Surgery (perioperative period)

Surgery is any procedure in which a surgeon cuts into the body to repair, remove or examine tissue, and the perioperative period spans preparation, the operation itself and recovery.

Before an operation, the anesthesia team reviews every medication, supplement and substance a patient uses because many affect bleeding, blood pressure, sedation depth or how quickly anesthetic drugs are metabolized. Cannabis and cannabinoid use is now a standard pre-anesthesia question: regular cannabis users may need different amounts of anesthetic and can have more nausea and pain after surgery, and cannabidiol inhibits liver enzymes that process several anesthetic, sedative and pain medications. Professional anesthesia guidelines recommend disclosing all cannabinoid use so the surgical team can give instructions about stopping beforehand.

After surgery, postoperative pain, wound healing, infection risk and blood clots are the main concerns, and pain is managed with a combination of local anesthetics, non-opioid medications and, when necessary, opioids. Cannabinoids have been studied for postoperative pain in small trials with mixed results, and no cannabinoid has an approved perioperative use. Veterinary surgeons ask the same disclosure questions about pets.