Mechanically Induced Intravascular and Extravascular Hemolysis in Dogs

Abstract

The endogenous production of carbon monoxide and the flow of hemoglobin to and from plasma were measured in 11 anesthetized dogs after pumping blood through an extracorporeal circuit for short periods. Two different pumps were used. In all animals the increase in CO production was greater than could be explained by catabolism of hemoglobin lost from plasma, an average of 11.4 times greater with one pump and 2.49 times greater with the other pump. Evidence is presented that this discrepancy could not be explained by catabolism of heme other than that of hemoglobin, and we therefore concluded that rates of hemoglobin catabolism were much greater than indicated by plasma hemoglobin kinetics and that extravascular hemolysis is a major cause of erythrocyte destruction during mechanically induced hemolysis. Extravascular hemolysis apparently caused an average of 72.9% and 37.2% (with the two pumps) of the total quantity of erythrocytes destroyed during pumping and for 3 hours after pumping.