Blood exchange with pyridoxalated and polymerized hemoglobin solution.

A solution of pyridoxalated and polymerized hemoglobin has been used for total blood exchange in the rat to test its effectiveness in vivo. Two groups of eight rats each were transfused to 93 to 95 per cent blood replacement with hemoglobin, control group, or with modified hemoglobin, experimental group, solution. All of the rats in the experimental group survived and became hematologically and physiologically normal at eight days after transfusion, whereas the rats in the control group died at approximately five hours after transfusion. Immediately after transfusion, the circulating fluid in the two groups of rats showed the same oxygen carrying capacity. At three and five hours after transfusion, differences in the oxygen capacity were observed with values in the experimental group of 34 and 103 per cent higher, respectively, than in the control group. The P50 of the vascular fluid in the experimental rats was 47 to 49 per cent greater than the corresponding value in the control group at zero, three and five hours after transfusion. The disappearance of hemoglobin from plasma was faster in the control than in the experimental group with a plasma half-disappearance time of 3.5 and 25 hours, respectively. The differences observed in the rate of disappearance of plasma hemoglobin were reflected in the rate of accumulation of hemoglobin in the urine. A solution of pyridoxalated and polymerized hemoglobin appears to be beneficial in blood replacement, since it promotes survival after massive transfusions.