Nausea and vomiting at the end of life

Differential Diagnosis

• Head
  • Increased ICP
  • Meningeal irritation
  • Anxiety
  • Vestibular disorders
• Gastrointestinal
  • Esophageal: GERD, thrush
  • Gastric
    • Gastric irritation
    • Gastric stasis
  • Obstruction
  • Infection
• Organ failure
  • Renal failure
  • Liver failure
• Other causes
  • Medications
  • Hypercalcemia
  • Tumour-induced
  • Sepsis

Pathophysiology

• Four pathways
  • Vestibular system
    • Causes: motion, labyrinth disorders
    • Receptors: muscarinic acetylcholinergic and H1 histamine receptors
  • Chemoreceptor trigger zone (area outside blood-brain barrier)
    • Causes: drugs, metabolic products, bacterial toxins
    • Receptors: central D2 dopamine receptors (most important), 5HT3 serotonin receptors, and NK1 receptors
  • Cortex
    • Causes: sensory input, anxiety, meningeal irritation, increased ICP
  • Peripheral pathways
    • Causes: mechanical stretch, chemotherapy, radiotherapy, GERD, Candida, metastases, local drugs or toxins
    • Receptors: 5HT3 serotonin receptors (GI tract), mechanoreceptors and chemoreceptors in GI tract

Management

• Metabolic: D2 antagonist (e.g. haloperidol, metoclopramide)
• Chemotherapy: D2 antagonist (e.g. haloperidol, metoclopramide)
• Increased ICP: dexamethasone
• Obstruction: general surgery consult or medical management (AAAH)
  • Anti-emetic
    • Neuroleptics: haloperidol 0.5-2mg po/sc up to q1h prn
    • If partial: metoclopramide 5-10mg po/sc QID
  • Analgesic
    • Opioids
    • Anti-spasmodics: buscopan 10mg po/sc q6h (antikinetic)
  • Anti-secretory
    • Somatostatin analogues: octreotide 100-500 mcg sc TID
    • Anticholinergics: scopolamine, buscopan
  • Anti-inflammatory
    • Dexamethasone 4mg po/sc daily to QID
    • Decreases edema around obstruction to allow passage of some stool
  • Hydration