Lead image via

Doctors in legal weed states are pushing surgery patients to be honest about their cannabis use and to avoid consumption in the hours before going under the knife, or risk potential complications including heart attack or death.

Over the past year, a series of studies into pharmaceutical anesthetics and cannabis has found an inverse relationship between the effectiveness of pre-surgery sedation drugs and marijuana use. But in addition to decreased sensitivity to anesthetics, doctors are now warning patients to specifically avoid cannabis in the same ways that they would water and food in the hours before surgery. Since marijuana can raise our heart rate and lower our blood pressure, the combination of cannabis intoxication and surgical anesthetics can cause severe cardiac and respiratory complications.

“Most of the conditions, in the worst case scenario, may lead to death,” Dr. David Hepner, an anesthesiologist at Massachusetts’ Brigham and Women’s Hospital, told the Boston Globe. “I’m not saying that it’s very common, but the potential is there.”

Since California first legalized cannabis for medical use in the ‘90s, doctors have maintained a robust skepticism for cannabis. And since federal restrictions have stood in the way of in-depth clinical research, and piecemeal legalization has hindered product uniformity, physicians in both cannabis-friendly and prohibition states have largely dismissed or ignored weed altogether. When it comes to surgery, though, more anesthesiologists are beginning to dig deeper on patient pot use.

“We’re not going to have any judgment — there’s no stigma,” Dr. Hepner said. “It’s just important for us to know, because the cannabis could interact with the anesthetic, and we need to know how to adjust.”

On the other end of the communication divide, Hepner said that since legalization, patients have been more forthright with disclosing their cannabis use — a trend that he hopes will continue as general social stigmas dim even further. And while previous studies have shown that frequent cannabis use can necessitate increased doses of anesthesia in surgery patients, Hepner noted that the more serious heart and lung complications are only a threat for patients who consume marijuana in the hours immediately preceding a procedure.

Follow Zach Harris on Twitter