The association of blood transfusion with mortality after cardiac surgery Transfusion, 05/21/2012

Dixon B et al. – In the stratified analysis, chest tube drainage remained an independent predictor of mortality for patients not exposed to a blood transfusion. Furthermore, the risk of death of these patients was no different from patients exposed to a blood transfusion. The results argue that for patients undergoing cardiac surgery bleeding contributes to mortality through mechanisms unrelated to blood transfusion.

• The authors undertook a multivariate logistic regression analysis of the risk factors associated with mortality in 2599 consecutive patients undergoing cardiac surgery.
• Unlike previous studies the risk factors examined included the volume of chest tube drainage at 24hours.
• A stratified analysis was also undertaken that compared the adjusted risk of death for patients exposed or not exposed to a postoperative blood transfusion.

• Blood transfusion was not an independent predictor of mortality (p=0.4).
• Chest tube drainage was the strongest independent predictor of mortality (p<0.001).
• In the stratified analysis, chest tube drainage remained an independent predictor of mortality for patients not exposed to a blood transfusion (p<0.01).
• Furthermore, the risk of death of these patients was no different from patients exposed to a blood transfusion (p=0.7 for interaction).