CHS Audit: Young Males Dominated ER Presentations, with 43% Returning Within the Study Period | Research

The takeaway

A 6-year Melbourne ER audit identified 142 CHS presentations from 67 unique patients, with 43% returning during the study period, most within 3 months, and all reporting daily cannabis use.

Emergency physicians; gastroenterologists; hospital administrators assessing CHS burden.

43% of CHS patients re-presented to the ER, most within 3 months

What the researchers found

142 presentations from 67 unique patients. 43% (29 patients) represented during the study period, most within 3 months. Males were overrepresented (68.7%). Median age was 31. All had daily cannabis use. Cyclical nausea/vomiting was the most common feature. Lab findings: elevated white cells with neutrophilia (75.8%), mild low potassium (57.9%), normal lipase, and low CRP.

Why it matters

The high re-presentation rate (43%) highlights CHS as a chronic, recurring condition that significantly burdens emergency departments. The lab profile (normal lipase, low CRP) could help clinicians distinguish CHS from other causes of cyclic vomiting.

The numbers in context

142 presentations, 67 unique patients. Re-presentation rate: 43% (29/67). Most re-presented within 3 months. 68.7% male. Median age 31 (IQR 23-35). Neutrophilia: 75.8%. Hypokalaemia: 57.9%. Normal lipase. CRP <50: 98.2%. No ICU admissions. No deaths.

How the study worked

Retrospective chart review of adult CHS presentations at an urban Melbourne ED from January 2015 to January 2021. Examined demographics, cannabis use patterns, clinical features, lab results, imaging, treatment, and outcomes including re-presentation rates.

What this study cannot tell us

Single-center retrospective study in outer Melbourne. CHS diagnosis depended on documentation, which may vary by clinician. Patients who sought care elsewhere would be missed. The study could not assess cannabis cessation rates or long-term outcomes.

How to read the evidence

Moderate: 6-year audit at a single center with detailed clinical characterization, though limited by retrospective design.

When this study was published

Published in 2022, covering 2015-2021.

The bigger picture

This Australian data complements North American CHS studies, showing the condition is a global phenomenon. The detailed lab characterization is particularly useful for developing diagnostic criteria, as CHS remains a diagnosis of exclusion.

Questions still open

Would a CHS-specific discharge protocol reduce the 43% re-presentation rate? Could the lab profile (normal lipase, mild CRP, hypokalaemia) be incorporated into formal diagnostic criteria? What interventions best support cannabis cessation in CHS patients?

Common questions

How often do CHS patients come back to the ER?

In this study, 43% of CHS patients returned during the 6-year period, with most coming back within 3 months. Some patients had multiple return visits, suggesting the condition is highly recurrent without cannabis cessation.

What lab tests help diagnose CHS?

CHS patients typically had elevated white blood cells with neutrophilia (75.8%), mild low potassium (57.9%), normal lipase, and CRP below 50 (98.2%). The normal lipase is particularly useful for ruling out pancreatitis as the cause of vomiting.

Read the original research

Cannabinoid hyperemesis syndrome: A 6-year audit of adult presentations to an urban district hospital.

Emergency medicine Australasia : EMA, 34(4), 578-583

View on PubMed ↗Publisher’s paper ↗

Citation

Rotella, Joe A; Ferretti, Olivia G; Raisi, Elham; Seet, Hao Rui; Sarkar, Soham. (2022). Cannabinoid hyperemesis syndrome: A 6-year audit of adult presentations to an urban district hospital.. Emergency medicine Australasia : EMA, 34(4), 578-583. https://doi.org/10.1111/1742-6723.13944