Hematocrit is the ratio of the volume of formed elements to a unit of the total volume of whole blood, expressed as a percentage. Shaped elements can mean both exclusively erythrocytes and all blood cells in general, since there is no fundamental volumetric difference among them: RBCs make up more than 99% of all cell units in the vascular bed.
The norm for men is 40-48%, for women - 36-46%. The higher the HCT, the greater the oxygen transport capacity. Therefore, according to this indicator, one can judge the degree of oxygen supply to organs and tissues, but only under the condition of normal values of MCH, MCHC, MCV and RDW.
The hematocrit number reflects the cellular composition, therefore, this indicator is practically insensitive to factors affecting the synthesis of intracellular hemoglobin. Leads to an increase:
Loss of the liquid part by the body in case of extensive superficial burns, indomitable vomiting, diarrhea;
The exit of fluid from the vascular bed into the abdominal (ascites), chest (hydrothorax) cavity, intercellular space (edema);
Erythrocytosis, polycythemia with hypoxia, erythropoietin hypersecretion, primary erythremia;
An increase in the number of leukocytes in severe forms of leukemia, lymphoma.
Low NBT indicates:
Aplastic anemia (congenital and hereditary diseases, toxic damage to the bone marrow by cytostatics);
Hemolysis (poisoning with hemolytic poisons, congenital pathology of the shape of erythrocytes and their reduced elasticity, spleen diseases);
Overhydration against the background of increased infusion therapy;
An increased concentration of proteins and salts in plasma, which leads to a retention of plasma in the vessels and a relative decrease in the concentration of blood cells;
Pregnancy.
Pathological HCT values are an indication for a more in-depth diagnosis, the plan of which can only be formed by an experienced specialist. It is important not to miss the development of a serious pathology, since its progression significantly complicates the treatment process and worsens the prognosis. At the same time, it is very important to determine the physiological deviations of the hematocrit number in order to prevent overdiagnosis.
