The role of acute blood transfusion in the development of acute respiratory distress syndrome in patients with severe trauma

Background: Patients with major trauma necessitating the transfusion of packed red blood cells (PRBCs) are at increased risk for the acute respiratory distress syndrome (ARDS). However, it is presently unknown whether the amount of transfused blood is independently associated with development of ARDS in patients with severe trauma. Methods: This is a prospective cohort study of 102 consecutive patients with severe trauma from an intensive care unit in a Level I trauma center. Results: Patients were divided into three predetermined groups on the basis of the total number of units of PRBCs received in the initial 24 hours. A significant association was identified between an acute exposure to transfused blood and the development of ARDS. Twenty-one percent of patients who received 0 to 5 units of PRBCs developed ARDS, compared with 31% of those patients who received 6 to 10 units of PRBCs and 57% of those who received greater than 10 units of PRBCs (p = 0.007). The association between the amount of transfused blood and the development of ARDS remained significant in a multivariable logistic regression model accounting for differences in severity of illness, type of trauma, race, gender, and base deficit (p = 0.002; odds ratio, 14.4; 95% confidence interval, 3.2-78.7). Patients who received more units of PRBCs during the first 24 hours also had a higher hospital mortality rate (p = 0.03). Conclusion: In severely injured trauma patients who require administration of packed red blood cells, the amount of transfused blood is independently associated with both the development of ARDS and hospital mortality.