Studies of the Bodyhematocrit Phenomenon: Dynamic Hematocrit of a Large Vessel and Initial Distribution Space of Albumin and Fibrinogen in the Whole Body

Abstract

Larsen, O. A. Studies of the Bodyhematocrit Phenomenon: Dynamic Hematocrit of a Large Vessel and Initial Distribution Space of Albumin and Fibrinogen in the Whole Body. Scand. J. clin. Lab. Invest. 22, 189-195, 1968.

By measuring the mean circulation times of ¹²⁵I-labelled albumin and ⁵¹Cr-labelled red cells from the femoral vein to the pulmonary artery it has been shown that the dynamic hematocrit of this vascular area is 99 per cent of the hematocrit determined by centrifugation of a venous blood sample. It is therefore possible for all practical purposes to regard the centrifuge hematocrit as equal to the dynamic hematocrit in a large vessel.

The distribution volume of T-1824 and ¹³¹I-labelled fibrinogen has been determined simultaneously in 10 patients. T-1824 space exceeded fibrinogen space by 6.4 per cent. The explanation for the difference between the bod yhematocrit and the large vessel hematocrit appear to a major degree to be due to a low intravascular hematocrit caused by a more rapid passage of the red cells than of the plasma through the microvasculature and to a lesser degree to the fact that the normally used plasma indicators overestimate the plasma volume.

Key Words:

• Albumin distribution space
• erythrocyte circulation time
• fibrinogen distribution space
• hematocrit, body
• hematocrit, large vessel
• plasma circulation time