ASRA Recommends Screening for Cannabis Use Before Surgery

Frequent cannabis users may have poor response to pain control after surgery and may require more rescue medications such as opioids.

All patients undergoing surgical procedures requiring anesthesia should be screened for cannabis use, according to guidelines released by the American Society of Regional Anesthesia and Pain Medicine (ASRA Pain Medicine). Regular cannabis use may worsen pain and nausea after surgery and increase the need for opioids, according to ASRA Pain Medicine.

The guidelines were developed in response to the increased use of cannabis during the past 20 years and concerns that potential interactions between cannabis products and anesthesia. Recreational cannabis use has been legalized in 21 states, Washington DC, and Guam. Marijuana was used by 52.5 million people in the US in 2021, according to the Substance Abuse and Mental Health Services Administration (SAMHSA). The guidelines cover preoperative, intraoperative, and immediate postoperative care considerations.

Clinicians should ask patients if they use cannabis medicinally or recreationally before surgical procedures “and be prepared to possibly change the anesthesia plan or delay the procedure in certain situations,” said Samer Narouze, MD, PhD, senior author and ASRA Pain Medicine president. “They also need to counsel patients about the possible risks and effects of cannabis. For example, even though some people use cannabis therapeutically to help relieve pain, studies have shown regular users may have more pain and nausea after surgery, not less, and may need more medications, including opioids, to manage the discomfort. We hope the guidelines will serve as a roadmap to help better care for patients who use cannabis and need surgery.”

Recommendations with Grade A support include the following:

  • Universal screening for cannabinoid use should be performed before surgery and should include the type of cannabis or cannabinoid product, time of last consumption, route of administration, amount, and frequency of use
  • Counseling frequent, heavy users on the potentially negative effects of cannabis use on postoperative pain control
  • Postponing elective surgery in patients who have altered mental status or impaired decision-making capacity at the time of surgery
  • Counseling pregnant patients on the risks of cannabis use to the unborn child

Other recommendations include the following:

  • Delay elective surgery for a minimum of 2 hours after smoking cannabis because of increased perioperative risk of acute myocardial infarction (Grade C)
  • Consider adjusting anesthesia delivery for surgery based on the patient’s symptoms and timing of the last cannabis consumption (Grade C)
  • Do not automatically adjust ventilation settings during surgery in patients taking only oral cannabis since currently available evidence does not indicate adjustments are needed (Grade C)
  • Consider adjustment of ventilation settings during surgery in chronic cannabis smokers, particularly in those with other conditions that are associated with an increased risk of lung disease (Grade C)
  • Increase vigilance of cardiac and neurologic adverse events, which frequently occur after surgery, but the routine use of additional monitoring after surgery for cardiac or neurologic problems is not recommended (Grade C)
  • Use multiple methods of anesthesia and pain control including regional analgesia if appropriate and use opioids as rescue medication (Grade C)
  • Prescribe opioids when needed for management of perioperative pain in patients who use cannabis but with increased vigilance (Grade C)
  • Counsel patients about the risk of cannabis withdrawal symptoms and monitor after surgery for symptoms (Grade C)
  • Use a cannabinoid agonist such as dronabinol at a low dose to treat severe cannabis withdrawal symptoms postoperatively (Grade C)
  • Universal toxicology screening for cannabinoids is not currently indicated based on insufficient available evidence (Grade D)

The guidelines are based on an extensive literature review and experiences from the organization’s Perioperative Use of Cannabis and Cannabinoids Guidelines Committee, which included 13 experts including anesthesiologists, chronic pain physicians, and a patient advocate. The committee addressed 9 questions using a modified Delphi consensus method with ≥75% agreement required for recommendations to be approved. All 21 recommendations achieved full consensus.

This article originally appeared on Clinical Advisor


All patients should be screened for cannabis use before surgery, first US guidelines recommend. News release. American Society of Regional Anesthesia and Pain Medicine; January 3, 2023. Accessed January 4, 2022.

Shah S, Schwenk ES, Sondekoppam RV, et al. ASRA pain medicine consensus guidelines on the management of the perioperative patient on cannabis and cannabinoids. Reg Anesth Pain Med. 2023 Jan 3:rapm-2022-104013. doi:10.1136/rapm-2022-104013.