Early packed red blood cell transfusion and acute respiratory distress syndrome after trauma.

BACKGROUND Transfusion of packed red blood cells (PRBCs) is a risk factor for acute respiratory distress syndrome (ARDS) in trauma patients. Yet, there is a paucity of information regarding the risk of ARDS with incremental PRBCs exposure. METHODS For this retrospective analysis, eligible patients from National Study on Costs and Outcomes of Trauma were included. Our main exposure was defined as units of PRBCs transfused during the first 24 h after admission. The main outcome was ARDS. RESULTS A total of 521 (4.6%) of 14070 patients developed ARDS, and 331 patients (63.5%) who developed ARDS received PRBCs transfusion. Injury severity, thoracic injury, polytrauma, and pneumonia receiving more than 5 units of fresh frozen plasma and 6-10 units of PRBCs were independent predictors of ARDS. Patients receiving more than 5 units of PRBCs had higher risk of developing ARDS (patients who received 6-10 units: adjusted odds ratio 2.5, 95% CI 1.12-5.3; patients who received more than 10 units: odds ratio 2.6, 95% CI 1.1-6.4). Each additional unit of PRBCs transfused conferred a 6% higher risk of ARDS (adjusted odds ratio 1.06; 95% CI 1.03-1.10). CONCLUSIONS Early transfusion of PRBCs is an independent predictor of ARDS in adult trauma patients. Conservative transfusion strategies that decrease PRBC exposure by even 1 unit may be warranted to reduce the risk of ARDS in injured patients.