New guidelines aim to weed out surgery risks for cannabis users

“Do you drink? Do you smoke cigarettes? Do you use cannabis?”

That last question is becoming more common in medical practices across the country—and the answer could have major implications when it comes to elective surgeries and procedures.

With cannabis now legal for either medicinal or recreational use (or both) in many states, the American Society of Regional Anesthesia (ASRA) and Pain Medicine released recommended guidelines in January to help anesthesiologists gauge how often a patient uses cannabis (and in what form) before they’re sedated for a procedure.

It’s not a totally new concept. Some physicians have asked patients for years about cannabis use, but that can vary widely from state to state and from medical office to medical office.

Even if those conversations tend to happen in primary care settings, said David Dickerson, who chairs the American Society of Anesthesiologists’ Committee on Pain Medicine, surgeons don’t routinely screen patients for marijuana use as part of their standard of care.

That, he told Healthcare Brew, is why “the anesthesiologists have said, ‘Well, let’s at least make sure that on the day of surgery we really understand this component of our patients’ history.’”

The push to include cannabis in pre-surgery screenings comes amid a growing body of research suggesting that marijuana use can affect patient outcomes, including the amount of pain they may feel following an operation or how they may respond to different types of anesthesia.

The first of its kind in the US, the guidelines recommend that all patients should be “questioned about cannabinoid use, dose and frequency, route of administration, and time of last use.” The guidance also suggests postponing elective surgeries due to a patient’s “altered mental status…due to acute cannabis intoxication”; counseling frequent, heavy cannabis users on possible postoperative pain; and educating pregnant people on marijuana use, among other things.

“We’ve known that alcohol use increases anesthetic requirement…and we also know that tobacco use changes pulmonary function—even acutely in terms of people’s post-operative experience,” said Dickerson. “So adding in a question about cannabis, which many of us did within the last several years prior to these guidelines, has been an important part of understanding what sort of substances patients are using regularly.”

He added, “Then we can educate and, honestly, tailor our treatment with that awareness we get from talking to our patients.”

There are concerns, however, about adults who exhibit symptoms of marijuana intoxication and are unable to give consent; heavy cannabis users, who can require larger doses of anesthesia or experience more pain after surgery; and those who just smoked a joint and may have an elevated heart rate—even though most patients who use cannabis “will have [a] smooth surgery,” said Samer Narouze, ASRA Pain Medicine president and senior author of the guidelines.

The new guidelines aim to not just help improve outcomes for patients, but also educate physicians on potential cannabis-related drug interactions, surgical risks, and post-operative treatment options—things that weren’t traditionally taught in medical schools, he said.

“It’s a call for increasing awareness about potential issues during surgery, and how to be prepared for it,” Narouze said in an interview. “And, more importantly, how to educate the patient ahead of surgery.”

The recommendations could also help hospitals and outpatient surgical facilities better prepare for patients who use cannabis, such as ordering anesthesia and other medications, or post-operative discharge planning.

“If we plan ahead, we know this [is what] to expect, then we’ll have a multimodal approach—or the patient will be aware that [they] will have more pain than usual. Maybe the discharge criteria will be different for this patient,” he said. “Everyone’s striving to contain costs, so limiting extended stay in the recovery room, it’s one of the quality controls in every hospital, every ambulatory surgical center.”