The alterations in O2 extraction in hemodilution have been linked to fast red blood cell (RBC) velocity, which might affect the complete release of O2 from Hb. Fast RBC velocity might also explain the normal mucosal-arterial Pco2 (ΔPco2). Yet sublingual and intestinal microcirculation have not been completely characterized in extreme hemodilution. Our hypothesis was that the unchanged ΔPco2 in ...

OBJECTIVES To investigate the causes of wide variations in reported effects of hemodilution on flow resistance of vascular beds. METHODS (a) In a meta-analysis of 28 prior studies, resistance values at hematocrits of zero (R0) and 0.45 (R0.45) were derived. Study design characteristics (presence of vasodilatory reserve or leukocytes, species, tissue, hemodiluent) were tested by ANOVA for thei...

This study tested the hypothesis that a reduction in blood viscosity by means of isovolumetric hemodilution will permit an increase in maximal oxygen delivery to myocardium distal to a moderate coronary arterial stenosis. It is known that blood viscosity is a determinent of resistance to blood flow at both the stenotic and the arteriolar levels. Accordingly, a reduction in blood viscosity could...

The effect of isovolemic hemodilution on the circulation of red blood cells (RBCs) in the cerebrocortical capillary network was studied by intravital videomicroscopy with use of a closed-cranial-window technique in the rat. Velocity and supply rate of RBCs were measured by tracking the movement and counting the number of fluorescently labeled cells. Arterial blood was withdrawn in increments of...