What are the features of N&V caused by gastric stasis?
- Large-volume of vomitus
- Infrequent vomiting
- Relief of symptoms after vomiting
- Oesophageal reflux
- Epigastric fullness
- Early satiation
- Succussion splash (sloshing sound heard on auscultation) in some people.
What are the features of N&V caused by gastric outflow obstruction?
Symptoms similar to gastric stasis, but also forceful vomiting and rapid dehydration.
What are the features of N&V caused by "squashed stomach syndrome" (reduction in size of gastric cavity due to external compression)?
Symptoms similar to gastric stasis, but low-volume vomiting.
What are the features of N&V caused by oesophageal blockage?
- Vomiting soon after eating or drinking
- Vomitus consisting of what has just been swallowed
- Sensation of food sticking
What are the features of N&V caused by bowel obstruction?
- Intermittent nausea (often relieved by vomiting)
- Worsening nausea and/or faeculent vomiting as obstruction progresses
- Abdominal pain (may be colicky)
- Abdominal distention (may be absent if high obstruction).
What are the features of N&V caused by raised ICP?
- Effortless vomiting, often in the morning, which may be associated with headache (diurnal) and papilloedema
- Nausea (may be diurnal)
- Neurological signs and photophobia may be absent.
What are the features of N&V caused by motion?
Nausea and/or sudden vomiting on movement (for example turning in bed).
What are the features of N&V caused by anxiety?
Nausea present in waves — may be triggered by a previously experienced stimulus and may be relieved by distraction.
What are the features of N&V induced by chemical stimuli?
Constant nausea, variable vomiting.
What are the non-pharmacological approaches to managing nausea & vomiting?
- Calm, reassuring environment
- Small snacks, bland foods
- Avoid odours and control malodours
- Attention to food preparation
- Mouth care
- Acupuncture and acupressure
- NG/PEG tubes
How should nausea & vomiting be treated if cause is unknown or multiple causes?
Haloperidol 1st line
- If ineffective, add cyclizine
- If still ineffective, change to levomepromazine (generally 1st line if multiple causes are suspected)
- If still ineffective, change to dexamethsone
How should nausea & vomiting caused by chemical stimuli be treated?
- Haloperiodol or metoclopromide 1st line
- Ondansetron 2nd line
How should nausea & vomiting caused by bowel obstruction be treated?
No colic (obstruction due to peristaltic failure or gastric stasis):
- Metoclopromide 1st line
- If Parkinson's disease, use domperidone
Colic (obstruction is mechanical):
- Cyclizine 1st line
- Anti-muscarinics (e.g. hyoscine butylbromide) is often used to reduce intestinal secretions to reduce volume of vomitus
- Haloperidol or levomepromazine 2nd line
How should nausea & vomiting caused by intracranial disease be treated?
- Cyclizine 1st line
- If evidence of raised ICP, add dexamethasone
How should nausea & vomiting caused by motion be treated?
H1 antagonists (cyclizine 1st line)
What are the specific points for anti-emetic prescribing?
- Anti-emetics should be prescribed subcutaneously if patient actively vomiting. Only give anti-emetics orally if for prophylaxis
- Cyclizine and metoclopromide should never be used together as they have antagonistic actions
What laxatives are used for opioid-induced constipation?
Stimulant laxative (senna, bisacodyl) + osmotic laxative (macrogol, lactulose or phosphate enema) +/- stool softener (glycerol, docusate, arachis oil)