The Use of K42 or P32 Labeled Erythrocytes and I131 Tagged Human Serum Albumin in Simultaneous Blood Volume Determinations 1

Blood Volume Alterations in Congestive Heart Failure

“…The arterial time concentration curves of I'8'-labeled albumin and p32 tagged erythrocytes do not differ significantly between 1 or 1% minutes and 15 minutes, and venous concentrations of I181-labeled albumin do not change significantly between 4 and 20 minutes after injection (16). Therefore, if the difference between the spaces of distribution of Ill3-labeled albumin and tagged red cells is to be attributed to leakage from the blood stream, this leakage must be completed within a very few minutes.…”

“…According to presently accepted concepts, the total body relative cell volume, RBC volume RBC volume + plasma volume' is appreciably lower than the relative cell volume of the blood withdrawn from the large vessels (hematocrit value) (8)(9)(10)(11)(12)(13)(14)(15)(16), and the ratio between these two is not necessarily constant (17). It is, therefore, theoretically possible for total erythrocyte volume and venous hematocrit value to remain unchanged in the presence of a significant increase in plasma volume, if the ratio, total body relative cell volume venous hematocrit value decreases.…”

Precision of red cell volume measurement using 32P‐labelled cells

“…It remains to be decided whether it is more reliable to deduce blood volume from the measurement of plasma volume or of red cell volume. Much has been written concerning the reliability of blood volume estimations based upon measurement of plasma volume alone, using both the dye method and radio-activated albumin (see Berson & Yallow, 1952). It seems likely that in the normal subject, these measurements have a high degree of accuracy.…”

Polycythemia vera: myths, mechanisms, and management

“…109,[133][134][135][136] Indeed, the assumption that the hematocrit accurately reflects the red cell mass or, stated differently, that the red cell mass:plasma volume ratio is constant in health and disease or even for all parts of the circulation, is simply incorrect and nowhere more so than when erythrocytosis is present. 114,127,134,136 Remarkably, although it was established in 1921 123 and repeatedly confirmed 125,126,137,138 that only by independently measuring the red cell mass (currently with 51 chromium) and the plasma volume (with 125 I-albumin) could an accurate assessment of each as well as the total blood volume be obtained, there is still resistance to this standard of practice. The reasons for this are several.…”

“…[123][124][125] Rather, as demonstrated by independent determinations of the red cell mass and plasma volume, the ratio of red cells to plasma is higher in the peripheral vessels, venous or arterial, than it is in the body as a whole (ie, whole body hematocrit derived from independent measurements of red cell mass and plasma volume/peripheral venous hematocrit ϭ 0.92). 126,127 This is a consequence of both the slower flow of the peripherally displaced plasma compared with the axial red cells and plasma skimming in the smaller vessels. 123,125,128,129 With disease, changes occur in the plasma volume and red cell mass or in their distribution, particularly if there is splenomegaly 121,130-132 that will not be evident by hematocrit level determination alone.…”