Regular cannabis users made up 19% of ED vomiting cases and 43% had repeat visits for the same complaint | Research

The takeaway

A 2-year chart review of 494 ED patients presenting with vomiting found that 19.4% reported cannabis use, and among regular users (3+ times/week), 43% had repeat ED visits for similar complaints, suggesting widespread CHS underdiagnosis.

Read this if you experience repeated episodes of vomiting and use cannabis regularly, or if you work in emergency medicine.

43% of regular cannabis users with vomiting had repeat ED visits

What the researchers found

Researchers reviewed charts of all adults aged 18-55 presenting to two major urban tertiary care EDs and one urgent care centre with vomiting complaints over two years.

Of 494 cases, 19.4% of charts specifically reported cannabis use. Among regular cannabis users (more than three times per week), 43% had repeat ED visits for similar complaints.

The resource utilization was substantial: 92% had bloodwork, 92% received IV fluids, 89% received antiemetics, 27% received opiates, 19% underwent imaging, 8% were admitted to hospital, and 8% were referred to gastroenterology.

The findings suggest that CHS may be frequently overlooked as a diagnosis, leading to unnecessary investigations and repeat visits. The authors noted a lack of screening for CHS in ED history-taking, particularly in quantifying cannabis use and eliciting the hallmark symptoms.

Why it matters

The high rate of repeat visits, unnecessary investigations, and opiate prescriptions in cannabis-using patients with vomiting suggests significant healthcare waste and potential patient harm from missed CHS diagnoses. Simple screening questions about cannabis use frequency could prevent expensive workups.

The numbers in context

494 cases reviewed. 19.4% reported cannabis use. 43% of regular users had repeat visits. 92% bloodwork, 92% IV fluids, 89% antiemetics, 27% opiates, 19% imaging, 8% admitted, 8% GI referral. Inter-rater kappa=1.

How the study worked

Retrospective chart review of adults aged 18-55 presenting with vomiting or discharged with vomiting/cyclical vomiting diagnosis at two urban tertiary care EDs and one urgent care centre over 2 years. Standardized abstraction with trained abstractors. Inter-rater reliability kappa=1.

What this study cannot tell us

Retrospective chart review depends on documentation quality. Cannabis use may be under-documented in charts. Cannot confirm CHS diagnosis without hot shower relief assessment. Single urban centre may not represent all EDs. The 19.4% cannabis use rate likely underestimates true prevalence.

How to read the evidence

Well-conducted retrospective chart review with high inter-rater reliability provides moderate evidence on CHS prevalence patterns in the ED setting.

When this study was published

Published in 2018. CHS awareness among emergency physicians has improved since, though screening practices remain inconsistent.

The bigger picture

This study quantifies the healthcare burden of undiagnosed CHS. When clinicians do not screen for cannabis use in vomiting patients, the result is a cycle of repeat visits, costly investigations that find nothing, and treatments that do not address the underlying cause.

Questions still open

Would implementing a CHS screening protocol in EDs reduce repeat visits and unnecessary investigations? How much healthcare spending could be saved by earlier CHS diagnosis? Should all vomiting patients under 55 be screened for cannabis use?

Common questions

How common is cannabinoid hyperemesis in the ED?

Of 494 patients presenting with vomiting, 19.4% reported cannabis use. Since cannabis use is often not documented, the true proportion may be higher. Among regular users, 43% returned to the ED with the same complaint.

Why is CHS often missed?

The study found a lack of screening for CHS in ED history-taking. Without asking about cannabis use frequency and CHS-specific symptoms (like hot shower relief), clinicians often pursue expensive workups and prescribe treatments that do not address the underlying cause.

Read the original research

Cannabinoid hyperemesis syndrome presentation to the emergency department: A two-year multicentre retrospective chart review in a major urban area.

CJEM, 20(4), 550-555

View on PubMed ↗Publisher’s paper ↗

Citation

Hernandez, Jeremy M; Paty, Jared; Price, Ira M. (2018). Cannabinoid hyperemesis syndrome presentation to the emergency department: A two-year multicentre retrospective chart review in a major urban area.. CJEM, 20(4), 550-555. https://doi.org/10.1017/cem.2017.381