View source for 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

[[Category:Gastroenterology]]