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Uses of marijuana and narcotic drugs among youths are alarming Anesthesiologists to be careful for the addicted patients during surgery: Dr Muppuri
By Faruque Ahamed
KALYANI, 9 JANUARY–
Originally appreciated for its utility as fiber, later marijuana started use as a drug of abuse.
Marijuana use dates back at least three thousand years before Christ to Chinese Emperor Shen Nung.
After traveling half a world to the Middle East, it was brought to the West by the Spanish.
According to the National Institutes of Health (NIH), marijuana use in 2016 rose from 4.1% to 9.5% of the U.S. adult population.
The use of marijuana in India is known for centuries. In Kolkata, addictions of marijuana and other narcotic drugs among a section of young boys and girls, college and school students belonging to middle, upper middle and higher classes in the society are on the rise. Some city doctors have already pressed an alarm bell saying how the addiction could increase the number of heart diseases that
ultimately require surgeries.
Given the commonality of its symptoms of use, we reached out to Dr. Rudram Muppuri, a US based NRI anesthesiologist affiliated with the McLaren Clinic in Flint, Michigan, who was one of the first to identify the cardiac and other risks of marijuana in preanesthetic evaluation and in surgery.
Faruque Ahamed (FA) of ibgnews.com discussed the health implications of use of marijuana, especially in
relation to surgical preparation and anesthesia, with Dr. Muppuri.
Q. The medical community has joined the debate in marijuana. Could you please elaborate the key issues
Dr. Muppuri?
RM: The most obvious matter in hand between medicine and marijuana is medicinal marijuana. The effects of marijuana have been well documented, allowing the push for its use as medicine within multiple medical disciplines. Proponents of its use advocate its action on the endocannabinoid system.
Studies show that it may be used as an analgesic, immunosuppressant, muscle relaxant, anti-inflammatory agent, appetite stimulant, antidepressant, antiemetic, bronchodilator, neuroleptic, antineoplastic and
even as an anti-allergen.
There is however, very little information, if any research evaluating use of marijuana in surgery and impact on anesthesia. This gap of information posits a problem. While many surgeons may obtain history about recreation drug use including marijuana, many other drugs have established evidence-based outcomes that allow variation in surgical planning as needed.
However, when it comes to marijuana, surgeons have to make their own decisions. With a reported estimation of 10%–20% of patients between the ages of 18 and 25 years regularly using marijuana, it is
highly important that we become cognizant of issues pertinent to the care of the patients on marijuana prior to surgery and provide special intra- and post-operative care (please also see below).
Q. How does marijuana enter the body system?
RM: When marijuana is smoked, tetrahydrocannabinol (THC) and other cannabinoids are absorbed rapidly
through the lungs with effects peaking in 15 minutes. These effects can persist for up to a dose-dependent 4 hours in the acute setting. When ingested orally however, onset of effects is slower (15 minutes in contrast to 90 minutes) but has a longer duration of action (4 hours versus 5–6 hours), due to continued absorption in the gut. This is despite a lower bioavailability due to first-pass metabolism by the liver which results in a blood concentration 25% of what is obtained if smoked.
The cognitive/psychomotor effects can be present for up to 24 hours regardless of administration route. Cannabinoids are highly lipid soluble, meaning that it can stay in the body system for very prolonged periods of time. This leads to a slow release into the bloodstream with a single dose not fully eliminated for up to 30 days. This has very important impact on surgical patients, as the drug tends to be retained in the body for long periods and can significantly alter the postoperative course.
Q. How can marijuana predispose to heart attack and poses special risk for anesthesia?
M: The cardiovascular effects of marijuana use range from benign to worrisome based on the timeline of use and dosage. Tachycardia or rapid heart rate may be induced beginning within the time of inhalation,
and persisting at least 90 minutes, with the maximum heart rate reached at an average of 30 minutes.
There can be a significant elevation in both the systolic and diastolic blood pressures as well as the presence of premature ventricular contractions (PVCs), which are serious heart rhythm disturbances. In
addition to sinus tachycardia, marijuana use has been linked to multiple electrocardiogram (ECG)
changes. In fact, Brugada-like features, which portends sudden cardiac death, can be seen. Marijuana
use also has a role as a risk factor for myocardial infarction.
Q. Can marijuana cause stroke?
RM: Marijuana has also been reported as a risk factor for stroke, especially ischemic strokes. These
are associated with either a recent increase, in the days leading up to the event, or chronic history of heavy marijuana use. When cohort studies were performed comparing marijuana users with resultant
limb arteritis to patients suffering from thromboangiitis obliterans, marijuana associated arteritis
occurred in younger, usually male patients with a unilateral, lower limb as the common presentation.
This disease, also called Burger’s disease, is comm..only seen in India, as smoking tobacco in
different forms is the root cause and a common occurrence.
Q. Apart from marijuana, smoking tobacco poses risk during anesthesia. Can you distinguish the effects between the two?
RM: The commonest route of marijuana administration is inhalation via smoking. Due to the unfiltered
nature of the marijuana cigarette compared to commercially available tobacco cigarettes, the amount of carcinogens and irritants, like tar, that gain entry to the upper airway is increased, with
approximately a three-fold increase in tar inhalation and one third more tar deposition in the respiratory tract. More specifically, the tar from the cannabis smoke contains greater concentration of
benzanthracenes and benzopyrenes (each a carcinogen) than tobacco smoke.
In addition, as compared to smoking tobacco, there is a two-thirds greater puff volume, one-third greater depth of inhalation and a four-fold longer breath-holding time, all of which are common smoking
behavior to try to enhance and maximize absorption of the active components, which is around 50% of cigarette content. These practices result in five times the amount of carboxyhemoglobin levels as compared to the typical tobacco smoker.
Q. What are the anesthetic risks in individuals who have used marijuana and undergoing surgery?
RM: There are significant drug interactions between active components of marijuana and commonly used
anesthetic medications. There is cross-tolerance between marijuana and several anesthetic drugs
including barbiturates, opioids, prostaglandins, chlorpromazine and alcohol. As a result of fat solubility and slow elimination from the tissues, cannabinoids may be present to interact with multiple
anesthetic agents. Multiple boluses of propofol and midazolam are required to achieve appropriate sedation.
Significantly increased doses of propofol needs to be administered to facilitate successful insertion of the laryngeal mask and thus suggesting that the increased doses in chronic marijuana users may be a requirement for appropriate loss of consciousness as well as jaw relaxation and airway reflex
depression.
The synergistic effects of cannabis include significant impact on the autonomic nervous system and its
pharmacology. This system maintains the cardiocirculatory integrity. These include potentiation of
nondepolarizing muscle relaxants, potentiation of norepinephrine, the augmentation of any drug causing
respiratory or cardiac depression, as well as a more profound response to inhaled anesthetics
sensitization of the myocardium to catecholamines due to the increased level of epinephrine. All of
these cumulatively can lead to fatal cardiovascular outcomes.
Q.What are the need for postsurgical pain medications reduced in individuals who habitually use
marijuana?
RM: With advancement of surgical techniques, more complicated and potentially painful procedures are becoming common. Over 80% experience postoperative pain that was rated as either moderate or severe.
This pain can set off a series of changes that may harm various systems ranging from cardiovascular to
the central nervous system and has been shown to lengthen hospital stays and time to first ambulation,
cause significant barriers in postoperative nursing and physiotherapy, increase healthcare costs, and reduce the patient’s satisfaction with the surgical outcome.
However, appropriate and adequate postoperative analgesia improves recovery, including improving cardiac function and decreasing mortality and morbidity related to pulmonary function, decreases risk
of blood clots, diminishes the possibility of chronic pain syndrome, and improves overall outcome.
Appropriate pain control is also at the root of starting another long-term opioid abuser.
Marijuana plays a role now in medicine as an analgesic and is being increasingly legalized across the different states in the USA. Prescribed for a number of diagnoses, medical marijuana has been shown to
be both effective and safe in the treatment of chronic pain and has gained popularity as a medication
for neuropathic pain. Marijuana may play a more important role in pain management when combined with
opioids.
However, the appropriate management of marijuana users with opioids postoperatively is more
complicated and is not a linear interaction effect. In chronic marijuana users, the perioperative
narcotic requirements to gain appropriate analgesia are enhanced to a great degree.
Q. Is there any contraindication for bariatric surgery in individuals who have used marijuana?
RM: Whether marijuana use should be a contraindication to bariatric surgery is a debatable topic. Due
to the many effects marijuana has on the cardiovascular, pulmonary, immunologic, and central nervous
system, cannabis use worsens and produces adverse outcomes in the postoperative period. These potential
risks and lack of screening resulted in the recommendation that practitioners of bariatric surgery should be devoted to assessing controlled and problematic levels of preoperative substance use and take the time to discuss the potential postoperative risks with patients.
Q. Any final comments Dr. Muppuri?
RM: The documented evidence of the effects of marijuana is of great concern for surgery. Whether it be the presentation of arrhythmias, myocardial infarction, stroke, pulmonary obstruction as well as anesthetic concerns and/or thromboembolus or bleeding, marijuana’s multi-system, multi-organ effects are possible confounders to a variety of medical outcomes, including surgical events.
