Effect of Blood Transfusion and Hemorrhage on Cardiac Output and on the Venous Return Curve

Abstract

The effect of blood transfusion or hemorrhage on the venous return curve has been studied in 10 dogs with normal circulatory reflexes and in 10 additional areflex dogs. At all right atrial pressures transfusion increased the venous return and hemorrhage decreased it. Following transfusion the venous return remained elevated only transiently, returning progressively toward the control value during the ensuing 10–20 minutes. Following hemorrhage, however, the venous return remained depressed for prolonged periods of time. The same effects were observed after infusion of Tyrode's solution as after transfusion of blood.

Hemodynamic Relationships of Anaerobic Metabolism and Plasma Free Fatty Acids During Prolonged, Strenuous Exercise in Trained and Untrained Subjects*

“…Since the hemodynamic effects of acute bleeding are to some extent transient (23) and since the amount removed was relatively small, we believe that the observed reduction of stroke index was largely unrelated to loss of blood volume.…”

Pharmacodynamic Analysis of a Fluid Challenge

“…Nunes et al (33) also reported a transitory effect using 500 mL infused over 30 minutes in septic patients. Importantly, stress-relaxation and redistribution of the intravascular volume between stressed and non-stressed volume are physiological mechanisms that allow adaptation to different intravascular volume status, so that they take place in hypovolaemic, euvolaemic and hypervolaemic states (44,45). Regardless the baseline intravascular volume status, the transitory effect of a fluid challenge is also determined by the dose of fluids given: in this study the average dose would be 3.3 ml/kg, which is a lot less than the doses used in Guyton's experiments where a slower decay effect was observed.…”

Circulatory Effects of Chronic Hypervolemia in Polycythemia Vera*

“…That hypervolemia exerts its effect through increased central blood volume and enhanced diastolic filling seems logical (14). It is possible that the increased cardiac output observed in five of the ten subjects was in part dependent upon increased venous return, similar to the transient effects described with acute hypervolemia in dogs (15). From other studies there is evidence that acute hypervolemia achieved by the infusion of dextran and other blood volume expanders increases output (2,4,6,16).…”