Transfusion-related leukocytosis in critically ill patients*

OBJECTIVE We observed that many critically ill patients developed leukocytosis following blood transfusions. To validate this observation and to explore a possible mechanism, a prospective study was designed. DESIGN Prospective, non-interventional study. SETTING Surgical/medical intensive care unit in a university-affiliated community hospital. PATIENTS Consecutive patients who required packed red blood cells transfusion. INTERVENTIONS White blood cell count (mean +/- SD) x 10(9)/L before and 2, 4, 6, 12, and 24 hrs following transfusion of non-filtered packed red cells was measured in 96 patients. MEASUREMENTS AND MAIN RESULTS Twenty patients were septic at the time of transfusion, whereas 76 were not. The incidence of post-transfusion leukocytosis in septic vs. nonseptic patients was 15% vs. 76%, respectively (p