Red blood cell transfusions have been associated with worse outcomes in several populations of patients, including critically ill patients. In a recent systematic review of 45 observational studies reporting the impact of transfusions on patient outcome (mortality, infections, acute respiratory distress syndrome [ARDS]) in populations of trauma, general surgery, orthopedic surgery, acute coronary syndrome, and ICU patients, Marik and Corwin [32] identified RBC transfusion as an independent predictor of death (pooled odds ratio (OR) from 12 studies, 1.7; 95% confidence interval (CI), 1.4-1.9), infectious complications (pooled OR from 9 studies, 1.8; 95% CI, 1.5-2.2), and ARDS (pooled OR from 6 studies, 2.5; 95% CI, 1.6-3.3). In ICU patients, the three studies included in the review (ABC study [3] , CRIT study [5] , and a study by Gong et al. [33] ) consistently showed a statistically significant association of RBC transfusion with mortality.