Effect of Age of Transfused Red Blood Cell Units on Clinical Outcomes in Critically Ill Patients.

Anemia in critically ill patients requires red cell transfusions to increase oxygen delivery and prevent deleterious outcomes. The primary objective of the present study was to determine the effect of storage age of transfused red cells on 30-day mortality in critically ill patients, with secondary objectives of determining the effect on length of stay, organ failure, and adverse transfusion reactions. This prospective study was conducted on patients admitted to the intensive care unit after obtaining approval from institutional ethics committee. Patients were randomized to transfusion with packed red blood cells (PRBC) with age of collection either ≤ 14 days (Group 1) or > 14 days (Group 2). APACHE II scores were calculated at admission. Patients were followed up for primary outcome of 30-day mortality, and secondary outcomes including length of stay, infections, organ dysfunction, and adverse transfusion reactions. The 30-day mortality was 20% in Group 1 and 28% in Group 2 ( p  = 0.508). The mean storage duration of PRBC in Group 1 versus Group 2 was 8.48 days versus 21.43 days ( p  < 0.001). There was no significant difference in total number of PRBC transfusions, donor exposures, hemoglobin and hematocrit increment, adverse transfusion reactions, length of stay and organ dysfunction scores between the two groups. Transfusion of packed red cells of less than 14 days showed no benefit over red cells stored more than 14 days in terms of 30-day mortality, length of stay and infections in critically ill patients, however studies with larger sample size and longer follow up are recommended.