The effects of marijuana on your perception and mood are well known, but there are other aspects of marijuana use that have the potential to negatively impact your surgical outcome.

Effects of Tetrahydrocannabinol (THC)

If you’ve used marijuana, or Cannabis sativa, recreationally, you’re familiar with tetrahydrocannabinol (THC). THC is what makes you feel intoxicated, happy and social, what heightens your senses and distorts your sense of time. Or, on the flip side, if you’re predisposed to anxiety or have psychotic disorders, THC is what causes you to feel more paranoid and anxious, and it can aggravate psychosis.¹

The strength and duration of these effects depends on your dose, meaning how much THC you consume either through inhalation or consumption.

Methods of Use

There are different ways that you might use marijuana to experience the effects of THC, but the most common methods of use in the US are through smoking and eating it.

Smoking

Smoking marijuana is the most common way that marijuana is consumed in the U.S. It can be smoked in a pipe, or rolled into marijuana cigarettes. Some people roll marijuana with tobacco leaf papers, in what is called a blunt, if this is your preferred method of marijuana smoking, click here to read about how smoking tobacco can impact your surgical outcomes.²

When you smoke marijuana, the THC will affect you pretty quickly, usually only within a few minutes.³

Edible

Marijuana can be baked, cooked into different foods, or made into an extract that is used in beverages. Consuming marijuana through edibles is more common with women than men.⁴

When you consume marijuana, it gets digested which means the THC takes longer to be absorbed. That means, it’ll take you longer to feel the effects of the THC, but the effects last longer than with smoking it.⁵

Why Does It Matter?

The way you use marijuana affects the way that your body absorbs the THC, in how soon you’ll feel the effects and how long they’ll last. But, there are other ways that THC affects your body beyond the “high” you experience, that you might not be aware of. The effects of THC could increase your risks of certain complications, and could negatively impact your surgical experience and healing.

Nervous System Effects

Depression

THC is a central nervous system depressant, which means it slows down your brain’s activity. That’s why using marijuana makes you feel relaxed, drowsy, and sleepy.⁶

Cardiovascular/Peripheral Vascular Effects

Tachycardia

THC causes tachycardia, which is an elevated heart rate.⁷ Your heart muscle has to work harder to pump faster, which also increases its need for oxygen.

Vasodilation/Vasoconstriction

THC causes certain blood vessels to dilate, which can lower your blood pressure. This can cause something called postural hypotension, which can cause fainting when you stand up from sitting or lying down. However, while THC causes vasodilation in some blood vessels, it actually causes vessels in your brain to constrict.⁸

Respiratory Effects From Smoking

It’s commonly believed that smoking marijuana is healthier than smoking tobacco or cigarettes, because there’s no nicotine – it’s “just marijuana”. However, frequent and long-term smoking of marijuana causes a lot of the same complications associated with cigarette smoking. Also, the practice of holding in marijuana smoke before exhaling can cause these effects to occur more quickly in marijuana smokers than in tobacco smokers.⁹

Less Cilia, More Mucus

Smoking marijuana or cigarettes causes you to lose cilia in your airways. Cilia are like tiny little hairs that keep your airways clear of dirt, dust, and extra mucus. When you lose your cilia, you aren’t able to clear your airways as easily, and they’re more easily irritated. You also produce more mucus when you’re a chronic smoker. That extra mucus irritates your airways, and since there’s no cilia to clear it out, you can develop a chronic cough or COPD.¹⁰

More Carbon Dioxide in Blood

Smoking also causes your blood to carry more carbon dioxide and less oxygen.¹¹ Which means that while your heart is beating more rapidly, and requiring more oxygen, there’s actually less oxygen available for it to use.

How Does This Affect My Surgery?

The effects of THC and the effects of smoking it, can impact the way your anesthesia provider does their job and also the way that you heal following surgery.

Anesthesia Management

Any time you’re going to be placed under general anesthesia for surgery, it’s important to be honest with your anesthesia provider about any and all substances you might be using, in order to avoid serious complications. Marijuana smokers are at risk for bronchospasm, pneumonia, and lung collapse.

Those are things that your anesthesia provider will need to be prepared for during your procedure. If you’re a long-term marijuana user, you probably have a higher tolerance for anesthetic drugs, which means that you may need more drugs to be placed in an adequate anesthetic state.¹²

Also, increased heart-rate from THC, and higher blood carbon dioxide, can increase your risk for a heart attack or stroke.¹³

Postoperative Effect

In addition to the way marijuana can affect your surgical procedure, it could also impact the way you heal, especially if you smoke marijuana. Smoking increases the time that it takes for you to heal from your surgery. Good healing requires adequate blood flow to bring nutrition and oxygen to the surgical site. Since smoking increases the amount of carbon dioxide carried by your blood, that also means it can carry less oxygen, so your healing takes longer.¹⁴

The longer your wound takes to heal, the longer it’s open and vulnerable to infection. Also, you could experience tissue necrosis, or tissue death, if your wound isn’t getting enough oxygen.¹⁵

What Should You Do?

There are ways to help increase the likelihood that you’ll have positive surgical outcomes.

Stop Smoking Marijuana

Quitting smoking marijuana is one of the best things you can do to help get your body ready for your surgery. It helps to reverse the damage done to your airway, and it increases your blood oxygen. It’s preferred that you stop smoking for at least four weeks before your surgery, but stopping for a longer before your procedure is even better.¹⁶

It’s especially important to remember that smoking marijuana will delay your healing processes, so don’t smoke through your recovery period either. For optimal healing, don’t smoke for six to eight weeks following your procedure.

Do NOT Use Before Surgery

Even though you might experience anxiety leading up to your procedure, it’s important not to use immediately before your surgery. Especially, don’t smoke right before surgery! The effects of the THC, taken in the form of smoking it or edibles, could put you at unnecessary risk for surgical and anesthesia related complications during your procedure. Also, as we already mentioned, the smoke can irritate your airway and put you at risk of bronchospasm.

Be Honest With Your Anesthesia Provider

Being honest with your anesthesia provider before your surgery is the most important thing you can do when it comes to avoiding complications. You don’t need to worry about their opinions on your recreational marijuana use, because they’re not there to judge that. They’re there for you to safely care for you during your surgery. If they know about marijuana and any other substances you use regularly, they’ll be better prepared to manage your anesthesia during the procedure. It’ll prepare them for any potential complications that might come up. 

Be Transparent and Be Aware of the Risks

Recreational use of marijuana may be legal in some places, but there are more complications associated with marijuana use than most people are aware of. If you’re concerned about your surgical outcome, don’t hesitate to mention it to your doctor during your consultation appointment. 

1. Ashton, C. Heather. “Pharmacology and effects of cannabis: a brief review.” The British Journal of Psychiatry 178, no. 2 (2001): 101-106.
2. Russell, Cayley, Sergio Rueda, Robin Room, Mark Tyndall, and Benedikt Fischer. “Routes of administration for cannabis use–basic prevalence and related health outcomes: A scoping review and synthesis.” International Journal of Drug Policy 52 (2018): 87-96.
3. Ashton, C. Heather. “Pharmacology and effects of cannabis: a brief review.” The British Journal of Psychiatry 178, no. 2 (2001): 101-106.
4. Russell, Cayley, Sergio Rueda, Robin Room, Mark Tyndall, and Benedikt Fischer. “Routes of administration for cannabis use–basic prevalence and related health outcomes: A scoping review and synthesis.” International Journal of Drug Policy 52 (2018): 87-96.
5. Ashton, C. Heather. “Pharmacology and effects of cannabis: a brief review.” The British Journal of Psychiatry 178, no. 2 (2001): 101-106.
6. Lucas, Catherine J., Peter Galettis, and Jennifer Schneider. “The pharmacokinetics and the pharmacodynamics of cannabinoids.” British journal of clinical pharmacology (2018).
7. Thomas, Grace, Robert A. Kloner, and Shereif Rezkalla. “Adverse cardiovascular, cerebrovascular, and peripheral vascular effects of marijuana inhalation: what cardiologists need to know.” The American journal of cardiology 113, no. 1 (2014): 187-190.
8. Thomas, Grace, Robert A. Kloner, and Shereif Rezkalla. “Adverse cardiovascular, cerebrovascular, and peripheral vascular effects of marijuana inhalation: what cardiologists need to know.” The American journal of cardiology 113, no. 1 (2014): 187-190.
9. Bryson, Ethan O., and Elizabeth AM Frost. “The perioperative implications of tobacco, marijuana, and other inhaled toxins.” International anesthesiology clinics 49, no. 1 (2011): 103-118.
10. Tetrault, Jeanette M., Kristina Crothers, Brent A. Moore, Reena Mehra, John Concato, and David A. Fiellin. “Effects of marijuana smoking on pulmonary function and respiratory complications: a systematic review.” Archives of internal medicine 167, no. 3 (2007): 221-228.
11. Ashton, C. Heather. “Pharmacology and effects of cannabis: a brief review.” The British Journal of Psychiatry 178, no. 2 (2001): 101-106.
12. Bryson, Ethan O., and Elizabeth AM Frost. “The perioperative implications of tobacco, marijuana, and other inhaled toxins.” International anesthesiology clinics 49, no. 1 (2011): 103-118.
13. Singh, Amitoj, Sajeev Saluja, Akshat Kumar, Sahil Agrawal, Munveer Thind, Sudip Nanda, and Jamshid Shirani. “Cardiovascular complications of marijuana and related substances: a review.” Cardiology and therapy (2017): 1-15.
14. Ashton, C. Heather. “Pharmacology and effects of cannabis: a brief review.” The British Journal of Psychiatry 178, no. 2 (2001): 101-106.
15. Vidal, Pedro, Juan Enrique Berner, and Patrick A. Will. “Managing Complications in Abdominoplasty: A Literature Review.” Archives of Plastic Surgery 44, no. 5 (2017): 457-468.
16. Bryson, Ethan O., and Elizabeth AM Frost. “The perioperative implications of tobacco, marijuana, and other inhaled toxins.” International anesthesiology clinics 49, no. 1 (2011): 103-118.