Loss of red cells from the use of blood warmers during apheresis procedures.

Abstract

In-line blood warmers increase the extracorporeal volume of apheresis procedures. A saline rinse of the blood warmer may be employed to minimize the loss of red blood cells (RBCs) from this extra volume. We measured the amount of RBCs remaining in three different brands of blood warmers at the end of a COBE Spectra rinseback to determine the clinical significance of blood warmer saline rinses. The volume of RBCs removed by a warmer rinse ranged from 15 to 24 ml per procedure and was statistically different among the three brands of warmers. The COBE warmer contained significantly less RBCs than either the Fenwal or Pharmaseal warmers. Patient hematocrit was not highly correlated with the residual RBC volume (r = 0.30). We estimate that 15-20 procedures are required before the equivalent of one unit of packed RBCs is lost to blood warmers. We conclude that the blood warmer saline rinse may be safely omitted for most patients.