Abstract and Introduction
Background: Although cannabis is known to have cardiovascular and psychoactive effects, the implications of its use before surgery are currently unknown. The objective of the present study was to determine whether patients with an active cannabis use disorder have an elevated risk of postoperative complications.
Methods: The authors conducted a retrospective population-based cohort study of patients undergoing elective surgery in the United States using the Nationwide Inpatient Sample from 2006 to 2015. A sample of 4,186,622 inpatients 18 to 65 yr of age presenting for 1 of 11 elective surgeries including total knee replacement, total hip replacement, coronary artery bypass graft, caesarian section, cholecystectomy, colectomy, hysterectomy, breast surgery, hernia repair, laminectomy, and other spine surgeries was selected. The principal exposure was an active cannabis use disorder, as defined by International Classification of Diseases, Ninth Edition, Clinical Modification (ICD-9-CM) diagnostic codes for cannabis dependence and cannabis abuse. The primary outcome was a composite endpoint of in-hospital postoperative myocardial infarction, stroke, sepsis, deep vein thrombosis, pulmonary embolus, acute kidney injury requiring dialysis, respiratory failure, and in-hospital mortality. Secondary outcomes included hospital length of stay, total hospital costs, and the individual components of the composite endpoint.
Results: The propensity-score matched-pairs cohort consisted of 27,206 patients. There was no statistically significant difference between patients with (400 of 13,603; 2.9%) and without (415 of 13,603; 3.1%) a reported active cannabis use disorder with regard to the composite perioperative outcome (unadjusted odds ratio = 1.29; 95% CI, 1.17 to 1.42; P < 0.001; Adjusted odds ratio = 0.97; 95% CI, 0.84 to 1.11; P = 0.63). However, the adjusted odds of postoperative myocardial infarction was 1.88 (95% CI, 1.31 to 2.69; P < 0.001) times higher for patients with a reported active cannabis use disorder (89 of 13,603; 0.7%) compared with those without (46 of 13,603; 0.3%) an active cannabis use disorder (unadjusted odds ratio = 2.88; 95% CI, 2.34 to 3.55; P < 0.001).
Conclusions:An active cannabis use disorder is associated with an increased perioperative risk of myocardial infarction.
Although cannabis has been used in the United States since the 1800s, recent changes regarding the legality of its recreational and medical use have led to an increase in its consumption. The 2016 American National Survey on Drug Use and Health showed that among the 7.4 million individuals with an illicit drug use disorder, the most common substance used was cannabis (4.0 million people). An estimated 24.0 million Americans aged 12 or older in 2016 reported using cannabis in the last month. Medical cannabis is currently legal in the District of Columbia and 33 states. Given that the prevalence of cannabis use is expected to continue to grow, healthcare providers are likely to encounter the sequelae associated with its use.
Recent literature has highlighted potential detrimental effects associated with cannabis use such as increased bronchial reactivity, cerebrovascular accidents, and myocardial infarctions (MI).[2–8] Surgical patients with an active cannabis use disorder may be at an increased risk of adverse outcomes given the potential for psychoactive and hemodynamic effects within the perioperative setting. No large cohort study has yet evaluated the perioperative outcomes of patients with cannabis use disorder. To anticipate and prevent postoperative complications, perioperative healthcare providers need to be aware of the associated risks of cannabis to ensure that appropriate counseling, safeguards, and monitoring can be applied.
We therefore conducted a retrospective cohort study to (1) identify whether patients with an active cannabis use disorder experienced worse postoperative outcomes and (2) describe national trends in the prevalence of cannabis use disorders in patients presenting for major elective operations. We hypothesized that patients with an active cannabis use disorder have a higher risk of postoperative complications and higher resource utilization.
Anesthesiology. 2020;132(4):625-635. © 2020 American Society of Anesthesiologists | Lippincott Williams & Wilkins