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Cannabis: How it May Affect Anesthesia

Cannabis boasts a number of health benefits, including easing chronic pain and insomnia, and making it easier to deal with anxiety, depression, and PTSD to find peace and enjoy life. However, cannabis doesn’t always interact well with other drugs, and in fact, can be downright dangerous depending on the drug. This is certainly the case when it comes to cannabis and anesthesia.

Preparing for surgery can be scary for a number of reasons, so we’ll talk about the importance of communicating with your anesthesia provider about your cannabis routine and the impact of different methods of cannabis consumption on anesthesia, so you can reduce your risk of complications.

Be honest about your cannabis routine

If you’re currently living in a cannabis prohibition state, or even a state where cannabis has been legalized for medical use only, you might wonder if it’s legally safe to talk to your anesthesia provider about your cannabis routine.

Because of the HIPAA Privacy Law, conversations between you, your physician, nurses, and other healthcare staff are considered protected health information, as is information added to your medical record by healthcare providers.

Healthcare providers are only permitted to disclose your protected health information to members of law enforcement agencies under a few very specific circumstances, such as when the safety of an individual or the public is at risk, or in order to comply with a court order.

“The only break in that agreement comes with legal and ethical responsibility to report circumstances that have potential for severe bodily harm to one’s self or others,” said Dr. Daniel King, CRNA, and member of the American Association of Nurse Anesthetists (AANA). “In my practice, our focus is to fully understand the medical background of our patients and ensure positive outcomes for them.”

In fact, it is crucial to talk to your anesthesia provider about your habits because cannabis can have effects on the cardiovascular and respiratory systems that may pose higher-than-normal risks while under anesthesia.

“These risks include spasm of the vocal cords or small airways of the lung,” said King. “Additionally, there is concern for cross-tolerance to commonly used anesthetic drugs, and cannabis users may require higher doses and/or use of other agents.”

Patients should trust their anesthesia provider as being knowledgeable and well prepared to care for them, and know there is a growing acceptance of cannabis consumption among the medical community.

When you talk to your anesthesia provider about your cannabis routine, provide information on: the type of cannabinoid consumed (THC, CBD, etc.), any periods of abstinence from the product, patterns of use, such as dose, method, frequency, and length of use, and whether it is being used for medical purposes.

How CBD and THC products impact anesthesia differently

There are many differences between how THC and CBD impact anesthesia. In particular, the effects between the two in the cardiovascular and gastrointestinal systems are virtually opposite.

“THC is more likely to lead to fast heart rhythms and high blood pressure, whereas CBD slows the heart rate and brings down blood pressure,” said King. “In the gastrointestinal system, THC stimulates appetite but has also been linked to slowed gastric motility with long-term use—this could increase the risk for adverse events such as aspiration pneumonia.”

He continued: “Tolerance to THC tends to develop rather quickly—meaning after only a few doses the patient may become dose tolerant and require higher doses to achieve the same effects.”

He went on to say that THC is broken down in the body by a similar cellular process as common anesthesia drugs, so there is concern that a high THC tolerance may require higher doses of anesthesia drugs.

King noted that, “We currently do not have the level of researched evidence available to be able to provide formal recommendations for use of one or the other in either the pre-op or post-op period.”

For example, this scientific review cites more than one study in which cannabis consumers exhibited higher pain scores and a greater need for pain-relieving medications after surgery. More research on how THC interacts with anesthesia drugs is definitely needed.

How different methods of cannabis consumption can impact anesthesia

Anesthesia providers are intimately familiar with airway anatomy and physiology, as patients routinely require procedures such as intubation and mechanical ventilation during surgery. As such, management of the respiratory system as it relates to smoking or vaping cannabis is of great concern.

“Patients who smoke or vape may have increased incidence of symptoms such as coughing, wheezing, or spasm of the vocal cords and small airways,” said King. “Cannabis burns at a higher temperature than cigarettes, leading to the potential for weakening of the linings of airway passages and even potential scarring of lung tissue over time. All of these make respiratory management more concerning if the patient smokes or vapes products when compared to oral consumption.”

King provides some basic recommendations for pre-op and post-op consumption: “Abstain from smoking for 24-72 hours prior to surgery in order to decrease airway reactivity and improve wound healing, but ideally for as long as possible.”

Additionally, patients shouldn’t resume cannabis consumption until the effects of their anesthetic and pain medications have completely worn off after surgery.

On top of that, mixing cannabis with opioids or alcohol can cause decreased reflexes and increased sedation levels, and may compromise memory and cognitive function, according to King.

He said there is also concern that mixing cannabis products with opioids or alcohol can lead to addiction and use disorders in the long-term.

Source: Leafly


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