Vomiting

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

  1. Disorders of the gastro-intestinal tract (GIT) and liver:
    • Intestinal obstruction
    • Peptic ulcer
    • Pancreatitis
    • Cholecystitis
    • Gastroenteritis
    • Hepatitis
  2. Neurological disorders:
  3. Endocrine and metabolic:
  4. Intestinal pseudo-obstruction
  5. Psychiatric disorders:
    • Anxiety
    • Depression
    • Severe emotional upset
    • Psychogenic vomiting
  6. Drugs:
    • Cancer chemotherapy
    • Aspirin
    • Allopurinol
    • Digoxin
    • Erythromycin
    • Anticonvulsants
    • Opioids
  7. Infections:
  8. Cardiovascular diseases:
    • Acute myocardial infarction
  9. Renal:
    • uraemia from acute or chronic kidney disease
  10. Miscellaneous:
    • pregnancy
    • cyclical vomiting syndrome
    • myocardial infarction
    • labyrinthitis
    • otitis media

Symptoms of vomiting

Vomiting may be associated with:

  1. Abdominal pain
  2. Diarrhoea: gastroenteritis
  3. Abdominal distension: suspected bowel obstruction
  4. Heartburn: suspected gastro-oesophageal reflux disease
  5. Chest pain
  6. Jaundice: hepato-biliary disease
  7. Vertigo and nystagmus: suspected vestibular neuronitis
  8. 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

  1. Abdominal tenderness.
  2. Dehydration (reduced skin turgor, dry tongue, hypotension, tachycardia)
  3. Abdominal distension
  4. Succussion splash
  5. Jaundice
  6. Signs of peritonitis (rebound tenderness, rigidity, guarding)
  7. Miscellaneous: e.g. vertigo, nystagmus, focal neurological signs,
  8. 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

  1. To identify and treat the underlying cause of vomiting
  2. To prevent dehydration and electrolyte imbalance
  3. To maintain nutrition by ensuring adequate dietary intake during illness
  4. To maintain personal hygiene
  5. 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, 10-20 mg 8 hourly as needed

Or

Promethazine, IM, 12.5-25 mg 8 hourly as needed

Or

Metoclopramide, oral, 10 mg 8 hourly

Or

Metoclopramide, IV/IM, 10 mg 8 hourly as needed.