Red Blood Cell Storage Duration Is Associated with Various Clinical Outcomes in Pediatric Cardiac Surgery

Background: Recommendations on the use of fresh red blood cells (RBCs) in pediatric patients undergoing cardiac surgery are based on limited information. Furthermore, the RBC storage time cut-off of fresh units remains unknown. Methods: Data from 139 pediatric patients who underwent cardiac surgery and received RBCs from a single unit within 14 days of storage were analyzed. To identify the optimal cut-off storage time of RBCs for transfusion, multiple multivariate analyses aimed at different outcome parameters were performed. Results: 26 patients received RBC units stored for ≤3 days, while 126 patients received RBCs that were stored for 4-14 days. The latter group required more RBC transfusions and fresh frozen plasma (FFP) than the former group (19 vs. 25 ml/kg, p = 0.003 and 73% vs. 35%, p = 0.0006, respectively). In addition, the odds for the administration of FFP increased with the transfusion of RBCs stored for more than 4 days. The optimal cut-off for post-operative morbidity was observed with a storage time of ≤6 days for length of ventilation (p = 0.02) and peak of C-reactive protein (CRP; p = 0.008). Conclusions: The obtained results indicate that the hazard of blood transfusion increased with increasing storage time of RBCs. The results of this study suggest that transfusion of fresh RBCs with a storage time of ≤2 or 4 days (concerning transfusion requirements) or ≤6 days (concerning postoperative morbidity) may be beneficial in pediatric patients undergoing cardiac surgery. However, further prospective randomized studies are required in order to draw any final conclusions.