Introduction
Vomiting can be induced by a variety of disease processes including gastrointestinal, neurologic, renal, psychiatric, cardiovascular, endocrine, pain and the effects of drugs.
The best course of action in identifying the underlying cause is to carry out a detailed clinical evaluation and management plan, looking out for the aetiology, consequences and potential complications of vomiting.
Severe uncontrolled vomiting can result in significant dehydration and electrolyte imbalance accompanied by renal complications.
Anti-emetics should be prescribed only when the cause of vomiting is known as they may delay diagnosis.
Causes of vomiting
- Disorders of the gastro-intestinal tract (GIT) and liver:
- Intestinal obstruction
- Peptic ulcer
- Pancreatitis
- Cholecystitis
- Gastroenteritis
- Hepatitis
- Neurological disorders:
- Severe pain
- Migraine
- Raised intracranial pressure (i.e. tumours, haemorrhage; meningitis)
- Seizures
- Stroke
- Endocrine and metabolic:
- Diabetic ketoacidosis
- Uraemia
- Hypercalcaemia
- Intestinal pseudo-obstruction
- Psychiatric disorders:
- Anxiety
- Depression
- Severe emotional upset
- Psychogenic vomiting
- Drugs:
- Cancer chemotherapy
- Aspirin
- Allopurinol
- Digoxin
- Erythromycin
- Anticonvulsants
- Opioids
- Infections:
- Malaria
- Urinary tract infections
- Cardiovascular diseases:
- Acute myocardial infarction
- Renal:
- uraemia from acute or chronic kidney disease
- Miscellaneous:
- pregnancy
- cyclical vomiting syndrome
- myocardial infarction
- labyrinthitis
- otitis media
Symptoms of vomiting
Vomiting may be associated with:
- Abdominal pain
- Diarrhoea: gastroenteritis
- Abdominal distension: suspected bowel obstruction
- Heartburn: suspected gastro-oesophageal reflux disease
- Chest pain
- Jaundice: hepato-biliary disease
- Vertigo and nystagmus: suspected vestibular neuronitis
- Anxiety Depression
Vomiting may have diagnostic clues
We may not be wrong if we call these medical uses of vomiting. For instance;
- Vomiting of food eaten several hours earlier suggests gastroparesis or gastric outlet obstruction
- Vomiting with blood is suggestive of oesophageal, gastric or duodenal lesion
- Early morning vomiting: pregnancy
- Faeculent vomiting: intestinal obstruction, gastro-colic fistula
- Projectile: if pyloric stenosis
Signs of vomiting
- Abdominal tenderness.
- Dehydration (reduced skin turgor, dry tongue, hypotension, tachycardia)
- Abdominal distension
- Succussion splash
- Jaundice
- Signs of peritonitis (rebound tenderness, rigidity, guarding)
- Miscellaneous: e.g. vertigo, nystagmus, focal neurological signs,
- Kussmaul breathing (uraemia, diabetic ketoacidosis)
Investigations
- FBC
- BUE and Creatinine
- LFT
- Blood glucose Serum amylase
- Urine RE
- Urine Pregnancy test
- ECG (if myocardial infarction suspected)
- Abdominal X-ray: Intestinal obstruction
- Erect Chest X-ray: bowel perforation with air under diaphragm
Persistent Vomiting:
- Upper gastro-intestinal endoscopy
- Serum calcium level
- CT scan of brain
Treatment for vomiting
Objectives
- To identify and treat the underlying cause of vomiting
- To prevent dehydration and electrolyte imbalance
- To maintain nutrition by ensuring adequate dietary intake during illness
- To maintain personal hygiene
- To eliminate infecting organisms where appropriate
Non-pharmacological treatment
- Maintain adequate oral fluid intake (if tolerated)
- Maintain adequate nutrition
- Place naso-gastric tube when needed
- Surgical intervention in suspected intestinal obstruction, peritonitis
Pharmacological treatment
A. Suggested Anti-Emetics for use in Migraine
Evidence Rating: [B]
1. Metoclopramide, oral/IV/IM,
Adults
- 10 mg 8 hourly
Or
Domperidone, oral,
Adults
- 10 mg, 8 hourly
Children
- > 12 years (Body weight ≥ 35 kg); 10 mg 8-12 hourly (max. 30 mg per day)
- 1 month-12 years (Body weight ≤ 35 kg); 250 micrograms/kg 8-12 hourly (max. 750 microgram/kg per day)
Note:
Domperidone should be used at the lowest effective dose for the shortest possible duration.
The maximum duration of treatment should not exceed 7 days).
Or
2. Promethazine, IV/IM
Adults
- 12.5-25 mg 6-8 hourly as needed (max. 100 mg in 24 hours)
Or
3. Promethazine, oral,
Children
- 2-12 years; 0.25-1 mg 6-8 hourly as needed (max. 25 mg per dose)
- < 2 years; Not recommended
B. Suggested Anti-Emetics for use in Vestibular Nausea and vomiting
Promethazine, oral,
Adults
- 20-25 mg 12 hourly
Children
- 2-12 years; 0.25-1 mg 6-8 hourly as needed (max. 25 mg per dose)
- < 2 years; Not recommended
Or
Promethazine, IV/IM
Adults:
- 12.5-25 mg 6-8 hourly as needed (max. 100 mg in 24 hours)
Or
Cyclizine, oral,
Adults
- 50 mg 8 hourly as needed
Children
- 6-12 years; 25 mg 8 hourly as needed (max. 75 mg in 24 hours)
Or
Cinnarizine, IV/IM,
Adults and children > 12 years
- 30 mg 8 hourly as needed
Children
- 5-12 years; 15 mg 8 hourly as needed
- < 5 years; not recommended
C. Suggested Anti-Emetics for use in Gastroenteritis
Metoclopramide, oral/IV/IM,
Adults
- 10 mg 8 hourly
Or
Domperidone, oral,
Adults
- 10 mg, 8 hourly
Children
- > 12 years (Body weight 235 kg); 10 mg 8-12 hourly (max. 30 mg per day)
- 1 month-12 years (Body weight ≤ 35 kg); 250 micrograms/kg 8-12 hourly (max. 750 microgram/kg per day)
D. Suggested Anti-Emetics for use in Post-Operative Vomiting
Metoclopramide, oral/IV/IM,Adults
- 10 mg 8 hourly
Or
Cyclizine, oral/IV/IM,
Adults
- 50 mg 8 hourly as needed
Children
- 6-12 years; 25 mg 8 hourly as needed (max. 75 mg in 24 hours)
E. Suggested Anti-Emetics for use in Chemotherapy-Induced Vomiting
Ondansetron, IV,
Adults
- 8 mg/0.15 mg/kg (pre-chemotherapy) infused over 15 minutes
Children
- > 6 months; 0.15 mg/kg (pre-chemotherapy) infused over 15 minutes, then repeated 4 and 8 hours after first dose. (max is 16 mg/dose)
Or
Ondansetron, oral,
Adults
- 8 mg 12 hourly
Children
- 4-12 years; 4 mg 30 minutes before chemotherapy, then 4 mg 8 hourly for 24-48 hours as needed
- < 4 years; Not recommended
Or
Granisetron, IV,
Adults
- 1mg/10 microgram/kg (30 minutes before Chemotherapy)
Children
- 2-16 years; Same as adults
- <2 years; Not recommended
Or
Granisetron, oral,
Adults
- 1mg, 1 hour before chemotherapy, then 1 mg 12 hours after 1st dose
Or
2 mg, 1 hour before chemotherapy
Children: Not recommended
Or
Dexamethasone, oral/IV,
Adults
- 8-12 mg before chemotherapy, then 8 mg 24 hourly from days 2-4
Children: Not recommended
Or
Lorazepam, oral/IV,
Adults
- 0.5-2 mg 6 hourly as required
Children: Consult a specialist
F. Suggested Anti-Emetics for use in Pregnancy
(See severe vomiting in Pregnancy)
Promethazine teoclate, oral, 10 to 20 mg 8 hourly as needed
Or
Promethazine, IM, 12.5 to 25 mg 8 hourly as needed
Or
Metoclopramide, oral, 10 mg 8 hourly
Or
Metoclopramide, IV/IM, 10 mg 8 hourly as needed.