DEHYDRATIONAL THERAPY (Latin de-prefix extraction, destruction + hydration; grech, therapeia treatment) — set of the medical actions directed to reduction of amount of liquid in an organism or in separate bodies and systems. Of t. is symptomatic, but at some patol, states (e.g., at heart failure with widespread hypostases) it can be carried to methods of pathogenetic treatment.
On distribution of liquid in an organism it is accepted to distinguish its extracellular and intracellular volumes which size significantly depends on concentration of osmotically active agents, hl. obr. electrolytes: sodium — in the extracellular environment and potassium — in cells. Water of a body is distributed on an osmotic gradient. Increase in osmotic concentration in any of sectors causes redistribution of water, to-rogo the overhydratation of one sector at the expense of dehydration of others can result. Distinguish a cellular and extracellular overhydratation. Extracellular liquid is subdivided into intersticial and intravascular (plasma). At increase in amount of the general liquid in an organism the general is possible, so-called total, an overhydratation.
The overhydratation is most characteristic of hypostases of various origin (see. Swelled ). At the same time volume extracellular, hl increases. obr. intersticial, liquids. Intravascular volume is increased to a lesser extent. At the expressed hypostases also the intracellular overhydratation is possible.
D. of t is especially wide. it is applied at the hypostases arising at heart troubles, kidneys, a liver and also at limf, hypostasis of extremities; it is appointed also at an overhydratation of separate bodies (at secondary glaucoma, wet brain), is more rare at hypostases of a hormonal origin, in particular at a syndrome of premenstrual tension (see. Premenstrual syndrome ).
Of t. makes also a part of disintoxication actions at acute poisonings with poisons, water soluble, and at uraemic intoxication at patients with an acute renal failure. In these cases it is applied for the purpose of removal from an organism of toxicants together with liquid (see. Disintoxication therapy ).
Removal of excess liquid from an organism at hypostases of various origin is reached by means of a complex of actions. Among them treatment of the basic patol, the process which served as an origin of an edematous syndrome is important: increase in sokratitelny ability of a myocardium at heart failure, impact on inflammatory process at nephrite or on disturbance of intra renal blood circulation at cirrhosis, and also correction of a hypoproteinemia at diseases of kidneys and a liver. To D. of t. it is possible to refer also mechanical removal of liquid from an abdominal cavity at ascites, from pleural — at a hydrothorax and edematous liquid from hypodermic cellulose — at an anasarca. However as the amount of extracellular liquid in an organism is caused by the content of sodium and excess accumulation of this cation plays the main role in formation of hypostases, D. of t. includes, as a rule, actions for restriction of intake of sodium in an organism with food and to the strengthened its removal by increase in natriuretic ability of kidneys. The last is reached by use of various diuretic means (see. Diuretics ), though the diuretic effect (about a nek-eye increase in a natriuresis) is rendered also by means of preferential extrarenal action (heart glucosides, caffeine, an Euphyllinum).
Rational D. of t. at the hypostases connected with heart failure has versatile therapeutic effect. Owing to reduction of intravascular liquid and decrease in peripheral fabrics of resistance to a blood-groove load of heart decreases that promotes recovery of its sokratitelny function. At the expense of dehydration of lungs resistance in a small circle decreases and diffusion of oxygen from alveoluses in blood improves. Besides, reduction of hydration of the cellular sector and normalization of the osmotic relations between cells and extracellular liquid recover cellular respiration and fabric metabolism.
Use D, t is studied. for the purpose of redistribution of liquid from fabrics in a vascular bed for increase in intravascular volume. Indications to such use of D. of t. are possible at oligemic shock of various origin (an injury, operation) or at heavy intoxications when accumulation of a histamine and histamine-like substances leads to increase in permeability of a vascular wall and vykhozhdeniye) water and low-molecular proteins from a vascular bed in fabric that leads to reduction of intravascular volume and to intersticial and even cellular overhydratation. Increase in volume of the circulating blood due to sloshing from intersticial space shall improve the central hemodynamics in such cases and normalize function of kidneys due to increase in a renal blood-groove and glomerular filtering.
Importance of D. of t. has in a heart surgery — during the carrying out operations with artificial circulation (see) and managed hemodilution (see). In these cases D.'s use t. leads to removal from the organism of excess of water and plasma substitutes used for a dilyution, and with them nitrogenous slags, products of a catabolism and hemolysis, and also toxins which appear in the conditions of operational shock. At the same time it is more preferable to use osmotic diuretics (Mannitolum, sorbitol) which natriuretic effect at the same size of a diuresis is less, than at the drugs operating on enzymes of renal tubules (hypothiazid, furosemide, ethacrynic to - that). Ability of osmotic diuretics to increase osmotic concentration of blood and to cause sloshing from fabrics in a vascular bed is useful at elimination of the postoperative oligemiya and oliguria caused by decrease in glomerular filtering and an effective renal blood-groove. In these cases also hypertensive solutions of glucose, sodium chloride or blood-substituting liquids are applied.
Ability of the hypertensive solutions and osmotic diuretics entered intravenously to attract in a vascular bed liquid from intersticial space, and with it together and water soluble toxicants is used at treatment of various poisonings. Toxic products are allocated then from an organism with kidneys therefore to lay down. D.'s effect of t. at intoxications depends on character of poison and function of kidneys.
Effective remedy of extracorporal D. of t. at treatment of the poisonings in particular proceeding with an acute renal failure the hemodialysis the device «Artificial Kidney» is (see. Hemodialysis ).
Character, volume and D.'s duration of t. are defined by specific conditions and indications in each separate case. When the edematous syndrome represents hron, a state as, e.g., at a circulatory unefficiency, D. of t. it is carried out it is long — months and years. At hemodilution, and also at poisonings, oligemic shock, glaucoma or wet brain of D. of t. enters a complex urgent to lay down. actions.
Of t. demands careful medical control since its irrational use can be followed by complications. Removal of large amounts of liquid from an organism, especially at patients without edematous syndrome, can lead to undesirable cellular dehydration. Thirst, dryness of mucous membranes, weakness, disturbances of consciousness are characteristic of this state. As a result of reduction of volume of the circulating blood and decrease in glomerular filtering increase in level of urea and creatinine in blood is possible. In certain cases, in particular at an initial hypovolemia, D. of t. can reduce the intravascular volume of liquid in such degree that will cause decrease in cordial emission and emergence or strengthening of circulatory disturbances. Excess increase in intravascular volume and increase in venous return to heart can also serve in the first phase of action of diuretic means in certain cases as the reason of strengthening of already existing heart failure. These complications arise at D. of t more often. in the conditions of intensive treatment of various states demanding acute management. At it is long in the t which is carried out by D. complications are caused by generally various disturbances of water and electrolytic exchange (see. Water salt metabolism ) and acid-base equilibrium (see). Development of a hyponatremia from cultivation is possible (see. Hyponatremia ), metabolic alkalosis (see) or acidosis (see), it is most often observed hypopotassemia (see) and deficit of potassium in an organism. Removal of sodium from an organism and reduction of intravascular volume of liquid under the influence of D. of t. are an incentive for increase in products of Aldosteronum and development of a syndrome of a secondary aldosteronism (see. Giperaldosteronizm ). Hypersensitivity of a myocardium to toxic effect of heart glucosides and inability to compensate a metabolic alkalosis happens a frequent consequence of deficit of potassium. Deficit of potassium in an organism and an alkalosis can promote emergence of a hepatic coma or strengthen it.
Control of action of D. of t. the wedge, symptoms, the weight of the patient and concentration of electrolytes in a blood plasma includes, at least, assessment of dynamics. In a wedge, conditions it can be added with dynamic overseeing by amount of the circulating blood, an indicator of a hematocrit and a condition of acid-base balance that specifies assessment of the changes happening in the extracellular environment. Methods of studying of intracellular liquid which could be used widely in daily practice are not developed yet. About cellular hyper - or dehydrations judge indirectly on existing a wedge, to signs.
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