LOSS OF RED-CELLS FROM THE USE OF BLOOD WARMERS DURING APHERESIS PROCEDURES

In-line blood warmers increase the extracorporeal volume of apheresis procedures. A saline rinse of the blood warmer may be employed to mini mize the loss of red blood cells (RBCs) from this extra volume. We mea sured the amount of RBCs remaining in three different brands of blood warmers at the end of a COBE Spectra rinsebock to determine the clinic al significance of blood warmer saline rinses. The volume of RBCs remo ved by a warmer rinse ranged from 15 to 24 ml per procedure and was st atistically different among the three brands of warmers. The COBE warm er contained significantly less RBCs than either the Fenwal or Pharmas eal warmers. Patient hematocrit was not highly correlated with the res idual RBC volume (r = 0.30). We estimate that 15-20 procedures are req uired before the equivalent of one unit of packed RBCs is lost to bloo d warmers. We conclude that the blood warmer saline rinse may be safel y omitted for most patients. (C) 1997 Wiley-Liss, Inc.