With the growing acceptance of medical marijuana, many patients now use it to manage various health issues—from chronic pain and anxiety to sleep disorders. But if you’re a regular user of medical marijuana and preparing for surgery, you might wonder: does ongoing cannabis use affect anesthesia risk?
As a cannabis specialist and anesthesiologist, I’ll walk you through the key points of how ongoing cannabis use could interact with anesthesia and what you should consider when discussing your cannabis use with your medical team. I’ll also address an often-overlooked area: the potential benefits of using cannabis as a post-op pain therapy, which may reduce reliance on opioids and other pain medications that carry more risks.
How Anesthesia Works
To understand how regular cannabis use may impact anesthesia, let’s first cover the basics of anesthesia. Anesthesia is designed to block pain, induce relaxation, or put patients to sleep during medical procedures. It essentially slows down the nervous system, producing effects that range from mild sedation to full unconsciousness.
There are three main types of anesthesia:
General Anesthesia: Puts you into a deep sleep so you don’t feel or remember anything during surgery.
Regional Anesthesia: Numbs a larger part of the body, like an arm or leg, while you stay awake.
Local Anesthesia: Numbs only a small, targeted area, often for minor procedures.
Each type affects your body in different ways, and ongoing cannabis use can influence how your body responds to these anesthetics, even if you haven’t recently used cannabis.
Cannabinoids and Their Effects on the Body
Medical marijuana contains compounds like THC (tetrahydrocannabinol) and CBD (cannabidiol). THC is the psychoactive compound that produces the “high,” while CBD has more calming effects without intoxication. These compounds interact with the endocannabinoid system (ECS), a network of receptors throughout the brain and body that helps regulate pain, mood, immune response, and sleep.
Regular exposure to THC and CBD can bring about long-term changes in the ECS, which may influence how you respond to anesthesia and other medications, even when not used concurrently.
Effects of Ongoing Medical Marijuana Use on Anesthesia
- Increased Anesthetic Dosage Requirements
Regular marijuana use can lead to a tolerance effect, particularly with THC. This means that the body may become less responsive to the sedative effects of certain anesthetics. Research shows that regular cannabis users may require higher doses of anesthesia—some studies suggest up to 20% more—to achieve the desired level of sedation or unconsciousness.
While this doesn’t necessarily increase risk, it does mean that your anesthesiologist needs to know about your cannabis use. By being open, you can help ensure that the anesthesia dosage is carefully adjusted for your needs.
- Heart Rate and Blood Pressure Considerations
THC can affect the cardiovascular system, sometimes increasing heart rate and, less frequently, blood pressure. During anesthesia, the body naturally experiences shifts in heart rate and blood pressure, especially during general anesthesia, which often causes blood pressure to drop.
For ongoing cannabis users, these shifts may be more pronounced or erratic. Your anesthesiologist might need to monitor these factors closely during surgery to ensure stable blood pressure and heart rate, especially if your body has adapted to regular THC exposure.
- Respiratory Function and Airway Management
Cannabis, particularly when smoked or vaped, can influence lung health, potentially complicating respiratory management under anesthesia. In people who smoke or vape, the lungs may retain more mucus or show signs of airway irritation, which can make breathing and airway management more challenging during anesthesia.
Even with non-smoked forms of cannabis, THC can impact the brain’s regulation of breathing, which is essential for anesthesia. When deeper sedation is required, this can pose additional challenges. Understanding this risk allows anesthesiologists to be prepared and take extra care with respiratory monitoring.
- Altered Pain Response and Post-Surgery Pain Management
Regular cannabis use can alter the body’s pain perception, which may influence both anesthesia and post-operative pain management. Some cannabis users develop a higher tolerance to pain, while others may experience heightened sensitivity, depending on how long they’ve used cannabis and for what conditions.
After surgery, this altered pain response may mean that some cannabis users find traditional post-op pain medications less effective or may need alternative options. THC and CBD may interact with opioids and other painkillers, potentially enhancing or changing their effects. Proper pain management planning with your anesthesiologist and surgical team can help mitigate this risk.
- Delayed Recovery from Anesthesia
Recovery from anesthesia involves both physical and cognitive aspects, and regular cannabis use, particularly THC, can extend the time it takes to fully regain alertness and physical function post-surgery. People who use marijuana regularly may take longer to “wake up” fully after anesthesia and may feel drowsy or disoriented for a longer time.
While this extended recovery is not typically harmful, it may mean a longer stay in the recovery room with additional monitoring. Knowing this, your anesthesia team can provide extra support to ensure you wake up safely and fully.
Post-Surgery Pain Management: Cannabis as a Potential Solution
After surgery, effective pain management is critical to a smooth recovery. Traditionally, opioids have been a standard option for managing post-op pain, but they come with risks of dependence, overdose, and numerous side effects. For patients who use medical marijuana, cannabis may offer a viable alternative or supplemental pain therapy to reduce the need for high doses of opioids.
How Cannabis Can Reduce Opioid Use Post-Op
Medical marijuana, specifically CBD, has shown promise as an effective pain reliever with fewer risks than opioids. Research has found that patients who use cannabis for pain often require fewer opioids to manage discomfort. This can be a significant benefit in post-operative care, as it reduces the risk of opioid-related complications, such as dependency, nausea, constipation, and respiratory depression.
Regular cannabis users may be able to incorporate cannabis into their post-surgery pain management plan, allowing for a more holistic and safer approach to recovery. If you’re a medical marijuana user, it’s worth discussing this option with your surgical and anesthesiology teams. They can help design a plan that effectively manages your pain without the same level of reliance on opioids.
Safety Considerations for Cannabis as Post-Op Pain Therapy
It’s important to approach post-op cannabis use carefully, especially in the early stages of recovery. The sedative effects of THC, combined with post-anesthesia grogginess, could delay cognitive recovery. Starting with lower doses and focusing on non-intoxicating options, like CBD-rich products, may be advisable until you’ve fully recovered from the anesthesia.
Your doctors may recommend a mix of conventional pain relief and cannabis to balance immediate pain needs with longer-term safety. By following their advice, you can leverage the pain-relieving benefits of cannabis while minimizing risks.
Talking with Your Medical Team About Cannabis Use
To ensure a safe experience with anesthesia, it’s essential to be open and transparent with your medical team about your cannabis use. Here are some helpful details to share:
Frequency of Use: How often do you use cannabis—daily, weekly, or occasionally?
Product Type: Do you smoke, vape, use edibles, or apply cannabis topically?
Last Use: Although this article focuses on ongoing use, it can still help your team to know how recently you last used cannabis.
When your anesthesiologist knows about your regular cannabis use, they can adjust your anesthesia dosage and monitor you more closely to ensure a safe and effective response.
Should You Pause Cannabis Use Before Surgery?
While there’s no set “safe gap” period, taking a break from cannabis use one to two weeks before surgery may help reduce potential anesthesia interactions. This can make it easier to gauge anesthesia response and recovery time. However, this decision should be made with your medical team based on your specific health, procedure, and level of cannabis use.
Final Thoughts: Ensuring Safety and Comfort as a Cannabis User
Medical marijuana offers therapeutic benefits that can improve quality of life, but it also brings unique considerations for surgery and anesthesia. By sharing details of your cannabis use with your medical team and discussing the potential for cannabis as a post-op pain solution, you can play an active role in planning a safe and effective surgical experience.
Your anesthesiologist and surgical team are there to ensure your safety and comfort. Through open communication and collaborative planning, you can navigate anesthesia risks while enjoying the benefits of medical marijuana for both pre- and post-operative care.
Dr. Nicholas Marsh has been a respected board-certified anesthesiologist in Northern Virginia for over 35 years. Recognized as a top doctor by FindaTopDoc.com, his vision for providing top-quality medical services is driven by his passion for patient comfort and dignity.