Z. M. Abdelsattar1, S. Hendren1, S. L. WONG1, D. A. Campbell1, P. K. Henke1 1University Of Michigan,Department Of Surgery,Ann Arbor, MI, USA
Introduction: There are no definitive data on the efficacy of blood transfusion in improving outcomes, and recent data suggest alarming associations with harm. Postoperative transfusion practices and their effect on short-term outcomes in patients undergoing non-cardiac general and vascular surgery are not well understood.
Methods: This is a retrospective cohort study using prospectively collected data. Demographic, operative and outcomes data for 48,720 patients undergoing general or vascular surgery at 52 hospitals between 7/2012 and 4/2014 were reviewed. Receipt of a blood transfusion within 72 hours after the operation was the main exposure variable. Thirty-day infectious complications, ischemic cardiac events, any morbidity, and mortality were the outcomes of interest. Propensity score matching across 64 different variables was used to estimate the effect of transfusion on outcomes. Hospitals were divided into restrictive, average, or liberal transfusers based on aggregate averages of nadir postoperative hematocrit values in transfused patients. Hierarchical models were used to estimate hospital level risk-adjusted outcomes.
Results: In this cohort, 2,243 (4.6%) patients received a postoperative blood transfusion. After propensity matching, a postoperative transfusion was associated with increased 30-day mortality (3.6% excess absolute risk; p=0.001), any morbidity (9.7% excess absolute risk; p<0.001), and infectious morbidity (5.4% excess absolute risk; p<0.001). However, a transfusion was associated with a 4.7% absolute risk reduction in postoperative ischemic cardiac events (p=0.001). At the hospital level there was wide variation in transfusion practices as evident by nadir hematocrit values for transfusions (Figure). Hospitals with liberal transfusion practices were twice as likely to transfuse patients and had higher risk-adjusted mortality rates than restrictive hospitals (3.1% vs. 2.2%; p<0.001)
Conclusion: Postoperative transfusions are associated with significantly increased adverse postoperative outcomes with the exception of ischemic cardiac events. Hospitals that are liberal in their transfusion practices also have markedly worse outcomes, suggesting potential interventions for quality improvement.
