Transfusion of platelets, but not of red blood cells, is independently associated with nosocomial infections in the critically ill

Background Red blood cell (RBC) transfusion has been associated with nosocomial infection in the critically ill patients. However, this association may be confounded by length of stay, as prolonged intensive care unit (ICU stay) increases both risk of infection and risk of transfusion. Also, it is not known whether specific blood products have differential risks. Methods In this prospective multicentre cohort study, the risk of bacterial infections associated with transfusion products in critically ill (ICU) patients was determined in an integrated statistical model, using Cox proportional hazard analysis to account for attrition bias. In all acutely admitted patients with a length of stay of >48 h between 1 January 2011 and 31 December 2012, the occurrence of nosocomial infections in the ICU was prospectively monitored using CDC criteria. Results Of 3502 screened patients, 476 (13.6 %) developed a nosocomial infection. These patients had higher APACHE IV scores, had longer ICU length of stay and were more frequently transfused compared to patients without an infection. Logistic regression showed that RBC transfusion was a risk factor for infection [odds ratio (OR) 1.98, 95 % confidence interval (CI) 1.54–2.55, p