[Effect of body position on laboratory hematological indices]

The influence which the position of the body (recumbent, sitting or erect) exerts on the hematologic laboratory indices was studied in 32 clinically healthy persons from both sexes, 19 to 48 years of age. Blood was taken by venepuncture in each of three positions. The analyses were carried out by a hematologic analyzer "H 1 Technicon". The differences of the results were processed by the pair analysis. The values of hemoglobin, hematocrit, erythrocytes, leucocytes and platelets increase with the change of the body position from recumbent to sitting and to erect and the differences are statistically significant. The changes are due to a reversible hemoconcentration and redistribution of the blood. The analysis of the differential count revealed that the greatest increase is of the neutrophils which is probably due to the mobilization of the pool of neutrophils which are nearest to the vascular wall, the process being parallel to the process of hemoconcentration.