Tags: anaesthesiology; cannabinoids; cannabis; pain; perioperative care; postoperative nausea and vomiting

 

 

Thumbnail: This report offers recommendations for the perioperative care of patients who use cannabis, as cannabis may have an impact on surgical outcomes. The recommendations are the result of a medical literature review combined with input from a panel of experts. The recommendations include major points such as emphasizing the importance of knowing the history of a patient’s cannabis use, quantifying it, and ensuring that patients are in contact with an authorized cannabis prescriber, as well as several minor recommendations.                                               

 

The problem: The number of regular cannabis users has significantly increased in recent years, and recent data suggests that cannabis use can impact perioperative outcomes. Cannabis has been implicated in effects on a number of organ systems, including gastrointestinal, respiratory, cardiovascular, hematological and central nervous systems. However, there has been no comprehensive evaluation of how to best manage surgical patients who are using cannabis.

 

The study: The authors reviewed medical literature about the perioperative care of patients who use cannabis and surveyed a panel of 17 experts to independently identify and evaluate relevant perioperative care measures. The elements identified in this assessment were then discussed among the experts and sent to 4 independent reviewers (a surgeon, a nurse practitioner, and two patients). The feedback from the experts and the reviewers were used to finalize the recommendations.

 

Main Points:

• The recommendations are intended for professionals involved in the perioperative care of surgical patients; such as anesthesiologists, surgeons, pharmacists, nurse practitioners and nurses.

• Major recommendations: emphasizing the importance of knowing the history of a patient’s cannabis use, quantifying their use, and ensuring that they are in contact with an approved cannabis prescriber.

  • During preoperative assessments, patients should be routinely screened for cannabis consumption.

  • Cannabis prescribers should be included in discharge planning, especially among patients on higher doses of cannabis or those who’s cannabis dose has been stopped, changed or substituted. This will ensure that patients are following up with informed healthcare providers.

• Minor recommendations: considerations for weaning a patient off of cannabis prior to surgery, additional or alternative prophylaxis for postoperative nausea and vomiting, and additional attention to monitoring and maintaining anesthetic depth.

  • Weaning patients from cannabis use should be considered if there is more than 7 days until surgery. Weaning should not be considered 24hrs or less before surgery

  • Cannabis is acknowledged as useful in managing nausea and vomiting in some situations.However, some patients can develop severe cyclic nausea and vomiting due to cannabinoid hyperemesis syndrome or can develop nausea associated with cannabis withdrawal syndrome and traditional anti-emetics are generally not very effective in these patients.

  • Research suggests that patients using cannabis may need more anesthetic to reach an adequate depth of anesthesia.

• Discussion of perioperative cannabis management would be recommended if patients report a history of significant cannabis consumption, of greater than 1.5 g/day of inhaled cannabis, 300 mg/day of CBD oil, 20 mg/day of THC oil or use of an unknown/unquantified cannabis product more than 2-3 times/day.

• The authors note that there were not a large number of studies available from which to draw data on this topic, so more research is needed to expand on all of these recommendations

 

Conclusions: These authors report that it is necessary to consider a patients cannabis use when managing perioperative patient care. It is most important to establish a patient’s history of cannabis use (frequency and quantity), and to ensure that discharged patients are in contact with an authorized cannabis prescriber. Secondary to these are recommendations to consider weaning patients from cannabis, additional or alternative prophylaxis for nausea and vomiting and particular attention to monitoring and maintaining anesthesia during surgery.

 

Why this is a good study:

• This study consulted a number of international experts, resulting in well-informed recommendations

• This report considered the effects of cannabis on multiple aspects of perioperative care, providing well-rounded recommendations

 

Why this isn’t a perfect study:

• This study offers only general suggestions about what level of cannabis use may be relevant for perioperative management (due, in part, to the inconsistencies between available cannabis products)

 

What this study adds:

• This study outlines formal recommendations for the perioperative management of patients who use cannabis, where there were none before

 

What it doesn’t:

• These recommendations are influenced by the limited number of relevant studies available from which to draw data. Without more studies in this area, the authors are unable to offer more precise recommendations.

• This report offers an informed summary of the currently available data relating to cannabis and perioperative outcomes, but it does not add new data to the field.

 

Funder: None stated

 

Author conflicts: None declared