Abstract
Traumatic brain injury (TBI) causes significant mortality. Dexmedetomidine (DEX) shows neuroprotective potential in animals, but clinical evidence remains inconsistent. We evaluated the impact of early DEX, initiated within 48 h of admission with a treatment duration of at least 4 h, on survival in intensive care unit (ICU) patients with TBI using the Medical Information Mart for Intensive Care-IV (MIMIC-IV) database. Outcomes included 28-day, hospital, and 1-year mortality, analyzed via propensity score matching (PSM), multivariable Cox models, and subgroup analyses. Of 2378 patients, 241 received DEX. After PSM (235 pairs), early DEX use significantly reduced 28-day (HR 0.45, 95% CI 0.30-0.69, p < 0.001) and hospital mortality (HR 0.25, 95% CI 0.15-0.42, p < 0.001). These results remained robust across sensitivity analyses. Similarly, 1-year mortality decreased (HR 0.64, 95% CI 0.47-0.87, p < 0.01) and further supported by the Boruta algorithm, although inverse probability of treatment weighting analysis showed only a non-significant trend (p = 0.08). Survival benefits were more pronounced in patients aged <65 and those requiring mechanical ventilation. In conclusion, early DEX use is associated with improved short- and long-term survival in ICU patients with TBI, particularly in younger individuals and those requiring mechanical ventilation. Randomized controlled trials are warranted to establish causality.