“As cannabinoid compounds have been shown to be effective treatments for chemotherapy induced nausea and vomiting (CINV), it seems reasonable to conjecture that cannabis use could exert a prophylactic or therapeutic effect for patients at risk for or suffering from postoperative nausea and vomiting (PONV). While several studies have examined the role of therapeutically administered cannabinoids in the prevention and treatment of PONV, almost nothing is known about the impact of chronic use of cannabis on the risk for developing PONV. The present investigation examines whether an association exists between patient-described use and/or frequency of cannabis and the occurrence of PONV following general anesthesia.”

“Patients who chronically use cannabis may be at increased risk of postoperative nausea and vomiting following general anesthesia. Further studies seeking to confirm and extend our findings could examine as to the symptoms being managed by cannabis use (if patients
are using it medicinally). Furthermore, future studies would benefit from a finer grained understanding of patient’s frequency, chronicity, route, and quantity of cannabis use, as well as whether the patient has experienced symptoms during abstention from cannabis use in the past. Finally, we believe it would be inappropriate on the basis of our study alone to recommend any modification in the approach to PONV prophylaxis for the chronic
cannabis user, and encourage providers to wait for further data to integrate our findings into their clinical practice.”

Suhre, Wendy et al. “Cannabis use is associated with a small increase in the risk of postoperative nausea and vomiting: a retrospective machine-learning causal analysis.” BMC anesthesiology vol. 20,1 115. 18 May. 2020, Free Full Text