Allogeneic blood transfusion and postoperative duration of mechanical ventilation: effects of red cell supernatant, platelet supernatant, plasma components and total transfused fluid

BACKGROUND AND OBJECTIVES: In patients undergoing open-heart surgery, allogeneic blood transfusion (ABT) may be related to an enhanced inflammatory response and impaired pulmonary function, resulting in a need for prolonged mechanical ventilation. Transfused red blood cell (RBC) supernatant, platelet supernatant or plasma components, may exercise varying effects on pulmonary function, because these fluids differ in their content of soluble biological-response modifiers. MATERIALS AND METHODS: The records of 416 patients undergoing coronary artery bypass graft operations at the Massachusetts General Hospital were reviewed. Possible predictors and the number of days of postoperative ventilation, as well as the number of all transfused blood components, were recorded. The association between mechanical ventilation past the day of operation and the volume of transfused RBC supernatant, platelet supernatant, or plasma components, was calculated by logistic regression analyses. RESULTS: The volume of each transfused fluid differed (P < 0.0001) among patients ventilated for 0, 1, 2, 3, or > or = 4 days after the day of the operation. After adjusting for the effects of confounding factors, the volume of administered RBC supernatant was associated (P = 0.0312) with the likelihood of postoperative ventilation past the day of operation, but the volume of platelet supernatant, plasma components, or total transfused fluid was not (P = 0.1528, P = 0.1847, and P = 0.0504, respectively). CONCLUSIONS: These results are congruent with the hypotheses that ABT may impair postoperative pulmonary function and that any such adverse effect of ABT is probably mediated by the supernatant fluid of stored RBCs. Both hypotheses should be examined further, in future studies of the outcomes of ABT.