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Study breakdown

Expert panel created consensus guidelines for managing cannabis users before and after surgery

ReviewModerate evidence
The takeaway

A panel of 17 experts used a Delphi process to develop recommendations for perioperative cannabis management, including screening, potential weaning, extra nausea prevention, and anticipating higher pain medication needs.

Anesthesiologists, surgeons, perioperative nurses, and cannabis-using patients facing surgery.

First formal consensus guidelines for perioperative cannabis management

What the researchers found

Major consensus recommendations included: elicit and quantify cannabis use history, contact the cannabis authorizer if one exists, consider perioperative cannabis weaning, provide additional postoperative nausea/vomiting prophylaxis, pay extra attention to anesthetic depth monitoring, anticipate increased postoperative analgesic requirements, and watch for cannabis withdrawal syndrome.

Why it matters

As cannabis use increases, more surgical patients use cannabis regularly. Without guidelines, clinicians may not know that cannabis users may need different anesthetic management, more pain medication, and monitoring for withdrawal. These are the first formal consensus recommendations.

The numbers in context

17 expert panelists. 4 independent reviewers. Key recommendations: screen for cannabis use, consider weaning, extra PONV prophylaxis, monitor anesthetic depth, anticipate higher analgesic needs, watch for withdrawal.

How the study worked

Modified Delphi method with 17 expert panelists. Literature review followed by blinded rater forms, analysis for consensus, unblinded discussion, draft recommendations, and review by 4 independent reviewers (surgeon, nurse practitioner, 2 patients).

What this study cannot tell us

Consensus-based, not evidence-based. Limited randomized trial data available. Expert opinion subject to bias. Recommendations may not apply to all cannabis products or use patterns.

How to read the evidence

Rigorous Delphi methodology but based on limited underlying evidence. Strong consensus process compensates somewhat for weak evidence base.

When this study was published

2021 consensus recommendations via modified Delphi process.

The bigger picture

Cannabis interacts with anesthetic agents, pain pathways, and recovery in ways most surgeons and anesthesiologists were not trained to manage. As use normalizes, perioperative cannabis protocols could become as routine as preoperative tobacco cessation counseling.

Questions still open

  • How far in advance of surgery should cannabis weaning begin? What is the magnitude of increased analgesic need? Can perioperative cannabis guidelines reduce complications?

Common questions

Should I stop using cannabis before surgery?
The expert panel recommends considering cannabis weaning before surgery. Cannabis users may need more anesthesia, more pain medication afterward, and may experience withdrawal symptoms if they stop abruptly.
Does cannabis affect anesthesia?
Yes. The guidelines recommend extra attention to monitoring anesthetic depth in cannabis users, additional nausea/vomiting prevention, and anticipating higher postoperative pain medication needs.

Read the original research

Perioperative Pain and Addiction Interdisciplinary Network (PAIN): consensus recommendations for perioperative management of cannabis and cannabinoid-based medicine users by a modified Delphi process.

British journal of anaesthesia, 126(1), 304-318

Citation

Ladha, Karim S; McLaren-Blades, Alexander; Goel, Akash; Buys, Michael J; Farquhar-Smith, Paul; Haroutounian, Simon; Kotteeswaran, Yuvaraj; Kwofie, Kwesi; Le Foll, Bernard; Lightfoot, Nicholas J; Loiselle, Joel; Mace, Hamish; Nicholls, Judith; Regev, Aviva; Rosseland, Leiv Arne; Shanthanna, Harsha; Sinha, Avinash; Sutherland, Ainsley; Tanguay, Rob; Yafai, Sherry; Glenny, Martha; Choi, Paul; Ladak, Salima S J; Leroux, Timothy Sean; Kawpeng, Ian; Samman, Bana; Singh, Rajbir; Clarke, Hance. (2021). Perioperative Pain and Addiction Interdisciplinary Network (PAIN): consensus recommendations for perioperative management of cannabis and cannabinoid-based medicine users by a modified Delphi process.. British journal of anaesthesia, 126(1), 304-318. https://doi.org/10.1016/j.bja.2020.09.026

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