A state task force has reported that marijuana use and abuse in Colorado has risen steadily in recent years in the 55-64 age group, with an even more dramatic increase in the age 65+ group. One of the most common self-reported reasons for use in these age groups is pain control. UCHealth, a medical facilities network with locations around the state, has offered a caution to marijuana users to be open and honest about their use in the context of surgery. UCH underscores the caution with the hard-to-ignore statement that “Marijuana users may require 10 times more anesthesia than a non-user to stay ‘asleep’ during surgery.”

Erin Emery, writing for the medical news hub UCHealth Today, confirms that anesthesiologists can find it more challenging to properly sedate patients who use marijuana—whether that be smoking, vaping, eating edibles or using tincture. The simple fact is marijuana can affect how anesthesia works. This is particularly true for chronic users, defined as those who use marijuana at least once a week.

Colorado anesthesiologist explains risks about Marijuana Use if you need surgery

“It’s extremely important that patients are honest with us,’’ says Dr. Jennifer Kollman, an anesthesiologist and senior medical director for anesthesia at UCHealth in southern Colorado. “We can figure it out once you are asleep, but it is best if we don’t have to. There are some increased risks with recent marijuana use and continuous long-term marijuana use.’’ Among those risks, she cited that it may take longer for recent or chronic users of marijuana to empty the contents of their stomach, which risks having contents sucked into your lungs before an anesthesiologist can insert a breathing tube. She added that if you have pre-existing heart disease, there is a risk of heart attack if you use marijuana within 60 minutes of receiving anesthesia.

As noted above, it can take 10 times more anesthesia to get someone to fall asleep and stay asleep depending upon their marijuana use and when they last used. Kollman says marijuana use can affect how people respond to pain medications after surgery as well. It may require using other types of medications to control pain or using non-medicinal approaches to treating pain. This is because chronic use of marijuana can lead to pain-relieving opiate medicines not working as well as they otherwise would.

Other concerns with mixing marijuana and surgery in Colorado

According to UCHealth, people who are in the hospital following surgery may also experience marijuana withdrawal. This could include tachycardia, an increased heart rate; irritability; and in some cases excessive nausea. “These things can easily be mistaken as symptoms of other problems,” UCH says, “so if we don’t know specifically to look for cannabis withdrawal, then we may miss it.” It’s one more reason for patients to be fully candid about marijuana use prior to surgery. UCH does note that following legalization of marijuana in Colorado, people have become a little more willing to be honest about using it.

Anesthesiologist Kollman says, “I’ve always told people that I really don’t care what they use. What I care about is taking good care of them. If they let me know what they have been using and how much, I can adjust the medications to ensure they have the best experience possible.” She adds that medical personnel are not going “turn people into the cops” because that’s not their job. “Our job is to be the best doctor that we can for that one person at that one time.”

Not surprisingly, Kollman makes it a habit to ask about marijuana use. “And I specifically want to know if it is something that you are smoking, vaping, an edible or tincture. All of that can have different effects on the body for different lengths of time. The next thing that I would want to know is, ‘How long ago did you last use it?’ Because, again, within certain amounts of time, there are different effects on the body, and I want to be aware of that.” In addition, she says she wants to know how often the patient uses it because this will affect what will need to be monitored.

Altering the mind, monitoring the body if using marijuana

“We use a person’s body type and body weight to get a rough estimate of doses of anesthesia that will be needed,” Kollman says. “And we can also take into account their different physiology, their organ systems and what type of surgery they are going to have. Beyond that, we use their vital signs, for instance, their heart rate. Is it too fast or too slow? What’s their blood pressure doing? The body really tells us what it needs. When we think that somebody has ingested a mind-altering substance, we monitor brain waves to tell us exactly where that person is in terms of consciousness.”

What about cannabidiol (CBD), the chemical found in marijuana that supposedly does not contain tetrahydrocannabinol (THC), the psychoactive marijuana ingredient that produces a high? Kollman explains that CBD doesn’t tend to have the same effects as THC. It can have a more sedative effect on people. She adds, however, that in a recent study, about one-fifth of CBD products that were labeled as pure CBD still had a significant amount of THC in them. So, she concludes, it is hard to know what you are actually ingesting. And here again, being candid about any marijuana use prior to surgery is the best course of action for the patient.

A final question some people may have is: Can someone be such a heavy marijuana user that the anesthesiologist cannot put them under? Kollman’s answer: “No, we can always put someone under using anesthesia.”

(Acknowledgement: AgeWise Colorado thanks Erin Emery and UCHealth Today as a key source for information in this article.)