April FY24

[kristenhorsman]

I chose an article this month about medical marijuana. I found it interesting that the article said that there is a synergistic effect of marijuana with opioids. Therefore, theoretically, a lower dose of opioids might be needed in patients that use marijuana. On the other hand, cannabis can be used as an analgesic for medical purposes and, therefore, a patient taking cannabis could potentially have increased postoperative analgesic requirements. I thought it was an interesting read with the significant increase in patients taking marijuana in various forms.

Please answer the following two questions:

1. What are some anesthetic considerations for both acute and chronic use of marijuana?
2. How do you alter your anesthetic, if at all, for marijuana users? 

[Sarah Brown, CRNA]

Thank you for submitting this article. I had read this one myself recently and found it interesting as well. I have had experience with patients being more sensitive to anesthesia because they are chronic marijuana users. Alternatively, I have also experienced patients being more tolerant to anesthetic drugs if they use marijuana. I am not so sure that it is easy to determine which way the patient will behave. I believe the type of marijuana, the manner in which they take it, the doses that they use, and whether or not the patient uses CBD in addition, effects the way patients respond to anesthesia. I think it's important to give small doses of anesthetics at a time and titrate to a desired effect instead of assuming one way or another. Patient history seems to be key in preventing issues that may arise pertaining to a patient marijuana use. One thing that I have noticed is an increase in airway reactivity pertaining to vaping.

[Sue Kim, CRNA]

Anesthetic considerations for acute and chronic use of marijuana include: Sympathetic vs parasympathetic cardiovascular changes, airway hyperactivity and bronchodilation vs bronchitis, anxiety/euphoria, antiemetic vs hyperemesis syndrome. In terms of tailoring the anesthetic for marijuana users, it is important to know the frequency and amount of use, especially if there is recent use prior to the onset of anesthesia. Generally the marijuana user does indeed require an increased induction dose than the non-user. And I am more inclined to use a multi-modal anesthetic approach to maintaining their anesthesia and treating post op pain.

[Rachael Wardrop, CRNA]

For acute marijuana use anesthetic considerations include both cardiac and respiratory effects. Cardiac effects include increased heart rate, contractility, cardiac output and hypertension. It has been found there is a significant increase in myocardial infarction within the first hour of using marijuana. Higher doses of marijuana have also shown orthostasis and bradycardia. Respiratory side effects include airway edema and hyperreactivity. In more chronic marijuana users, anesthesia considerations include increased risk of cardiac arrythmias, tachycardia, airway hyperreactivity, risk ischemic strokes, hyperemesis, and withdrawal symptoms postoperatively. Chronic users typically require increased doses of propofol for induction as well.

I alter my anesthetic for marijuana users based on the frequency and administration route. For all marijuana users I keep in mind they may require a larger dose of propofol for induction and maintenance of anesthesia and titrate to effect. I typically use multimodal analgesia due to the increased risk of tolerance to anesthetic and analgesic medications. For patients who smoke marijuana, I am aware of the respiratory side effects and treat any airway hyperreactivity.

[kels]

1. Some anesthetic considerations for acute marijuana use include increased HR and BP and some anesthetic considerations for chronic use of marijuana include increased airway reactivity and increased HR.
2. I titrate medications and use multimodal analgesia for marijuana users?

[Amy Swank]

1. Anesthetic considerations for acute and chronic use of MJ: 
Acute: interestingly, it has been shown that there is a 500% increased risk of MI within 1 hour after smoking MJ - so it is advisable to delaying anesthesia beyond this initial hour. Can also cause airway edema and airway hyper-reactivity. There is increased HR, contractility, cardiac output and HTN. 
Chronic:  studies have show that there is an increased risk of ischemic strokes in chronic users. Also chronic users more prone to various arrhythmias including Aflutter, 2nd degree AVB, VT and VF.

2.  How do you alter your anesthetic, if at all, for marijuana users?
Keeping in mind that the most relevant anesthetic consideration is that MJH can cause tachycardia and airway reactivity. And delaying for at least an hour from one hour of a patient smoking to decrease the risk of an MI. 

[aileenm4]

anesthesia considerations include a very important issue is increased airway reactivity, also increased risk of MI and stroke, hyperemesis syndrome, irritability and withdrawl s/s

How to alter the management is to ask about most recent use and how much they are using daily/weekly or monthly, and do they currently have any of the s/s of the chronic pot user also how to they use the pot? eat it, smoke it, etc

[Tracey Trainum]

1. Acute effects- Most acute effects are related to the central nervous system. Lower doses cause activation of the sympathetic nervous system and higher doses cause activation of the parasympathetic nervous systems. Therefore, these effects include anxiety and anxiolysis, paranoia, euphoria, headache, dizziness, analgesia. Other acute effects include tachycardia, vasodilation, bronchodilation, and airway hyperreactivity. Most notable acute risk is a 500% increase in the risk for and MI within 1 hour after smoking marijuana.

Chronic effects - Bradycardia, cardiac arrhythmias (aflutter, second degree AV block, vfib/vtach) orthostasis, bronchitis, hyperemesis syndrome. Most notable chronic use risk is the risk of ischemic stroke.

2. Anesthetic adjustments: A thorough preoperative exam/history is very important in these patients as the risks vary depending on acute vs chronic use, and time of last use. Knowing this data will help with the anesthetic approach. Paying close attention to cardiac risk factors and therefore cardiac rhythm and changes during any case with marijuana users is very important. As far as adjusting doses, narcotics etc. I find these patients can be all over the place in their requirements- some have high requirements whereas others do not. With all of these factors in mind I do not make any adjustments up front- I just keep in mind their history and see how they respond to initial doses of anesthesia.