Ability of Stored Blood to Transport Oxygen.

摘要

Effects of altering oxygen availability during hypovolemic shock were studied in rats. A 50% reduction in circulating hemoglobin concentration produced no effect on duration of time rats were able to tolerate shock,acid-base balance,mortality,or total oxygen consumption. Tolerance was shown to be due to an increase in cardiac output in anemic animals,probably due to a decrease in whole blood viscosity. Since animals with increased oxygen affinity and normal hemoglobin concentration would have normal blood viscosity,these animals may tolerate shock significantly less well than anemic animals. Effect of altered P50when combined with anemia was studied in normal human volunteers. Acute induction of anemia produced increases in 2,3 Diphosphoglycerate (DPG) and P50but no significant change in pH over the subsequent 10-14days. Anemia caused a striking reduction in maximal exercise capacity and maximal oxygen consumption. Cardiac output was higher at rest and during exercise immediately after induction of anemia than when measured two weeks later.