When Cannabis Use Goes Wrong: An Epidemiologic Study of Cardiopulmonary Symptoms in Patients That Present to Emergency Departments

Please enjoy this new addition to our Fall Issue!


Background: Increased availability and use of cannabis in Michigan have led to a marked increase in emergency department (ED) visits associated with the drug’s adverse cardiopulmonary effects. However, few people are aware of these potential cardiopulmonary side effects. Recognition of these presenting symptoms is critical for emergency clinicians to provide timely and effective care, make accurate diagnoses, and safeguard the health of patients who may be experiencing toxic effects from cannabis use.

Study objective: To describe the prevalence, clinical features, and disposition of cannabis cardiopulmonary toxicity in a community- based study.

Methods: This was a retrospective cohort analysis of all patients diagnosed with toxicity related to cannabis use. Patients were seen at eight EDs over a 26-month study period (November 2018–December 2020). Affiliated institutions included three university-affiliated hospitals, a children’s tertiary care facility, and four rural medical centers. Data collected included demographics, clinical features, and treatment outcomes in patients presenting to the ED with cardiopulmonary symptoms (CPS) versus those experiencing other forms of cannabis toxicity.

Results: During the study period, 1,174 patients were evaluated for cannabis toxicity. A total of 318 patients (27.1%) had a cardiopulmonary chief complaint (CPS group) and 856 (72.9%) experienced other forms of cannabis toxicity, predominantly symptoms of intoxication, cannabis hyperemesis syndrome, or neuropsychiatric complaints. The CPS group presented with tachycardia (36.5%), dyspnea (34.3%), chest tightness (28.6%), palpitations (17.9%), and hypertension (8.2%). CPS patients were more likely to be older (32.6 vs. 24.3 years, p < 0.001), ingested edible cannabis (36.8% vs. 9.2%, p < 0.001), and have a history of polysubstance abuse (17.6 vs. 12.0%, p = 0.013). These patients also had a longer ED length of stay (4.9 vs. 3.8 h, p < 0.001) and significantly more hospital admissions (10.1% vs. 6.3%, p = 0.027).

Conclusions: Cardiopulmonary toxicity is common after acute or chronic cannabis exposures, occurring in over one-quarter of ED patients in this community-based study. These troublesome findings highlight the risks associated with using cannabis for recreational or therapeutic purposes.