Impact of Cannabis Use on Intraoperative Anesthetic and Analgesic Requirements: A Systematic Review

Dhruvi Patel, OMS-II
Nova Southeastern University

Co-authors: Dhruvi Patel¹, Kevin Tran¹, Amani Ally¹, Sajan Parikh¹, Khavir Sharieff^1
1Nova Southeastern University

Background: The association between cannabis use and intraoperative anesthetic and analgesic requirements among adult surgical patients remains uncertain. Heterogeneity in exposure definitions, surgical populations, anesthetic techniques, and outcomes limits evidence-based perioperative dosing recommendations.

Objective: To systematically review whether adult surgical patients with documented cannabis use require higher intraoperative anesthetic or analgesic dosing compared with non-users during surgical procedures requiring general anesthesia.

Methods: A systematic review of studies published January 2016–July 2026 was conducted using PubMed, Embase, and Web of Science. Eligible studies included prospective/retrospective cohorts of adults (>18 years) undergoing surgery requiring general anesthesia with documented cannabis exposure. Excluded were pediatric populations, animal/in vitro models, emergent cases, conditions associated with altered anesthetic requirements, case reports/series (<10 patients), conference abstracts, and reviews. Risk of bias was assessed using the Joanna Briggs Institute Critical Appraisal Checklist for Cohort Studies. Due to heterogeneity across exposures, populations, and outcomes, findings were synthesized narratively.

Results: Seven observational studies comprising 26,700 surgical patients were included, representing orthopedic, bariatric, oral/maxillofacial, and general surgery populations. Cannabis exposure
definitions varied, with limited reporting of dose, frequency, route, or use type. Cannabis exposure was variably associated with intraoperative anesthetic and analgesic requirements. The strongest evidence involved volatile anesthetics, with two studies reporting significantly increased requirements. Findings included higher time-weighted minimum alveolar concentration (MAC) values among cannabis users (0.58 vs 0.54; MD, 0.04; 95% CI, 0.01–0.06; p = 0.021) and increased sevoflurane volumes (37.4 mL vs 25.0 mL; p = 0.023). One large prospective cohort reported greater intraoperative fentanyl administration among cannabis-positive patients versus non-users (174.5 mcg vs 124.7 mcg; MD, 49.80 mcg; 95% CI, 47.28–52.32; p < 0.001). Propofol findings were inconsistent. Three studies reported no significant dosing differences between cannabis-exposed patients and non-users, while one oral/maxillofacial cohort demonstrated significantly higher propofol administration among cannabis users (152.5 mg vs 117.5 mg; p < 0.05). No consistent differences emerged for midazolam, ketamine, desflurane, neuromuscular blockers, or reversal agents.

Conclusions: Evidence is insufficient to support definitive cannabis-specific intraoperative dosing recommendations. Cannabis use may be associated with increased intraoperative volatile anesthetic and opioid requirements in some adult surgical populations. Findings regarding propofol and adjunct anesthetics remain inconsistent. Heterogeneity across studies limits definitive conclusions. Future research should standardize exposure assessment, differentiate recreational from medicinal use, and evaluate dose-response relationships to better guide anesthetic management.