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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.
Methods- 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).