Early Coagulopathy Predicts Mortality in Trauma

Abstract

BACKGROUND: Coagulopathy and hemorrhage are known contributors to trauma mortality; however, the actual relationship of prothrombin time (PT) and partial thromboplastin time (PTT) to mortality is unknown. Our objective was to measure the predictive value of the initial coagulopathy profile for trauma-related mortality. METHODS: We reviewed prospectively collected data on trauma patients presenting to a Level I trauma center. A logistic regression analysis was performed of PT, PTT, platelet count, and confounders to determine whether coagulopathy is a predictor of all-cause mortality. RESULTS: From a trauma registry cohort of 20103 patients, 14397 had complete disposition data for initial analysis and 7638 had complete data for all variables in the final analysis. The total cohort was 76.2% male, the mean age was 38 years (range, 1-108 years), and the median Injury Severity Score was 9. There were 1276 deaths (all-cause mortality, 8.9%). The prevalence of coagulopathy early in the postinjury period was substantial, with 28% of patients having an abnormal PT (2994 of 10790) and 8% of patients having an abnormal PTT (826 of 10453) on arrival at the trauma bay. In patients with disposition data and a normal PT, 489 of 7796 died, as compared with 579 of 2994 with an abnormal PT (6.3% vs. 19.3%; chi2 = 414.1, p < 0.001). Univariate analysis generated an odds ratio of 3.6 (95% confidence interval [CI], 3.15-4.08; p < 0.0001) for death with abnormal PT and 7.81 (95% CI, 6.65-9.17; p < 0.001) for deaths with an abnormal PTT. The PT and PTT remained independent predictors of mortality in a multiple regression model, whereas platelet count did not. The model also included the independent risk factors age, Injury Severity Score, scene and trauma-bay blood pressure, hematocrit, base deficit, and head injury. The model generated an adjusted odds ratio of 1.35 for PT (95% CI, 1.11-1.68; p < 0.001) and 4.26 for PTT (95% CI, 3.23-5.63; p < 0.001). CONCLUSION: The incidence of coagulation abnormalities, early after trauma, is high and they are independent predictors of mortality even in the presence of other risk factors. An initial abnormal PT increases the adjusted odds of dying by 35% and an initial abnormal PTT increases the adjusted odds of dying by 326%.