Association between Storage Time of Transfused Red Blood Cells and Infection after Clean-contaminated Surgery

Abstract

Objective: The aim of this study was to investigate the association between storage time of transfused red blood cells and risks of infections after clean-contaminated surgery. Summary Background Data: Storage lesions of red blood cells can aggravate transfusion-related immunomodulation. Very few randomized controlled trials have investigated the impacts of storage time on postoperative outcomes in non-cardiac patients. Methods: We included adult patients who had undergone clean-contaminated surgery from 2014 to 2018 and received allogeneic red blood cell transfusion. In transfusion episode-level analysis, the exposure was the storage time of each transfusion episode. In patient-level analysis, the exposures were the mean, weighted mean, maximum storage time, and Scalar Age of Blood Index of red blood cells transfused into each patient. The primary outcome was infections that developed after transfusions within postoperative Day 30. Results: The 4046 included patients received 11604 transfusion episodes. Of these, 1025 (25.3%) patients developed postoperative infections. An increased storage time of transfused red blood cells was not associated with increased odds of postoperative infections in either transfusion episode-level analysis [odds ratio (OR) 1.03 per five days, 95% confidence interval (CI) 0.95 to 1.11] or patient-level analysis (mean: OR 1.02, 95% CI 0.95 to 1.10; weighted mean: OR 1.02, 95% CI 0.95 to 1.10; maximum: OR 1.06, 95% CI 0.98 to 1.14; Scalar Age of Blood Index: OR 0.99, 95% CI 0.96 to 1.03), after adjusting 17 confounders. Conclusions: Prolonged storage time of transfused red blood cells was not associated with increased risks of infections after clean-contaminated surgery.