Fresh red blood cell transfusion and short-term pulmonary, immunologic, and coagulation status: A randomized clinical trial

Rationale: Transfusion-related pulmonary complications are leading causes of morbidity and mortality attributed to transfusion. Observational studies suggest an important role for red blood cell (RBC) storage duration in these adverse outcomes. Objectives: To evaluate the impact of RBC storage duration on shortterm pulmonary function as well as immunologic and coagulation status inmechanically ventilated patients receiving RBC transfusion. Methods: This is a double-blind, randomized, clinical trial comparing fresh (≤5 d of storage) versus standard issue single-unit RBC transfusion in adult intubated and mechanically ventilated patients. The primary outcomeis the change in pulmonary gas exchange as assessed by the partial pressure of arterial oxygen to fraction of inspired oxygen concentration ratio (ΔPa _O2/FI _O2). Secondary outcomes include changes in immune and coagulation status. Measurements and Main Results: Fifty patients were randomized to receive fresh RBCs and an additional 50 patients to standard issue RBCs. Median storage age was 4.0 days (interquartile range, 3.0-5.0) and 26.5 days (interquartile range, 21.0-36.0) in the freshRBCgroupandstandard issue RBC group, respectively. No differences were noted in the primary outcome of ΔPa _O2/FI _O2 (difference between the mean ΔPa _O2/FI _O2 in the standardissueRBCgroupvs. the freshRBCgroup, -11.5;95%confidence interval, -35.3 to 12.3; P=0.22). Similarly, no significant differences were noted in markers of immunologic or coagulation status. Conclusions: In this randomized clinical trial, no differences were noted in early measures of pulmonary function or in immunologic or coagulation status when comparing fresh versus standard issue single unit RBC transfusion. Clinical trial registered with ClinicalTrials.gov (NCT00751322).