The possible diagnoses for a patient presenting with persistent nausea and/or vomiting are many and varied, but in the main may be considered under five main headings:

• Pregnancy
• Visceral disease
• Metabolic or toxic
• Central nervous system disease
• Psychiatric illness

Assessment of the patient

Assessment of the patient with persistent nausea and vomiting should fall into two categories:

• Assessment of the physical state of the patient, which has occurred as a consequence of the nausea/vomiting. Look for evidence of:
  • Poor nutritional state
  • Dehydration
  • Electrolyte imbalance
• Assessment of the patient with regard to the potential underlying cause.¹

Pregnancy

80% of pregnant women experience some form of nausea and/or vomiting related to pregnancy.² Consider the following:

• Morning sickness.
• Hyperemesis gravidarum.
• Urinary tract infection.
• Reflux oesophagitis.
• Mechanical pressure from the gravid uterus.

Common causes of persistent nausea and vomiting

Visceral disease

• Reflux oesophagitis or gastro-oesophageal reflux disease (GORD).
• Obstruction, e.g. due to malignancy or chronic constipation.
• Cholecystitis.
• Hepatitis.
• Urinary tract infection.

Metabolic/toxic

• Drugs, e.g. cytotoxic agents, erythromycin, digoxin toxicity, theophylline.
• Alcohol.
• Hypercalcaemia.
• Uraemia.
• Diabetic ketoacidosis.

Central nervous system disease

• Cyclical vomiting syndrome.
• Vestibular labyrinthitis and Ménière's disease.³
• Raised intracranial pressure, e.g. due to space-occupying lesion, intracranial bleed.

Psychiatric disease

• Bulimia nervosa.
• Functional.⁴
• Rumination disorder - also called merycism. (This is found most commonly in infants and associated with mental retardation. Previously eaten food is intentionally brought back into the mouth. Sometimes the child spits it out but, in other cases, the food is re-chewed and re-swallowed. This is not caused by a medical condition.)
• Psychogenic.

Investigations

Full history

Pay particular attention to duration, severity, aggravating and relieving factors, associated features, drug and occupational history, social history, last menstrual period, previous medical history, recent trauma.

Full examination

In particular, assess hydration, nutritional state, examine the abdomen, sclera and optic discs, check for nystagmus.

• Urine dipstick - for protein, blood, glucose, pH, bilirubin, urobilinogen.
• Serum urea.
• Serum calcium.
• LFTs.
• FBC.
• Pregnancy test.
• Plain abdominal film.
• Abdominal ultrasound.
• Endoscopy.
• Abdominal CT/MRI scan.
• Cranial CT if there is suspicion of raised intracranial pressure.

Management

General measures

• Patients with persistent nausea and/or vomiting will require appropriate dietary advice and advice on fluid intake.
• Patients with severe dehydration may require treatment for a time with intravenous fluids.
• Psychiatric or psychology referral may be appropriate for those thought to have an underlying psychiatric/psychological cause.
• Pregnant patients should be given emotional support, advice concerning diet, adequate nutritional intake, avoiding large-volume meals and tight clothing, and be advised to avoid taking antiemetic preparations available over the counter.
  • Complimentary therapies, such as ginger or acupressure, may be useful.⁵ Pregnant women who have severe vomiting may require hospitalisation, where they can receive orally or intravenously administered corticosteroid therapy and total parenteral nutrition.
• There is some evidence for the use of acupuncture for the symptomatic relief of nausea and vomiting and this may be an option for some patients.⁶ It is particularly efficacious against nausea in postoperative patients, who have not received pre-medication.

Pharmacological

Once the cause of vomiting has been established, symptomatic relief may be given (if appropriate) in the form of antiemetic therapy. Many classes of drugs exhibit antiemetic properties, e.g. antihistamines, phenothiazines (such as prochlorperazine) and antipsychotic drugs (such as haloperidol).

• Metoclopramide acts directly on the gastrointestinal tract and may be the drug of choice for visceral causes.
• Medications including pyridoxine and doxylamine have been shown to be safe and effective treatments in pregnancy, although neither is in widespread use.^6,7
• Domperidone acts at the chemoreceptor trigger zone and is especially useful for nausea and vomiting associated with chemotherapy.
• Granisetron and ondansetron are specific 5HT₃ antagonists and, as such, are particularly useful for postoperative nausea and vomiting and that associated with cytotoxic therapy.
• Dexamethasone and nabilone (a synthetic cannabinoid) may be useful for patients on cytotoxic drugs, with nausea that is resistant to other therapy.

Surgical

Surgery may be required to treat some underlying causes of nausea and vomiting, e.g. raised intracranial pressure and some forms of obstruction.

Complications

Recurrent vomiting may result in:

• Dehydration
• Electrolyte disturbance
• Oesophagitis/gastritis
• Mallory-Weiss syndrome

Document references

1. Quigley EM, Hasler WL, Parkman HP; AGA technical review on nausea and vomiting. Gastroenterology. 2001 Jan;120(1):263-86.
2. Koch KL, Frissora CL; Nausea and vomiting during pregnancy.; Gastroenterol Clin North Am. 2003 Mar;32(1):201-34, vi. [abstract]
3. Meniere's disease, Prodigy (October 2007)
4. Talley NJ; Functional nausea and vomiting. Aust Fam Physician. 2007 Sep;36(9):694-7. [abstract]
5. Quinla JD, Hill DA; Nausea and vomiting of pregnancy.; Am Fam Physician. 2003 Jul 1;68(1):121-8. [abstract]
6. Lee A, Fan LT; Stimulation of the wrist acupuncture point P6 for preventing postoperative nausea Cochrane Database Syst Rev. 2009 Apr 15;(2):CD003281. [abstract]
7. Matthews A, Dowswell T, Haas DM, et al; Interventions for nausea and vomiting in early pregnancy. Cochrane Database Syst Rev. 2010 Sep 8;(9):CD007575. [abstract]

Internet and further reading

• Nausea and vomiting in pregnancy, Prodigy (May 2008)
• Palliative cancer care - nausea & vomiting, Prodigy (October 2007)