Infusion pump-mediated mechanical hemolysis in pediatric patients

Context. Hemoglobinuria was observed after packed red blood cell transfusion in a series of patients at our pediatric treatment center. Laboratory testing was suggestive of intravascular hemolysis with no support for an immunohematologic process. Objective. We investigated these adverse events to define a quality improvement plan and to prevent future hemolytic adverse events. Multiple factors were investigated, and the only change identified was the implementation of a new infusion pump (Pump A) that replaced a previous model (Pump B). Design. In vitro pump analyses, a retrospective review of urinalyses, and prospective urinalysis and nursing surveillances were also performed. Results. In in vitro analysis of the pumps, irradiated units with higher hematocrit at a low flow rate through Pump A had a greater than thirty-fold increase in free hemoglobin from baseline compared to minimal free hemoglobin changes seen with Pump B. Irradiated units with a lower hematocrit had a minimal change in free hemoglobin from baseline with both Pumps A and B at either low or high flow rate. Subsequently, only units with lower hematocrits were issued for transfusion of pediatric patients, and Pump A was replaced by Pump B in the outpatient unit. Retrospective and prospective surveillances found no additional unexplained cases of gross hemoglobinuria associated with transfusion. Conclusion. The investigation determined that infusion of higher hematocrit units using a specific commercial pump was associated with mechanical hemolysis. The change to units with lower hematocrit through an alternative pump has been an effective corrective action to date.