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Nausea and vomiting in palliative care |
Nausea and vomiting occurs in about 50% of patients with advanced cancer at some time. Patients rate nausea as a more unpleasant symptom than vomiting alone and also rate it to be as distressing as pain.
Nausea and vomiting are separate clinical entities although they often accompany each other. It can be difficult to elucidate from the history the exact complaint the patient has as nausea can be variably described by interchangeable symptoms such as ‘feeling sick’, ‘heartburn’, ‘bloat’, ‘touch of gastric’, ‘no appetite’, ‘indigestion’, etc.
Definitions
Nausea is an unpleasant subjective sensation involving the upper gastro intestinal tract usually associated with a feeling of the need to vomit.
Retching consists of rhythmic spasmodic contractions of the diaphragm and abdominal muscles.
Vomiting is the expulsion of the gastric content through the mouth caused by forceful and sustained contraction of the abdominal muscles and the diaphragm.
The history is the key to patient assessment as the description of the pattern of vomiting may provide important diagnostic information, and there is often little to find on examination.
Points in the history
1. Nausea
Is it constant/variable/worse with movement?
? related to drugs.
? associated with vomiting or relieved with vomiting.
2. Vomiting
? on movement.
Large volume/small volume/? undigested food.
3. Bowels
When last open.
? constipated/? impacted/ ? obstructed.
4. ? Headaches (raised intracranial pressure)
5. Coughing bouts (produces vomiting with little nausea)
6. Previous antiemetics including dose/route (? Try higher dose/parenteral route)
7. ? Exacerbating factors eg. pain, fear, anxiety, wound odours, etc.
Points in examination
Oral candida, post nasal drip, abdomen including PR, hydration state, neurological signs +/- papilloedema.
Possible investigations
FBC (infection), U & E, Cr (Uraemia), LFT (hepatic failure), Ca, Digoxin level, MSU, and AXR (severe constipation/ impaction/obstruction).
The pathophysiology of nausea and vomiting can broadly be divided into the five following syndromes, which a clear history should indicate.
1. Chemically induced
Causes: Drugs (opioids, antibiotics, anticonvulsants, digoxin), metabolic (hypercalcaemia, uraemia, liver failure), cytotoxics, toxics (infection, food poisoning).
Clinical features:
- Nausea and retching more prominent than vomiting.
- Vomiting does not relieve nausea.
- Nausea usually constant.
- 1st line: Haloperidol 1.5-5mg/day subcut/oral
- 2nd line: Metoclopramide 10-80mg/day subcut/oral
2. Gastric stasis +/- gastric outflow obstruction
Causes: Anticholinergic drugs, ascites, autonomic failure, hepatomegaly, peptic ulcer, gastritis.
Clinical features:
- Epigastric fullness and discomfort, early satiety, flatulence, reflux and regurgitation.
- Large volume vomits +/- undigested food (small volume vomits with squashed stomach syndrome).
- Vomiting more prominent than nausea.
- Nausea relieved with vomiting.
- 1st line: Metoclopramide 10-80mg/day subcut/oral
- 2nd line: Cisapride 20mg bd/30mg tds PR
3. Stretch/distortion GI tract
Causes: Constipation, obstruction, mesenteric metastases.
Clinical features:
- Altered bowel habit.
- Nausea, colic.
- Faeculent vomiting.
- 1st line: Treat underlying cause. See next issue for management of bowel obstruction and previous issue for management of constipation.
4. Movement associated emesis
Causes: Opioids, gut distortion, gastroparesis.
Clinical features:
- Nausea/sudden vomits on movement.
- 1st line: Prochlorperazine 25mg tds PR/Cyclizine (antihistamine) 25mg tds sc
- 2nd line: Hyoscine 0.3mg sl qds (Kwells)
5. Raised ICP
Causes: Cerebral tumour, intracranial bleed, meningeal disease.
Clinical features:
- Drowsiness
- Headache (diurnal)
- Nausea (may be diurnal).
- 1st line: Cyclizine 25mg tds oral/subcut per 24 hours Adjunct: Dexamethasone
Choosing an antiemetic
Choosing an effective antiemetic depends firstly on diagnosing the likely syndrome and choosing the 1st line treatment outlined above.
Generally the initial choice lies between metoclopramide, haloperidol and prochlorperazine and is often dependent on whether gastro-intestinal motility needs to be stimulated. Metoclopramide and Cisapride are prokinetic drugs, ie. aid GI motility but are contraindicated in absolute bowel obstruction (see next issue).
30% of patients require two or more antiemetics as there is often a combination of causes in the palliative care setting.
Parenteral administration is needed for drug absorption.
Adjunct antiemetics to consider are dexamethasone and/or alprazolam/lorazepam (for anxiety/anticipatory vomiting).
5HT3 antagonists, eg. ondansetron, tropisetron, are only licensed as 1st line agents for chemotherapy/radiation induced nausea and vomiting. They are not 1st line treatments for any other causes.
Non-drug measures include avoiding strong smells, small meals (2-3 teaspoons), try cold foods, try tonic water/fizzy drinks.
This is not a complete reference for the use of antiemetics and does not include receptor sites or neurotransmitters involved. For more information please consult the following references:
Oxford Textbook of Palliative Medicine
Symptom Management in Advanced Cancer, Robert Twycross
The Management of Nausea and Vomiting in Advanced Cancer, Campbell and Hatley
International Journal of Palliative Nursing 2000, Volume 6 No. 1
www.palliativedrugs.com
Joanne Doran (jdoran@nor.com.au) is the area medical director of palliative care, based in St Vincent’s Hospital, Lismore, NSW, Australia.
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