May
11
23:01
Diseases of the blood

Hypovolemia

Hypovolaemia

hypovolemia photo Hypovolaemia - is to reduce the volume of blood circulating in the body (bcc).When hypovolemia is a decrease in blood volume levels well below regulatory indicators.In males, the normal rate is 70 ml / kg of total circulating blood and 40ml / kg plasma.Women - 66 ml / kg of BCC and 41 ml / kg of the circulating plasma.

blood volume is a component of the extracellular fluid, and therefore almost all causes of dehydration give the development of hypovolemia.A special role in its development also plays a redistribution of the interstitial fluid from the intravascular space.

Hypovolaemia reasons

due to incorrect distribution of extracellular fluid are: decrease in oncotic pressure in the blood plasma, increased permeability of blood vessels, increasing the hydrostatic pressure in the arterioles, increased arterial and venous pressure.

oncotic pressure may be reduced in the first place in renal disorders.Diuretics as other conditions lead to loss of water and salts of sodium

by the kidneys.In particular diuretics increase the excretion of sodium.Also reabsorption of sodium salts may be compromised due to increased filtration of substances that cause osmotic diuresis (urea and glucose).Such a condition can be diabetes mellitus in decompensated form or the diet of people with high protein content.

increased secretion of water by the kidneys leads to hypovolemia, but decreases the level of intracellular fluid (two thirds of all losses) and because gipovlemiya when this process is moderate.Such a condition can occur when diabetes insipidus central and nephrogenic diabetes.These conditions are caused by a violation of secretion of ADH and lowering it to the sensitivity of the kidneys.

fluid loss through the kidneys do not include losses from the gastrointestinal tract, lungs, skin, and penetration of liquid into extraneous space (burns, peritonitis, acute pancreatitis).In case of burns or allergic reactions, as a rule, there is increased permeability of the vessel walls.

for 24 hours in the gastrointestinal tract secreted approximately 7.5 liters of liquid, and about two liters ingested in the diet.Approximately 98% of the absorbed fluid due to a loss of water from the feces with bowel movements around 200 ml / day.Therefore, hypovolemia can lead to increased secretion of the digestive tract and decreased reabsorption of fluid in it.Such conditions may include diarrhea and vomiting.

also known that occurs when breathing liquid excretion and perspiration through the skin.These are called hidden water losses.They are about half a liter a day.With feverish conditions, physical activity and hot weather, sweating is greatly enhanced.The concentration of sodium in liquid potootdelyaemoy approximately 30-50 mmol / l, and based on this fluid lost during perspiration hypotonic nature, which leads to loss of thirst and water are replenished.But when profuse sweating may begin hypovolemia, because if such a state occurs severity and duration of the excretion of sodium.

fluid loss through the organs of the chest increases when ventilation.Yield fluid into another space observed at a number of states.Such a space can not communicate with either fluid intracellular or extracellular.Since the output to another space from the extracellular fluid, then develop severe hypovolemia.Other spaces include: the subcutaneous tissue when expressed burns, intestinal lumen in its obstruction, the space behind the peritoneum at an attack of acute pancreatitis, the area of ​​the peritoneum in the development of peritonitis.

In some cases can observe hypovolemia thyroid whereby significantly reduced level not only liquids and hormones produced by it.But this condition is extremely rare.As a rule, preceded by a severe hypovolemia, which is observed during prolonged blood loss.

Hypovolaemia symptoms

Lowering the volume of fluid inside the cells shown a decrease in blood pressure and a decrease in the volume of circulating plasma.Hypotension develops due to the preload of the venous system and slow the cardiac output.This leads to reduced pulsation of the b-receptors of the carotid sinus and low pulsation b receptors of the aortic arch.Because of this, it starts to develop increased excitability of the sympathetic nervous and renin-angiotensin systems.Such responses are adaptive in nature, to maintain blood pressure and maintain heart and brain perfusion.Adaptable reactions on the part of the renal system are aimed at filling the plasma volume.

most typical complaints of hypovolemia are: thirst, high fatigue, muscle spasms, dizziness when changing body from vertical to horizontal position and vice versa.These symptoms are non-specific and cause secondary tissue perfusion and impaired electrolyte balance.Also, there is a decrease in urine output, pale mucous membranes and skin, low body temperature, increased heart rate and a decrease in the filling rate.

severe hypovolemia accompanied by a violation of the perfusion of the abdomen and chest.It is manifested by pain in the abdomen, chest, stupor, stunning, cyanosis, oliguria.Also, hypovolemic shock may occur when the loss of large amounts of liquid.

On physical examination, there spadenie veins in the neck, as well as tachycardia and orthostatic hypotension.Lowering the skin turgor and dry mucous membranes are not considered very reliable criteria for determining the degree of hypovolemia.

Hypovolaemia treatment

For diagnosis hypovolemia enough history and physical examination.Laboratory diagnostics is to confirm the diagnosis.

level of sodium in the blood plasma volume depletion can vary from the normal range to higher or lower.It all depends on the amount of lost fluid and how quickly it is filled with water intake.

When potassium loss through the gastrointestinal tract and kidneys, hypovolemia may be associated with hypokalemia, and hyperkalemia - in patients with renal insufficiency, disturbances in the adrenal glands and in some types of acidosis.

hypovolemia Treatment is aimed at eliminating its causes, as well as to fill the volume of extra- and intracellular fluid.Solutions of renewable liquid should be similar in composition to the lost.The severity of hypovolemia is determined on the basis of clinical symptoms.By the same criteria to evaluate the impact of therapy of hypovolemia.

In moderate hypovolemia prescribed intake of fluids inside, with severe - intravenously.If the hypovolemia is accompanied by reduced levels of several plasma sodium, then apply a solution of sodium chlorine with its concentration of 145 mmol / l.It is also indicated for shock and hypotension.If sodium in plasma was reduced to a critical level using sodium chlorine concentration 515 mmol / l.

When expressed bleeding, anemia, transfusion of red blood cells is expedient and in / with the introduction of albumin and dextran.

When hypovolemia thyroid hormonal drugs prescribed in combination with iodine.Subsequently, it is necessary on a quarterly basis to measure the level of hormones like TSH, T3 and T4.

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