Association between blood transfusion and infection in injured patients.

The association between red blood cell transfusions and infectious complications in 484 patients with acute injuries was studied in 1989. The median age was 62 years (0.5-97) and the median stay 7 days (3-141). Infectious complications developed in 46 (9.5%) patients. A number of potential risk factors, except blood transfusion, were analyzed in a logistic regression model to determine significant predictors of infectious complications. Blood transfusion as a cofactor was then added to this model. The final logistic regression analysis showed a relationship between blood transfusions and infectious morbidity that was independent of the other significant factors; Injury Severity Score, age, and surgical procedure. The corrected odds ratios for infection were 1.6 (95% confidence interval: 0.7-3.7) when 1-4 units of blood were given and 6.4 (95% CI: 2.3-18.3) when more than 4 units were used.