Hypovolemia

A volume deficiency or ECF volume contraction occurs as a result of the loss on the total amount of sodium body. The reasons include vomiting, excessive sweating, diarrhea, burns, diuretic therapy and renal failure. The clinical signs are reduced skin turgor, dry mucous membranes, tachycardia and orthostatic hypotension. The diagnosis is made clinically. The treatment consists in the supply of sodium and water.

Since water crosses plasma membranes in the body by passive osmosis, the loss of the most important extracellular cation leads (Na) is also fast to water loss from the ECF-space. In this way, the loss of sodium always causes a loss of water. However, the serum sodium concentration may depend on many factors, high in patients with volume depletion, low or normal (despite the reduced total body amount of sodium). The ECF volume is related to the effective circulating volume. A decrease of ECF (hypovolemia) generally causes a decrease in the effective circulating volume, which in turn leads to decreased organ perfusion and clinical sequelae. Common causes a decrease in ECF volume are listed in Common causes of volume depletion.

A volume deficiency or ECF volume contraction occurs as a result of the loss on the total amount of sodium body. The reasons include vomiting, excessive sweating, diarrhea, burns, diuretic therapy and renal failure. The clinical signs are reduced skin turgor, dry mucous membranes, tachycardia and orthostatic hypotension. The diagnosis is made clinically. The treatment consists in the supply of sodium and water. Since water crosses plasma membranes in the body by passive osmosis, the loss of the most important extracellular cation leads (Na) is also fast to water loss from the ECF-space. In this way, the loss of sodium always causes a loss of water. However, the serum sodium concentration may depend on many factors, high in patients with volume depletion, low or normal (despite the reduced total body amount of sodium). The ECF volume is related to the effective circulating volume. A decrease of ECF (hypovolemia) generally causes a decrease in the effective circulating volume, which in turn leads to decreased organ perfusion and clinical sequelae. Common causes a decrease in ECF volume are listed in Common causes of volume depletion. Common causes of volume depletion type Examples Extra Renal bleeding Gastrointestinal bleeding trauma dialysis hemodialysis peritoneal dialysis gastrointestinal tract diarrhea vomiting stomach tube appearance burns Excessive S chwitzen exfoliation losses in the third space intestinal lumen intraperitoneally retroperitoneal kidney, adrenal and pituitary Acute renal failure Diuretic recovery phase disturbances of adrenal adrenal insufficiency (caused steroid deficiency of the adrenal glands), including Addison’s disease hypoaldosteronism Genetic diseases hyperaldosteronism, and sodium and potassium deficiency of the Ni older cause Bartter syndrome Gitelman syndrome disorders of the hypothalamus and pituitary gland, the vasopressin (ADH) deficiency causes diabetes insipidus (central, z. As a result of trauma, tumor, infection) osmotic diuresis diabetes mellitus with extreme glucosuria diuretics Loop diuretics thiazide diuretics Salt-wasting renal disease Interstitial nephritis Medullary cystic kidney disease myeloma (occasionally) pyelonephritis (sometimes) Symptoms and complaints If the fluid loss <5% of ECF is (low volume depletion), the only sign may be a ver any reduction turgor be (best observed on the upper body). The skin turgor may be low in older patients, regardless of volume status. Patients can suffer from thirst. Dry mucous membranes correlated, especially in elderly patients and in patients who breathe through their mouths, not always with a volume deficiency. Oliguria is typical. When the ECF volume is reduced by 5-10% (moderate volume depletion), usually occur, but not always, orthostatic tachycardia, hypotension, or both on. Also orthostatic changes in patients can occur without ECF volume depletion, particularly in patients in poor physical condition or for bedridden patients. The skin turgor may continue to decline. If the fluid loss exceeds 10% of the ECF volume (severe volume depletion) may signs of circulatory failure occur (eg. As tachypnea, tachycardia, hypotension, confusion, delayed Rekapillarisierung). Diagnosis Clinical findings Sometimes determination of serum electrolytes, BUN and creatinine Rare plasma osmolality and urine values ??A reduction in volume is suspected in patients at risk, mostly in patients with decreased fluid intake in the medical history (especially in comatose or confused patients), at elevated liquid losses, diuretic therapy and renal or adrenal diseases. The diagnosis is made clinically in general. If the cause is obvious and easy to be corrected (e.g., an acute gastroenteritis in otherwise healthy patients.), Further laboratory tests are unnecessary; recommended is the determination of serum electrolytes, BUN and creatinine. The plasma osmolality and sodium, creatinine and osmolality in urine are measured when a suspicion of clinically significant electrolyte imbalance exists that can not be resolved by serum levels alone, in patients with heart or kidney disease. In a metabolic alkalosis the urine-Cl-concentration is measured. In a lack of volume of the central venous pressure and pulmonary artery wedge pressure is decreased, but a measurement is rarely necessary. A measurement which requires an invasive procedure is sometimes necessary for patients in which a small amount of additional volume already can be detrimental, such as those with unstable heart failure or advanced chronic kidney disease. The following concepts are useful to assess the values ??of urinary electrolytes and osmolality: During a volume depletion healthy kidneys retinieren sodium. As a result, the sodium concentration in the urine usually <15 mEq / L; the fractional sodium excretion (urine sodium / serum sodium divided by urine creatinine / serum creatinine) is usually <1%, d. h., the urine osmolality is often> 450 mOsm / kg. If metabolic alkalosis occurs together with a lack of volume, the sodium concentration can be high, since large amounts are released into the urine HCO3, making for maintaining electrical neutrality a corresponding sodium excretion necessary. In this case, a urine-Cl concentration is <10 mEq / l has a volume lack of reliable. Misleading high urine sodium (usually> 20 mEq / L) or low urine osmolality can also occur in the context of renal sodium losses in kidney disease, diuretics, or adrenal insufficiency. A lack of volume often increases the concentrations of BUN and creatinine in serum at a ratio of BUN to creatinine on often> 20: 1. Certain values ??such. in a lack of fluid as the hematocrit rise. Replacement therapy of sodium and water The cause of the defect is corrected volume and liquid is administered to replace the existing volume deficit plus the maintenance requirement. A mild to moderate volume deficiency can be treated by increased oral sodium and water absorption when the patient is conscious and his not vomit. If the volume deficit difficult or an oral fluid replacement is not feasible, 0.9% saline is injected i.v. administered. For typical I.V. Treatment plans, intravenous fluid replacement; for oral treatment plans, oral rehydration.

Health Life Media Team

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