Many studies on the risks associated with cannabis are inconclusive. A new analysis of the plant’s impact on anesthesia is also dicey—though headlines suggest the association is negative. We read the study (and the associated write-up) and were left with more questions than answers.
In the review, researchers from Duke University examined available research. The review included a separate meta-analysis of eight cannabis and anesthesia-related studies. The studies examined health data and did not actually look into the direct impact of cannabis on aesthetic drugs.
The bottom line? More research is needed to determine what, if any, impact the use of cannabis has on the performance of anesthesia. The Duke team, along with the authors of the studies they reviewed, called for further inquiry to help better inform medical teams in the future.
RELATED: Cannabis and organ transplants: what you need to know
Cannabis and aesthesia: research provokes inquiry
The team’s analysis revealed that people who use weed may need more propofol, a common anesthetic drug, to be free from pain and/or sedated during surgery. Some of the research indicated cannabis consumers needed a dose that was 15 to 30 percent higher than non-consumers.
While generally well-tolerated when administered by professionals, propofol is not without its risks. It may lower blood pressure to dangerous levels, reduce breathing rates, or cause other issues. According to Duke, “adjusting doses increases the risk of complications, including under-sedation and cardiovascular side effects.”
The theory that cannabis users may need more propofol (or that weed impacts how the drug works at all) may seem concerning at first. But dig deeper into the studies, and it’s clear that much more inquiry is needed.
RELATED: The subtle risk that sets alcohol apart from cannabis
The meta-analysis referenced in the Duke review has several limitations noted. This included selection bias due to a small sample size, self-reported cannabis consumption, lack of long-term data, focus on English-language publications, and variation in cannabis potency.
But the main issue with that research? The lack of discernment between tobacco and cannabis.
“Cannabis users in the included studies were more likely to smoke cigarettes, yet data on the independent effects of smoking on propofol dosing were inconsistently reported. While some studies adjusted for tobacco use, this was not uniform across all analyses,” the authors wrote.
RELATED: Fatal infection could be treated by cannabis
The researchers went on to say that, “given the low certainty of evidence, our findings should be interpreted with caution.”
Despite its severe limitations, the study did raise some good points, mostly centering on drug contraindications. The researchers theorized that how THC interacts with the central nervous system could impact the efficacy of drugs like propofol. They also noted the anesthetic may boost levels of the body’s own cannabinoid anandamide.
It will take more time and research before the theories are confirmed and for medical professionals to understand how cannabis may impact people undergoing anesthesia. In the meantime, it’s important to note that one headline does not tell the whole story.
