Cannabinoid Hyperemesis Syndrome. Prospective Multicenter Study of Patients Admitted to Adult Emergency Departments in Maine-et-Loire.

Cannabinoid hyperemesis syndrome (CHS) is characterized by incoercible abdominal pain and vomiting in patients with chronic cannabis use. Patients are relieved by hot showers, an easily performed diagnostic test. The prevalence of this syndrome in France is not well known. A single French study from 2021, carried out in two Marseille emergency departments, estimated a 1.6% prevalence of CHS (48 cases / 2848 patients) in patients consulting for acute abdominal pain with no etiology found over a 10-month period. Cannabis is the most widely used illicit substance in France. France is also the second biggest cannabis consumer in Europe, with around 11% of the French population currently using the drug (use within the year). Despite growing attention to CHS, the diagnosis and management of this syndrome remains difficult, with repeated visits to emergency departments often required before a diagnosis is made. What's more, once the diagnosis has been made, the severity of symptoms can lengthen the emergency room length of stay. Main objective: To estimate the incidence of cannabinoid hyperemesis syndrome among patients admitted on a first visit for abdominal pain and/or vomiting to the Maine et Loire emergency department. Primary endpoint: The incidence of cannabinoid hyperemesis syndrome among patients presenting with abdominal pain and/or vomiting, consulting adult emergency departments in Maine et Loire. Cannabinoid hyperemesis syndrome will be considered in all patients admitted for abdominal pain and/or vomiting, who are regular cannabis users (weekly use for more than 6 months declared by questionnaire) and in whom no other etiology is accepted after any additional examinations. Research plan and procedure: It is an observational, prospective, multi-center cohort study. Participation in the study is offered to any emergency room patient who meets all inclusion criteria and none of the non-inclusion criteria. Patients are included after reading the informati