Platelet Transfusions in the PICU: Does Disease Severity Matter?*

OBJECTIVES: Pediatric intensivists frequently prescribe platelet transfusions to critically ill children, but there are limited data on platelet transfusion practice and platelet transfusion-related outcomes in the PICU. In this study, we evaluated the current platelet transfusion practice and platelet transfusion-related outcomes in the PICU. DESIGN: Institutional review board-approved, retrospective cohort study from January 2010 to March 2016. SETTING: Tertiary-level PICU. PATIENTS: Children less than 19 years old who received platelet transfusions in the PICU. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Thirty-six percent (1,547/4,339) of platelet transfusions in the institution were given to 2.4% of PICU patients (232/9,659). The patients who received a platelet transfusion (platelet transfusions, n = 232) compared with those who did not receive platelets (no platelet transfusions, n = 9,427) were younger, had similar gender distribution, had a higher median Pediatric Risk of Mortality-3 score, and stayed longer in the PICU. Fifty percent of platelet transfusions were prescribed prophylactically for thrombocytopenia to patients without extracorporeal membrane oxygenation support. The mortality was higher for platelet transfusions group (30% vs 2.3%) with an 18 times increased unadjusted odds of mortality when compared with no platelet transfusion group (odds ratio, 18.2; 95% CI, 13.3-24.8; p < 0.0001). In a multiple logistic regression analysis, the predicted probability of dying for platelet transfusion group compared with no platelet transfusion group depended on the median Pediatric Risk of Mortality-3 score. Patients who received platelet transfusion versus no platelet transfusion have increased odds of dying at lower median Pediatric Risk of Mortality-3 scores, but decreased odds of dying at higher median Pediatric Risk of Mortality-3 scores. CONCLUSIONS: This PICU cohort demonstrates that the odds or predicted probability of dying change in patients who received platelet transfusions based on underlying disease severity measured by Pediatric Risk of Mortality-3 score compared with patients who did not receive platelet transfusions. A large, prospective trial is required to confirm this association and determine whether to consider underlying disease severity in estimating risks and benefits of prophylactic platelet transfusions in critically ill children.