In vitro comparison of heated saline-blood admixture with a heat exchanger for rapid warming of red blood cells.

We compared the rapidity of rewarming and infusing red blood cells (RBCs) mixed with 24 degrees C, 50 degrees C, and 60 degrees C saline with the rapidity of administering undiluted RBCs through a heat exchanger. We measured flow rate, final temperature, and hemolysis in matched 41-45-day-old pooled AS-1 RBCs infused through high-flow tubing via a 14-gauge catheter under the influence of gravity. Undiluted RBCs were tested as controls. The final temperature of the 60 degrees C admixture technique was lower than that with the heat exchanger (28.5 +/- 0.2 degrees C vs. 32.7 +/- 0.2 degrees C), but the flow rate was higher (258 +/- 8 mL/min vs. 61 +/- 4 mL/min). Admixture with 60 degrees C saline resulted in no increase in hemolysis. This technique appears to be a simple, inexpensive method for rapid rewarming and infusion of RBCs and may be valuable for administration of RBCs simultaneously through multiple sites during resuscitation.