Admixture bloodwarming: a technique for rapid warming of erythrocytes

Admixture of erythrocytes (packed red blood cells) with heated saline solutions may provide a faster and safer method of bloodwarming and infusion than is currently available. We developed and tested such a system for ease and efficacy. One-day-old aliquots of erythrocytes (6 to 10 C) were combined with equal amounts of saline that had been heated to a temperature of 50 or 60 C. After this rapid admixture, equilibrated temperatures were 29.1 and 34.0 C, respectively. The procedure also was performed using 35-day-old erythrocytes and 60-C saline. Samples were obtained for analysis immediately after admixture. There was no significant plasma hemoglobin elevation, indicating no significant hemolysis, in any sample at either temperature. Rapid admixture bloodwarming appears to be a technique in which erythrocytes and heated saline may be combined rapidly without causing significant hemolysis. However, further studies of red cell function and survival will be needed before this technique should be put into clinical practice.