Background: A relationship may exist between the immunomodulatory effects of allogeneic blood transfusion and the volume of transfused allogeneic plasma and/or the number of transfused plasma-containing units.
Study design and methods: The records of 416 consecutive patients undergoing coronary artery bypass graft operations at the Massachusetts General Hospital were reviewed. Exposure to allogeneic plasma in units of transfused RBCs, platelets, FFP, and cryoprecipitate was recorded, and diagnoses of postoperative pneumonia and wound infection were made by CDC criteria. The association between postoperative infection and exposure to allogeneic plasma was calculated by logistic regression analyses adjusting for the effects of confounding factors that related to severity of illness, difficulty of operation, and risk of postoperative pneumonia.
Results: Two hundred seventy-four patients received (mean +/- SE) 636.2 +/- 64.3 mL of allogeneic plasma, contained in 8.5 +/- 0.7 units of blood components. Sixty-four patients (15.4%) developed pneumonia and/or wound infection, and 54 (13.0%) developed pneumonia. Patients who did (n = 64) or did not develop infection received 956.6 +/- 180.6 and 321.3 +/- 39.6 mL of plasma, respectively (p<0.0001). In multivariate analyses, the volume of transfused allogeneic plasma was not associated with postoperative pneumonia and/or wound infection (p = 0.24), pneumonia (p = 0.21), or wound infection (p = 0.74). Similarly, the number of transfused plasma-containing units was not associated with these outcomes (p = 0.08, p = 0.08, and p = 0.46, respectively).
Conclusion: A relationship between the exposure to allogeneic plasma and the risk of postoperative pneumonia and/or wound infection was not detected in this study population.