1014

Abstract

Introduction: Packed red blood cell transfusion (pRBC) is commonly used in the ICU setting to treat diminished tissue oxygen delivery. However, data supporting this therapy is limited, and pRBC’s are an independent risk factor for prolonged hospitalization and death. Direct observation and analysis of erythrocyte perfusion in tissue capillaries, through the use of sidestream darkfield imaging, may yield further insight into the utility of and indication for pRBC transfusion. Hypothesis: We hypthesized that that microvascular perfusion is improved with pRBC transfusion. Methods: Trauma and elective surgery patients requiring an ICU level of care due to receive pRBC’s were enrolled prior to transfusion after obtaining informed consent. Two-minute SDI imaging was obtained in order to measure the perfused capillary density (PCD) prior to, then one and three hours after transfusion. PCD measures underwent ANOVA analysis to detect a 5% difference between pre- and post-transfusion SDI values, with a p < 0.05 considered significant. Mean arterial pressure (MAP) and hemoglobin were serially analyzed in a similar fashion. Results: Thirteen patients were enrolled, who received an average of 1.4 +/-0.1 units of pRBC. PCD did not significantly change from the pre-transfusion baseline at the 1 hour reassessment, but increased at the 3 hour reassessment (F(2) = 7.1, p = 0.009) while MAP remained unchanged (F(2) = 0.02, p = 0.98). As expected, serum hemoglobin increased with transfusion (F(2) = 7.0, p = 0.005). Conclusions: Transfusion of pRBC’s did not initially alter capillary perfusion, but improved microvascular perfusion 3 hours post-transfusion.