Inhaled cannabis linked to higher anesthesia needs during endoscopy
A study of 264 patients undergoing upper endoscopy or colonoscopy found that those who smoked or vaped cannabis required a higher initial dose of propofol than nonusers. Patients who used edibles did not show the same increased need, and their average initial dose was lower than that of nonusers. The authors advise patients to tell their anesthesiologist how, how often, and when they last used cannabis.
The study reviewed 280 gastrointestinal endoscopies at one center, then analyzed 264 cases with complete cannabis-use information. That group included 217 nonusers, 38 people who inhaled cannabis, and nine who took oral products. Average starting propofol doses were 138.7 mg for nonusers, 168.5 mg for inhaled users, and 114.2 mg for oral users.
For upper endoscopy, inhaled users averaged 192.8 mg versus 151.4 mg for nonusers and 145.0 mg for oral users; colonoscopy results were similar across groups. Inhaled THC reaches the lungs quickly, while edible THC passes through the liver, yielding different metabolites and timing. Upper-airway irritation from inhaled cannabis may also play a role.
This finding may affect patients who use inhaled cannabis before procedures, anesthesiologists planning sedation, and endoscopy centers. Clearer disclosure could help clinicians adjust initial propofol doses, potentially improving comfort and safety, while avoiding unnecessary changes for edible users. Because the edible group was small and data come from one center, broader practice changes may be limited until larger studies confirm the pattern. Patients may be encouraged to discuss route, frequency, and timing of cannabis use.