Marijuana may lead to increased platelet activity in trauma patients.

Introduction: Delta-9-tetraydrocannabinol (THC) usage is associated with venous thromboembolic events (VTE) in trauma patients. We hypothesized that THC ​+ ​trauma patients would have less platelet inhibition than THC - patients using thromboelastography with platelet mapping (TEG-PM).

Methods: Results from initial TEG- PM assays and patient's UDS were reviewed between 2019 and 2023. Mean levels of arachidonic acid (AA) and adenosine diphosphate (ADP) percent inhibition were compared by THC status.

Results: 793 patients had TEG-PM and UDS data. Mean levels of arachidonic acid (AA) percentage inhibition were 32.6 ​± ​34.2. AA inhibition was lower for THC ​+ ​vs THC- patients (THC+ 23.9 ​± ​27.0 vs THC- 34.3 ​± ​35.3, P ​< ​0.001). There was no association between THC status and ADP inhibition (THC+ 32.5 ​± ​27.1 vs THC- 30.8 ​± ​28.4, P ​= ​0.536).

Discussion: To our knowledge, our data are the first to suggest a clinically measurable increase in platelet reactivity in THC ​+ ​trauma patients. More work is needed to determine if addition of aspirin to the chemoprophylaxis strategy for THC ​+ ​patients would mitigate the known association of THC with VTE.