Most observers have found that when circulating red cell volume is deduced from measurement of plasma volume and venous hematocrit a higher value is obtained than when the red cell volume is measured directly. It is widely believed that this is because the proportion of red cells in the blood in large vessels is higher than that in the body as a whole and various correction factors have been pr...

OBJECTIVE Intraoperative blood management during cardiac surgery is a multifaceted process incorporating various interventions directed at optimizing oxygen delivery and enhancing hemostasis. The purpose of this study was to evaluate the effects of acute normovolemic hemodilution (ANH) and autologous priming (AP) on preserving the hematocrit during cardiopulmonary bypass (CPB). METHOD Case re...

JOHNSON, PAUL C.,JON BLASCHKE, KENNETH S. BURTON, AND JOE H. DIAL. Infruence of Jzozo variations on capillary hematocrit in mcsenter-y. Am. J. Physiol. 221(l): 105-l 12. 1971.~Red cell spacing was measured on line in mesenteric capillaries of the cat by counting red cells passing through the capillary and simultaneously measuring red cell velocity. Most capillaries had reasonably stable hematoc...

Hematocrits and total plasma proteins were determined at 24 days old for 86 female and 85 male nestling American kestrels (Falco sparverius) from the wild in northern Saskatchewan. No sex differences were detected in either hematocrit or plasma protein. For females, hematocrit and plasma protein were not related to time of sampling, temperature at sampling, mass of nestlings or length of the te...

PHYSIOLOGICAL SYSTEMS are characterized by multiple interdependent components that collectively subserve various processes and functions. In seeking better understanding of the performance of such complex systems, we must identify and evaluate alternative ways and operating schemes, comparing their predicted performance with goals or objectives of interest. Optimization entails selecting a bett...

Estimates of the intrarenal hematocrit ratio vary widely, depending on the techniques used for its determination. Computation of blood volume from the product of mean transit time of labeled erythrocytes and albumin, and minute volume blood flow, yields values averaging approximately 90% of the systemic vessel hematocrit. To the other extreme are values that are slightly less than half of the s...

The mechanism by which angiotensin-converting enzyme inhibitors reduce red cell mass in renal transplant recipients with erythrocytosis is unclear. To examine the role of angiotensin II in this disorder, losartan (a competitive antagonist of the angiotensin II type 1 [AT1] receptor) was administered to 23 patients with erythrocytosis. Fourteen patients took 25 mg/d for 8 wk; nine others were tr...

The hematocrit is one of the main factors influencing platelet adherence to the vessel wall. Raising the hematocrit causes an increase of platelet accumulation of about an order of magnitude. Our studies concern the role of red cell size. We have studied this effect using an annular perfusion chamber, according to Baumgartner, with human umbilical arteries and a steady-flow system. Normal human...

In this prospective study, the association between hematocrit values measured in 1965-68 and subsequent cancer incidence was studied among 7737 Japanese-American men in Hawaii. With an increase in hematocrit levels, there was an increasing risk for lung cancer, especially squamous or small cell type, and for kidney cancer. However, a statistically significant trend remained only for kidney canc...

Albumin-Induced Hematocrit-Lowering and B-type Natriuretic Peptide Increase To the Editor: We read with great interest the article by Ginsberg et al concerning the safety of albumin therapy for acute ischemic stroke.1 The authors found that albumin doses ranging from 1.37 to 2.05 g/kg were generally well tolerated by stroke patients, and that the main adverse event, a mild-moderate pulmonary ed...