Abstract 1906: Association Between Longer Blood Conservation and Worse Post-Operative Outcomes in Pediatric Cardiac Surgery
Long-term storage of packed red blood cells (PRBC) for the purpose of blood transfusion is associated with biochemical changes and decreased function. The negative clinical effect of long-term PRBC storage on outcomes in adult cardiac surgery has already been established, but the evidence of a similar effect in children receiving blood transfusions for cardiac surgery is limited. A total of 1,037 consecutive pediatric cardiac surgeries with the use of cardiopulmonary bypass from September 2004 to December 2007 were reviewed. The maximum age of blood of all PRBC units given on the day of surgery was defined as the primary exposure in order to fully capture the effect of PRBC units with extended storage. Associations between outcomes and maximum age of all PRBC units were estimated in multivariable logistic and linear regression models adjusted for previous surgeries, age at operation, Aristotle score, bypass time, cross-clamp time, deep hypothermic circulatory arrest, surgeon, O2 saturation prior to operation, total heparin dose and use of antifibrinolytic agents. Cardiac surgical patients received a median of 3 PRBC units (95% CI: 1– 6 PRBC units) or 112 ml PRBC/kg (95% CI: 14 –332 ml PRBC/kg). Mean maximum age of PRBC units was 18±7 days. Older maximum age of blood was found to be associated with increase chest tube volume loss (EST +0.015 (0.001) log ml/kg per PRBC day, p<0.001) and PRBC transfusion requirements (EST +0.194 (0.001) log ml/kg per PRBC day, p<0.001) in the 24 hours after surgery, increased duration of intubation (EST +0.008 (0.002) log days per PRBC day, p=0.001), CCCU stay (EST +0.003 (0.001) log days per PRBC day, p=0.004) and hospital stay (EST +0.004 (0.001) log days per PRBC day, p<0.001). Furthermore, each additional day of PRBC storage was associated with an increased odds of reoperation for bleeding (OR: 1.08 per PRBC days, 95%CI (1.03–1.13), p=0.003) and in-hospital mortality (OR: 1.04 per PRBC days, 95%CI (1.01–1.08), p=0.03). Longer duration of PRBC storage was found to be associated with increased post-operative complications and poorer clinical outcomes after pediatric cardiac surgery. These results emphasize the need for a strict balance between maintaining an appropriate blood supply and minimizing the duration of PRBC storage.