Definition of "persistent vomiting" in current medical literature: A systematic review

Persistent vomiting is mentioned as a symptom of a large variety of systemic disorders. It is commonly used interchangeably with chronic, recurrent, or intractable vomiting and widely used as a warning sign of severe illness in dengue infection. However, it has been poorly defined in the medical literature. Therefore, we aimed to systematically review a definition of persistent vomiting in the medical literature.

A systematic search was done through; PubMed, Google Scholar, Web of Science, Scopus, VHL, WHO-GHL, Grey Literature Report, POPLINE, and SIGLE for the last 10 years. Consensus on the definition was considered to be reached if at least 50% of studies described the same definition using the Delphi consensus technique.

Of 2362 abstracts reviewed, 15 studies were selected based on the inclusion criteria. Three studies used the same definition. Another 2 studies defined it as vomiting of all foods and fluid in 24 hours. Three studies defined persistent vomiting in the units of days or weeks. Four studies used the number of episodes: ≥2 episodes 15 minutes apart, >3 episodes in 12 hours, and >3 episodes within 24 hours.

No consensus for the definition was found among authors. This is a point of concern that needs to be addressed by further studies.