title: Transfusion of platelets, but not of red blood cells, is independently associated with nosocomial infections in the critically ill.
abstract: 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 < 0.001], as well the number of RBC units transfused (OR 1.04, 95 % CI 1.03-1.06, p < 0.001). However, these associations disappeared in the Cox proportional hazard analysis. In contrast, we found an association between plasma transfusion and infection [hazard ratio (HR) 1.36, 95 % CI 1.10-1.69, p = 0.004] and between platelet transfusion and infection (HR 1.46, 95 % CI 1.18-1.81, p < 0.001). However, only platelet transfusion was associated with infection independently from other transfusion products (HR 1.40, 95 % CI 1.03-1.90, p = 0.03).
  
  
  CONCLUSIONS
  In critically ill patients, transfusion of platelets, but not of RBCs and plasma, is an independent risk factor for acquiring a nosocomial infection.
authors.affiliation: Department of Intensive Care Medicine, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
authors.forename: Leo J
authors.initials: LJ
authors.lastname: Engele
authors.affiliation: Department of Intensive Care Medicine, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
authors.forename: Marleen
authors.initials: M
authors.lastname: Straat
authors.affiliation: Transfusion Laboratory, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Ingeborg H M
authors.initials: IHM
authors.lastname: van Rooijen
authors.affiliation: Department of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Karen M K
authors.initials: KMK
authors.lastname: de Vooght
authors.affiliation: Department of Intensive Care Medicine, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Olaf L
authors.initials: OL
authors.lastname: Cremer
authors.affiliation: Department of Intensive Care Medicine, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.|Laboratory of Experimental Intensive Care and Anesthesiology (LEICA), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Marcus J
authors.initials: MJ
authors.lastname: Schultz
authors.affiliation: Department of Intensive Care Medicine, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
authors.forename: Lieuwe D J
authors.initials: LDJ
authors.lastname: Bos
authors.affiliation: Department of Intensive Care Medicine, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands. n.p.juffermans@amc.uva.nl.|Laboratory of Experimental Intensive Care and Anesthesiology (LEICA), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands. n.p.juffermans@amc.uva.nl.
authors.forename: Nicole P
authors.initials: NP
authors.lastname: Juffermans
keywords: Critically ill; Fresh-frozen plasma; Nosocomial infection; Platelets; Red blood cells; Transfusion