The effect of external pressure, catheter gauge, and storage time on hemolysis in RBC transfusion

BACKGROUND: RBC transfusions are often administered using externally applied pneumatic pressure. The effect of this practice on RBC hemolysis was studied during simulated transfusion performed in the laboratory. MATERIALS AND METHODS: RBC transfusions were performed sequentially via 16-, 18-, 20-, and 22-gauge cannulas with the application of a pneumatic pressure device at pressures of 150 and 300 mmHg. Hb concentration, Hct, RBC count, free Hb, potassium, and LDH concentrations were measured in 5 mL of transfusate. RESULTS: Forty-seven RBC units, 20 fresh units (mean age, 10.8 days) and 27 old units (mean age, 28.9 days) were studied under all conditions. Multiple regression analysis revealed that the age of the unit and the external pressure applied were significant determinants of the degree of hemolysis. CONCLUSIONS: The application of an external pressure device results in minimal destruction of transfused RBCs, even under the most stringent conditions examined. Thus external pressure application to expedite an RBC transfusion is likely to be a safe procedure for the majority of patients. Unusual clinical situations, such as massive transfusion in pediatric patients, should be specifically examined to confirm the safety of this procedure.