An unusual case of vomiting

A 28 year old male presented to an urgent care clinic with a 24 hour history of isolated vomiting. He reported 15-20 vomits per day with some vague central abdominal pain. There were no other symptoms fever, diarrhoea etc. He had no close contacts with similar symptoms. He had a history of hypertension and was on enalapril. It was unclear if his hypertension had been fully investigated. He had been seen in the clinic previously with similar symptoms and had been diagnosed with gastroenteritis. A quick review of his consultation history showed that over a four year period he had been seen six times with vomiting and had been diagnosed with gastroenteritis by six different doctors.On his last visit there was a concern about possible DKA and he had been referred to hospital. The nurse's triage had identified that he had been a cannabis user but he reported not having used any for three weeks. I asked him if his symptoms improved with having a hot shower and he confirmed this. Vitals and examination findings were unremarkable. The diagnosis I thought was suspicious of cannabis hyperemesis. He requested IV fluid and "iv painkillers". This sounded slightly unusual so I decided to check the hospital records. He had omitted to tell me that one month ago he had been admitted under General Medicine with a diagnosis of cannabis hyperemesis complicated by AKI with a creatinine over 300. I therefore suggested referral to the local emergency department. On initial investigation there he was again found to have an AKI with a Creatinine level 326 and Urea 9.6. Urine toxicology confirmed the presence of cananbinoids. He was given iv fluid, advised to stop using cannabis and was discharged the following day when his AKI had resolved.

Learning Nuggets

• Cannabis Hyperemesis Syndrome (CHS) is characterized by cyclic vomiting, nausea, and abdominal pain and is associated with the behaviour of long hot baths or showers.¹
• CHS was a not infrequent presentation during my ED days.The nurses would often put them straight in the shower. It still remains under recognized by patients and doctors. Patients often do not want to be open about their use of cannabis. There is often a delayed diagnosis as in this case.Some estimates suggest an average of 4.1 years from onset to diagnosis.²
• CHS is a subtype of cyclical vomiting syndrome with proposed diagnostic criteria:¹

1. Clinical features: stereotypical episodic vomiting resembling CVS in terms of onset, with frequency 3 or more times annually;
2. Cannabis use patterns: duration of cannabis use more than 1 year before symptom onset; frequency more than 4 times per week, on average;
3. Cannabis cessation: resolution of symptoms after a period of abstinence from cannabis use for at least 6 months, or at least equal to the total duration of 3 typical vomiting cycles in that patient.

• There is no confirmatory test. It is a clinical diagnosis.
• Other conditions need excluding first: bowel obstruction, pancreatitis, DKA, raised ICP, pregnancy, migraine etc ¹
• Isolated vomiting should always be a red flag since there are so many causes more serious than gastroenteritis.
• The physiology of improvement with hot showering is not fully understood
• It is not clear how long episodes can persist for after cessation of cannabis use.
• Complications include: electrolyte disturbances, AKI, aspiration pneumonia, Boerhaave's syndrome.¹ CHS should be taken very seriously.
• Patients often have difficulty accepting the diagnosis. This may be due to various factors:²
  -vomiting episodes are not related to an increase in cannabis use.
  -cannabis use often improves nausea.
  -patients may have significant periods( weeks to months) between episodes.
  -patients can develop the syndrome after using cannabis for less than 1 year, or greater than 11 years.
• Symptoms are often resistant to usual antiemetics.^1,2
• An Open Evidence search suggests topical capsaicin cream and haloperidol(iv/im) are probably the most useful as a first-line agents for resistant symptoms. Lorazepam is also useful but should be considered second-line due to the concern with sedation and dependence. Longterm amitriptyline may have benefit.
• In this particular case I found it interesting that the patient's ACEI was continued by the hospital team despite two epsiodes of AKI. ACEI's will increase the likelihood of AKI with any situation causing reduced renal perfusion e.g dehydration.

References

1. Rubio-Tapia A, McCallum R, Camilleri M. AGA Clinical Practice Update on Diagnosis and Management of Cannabinoid Hyperemesis Syndrome: Commentary. Gastroenterology [Internet]. 2024 May;166(5):930–934.e1. Available from: https://linkinghub.elsevier.com/retrieve/pii/S0016508524001276
2. Suspected Cannabinoid Hyperemesis Syndrome [Internet]. RCEM. 2023. Available from: https://rcem.ac.uk/clinical-guidelines/suspected-cannabinoid-hyperemesis-syndrome/