Regular cannabis users more likely to experience postoperative complications, study finds

People who are regular cannabis users are at an increased risk of experiencing complications before, during, and after surgery, according to a study by researchers with UTHealth Houston published today in JAMA Surgery.

Nearly 16.3 million people had a cannabis use disorder (CUD) in 2021, according to the National Institute on Drug Abuse. Defined by the Centers for Disease Control and Prevention, cannabis use disorder occurs when someone is unable to stop using cannabis even though it is causing health and social problems in their lives. Researchers found that patients with CUD are approximately 20% more likely to experience a significant postoperative complication than patients without CUD.

A significant number of patients' first encounter with the health care system is for surgery. Most have other health-related issues like high blood pressure and diabetes that they may not have previously known about. Cannabis use falls into the category of a health-related issue. It may not be as harmless as people think; it can have a significant impact on your health."

Paul Potnuru, MD, first author of the study and assistant professor in the Department of Anesthesiology, Critical Care and Pain Medicine at McGovern Medical School at UTHealth Houston

By using the National Inpatient Sample Database, researchers analyzed 62,110 hospitalizations from major elective inpatient surgeries performed in the United States from 2016 to 2019.

According to the study, patients with CUD had an increased risk of postoperative complications, including myocardial ischemia, acute kidney injury, stroke, respiratory failure, venous thromboembolism, hospital-acquired infection, and surgical procedure-related complications. Additionally, the cost of hospital stay was higher in patients with CUD than those without it.

With the growing rate of cannabis use and increasing potency of cannabis products, Potnuru said there are safety concerns for patients with frequent use of cannabis who undergo surgery. Earlier this year, the American Society of Regional Anesthesia and Pain Medicine released new guidelines for screening cannabis use in all patients before surgery, and recommends informing them of the increased risk of adverse outcomes.

"From the anesthesia perspective, cannabis users may need higher doses of anesthetic medications during surgery. They can also have higher pain levels after surgery and require more opioids. Doctors must be aware of the level of a patient's cannabis usage to tailor the amount of medications given and closely monitor for complications," Potnuru said.

Co-authors on the paper from McGovern Medical School were Srikar Jonna, MD, assistant professor of anesthesiology; and George W. Williams II, MD, professor, vice chair, and division chief of critical care medicine.

Journal reference:

Potnuru, P. P., et al. (2023) Cannabis Use Disorder and Perioperative Complications. JAMA Surgery.


  1. Mark Graham Mark Graham United States says:

    a study funded by big pharma?

    • Chad Christian Chad Christian United States says:


      Don't be part of the problem.

      This study is an analysis of a publicly available dataset. You can use the data yourself and perform the analysis yourself based on the listed methods to verify the information.

      This study merely presents one aspect of the health effects of cannabis overuse: the harms associated with surgery and cannabis use *disorder*. There are other beneficial aspects of cannabis that also need to be weighed and studied, such as potential benefits on anxiety, pain, and nausea.

      Dismissing any evidence of the negative impacts of cannabis and accusing the study of bias is, ironically, quite a biased view to have.

      Chad Christian, MD, FACS
      Chied of General Surgery
      Alpine Medical Center, Alpine, Texas

  2. Helen H. Helen H. Canada says:

    I think this may be a comorbidity rather than causation type scenario: folks with substance abuse disorders usually have personal histories of trauma/high ACE scores, and those with trauma backgrounds also tend to have more chronic health problems - that kind of stress is very damaging. Discovering undiagnosed conditions at the time of surgery is more likely in low income/uninsured/underinsured patients as well, those who are under stress due to socio-economic factors, and I would think that these conditions being previously unknown and untreated would also lead to worse outcomes.
    The anaesthetic and pain pieces are interesting, professionals need to be able to get accurate information about cannabis usage pre-surgery, perhaps by explaining why they need to know and by promising patient confidentiality.

The opinions expressed here are the views of the writer and do not necessarily reflect the views and opinions of News Medical.
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