Transient Postoperative Hypoxemia Associated With Cannabis Use Following General Anesthesia.

Cannabis use has increased worldwide, particularly with the rising availability of vaping products. While the cardiovascular and neurocognitive effects of cannabis are increasingly recognized in the perioperative setting, its pulmonary consequences remain less well defined. Cannabis inhalation has been associated with airway irritation, bronchial hyperreactivity, alveolar inflammation, and impaired gas exchange, which may predispose patients to perioperative respiratory complications. General anesthesia may exacerbate these subclinical abnormalities through reductions in functional residual capacity, atelectasis, and altered pulmonary perfusion. These mechanisms may unmask underlying disturbances in gas exchange. We report a case of transient postoperative hypoxemia following general anesthesia in a young patient with heavy cannabis vaping exposure and no known cardiopulmonary disease. The patient developed hypoxemia with minimal radiographic findings and preserved ventilation, requiring supplemental oxygen postoperatively. His condition resolved spontaneously within 24 hours. This case suggests that clinicians should consider cannabis-related pulmonary effects in the differential diagnosis of postoperative hypoxemia.