Analysis of 248 million ER encounters from 2016-2024 found 134,059 visits for cannabinoid hyperemesis syndrome, with 13.5% admission rates, affecting mainly young adults (mean age 32) and most commonly treated with haloperidol after ondansetron.
Emergency medicine physicians, gastroenterologists, health system administrators, and cannabis policy researchers.
What the researchers found
CHS accounted for 134,059 of 248,293,507 ED encounters (0.05%). Mean patient age was 32 years. Admission rate remained steady at ~13.5% with mean 3.8-day hospital stay. Ondansetron was the most common treatment (58.7%), followed uniquely by haloperidol (32.6%) rather than the metoclopramide used for gastroparesis and cyclic vomiting.
Why it matters
This is the largest dataset ever analyzed for CHS emergency department visits. The steady admission rate and distinctive treatment patterns (haloperidol for CHS vs. metoclopramide for other vomiting disorders) confirm CHS as a clinically distinct entity requiring different management than other vomiting syndromes.
The numbers in context
248,293,507 total ED encounters. GP: 165,857 (0.07%). CVS: 204,636 (0.08%). CHS: 134,059 (0.05%). CHS mean age: 32. CHS admission rate: ~13.5% (stable). CHS mean LOS: 3.8 days. CHS medications: ondansetron 58.7%, haloperidol 32.6%. All three conditions primarily affected females.
How the study worked
Retrospective cohort study of all ED presentations for gastroparesis, cyclic vomiting syndrome, and CHS from 2016-2024 in the Epic Cosmos database (248 million encounters). ICD-10 codes identified cases. Outcomes included incidence, admission rates, medications, and length of stay.
What this study cannot tell us
ICD-10 coding may undercount CHS (misdiagnosed as CVS) or overcount it (coding errors). Epic Cosmos captures only participating health systems. Cannot determine cannabis use patterns or product types. Admission rates and treatments reflect clinical practice variation, not evidence-based guidelines.
How to read the evidence
Massive national dataset with nine years of data, providing robust epidemiologic estimates despite ICD-10 coding limitations.
When this study was published
Published 2025, analyzing 2016-2024 Epic Cosmos data.
The bigger picture
The emergence of CHS as a condition generating over 134,000 ED visits in less than a decade underscores the real-world health burden of heavy cannabis use. The distinctive haloperidol treatment pattern reflects clinical learning about what actually works for CHS versus other vomiting disorders.
Questions still open
- Whether CHS incidence is increasing over this period as cannabis access expands
- Why haloperidol is effective for CHS but not for gastroparesis or cyclic vomiting
Common questions
Why is haloperidol used for CHS but not other vomiting conditions?
How common is CHS compared to other vomiting disorders?
Read the original research
Presentations to United States emergency departments for gastroparesis, cyclic vomiting, and cannabinoid hyperemesis syndrome from 2016 to 2024.
The American journal of emergency medicine, 96, 201-207
Citation
Shalaby, Michael; Moyer, Eric; Buell, Kevin G; Bernard, Kyle; Gottlieb, Michael. (2025). Presentations to United States emergency departments for gastroparesis, cyclic vomiting, and cannabinoid hyperemesis syndrome from 2016 to 2024.. The American journal of emergency medicine, 96, 201-207. https://doi.org/10.1016/j.ajem.2025.06.067