Predictors of Mortality Due to Severe Traumatic Brain Injury: a Prospective Observational Cohort Study With 1-year Analyses

Abstract

Background Many predictors are associated with higher risks of hospital mortality due to severe Traumatic Brain Injury (TBI). The identification of these predictive factors is important for reducing morbimortality. Thus, the aim of this study was to identify predictors of mortality due to severe TBI in a trauma referral hospital in Brazil. Methods A prospective observational cohort study was carried out at a trauma referral hospital. All individuals > 18 years old with severe TBI diagnosis were included. Binomial logistic regression analysis was performed for each variable individually to identify possible predictors of in-hospital mortality and death 12 after hospital discharge. Variables considered statistically significant were analyzed in a final binomial logistic regression model and the magnitude of the association was measured by the odds ratio (OR). Results After applying the enrollment criteria, 383 patients were included. Of these, 211 (55%) died, 172 (45%) survived hospitalization and 22 (15%) died within the first year. The mean age was 49 ± 19 years, 309 (81%) individuals were male, and fall (46.5%) was the main cause of injury. Most individuals had Injury Severity Score ≥ 25 (85.2%). On the final binomial logistic regression model, age greater than 65 years (OR = 6.60 95%CI 2.515–17.354) and pupillary changes such as anisocoria (OR = 2.440 95%CI 1.098–5.465) and mydriasis (6.906 95%CI 2.758- 17,293) were independent variables associated with a higher risk of hospital mortality. High respiratory rate (OR = 1.127 95%CI 1.025–1.240) and body temperature (OR = 0.758 0.606–0.949) collected on admission to the emergency room were also predictors of mortality. A higher risk of mortality was associated with values > 25 on the Injury Severity Score (OR = 3.69395%CI 1.556–8.766) and the performance of decompressive craniectomy (OR = 2.644 95%CI 1.343–5.204). Conclusions This study demonstrated higher mortality rate of patients with TBI when compared to other trauma centers in both high-income countries (HICs) and low- and middle-income countries (LMICs). Early clinical factors such as pupillary changes, high values in the ISS, the performance of decompressive craniectomy, increased respiratory rate and low body temperature were associated with a higher risk of hospital mortality. The study highlights the importance of accounting for regional disparities when developing and implementing TBI management strategies worldwide.