Deficit of circulatory blood.

Deficit of circulatory blood is a depression in the circulating blood volume per kilogram body weight and circulatory minute volume expansion. Exposure to the deficit of circulatory blood is attributed to the processes, regulating water-salt metabolism. It is understood that watersalt metabolism is influenced by the thyroid hormones. Combined interactions between pituitary antidiuretic hormones, somatotropic hormone, and kallikrein-kinin system are accompanied with changes in the plasma density and urine specific gravity. As the difference between plasma specific gravity and urine specific gravity is decreasing, we observe drop in the colloid-oncotic pressure, resulting in the rise of capillary hydrostatic pressure. The changes in colloid-oncotic pressure and hydrostatic pressure causes water outflow to the intercellular space and, depression in the circulatory minute volume, and so rise of the deficit of circulatory blood.

Circulating blood volume deficit occurs in the first stage of hypovolaemic shock.

The main causes of hypovolaemic shock:

profuse haemorrhage - external or internal;

indomitable vomiting;

polyuria - profuse urination (often occurs in non-sugar diabetes);

shock state, in which blood pressure drops, collapse - acute vascular insufficiency;

severe diarrhoea, usually against the background of infections;

hemolysis - increased destruction of red blood cells (occurs in some types of streptococcal infection and in congenital abnormalities of the hematopoietic system);

extensive burns, in which the body loses a large amount of fluid (tissues are destroyed, resulting in the release of a large amount of burn exudate - fluid from small blood vessels);

uncontrolled intake of diuretic medicines.