needs for various components

1. Calculation of physiological and pathological losses and fluid requirements andelectrolytes at various diseases and pathological conditions;

To correct water-electrolyte imbalances, complete information about the patient’s condition is necessary. Highest value has a definition of fluid deficiency, especially intravascular, plasma osmolarity and quality composition losses - electrolytes, protein and hemoglobin. When determining the balance of water and electrolytes, certain methodological difficulties arise.

Anamnestic data on the quantity and qualitative composition of losses (vomit, volume of urine, loose stool etc.) are indicative only.

Method for calculating fluid losses and gains. Organized accounting of all introduced fluids and losses during dynamic observation allows one to judge quite accurately the quantitative and qualitative characteristics of water-salt metabolism.

Volume. To account for income, the volume of liquid drunk and introduced into the stomach through a tube, infusion media administered subcutaneously, intramuscularly, intravenously, etc. are summed up. In the same way, they try to take into account all losses. Some losses (diuresis, vomiting, active aspiration of gastrointestinal contents, losses through drainages, fistulas, diarrhea, etc.) are easy to take into account. However, invisible losses due to perspiration must also be taken into account.

High-quality composition. By measuring the volume of actual losses, one can roughly judge the quantitative release of ions using tables of the composition of biological media. (See table).

Table Losses of electrolytes in biological media

Statewater and electrolyte balance according to the examination of the patient.

Determine the electrolyte, gas composition and acid-base balance, the concentration of glucose in the blood using generally accepted methods. Great importance have indicators: blood pressure, central venous pressure, blood volume and pulse.

Normal concentrations of hemoglobin, red blood cells, plasma protein and hematocrit are not absolutely reliable signs no disturbances in water balance. These indicators can be greatly altered by dehydration, overhydration and anemia. It is important to know the initial level of hemoglobin and hematocrit, which is almost impossible. Fluid deficit calculations should never be made based on these indicators for bleeding and hypoproteinemia. It is impossible to carry out calculations based only on the results of single laboratory studies. The interpretation of all this data can sometimes be difficult, and indicators considered in isolation can lead to false conclusions. Only comprehensive analysis allows you to give an objective assessment. Study of the body's water spaces. For this purpose, methods based on the principle of diluting indicators are used. To determine the circulating plasma volume (CPV), indicators are used - Evans blue and others, which do not penetrate through vascular wall.

To study the volume of extracellular fluid, chlorides, bromides, sodium thiocyanate, inulin, mannitol, etc. are used, which distribute throughout the extracellular space without penetrating into cells.

The volume of total body water is determined using deuterium oxide, tritium oxide, antipyrine, urea and other substances.

The indicator introduced into the vascular bed is distributed in the extracellular and cellular fluid for a certain time. Depending on the volume of total liquid, its concentration changes. The concentration is determined at regular intervals. To calculate the volumes of total, extracellular and plasma fluid, use the formula:

У=0/С

V - volume of liquid under study

О - amount of entered indicator

C - plasma concentration of the indicator

The volume of intracellular fluid is determined as the difference between the volume of total fluid and the volume of extracellular fluid of the body. The volume of interstitial fluid is equal to the difference between the volumes of the extracellular and intravascular space. Various combinations indicators can be used to simultaneously determine all water spaces of the body, which is of great practical importance. This method is not used in practical veterinary medicine. The content of sodium, potassium, chlorine and other electrolytes in blood plasma can be calculated if the volume of plasma and the concentration of the determined substances in it are known. The content of the desired substance in the plasma will be equal to the volume of plasma (in liters) and the concentration of this substance (in mmol per 1 liter of plasma). To determine electrolytes in extracellular fluid, it is necessary to know its volume and the concentration of electrolytes in plasma. The latter is determined by flame photometry.

+ + +
Na deficiency (mmol) = (Na d -Na f)x20% body weight (kg)

Where, Na+ d is the proper concentration of sodium in the blood, i.e. 142 mmol/l;
Na + f - actual concentration of sodium in plasma, mmol/l;
20% of body weight is the volume of extracellular fluid.

Chlorine deficiency is calculated in the same way.

When determining the potassium balance, they are guided by the results of a dynamic study of this cation in plasma, clinical symptoms and ECG signs, data on biological fluids.

K deficiency+ (mmol/l) = Outside QOL(l) 2

Where, K+ - potassium deficiency, 4.5 - normal potassium level in plasma;

K+ - actual plasma potassium concentration, mmol/l;

ExtraQOL - extracellular space equal to the massetela in (kg)"0.2;

2 - value obtained experimentally.

Calculationvolume of daily infusion therapy:

Universal method:(For all types of dehydration).

Volume = daily requirement + pathological losses + deficiency.

Daily requirement - 20-30 ml/kg; at a temperature environment more than 20 degrees

For each degree +1 ml/kg.

Pathological losses:

Vomiting - approximately 20-30 ml/kg (it is better to measure the volume of losses);

Diarrhea - 20-40 ml/kg (it is better to measure the volume of losses);

Intestinal paresis - 20-40 ml/kg;

Temperature - +1 degree = +10ml/kg;

RR more than 20 per minute - + 1 breath = +1ml/kg ;

Volume of discharge from drainage, probe, etc.;

Polyuria - diuresis exceeds the individual daily requirement.

For hypertensive dehydration:

Fluid deficiency (l) = ( Patient Na -142) /142 x BW x 0.6

For isotonic dehydration:

Fluid deficit (l) = ( Patient’s Ht -0.45) / 0.45 x BW x 0.2

Calculation of electrolyte deficiency:

Shortage (in mmol) = (El .Norm - El. patient) x Weight body x 0.2

Daily dose of electrolyte in infusion therapy = deficiency + daily requirement.

Daily requirement:

Na 1.0-1.5 mmol/kg;

K 0.7-1.0 mmol/kg;

C1 2.0-2.5 mmol/kg.

1 mmol of potassium, as well as mmol of chlorine, is contained in:

1.0 ml 7.5% r-raKS1

1.9 ml 4%r-raKS1

2.5 ml 3% solution KS1

1 mmol of sodium, as well as 1 mmol of chlorine, is contained in:

6.5 ml 0.9% NaCl solution

0.6 ml 10% NaCl solution

In case of polyion disorders (deficiencies), correction according to the formulas begins with the smallest disorder (smallest deficiency).

Fluid Therapy in Small Animals:

Water balance assessment:

Patient's medical history (anorexia, vomiting, diarrhea, polyuria, frequent shallow breathing, blood loss.);

Physiological examination:

Hypovolemic shock: 1.Pulse; 2. Mucous membranes (capillary refill time - VPK);

3. Peripheral temperature.

Dehydration: 1. Skin elasticity or turgor; 2. Contents of the bladder; 3. Body weight.

Physiological examination: skin elasticity or turgor is an approximate measure of dehydration:

< 5% ВТ - не определяется;

5-6% - skin turgor is slightly reduced;

6-8% - skin turgor/VNK>1 is noticeably reduced;

10-12% - skin fold remains in place/VNK;

Principle of hydration

1. For warning water and electrolyte disturbances the volume of infusion is determined at the rate of 30-40 ml/kg body per day.
2. Deficiencies of blood and fluid must be eliminated in a timely manner, only then can the inevitable compensatory and pathological reactions be prevented and limited.
3. The volume of infusion is subject to mandatory correction during dynamic observation, depending on losses.
4. The volume of fluid infused should be the sum of the fluid deficit daily requirement organism in water.
5. Renal fluid losses are compensated by administering 5% glucose solution and isotonic saline solutions.
6. Pathological losses and losses of extracellular fluid are compensated with polyionic solutions.
7. Blood losses are replaced with whole blood transfusions. Transfusion occurs when the hematocrit decreases to 0.30-0.28. Optimal conditions for microcirculation are created at a hematocrit of 0.30-0.35.
8. Normal extracellular fluid osmolality is maintained with introduction of isotonic electrolyte solutions (Ringer et al.), which create osmotic balance.
9. Deficiency of potassium and bicarbonate is specially corrected by adding molars.
10. Loss of calcium and magnesium.
11. Selected environments must provide protein and calories.
12. Monitoring: blood pressure, heart rate, respiratory rate, body temperature, central venous pressure, diuresis, recording pathological losses.
13. If the patient's condition worsens, infusions are temporarily stopped and resumed after the cause is determined.
14. The balance of income and losses per day is calculated, and available laboratory tests are carried out.

3. Route of administration:

IV peripheral or central veins;

Intraosseous;

4. Amount of liquid:

Isotonic crystalloid solutions

Half the blood volume (dogs 45 ml/kg, cats 35 ml/kg). But in reality to achieve the effect isotonic colloidal solutions:

1/3 the amount of crystalloid solutions;

V max. 20-40 ml/kg/day. Hypertensive solutions:

Dogs 4-7 ml/kg; cats 2-4 ml/kg.

5. Rate of administration:

Isotonic crystalloid solutions:

Until the effect is achieved;

Max. 90 ml/kg/hour (dogs) and 55 ml/kg/hour (cats);

Iso-oncotic colloid solution:

Until the effect is achieved;

Hypertonic solution: bolus 5-15 min.

6. Electrolyte and acid-base balance

Restoring electrolyte and acid-base balance is not necessary, except for certain diseases.

A solution with the same composition as extracellular fluid cannot be replaced in most cases, for example, Ringer's lactate.

7. Hypovolemia is corrected and shock overcome by fluid administration. 2. Repeat physical examination should show stable condition.

Fulfilling needs:

Hydration deficiency:

1. Fluid losses that occur before the start of therapy;

2. expressed as a percentage of body weight.

Simultaneous fluid losses:

1. Extra fluid loss during fluid therapy

2. Expressed in milliliters.

3. Promote diuresis:

Not helps correct fluid balance

Target - increase urine output and improve kidney excretory function.

1. Patient assessment.

Is there a hydration deficiency and can the patient maintain body fluid balance?;

2. Liquid type: Support fluids:

1. isotonic crystalloid “maintenance” fluids;

2. the composition is determined by the concentration of normal daily electrolytes

fluid loss Na 40-60 mmol/l; K 20-40 mmol/l.

Replacement fluids:

1. isotonic crystalloid “replacement” fluids;

2. the composition is similar to the composition of extracellular fluid;

3. synthetic colloidal solutions.

3. Route of administration:

Oral/enteral;

Subcutaneously;

IV peripheral, central.

4. Amount of liquid:

For maintenance: dogs 40-70 ml/kg/day, cats 40-50 ml/kg/day.

To compensate: hydration deficit%; simultaneous fluid loss ml.

Promote diuresis (2-7% VT).

5. Rate of administration:

Rate = total amount of fluid/time period. The time available to administer fluids varies among veterinary clinics. The period of time used to correct hydration deficiency should vary from several hours to 2 days.

6. Electrolyte balance:

Determined by the composition of plasma electrolytes and their abnormal losses or

savings.

A slight imbalance can only be restored by correcting the water balance.

Significant imbalances can be corrected with "replacement" fluids or electrolyte additions.

For most electrolyte imbalances, "maintenance" fluid needs must also be replaced.

Na^glucose 5%, 2.5%, NaCl 0.45%

Nav NaС1 0.9%

K^ in salt solutions potassium

Kv potassium additionally needs to be introduced: (4.3-[K+])x0.6xВV =? mm1/1

Phosphate Mg Ca^ electrolyte free in liquid

Phosphate Mg Ca2+ vadditional

7. Acid-base imbalance

1. Correction of water and electrolyte balance in most cases restores acid-base balance

2. Only in extreme cases is active therapy (adding bicarbonate) indicated to restore the acid-base imbalance.

8. Summary:

Hydration deficit corrected

Determined by: physical examinations, animal weight, laboratory diagnostics, measurement of central venous pressure.

The patient is able to maintain fluid balance on his own.

When implementing such plans, take into account other diseases, simplify, if possible, monitor.

Characteristics of the properties and features of the use of some infusion solutions, compatibility and incompatibility with other drugs.

IT for acute water and electrolyte disturbances consists of a number of emergency measures,

aimed at restoring the normal volume of circulating blood, the volume and qualitative composition of the body’s water sectors.

The most important parts of therapy are: 1.) elimination of hypovolemia, creation of the most economical modes of heart operation in conditions of sufficient venous inflow and peripheral blood supply; 2) elimination of the most dangerous imbalances of water and electrolytes. acid-base shifts; 3) restoration of diuresis, maintaining the achieved balance, ensuring adequate sectoral distribution of liquid volumes and electrolytes.

Infusion media

From the standpoint of IT water and electrolyte disturbances, it is advisable to distribute infusion media:

Volume-substituting solutions (plasma substitutes and blood). The main purpose of their use is fast recovery plasmatic and globular volumes.

Basic infusion solutions of glucose and electrolytes. They are used to maintain water-electrolyte balance for the required time.

Corrective infusion solutions, including molar solutions of electrolytes and sodium bicarbonate. They are intended for the correction of violations of hydroionic and SB.

Diuretic solutions. The main purpose of its use is to restore diuresis and prevent renal failure.

Volume-substituting solutions

These solutions include artificial plasma-substituting solutions of dextran, gelatin, starch and blood. They are superior in hemodynamic efficiency to whole blood. They restore the volume of circulating blood faster and more reliably, and have a positive effect on its rheological properties, microcirculation and hemodynamics in general.

Replenishment of blood volume means correction of the main cause of hypovolemia and, associated with it, cardiovascular failure. When normal venous return is restored, blood filling of the cardiac cavities and cardiac output increase. Simultaneously with ^BP, tissue perfusion increases and metabolic processes in tissues improve.

Colloidal volume- and plasma-substituting media include: solutions of dextran, gelatin and starch, but few people use them.

The biological property of these solutions is that they bind water well in the vascular bed and increase the residence time of colloidal particles. The higher the molecular weight of the solution, the longer it remains in the blood.

Dextrans are polysaccharides consisting of individual glucose molecules. They are based on 0.9% NaCl and 5% glucose. Dextrans have platelet and erythrocyte disaggregation properties, which prevents agglutination and sludge formation. Excreted through the kidneys. Dextrans are compatible with all electrolyte solutions and most pharmaceuticals.

Colloids

Colloids are rather large molecules and cannot penetrate the capillary membrane. They can be divided into two types: colloids of natural origin and synthetic colloids. The most important colloid of natural origin is serum albumin. However, in veterinary medicine it is administered only as part of whole blood plasma. The molecular weight of albumin is 69,000 Daltons. There are also several types of synthetic colloids (including gelatins, starches and dextrans, see below). The advantage of using colloid solutions compared to saline solutions is that large colloid molecules cannot penetrate through the walls of capillaries into tissue fluid and, accordingly, are able to retain water in the vascular bed for a long time. Therefore, the increase in circulating blood volume caused by the administration of colloids is more stable and long-lasting than that caused by the administration of saline solutions. Although intravenous colloids have been shown to be effective for many diseases in small animals, their utility in trauma patients has been poorly studied. From the results of clinical observations conducted on people, it follows that there is no significant difference in survival in trauma patients when using saline solutions and colloid solutions. And since colloid solutions are much more expensive than saline solutions, it is difficult to recommend such liquids for widespread use in veterinary traumatological practice.

The dosages of colloid solutions used are much less than the dosages of saline solutions, since almost the entire volume of the injected colloid solution remains inside the blood vessels, it is usually recommended to administer it in doses ranging from 1/5 to 1/4 of the amount of saline solutions. This corresponds to approximately a loading single dose of 10-20 ml/kg in dogs and 8-12 ml/kg in cats. The duration of stay of colloids in the vascular bed is determined by the average size and nature of the distribution of molecules of the applied colloid according to this indicator. Molecules small size are excreted faster, especially if their molecular weight is less than 55,000 Daltons - such molecules are excreted by the kidneys in the urine. Larger molecules are eliminated only after hydrolysis. However, some of them can be eliminated by the monocyte-macrophage system. Specific rates of removal from the vascular bed of the most common colloids will be given below.

Since virtually the entire volume of the injected colloid solution remains inside the blood vessels, it is usually recommended to administer it in doses ranging from 1/5 to 1/4 the amount of saline solutions. This corresponds to approximately a loading single dose of 10-20 ml/kg in dogs and 8-12 ml/kg in cats. The duration of stay of colloids in the vascular bed is determined by the average size and nature of the distribution of molecules of the applied colloid according to this indicator. Small molecules are excreted faster, especially if their molecular weight is less than 55,000 Daltons - such molecules are excreted by the kidneys in the urine. Larger molecules are eliminated only after hydrolysis. However, some of them can be eliminated by the monocyte-macrophage system. Specific rates of removal from the vascular bed of the most common colloids will be given below.

When using colloidal solutions to restore circulating blood volume together with saline solutions, the dosages of both types of liquids are correspondingly reduced. For example, in dogs with hypovolemic shock, to restore the volume of circulating blood in shock, it is enough to administer a single dose of some synthetic colloid of 10 ml/kg and a dose of saline solution of 30 ml/kg. The concentration of colloids in the vascular bed also gradually decreases over time, but this process proceeds much more slowly than in the case of saline solutions. However, clinical observations show that even when using colloids to eliminate hypovolemia, after administering the initial dose of fluid, a maintenance infusion is required, especially in the case of severe injuries. The rate of fluid administration during maintenance fluid therapy when using colloids is usually 0.5-2 ml/kg/hour. If the patient is suspected of having a lung injury, the rate of administration of colloid solutions should be reduced. In such cases, liquid should be administered in small portions of 3-5 ml/kg, assessing the animal’s reaction to the administration of each such dose.

All colloidal solutions can cause a decrease in blood clotting. This effect is due to blood dilution, on the one hand, and precipitation under the influence of colloids of a number of coagulation factors, on the other. In addition, colloids disrupt the function of von Willebrand factor. The decrease in blood clotting becomes especially pronounced when large volumes of colloidal solutions are administered, over 20 ml/kg. Reduced blood clotting can be a complicating factor in trauma patients with bleeding, so the hypocoagulative effect of colloids should be eliminated by administering blood plasma to the animal as a source of lost coagulation factors. It should also be remembered that when using colloids, the refractometric method of determining total protein plasma can give false results. Starches and dextrans give refractometer readings similar to protein at a concentration of 4.5 mg/100 ml, so synthetic colloids usually reduce the amount of detectable protein in plasma, except in cases where the value of this indicator before the use of colloids is below 4 .5 mg/100 ml. Despite the decrease in the measured protein concentration in plasma, colloids effectively increase its oncotic pressure.

Gelatins

In veterinary medicine, solutions of different types of gelatins are used. Most of them contain chemically modified gelatins that differ from the natural forms of these proteins. The molecular weights of the gelatins used are 30-35000 Daltons, so these compounds are excreted quite efficiently by the kidneys. Although gelatins cause a rapid increase in circulating blood volume, their effect is relatively short-lived, because the average time for removal of half of the administered amount of these substances from the vascular bed is

Hypertonic saline solution

Hypertonic saline is a solution of salts in water, but the amount of sodium chloride in it is much greater than in blood plasma. The most common hypertonic saline solutions contain 5 or 7.5% of this salt. When using such solutions, a very rapid, but short-term, increase in the volume of circulating blood is observed due to the entry of fluid into the capillaries from the interstitial space. The short duration of the increase in circulating blood volume is due to the rapid release of sodium and chloride ions through the capillary membranes from the blood into the tissue fluid and the balancing of the ionic composition of this fluid and blood plasma. To prolong the effect, hypertonic saline solutions are often used in combination with colloids, for example, Dextran 70 solution. To obtain such a mixture containing 7.5% NaCl, take 17 ml of NaCl solution with a concentration of 23.5% and 43 ml 6% Dextran 70 solution.

Because hypertonic saline solutions are highly effective in transiently increasing circulating blood volume, the volumes administered are much smaller than when using other types of fluids.

The use of hypertonic saline solutions is especially effective in very large animals and in cases where there is no time to administer isotonic fluid, because the patient is in critical condition and requires urgent assistance. Currently, head trauma is considered a direct indication for the use of a hypertonic solution, because the introduction of such a solution allows you to quickly reduce the amount of fluid in the brain tissue and prevent the development of cerebral edema. In such cases, since the severity of brain tissue ischemia is related both to the magnitude intracranial pressure, and with systemic blood pressure, it is very important to prevent the development of cerebral edema and, at the same time, to prevent a drop in blood pressure. In these situations, a hypertonic solution is an ideal remedy, because When administered intravenously, even in small quantities, a significant increase in blood pressure is observed.

Contraindications to the use of hypertensive saline solution are dehydration (in which the interstitial fluids do not contain enough water to increase the volume of circulating blood and dilute the hypertonic solution), hypernatremia, or severe uncontrolled bleeding, which may increase due to a sharp increase in blood pressure. In particular, due to the rapid increase in blood pressure when a hypertonic solution is administered to patients with lung injuries, they may experience increased pulmonary hemorrhage, although it is generally accepted that such a solution, due to the small volumes of fluid administered in these patients, is quite effective .

Basic solutions

Ringer's and Ringer-Locke solutions cannot provide the body with free water! To meet the daily water requirement and maintain electrolyte balance, you should use electrolyte infusion solutions containing less sodium and chlorine compared to plasma, or add solutions with glucose. And also, these solutions cannot meet the body’s need for potassium ions, much less correct hypokalemia.

It should be remembered that isotonic sugar solutions are the main source of free water (electrolyte-free) during infusion therapy! Sugar solutions are used both during maintenance hydration therapy and to correct emerging water balance disorders. With excessive introduction of sugar solutions, there is a danger of developing overhydration and water poisoning! Predominant use of sugar solutions with reduced plasma sodium concentration can lead to hypoosmolar syndrome.

Corrective solutions

Sodium bicarbonate used to treat decompensated metabolic acidosis. It quickly restores the pH of the extracellular fluid and has a lesser effect on the pH of the intracellular fluid. Being a buffer solution, bicarbonate affects a number of important indicators of homeostasis: it increases the pH of the blood, reducing the release of oxygen to tissues - affecting oxyhemoglobin. Does the alkalization process increase CO formation? to eliminate which you need to increase the volume pulmonary ventilation. Therefore, it is contraindicated in respiratory failure, if there is no respiratory support. When prescribing bicarbonate, which contains an equivalent amount of sodium, it is necessary to take into account the tendency of some patients to edema, with heart failure, hypertension, and eclampsia. Liver disease is not a contraindication to the use of sodium bicarbonate, but is a contraindication to the use of sodium lactate. Severe renal failure, hyperkalemia and anuria are not contraindications to the use of bicarbonate, but at the same time they are the main contraindications to the use of trisamine.

With excessive administration of sodium bicarbonate, there is a risk of decompensated alkalosis. For the treatment of ketoacidosis, it is not used at all, or is used in small doses. The use of a calculated dose of bicarbonate for the treatment of diabetic acidosis (which is largely eliminated by etiotropic therapy) leads to alkalosis. Jet injection of bicarbonate leads to tetanic convulsions. For infusion use 3-5% solution.

Potassium chloride administered diluted in glucose solution with the addition of an appropriate dose of insulin. Used for potassium deficiency, hypokalemic metabolic alkalosis, threat of overdose of glycosides. Potassium is contraindicated in: renal failure, oliguria and hyperkalemia. If necessary, increase the potassium dose gently under ECG monitoring. Magnesium sulfate 25% used for the prevention and correction of magnesium deficiency. Calcium chloride 10% used for the prevention and correction of calcium deficiency. Administer fractionally 3-4 times a day. Should be administered cautiously in case of hypokalemia.

Diuretics

Furosemide is prescribed for the treatment of oligoanuria after the elimination of hypovolemic shock. Unlike mannitol and sorbitol, it is not contraindicated in heart failure

Literature

• Elke Rudolf Rebecce Kirbi. Recovery from hypovolemic shock. Focus N°4 2001
• Lori S. Waddell and Lasly G. King. Fluid therapy for injured animals. Focus N°4 1999
• P. R. Pulnyashenko. Anesthesiology and resuscitation of dogs and cats. Kyiv "FAUNA SERVICE" 1997
• Theory and practice intensive care. Edited by Peter Varga, Zuzanna Btag, Miklos Giacinto, Kalman Sela. Kyiv "HEALTHY ME" 1983 pp. 185-190, 190-195, 215-230.
• Handbook of anesthesiology and resuscitation. Edited by Professor A.A. Bunyatyan. Moscow. "MEDICINE" 1982. Pages 67-74.

Polishchuk Victoria Vladimirovna

Once in a veterinary clinic, you can often encounter such concepts as: infusion therapy, infusion pump, and hear various complex names of solutions. Let's try to look at a few questions that will help you understand what these incomprehensible and therefore frightening terms mean.

1 What is “infusion therapy”?

2 Goals of fluid therapy and does the animal need fluids?

Infusion therapy (“drip”) prescribed to an animal solves several problems. First of all, this is replacement therapy for conditions accompanied by loss of fluid and salts: vomiting, diarrhea, high temperature, increased volume of urination. In case of intoxication caused by purulent-inflammatory processes (pyometra, abscesses, phlegmon), infusion therapy helps eliminate toxins.
A car injury, a fall from a height, or severe blood loss are always accompanied by shock, which in turn causes a large amount of fluid to leave the vascular bed, so infusion therapy is a necessary component of the treatment of shock.
Animals with diseases that lead to the accumulation of toxic products in the body, such as chronic renal failure, hepatitis, poisoning, also require infusion therapy.
If for some reason the animal is unable to eat food on its own (due to severe general condition, after operations on the gastrointestinal tract) he is prescribed parenteral nutrition, that is, all nutrients and vitamins are administered intravenously.
Many medications are administered with infusion solutions - antibiotics, hormones and vasoactive substances, etc.
For some reason, the animal may be deprived of access to water. This is especially true for cats. Some of them get used to drinking under certain conditions - for example, from a tap, and then the tap turns out to be closed for a long time, or adult cat could have been switched from natural or wet food to dry food, and out of habit she continues to drink a small amount of water. All these cats will start to become hydrated
Surgical interventions always require infusion support. On the day of surgery, the animal is usually deprived of food and water, almost any surgical intervention is accompanied by blood loss, add here evaporation from the surface of the surgical wound (this applies to a greater extent to operations on the abdominal and thoracic cavity), the need to remove drugs used for general anesthesia and some other points, and it becomes obvious that the patient needs additional volumes of solutions.
Thus, 3 stages of infusion therapy can be distinguished:
. Emergency stage
Substitute stage
Support stage

3 Conditions and what is necessary for infusion therapy

For moderate dehydration, fluids are administered subcutaneously. Isotonic solutions should be used. A cat weighing 3 kg with a degree of dehydration of 5% without vomiting and diarrhea, according to average calculations, requires 200 ml of solutions.
The rate of subcutaneous administration is usually determined by the comfort of the animal. Multiple injection sites are required to ensure adequate fluid volume. All subcutaneous solutions dissolve within 6 - 8 hours. If after this period fluid is still detected subcutaneously, to restore peripheral perfusion, you need to switch to intravenous administration of solutions. Subcutaneous fluid administration is not suitable for severely dehydrated patients for several reasons:
1. a severe patient needs a large volume; you cannot inject so much subcutaneously at one time;
2. a severe patient may need colloidal solutions, but they are not administered subcutaneously;
3. y seriously ill patient subside peripheral vessels(spasm), and the resorption of fluid from the subcutaneous fatty tissue occurs precisely thanks to them. As a result, the fluid does not resolve, so such patients are given an intravenous catheter. The peripheral catheter can remain in the paw for up to 5 days. If slow administration is necessary, intravenous dispensers (infusion pumps) are used. Some drugs that require exact dosage(a certain amount of ml/kg per minute). Infusion pump (perfusor, infusion syringe pump) - a device that allows you to administer medications and solutions with exceptionally high precision at controlled speeds.
The advantage of a perfuser over a conventional drip system is that the animal can be in almost any position convenient for it, which is very important for restless, frightened animals that often change their body position.
Perfusors are programmed to quickly respond to occlusion (blockage, obstruction to the flow of infusion solution) using a sound and light signal, are able to resume infusion with accurate reproduction of parameters, and are also equipped with a warning system when the infusion is completed.
The rate of administration is measured in milliliters per kilogram per hour. The minimum speed is 20-40 milliliters per kilogram per hour (from 10 ml per kitten weighing 500 grams and 1.5 liters per Great Dane weighing 70 kg). In case of severe shock, the initial rate of administration of solutions (maximum permissible) is 90 ml/kg/hour for dogs and 55 ml/kg/hour for cats. Intravenous fluid administration in dogs and cats is indicated when the degree of dehydration is more than 7%.
In very young patients with severe dehydration and difficulties with placing an intravenous catheter, intraosseous administration of fluids is possible: solutions are injected into tubular bones by piercing them with a thick needle. There are many vessels in the bone marrow canal, the fluid is absorbed quite quickly and efficiently.

4 . How to estimate the volume of fluid needed for an animal?

Volume deficit is calculated based on physical examination or changes in body weight. To calculate volume deficit, estimated dehydration is multiplied by body weight. It must be remembered that it is very difficult to make up the entire deficit in 24 hours. This, along with dehydration, can lead to urinary losses. Thus, during the first 24 hours it is recommended to replace 75% - 80% of the volume deficit. Also, do not forget, if the animal does not eat or drink, you need to also add the “daily maintenance volume” to the calculated volume deficit.
Maintenance volume is a natural loss. They are divided into explicit and implicit. Apparent losses can be measured as water losses in urine and feces. Normally, there are also implicit losses that are difficult to measure. This is the loss of water through breathing or sweating. Implicit losses make up a third of the maintenance volume, explicit losses - two thirds.

5. What needs to be monitored during infusion therapy and what complications may occur

Complications of infusion therapy may be associated with technical errors (hematoma, damage to neighboring organs and tissues, thrombophlebitis, embolism, sepsis), and also be a consequence of changes in homeostasis (water intoxication with excessive fluid administration, anasarca with excessive salt administration, acidosis due to dilution caused by prolonged intensive administration of isotonic sodium chloride solution; excessive hemodilution with a significant decrease in the concentration of protein, hemoglobin and blood coagulation factors, etc.).
Specific complications of infusion therapy are hyperthermia, reactions to the introduction of cold solutions, pyrogens, bacterially contaminated media, anaphylactic shock, overdose of individual ions. Sometimes there may be an overload of the right circulation, which leads to pulmonary edema.

Contraindications to infusion therapy are the possibility of compensating for fluid deficiency by the enteral route, allergic and anaphylactic reactions to various infusion solutions.

Vasiliev D.B., Dyagilets E.Yu.
Moscow Zoo.

XIII ALL-RUSSIAN VETERINARY CONGRESS

As in mammals, the body fluid of reptiles is functionally and anatomically divided by cell membranes into 2 main components: the intracellular space (ICS) and the extracellular space (ECS), consisting of plasma and interstitial fluid. In the green iguana, the total amount of fluid in the body is normally 71% of body weight, with the VCP accounting for about 54%, and the ECP accounting for 17%, including 13% interstitial fluid and 4% plasma (Thorson, 1968). The total amount of blood is about 6%. Thus, the distribution of fluid in the body of reptiles is comparable to what is known for mammals, the differences being a slight increase in the total amount of fluid and its proportion in the intracellular space.

For terrestrial reptiles, a 0.8% sodium chloride solution (approximately 274 mOsm/L) is isotonic, in contrast to mammals, for which the standard is 0.9% NaCl with an osmolarity of 308 mOsm/L (Marcus, 1981).

Therefore, the osmolarity of solutions that are usually prescribed to reptiles is usually lower than for mammals. Some authors recommend the use of specific electrolyte solutions prepared specifically for reptiles (Marcus, 1981; McDonald, 1976). Other researchers show that plasma oncotic pressure varies from 300 to 400 mOsm/L in many reptiles, for example, the desert iguana Dipsosaurus dorsalis has a plasma osmolarity of 300 mOsm/L (Minnich, 1982), and in a small number of green iguanas studied up to 330 mOsm/L (Maxwell, 2003). Therefore, a normal “saline solution” with an osmolarity of 308 mOsm/m should be acceptable, at least for iguanas. Other crystalloid solutions commonly used in reptiles, such as Hartmann's solution (LRS), Ringer-Locke solution, and 5% glucose also appear to be isotonic in iguanas. pure form”, without diluting them with water. For other reptile species, especially freshwater ones, the osmolarity of the solution should not exceed 280 mOsm/L.

Electrolyte mixtures for oral administration Several laboratories in the USA produce it specifically for reptiles, but for parenteral administration they still combine factory-made solutions from medical practice. Hartmann's solution (lactated Ringer's solution, LRS) is isotonic for mammals (osmolarity 274 mOsm/L) and contains a balanced composition of electrolytes. In reptiles it can be used in pure form or in dilution for rehydration, replacement or maintenance therapy, especially for replacement in the extracellular space, since the sodium content in this solution corresponds to its concentration in the extracellular space (Senior, 1995).

For young lizards, which almost always have mild hypocalcemia due to management errors, it is better to use another solution made by Baxter - the so-called “Complex sodium lactate solution” (Dina). It differs from Hartmann's solution only in twice the amount of calcium ions and usually gives a more pronounced clinical effect.

In cases of severe acidosis, Ringer's acetate solution may be recommended rather than lactate to avoid lactic acidosis. Hartmann's solution may be contraindicated in lizards with renal syndrome for hyperkalemia, as, indeed, all other polyionic electrolyte complexes containing potassium. In this case, it is better to prescribe a 0.45% sodium chloride solution in 2.5% glucose, the osmolarity of which is about 280 mOsm/L. The same solution is prescribed for maintenance therapy after correction of dehydration and compensated loss of sodium.

For replacement therapy, it is better to prescribe a combination of Ringer-Locke solution or Ringer-lactate with 5% glucose in a 1:1 ratio or these solutions in their pure form.

In case of dehydration with loss of potassium, for example, with diarrhea, vomiting and cachexia, potassium chloride can be additionally added to the composition. The addition of glucose to electrolyte composition is indicated for malnutrition and cachexia, but may be contraindicated in acute dehydration. A 5% glucose solution (osmolarity 252 mOsm/L) is practically isotonic for most lizards, but must be administered intravenously at this or more high concentrations. For subcutaneous and oral administration, the glucose concentration should not exceed 2.5% (Pokras, Sedgwick, Kaufman, 1992).

Hypertonic solutions, such as 3% sodium chloride solution, are used in mammals to rapidly increase plasma volume, in the form of slow boluses of 10-20 ml/kg intravenously, for example, in states of shock. We have not found any information on the use of hypertonic solutions in reptiles and have never had such experience ourselves. In any case, hypertonic solutions can be administered to these animals only after a port has been installed in a large peripheral vein.

The same restrictions apply to the use of colloids. Unfortunately, neither here nor abroad we have any experience in using plasma replacement solutions for reptiles. We tried to administer polyglucin intravenously to several lizards after bloody operations, but that experience is too small to make any recommendations. The promising drug Perftoran in humane medicine gave interesting results as a means of oxygen transport, but in veterinary medicine it had very limited use. It is technically possible to use it in reptiles only in a dilution of at least 1:10 in 5% glucose and only after catheterization of a vein or intraosseously, since the drug is very viscous. In the observed cases, we did not note anaphylactic reactions, but the danger of paravasate, thrombosis and vessel occlusion with subsequent tissue necrosis is quite high.

Perftoran may have some promise in the correction of severe blood loss, tissue anoxia, ischemia, and prolonged postoperative apnea in reptiles.

Hemodez is widely used as a detoxifying agent in the treatment of reptiles. It can be administered intravenously, intraosseously, intracoelomically and subcutaneously. In reptiles, the drug does not usually cause anaphylactic reactions, unlike mammals. Hemodez should be used with caution in reptiles with clinically significant dehydration, as it can sharply lower blood pressure. Hemodez should not be used in animals with hypocalcemia (only against the background of calcium replacement therapy), animals with acute renal failure and aquatic reptiles, which for some reason tolerate it worse.

The choice of method of administering the solution in reptiles does not differ from that for mammals. Depending on the nature, severity of hypovolemia and the size of the animal, oral, subcutaneous, intramuscular, intracoelomic, intravenous or intraosseous administration is used. When administering large volumes of crystalloids or colloid solutions, catheterization of large peripheral veins is necessary. In practice with lizards, it is more convenient to place the branula in the vein of the leg or forearm, and for small animals - in the ventral abdominal vein.

The volume of fluid required for hypovolemic animals can be calculated using a formula modified from humane medicine, adding the daily requirement and the volume of abnormal losses to the deficit. The daily fluid requirement in reptiles is 15-25 ml/kg or 2-3% of body weight, in lizards it is slightly less - 1-2%, in desert species it is even less, no more than 1% (Klingenberg, 1998). In addition, following the principle of scaling, the amount of fluid should progressively decrease with increasing body weight. For tropical species such as the green iguana, daily fluid requirements can be calculated using the formula (Nagy, 1982):

Daily requirement (ml) = 45 x Body weight (kg) 0.67

In sick reptiles in a state of anorexia, such calculations are pointless. The water balance in these animals changes dramatically due to general decline metabolic rate, influence gate system kidneys and fluid sequestration in bladder. The daily fluid requirement in such animals will be significantly reduced, and the dependence of the deficiency on body weight or biochemical changes in the blood will cease to be linear and will tend to zero. If we try to calculate the volume of replacement for a reptile fasting for one month, and add the daily requirement for 1 month, that is, 25 ml/kg x 30, to the volume of abnormal losses, the result will be a gigantic figure that does not reflect the true situation at all. Consequently, in the case of acute dehydration, the volume of replacement is calculated in the same way as in mammals, but the total amount should be approximately half as much, since the daily requirement is halved. In case of chronic dehydration, the volume of replacement should be calculated based on abnormal losses, without taking into account the daily requirement or reducing the maintenance dose to 5 ml/kg/day. In this case, 4% of the resulting volume must be administered immediately (this corresponds to plasma deficiency), and the rest of the liquid must be administered within 24-48 hours.

Approximate values ​​for replacement therapy:

Mild degree of dehydration (5-8%) - 30-40 ml/kg per day;
- average degree dehydration (8-12%) – 40-50 ml/kg per day;
- severe degree of dehydration (12-15%) – 60-75 ml/kg per day.

With severe dehydration, the replacement volume, taking into account the deficiency, can be 75–150 ml/kg per day (Frye, 1991). When using intravenous or intraosseous catheters, it is possible to regulate the infusion.

The recommended rate of continuous continuous infusion is 2-5 ml/kg/hour or 40 ml/kg/day in the form of 4-6 slow boluses when administered intraosseously. In case of hypovolemic shock, the rate can be increased to 1 ml/min, which corresponds to complete replacement of bcc within an hour (60 ml/kg/hour).

Literature.
1. Frye F.L., 1991. Biomedical and surgical aspects of captive reptile husbandry. Vol. 2. Krieger Publishing Co., Malabar, F., pp. 420-471.
2. Klingenberg R.J., 1998. Reptiles, in Aiello S.E. (ed). The Merck Veterinary Manual. 8th edn. Merck & Co, Whitehaus Station, NJ, pp. 1402-1421.
3. Marcus L., 1981. Veterinary biology and medicine of captive amphibians and reptiles. Bailliere/Tindall, London.
4. Maxwell L.K., Helmick K.E., 2003. Drug dosages and chemotherapeutics, in Jacobson E.R. (ed). Biology, husbandry, and medicine of the green iguana. Krieger Publishing Co., Malabar, FL, pp. 133-151.
5. Mc Donald H., 1976. Methods for the physiological study of reptiles, in Gans C., Dawson W. (eds). Biology of the Reptilia, vol. 5. Physiology-A. Academic Press, London, New York, pp. 19-125.
6. Minnich J., 1982. The uses of water, in Gans C., Pough F. (eds). Biology of the Reptilia. Vol. 12. Physiology-C: physiological ecology. Academic Press, London, New York, pp. 325-395.
7. Nagy K., 1982. Field studies of water relations, in Gans C., Pouch F. (eds). Biology of the Reptilia. Vol. 12. Physiology C: physiological ecology. Academic Press, London, New York, pp. 483-501.
8. Pokras M.A., Sedqwick C.J., Kaufman G.E., 1992. Therapeutics, in Beynon P.H., Lawton M.P., Cooper J.E. (eds). Manual of reptiles. Iowa State University Press, Ames, pp. 194-206.
9. Senior D., 1995. Fluid therapy, electrolytes, and acid-base control, in Ettinger S., Feldman E. (eds). Textbook of veterinary internal medicine, vol. 1. W.B. Saunders Co., Philadelphia, pp. 294-312.
10. Thorson T., 1968. Body fluid partitioning in Reptilia. Copeia, pp. 592-601.

Summary
Vasiliev D.B., Diaguiletz E.Y.: Infusion therapy in reptiles. Moscow Zoo
Physiology and liquid distribution in reptiles’ organisms, as well as methods for introduction, selecting solutions for replacement therapy and estimation of replacement volume are discussed.