Preinjury Use of Marijuana and Outcomes in Trauma Patients

Recent studies have examined the effects of marijuana in various populations; however, there has been limited research on the effect of marijuana use in severely injured trauma patients. We hypothesized that preinjury use of marijuana would be associated with improved outcomes in severely injured trauma patients.

All adult (18+ y) level I and level II trauma activations who presented to two large regional trauma centers between 2014 and 2018 were reviewed. Delta-9-tetrahydrocannabinol (THC)- indicated absence of drugs confirmed by testing and as THC + confirmed THC without another drug present.

Of the 4849 patients included, 1373 (28.3%) were THC+. The THC + cohort was younger, had more males, and was more likely to be injured by penetrating mechanism (P < 0.001 for all) than THC-. THC + patients had shorter median length of stay (LOS) (P < 0.001) and intensive care unit LOS (P < 0.001). Mortality rate was lower in the THC + group (4.3% versus 7.6%, P < 0.001), but not in multivariate analysis. THC + patients with traumatic brain injury had shorter hospital LOS (P = 0.025) and shorter ventilator days (P = 0.033) than THC- patients. In patients with Injury Severity Score ≥16, THC + patients had significantly lower intensive care unit LOS (P = 0.009) and mortality (19.3% versus 25.0% P = 0.038) than drug-negative patients.

Although preinjury use of marijuana does not improve survival in trauma patients, it may provide some improvement in outcomes in patients with traumatic brain injury and those that are more severely injured (Injury Severity Score ≥16). The mechanism behind this finding needs further evaluation.