METHODS: This is a retrospective cohort study of adults admitted to surgical, medical, or combined medical-surgical intensive care units (ICUs) at a single academic institution between January 1, 2009, and December 31, 2013. Inclusion criteria included age ≥18 years and a platelet count measured during ICU admission. Propensity-matched analyses were used to evaluate associations between prophylactic platelet transfusions and the outcomes of interest with a primary outcome of red blood cell transfusion in the ensuing 24 hours and secondary outcomes of ICU and hospital-free days and changes in sequential organ failure assessment scores.
RESULTS: A total of 40,693 patients were included in the investigation with 3227 (7.9%) receiving a platelet transfusion and 1065 (33.0%) for which platelet transfusion was prophylactic in nature. In propensity-matched analyses, 994 patients with prophylactic platelet transfusion were matched to those without a transfusion. Patients receiving prophylactic platelets had significantly higher red blood cell transfusion rates (odds ratio 7.5 [5.9–9.5]; P< .001), fewer ICU-free days (mean [standard deviation] 20.8 [9.1] vs 22.7 [8.3] days; P = .004), fewer hospital-free days (13.0 [9.7] vs 15.8 [9.4] days; P < .001), and less improvement in sequential organ failure assessment scores (mean decrease of 0.2 [3.6] vs 1.8 [3.3]; P < .001) in the subsequent 24 hours. These findings appeared robust, persisting in multiple predefined sensitivity analyses.
CONCLUSIONS: Prophylactic administration of platelets in the critically ill was not associated with improved clinical outcomes, though residual confounding may exist. Further investigation of platelet transfusion strategies in this population is warranted.