Relationship of Time of Injury Marijuana Exposure and Traumatic Brain Injury: A Systematic Review

Background: Traumatic brain injury (TBI) is a significant nursing concern, as it is a leading cause of mortality, morbidity, and disability in the United States. Notably, up to 51% of all TBI patients have substance use exposure at the time of injury. Marijuana remains the most widely used illicit drug in the United States. However, little is known about marijuana exposure and TBI incidence and severity, particularly at the time of injury. Methods: A systematic literature review was conducted following PRISMA guidelines in PubMed to determine the relationship between marijuana exposure and TBI severity. Heterogeneity of study designs, concepts, samples, and variables in included studies precluded a meta-analysis. Hence, a descriptive analysis of findings was conducted. Results: The search yielded 939 studies, of which eight met inclusion criteria. Only one study found a connection between positive marijuana toxicology screen and mortality outcomes in TBI patients. There was significant variation in how marijuana exposure was defined, conceptualized, and operationalized in the other studies. Conclusions: This review identified the need for larger, better-designed studies to address the significant knowledge gap about the relationship between marijuana use and its influence on TBI. Data and knowledge derived from such studies can help inform policy and aid in the development of nursing interventions that target prevention and increase awareness of TBI risk when under the influence of marijuana.