CLINICAL knowledge Understanding and in advanced

Author Colin Perdue, BN, RGN, DipN, is clinical nurse Definitions specialist in palliative medicine, Morriston Hospital, Nausea and vomiting are often regarded as a single Swansea. entity, but they are separate physiological conditions Abstract Perdue, C. (2005) Understanding nausea (Eckert, 2001). Nausea is an unpleasant feeling of the and vomiting in advanced cancer. Nursing Times; 101, need to vomit. It is often accompanied by autonomic 4, 32–35. symptoms such as pallor, cold sweat, salivation and tachy­ Nausea and vomiting are commonly experienced by cardia (Yarbro et al, 1999). Retching is a strong involuntary people with advanced cancer. Nausea and vomiting can effort to vomit. It occurs in the presence of nausea and References have an adverse effect on a patient’s physical, psycho- often culminates in vomiting (Twycross and Back, 1998). logical and social well-being. Knowledge of the physiol- Vomiting (emesis) is the forceful expulsion of gastric con- Allan, S.G. (1999) Nausea and vomiting. ogy of nausea and vomiting will promote a rational tents through the mouth (Twycross and Back, 1998). In: Doyle, D. et al (eds) Oxford Textbook choice of treatment. Nurses also need to be aware of After an episode of vomiting, there may be a post- of Palliative Medicine. Oxford: Oxford non-pharmacological measures that can reduce these ejection phase characterised by weakness, lethargy and University Press. distressing symptoms. shivering (Allan, 1999). Vomiting may ease the sensation Baines, M. (1997) Nausea, vomiting and of nausea. It may serve a protective function by expelling intestinal obstruction. British Medical It is estimated that 20–60 per cent of patients with noxious substances from the gut and stop further ingestion Journal; 315, 1148–1150. advanced cancer will experience nausea and vomiting of such substances (Allan, 1999; Yarbro et al, 1999). (Allan, 1999; Grond et al, 1994; Dunlop, 1989; Baines, Baines, M. (1988) Nausea and vomiting 1988). The patient with advanced cancer may have Physiology in the patient with advanced cancer. several potential causes for nausea and vomiting, Synchronous contractions of the diaphragm and abdominal Journal of Pain and Symptom although it is often possible to identify the primary muscles raise intra-abdominal pressure and compress Management; 3: 2, 81–85. cause. The primary cause, however, may change during the stomach. Atony of the stomach, oesophageal sphinc- the patient’s illness ter and pylorus are associated with retroperistalsis. As a Back, I. (2001) Palliative Medicine Nurses have a significant role in assessing symptoms, result, stomach contents are forced upwards to the Handbook. Cardiff: BPM Books. measuring the response to and providing mouth, culminating in the act of vomiting (Yarbro et al, non-pharmacological treatments. Thorough assessment, 1999; Twycross and Back, 1998; Marieb, 1989). knowledge of antiemetics and their mode of action, will Several neural structures and a variety of neurotrans- allow the nurse to provide individualised treatment. mitters and receptors have been identified that relate to Nausea and vomiting can cause , electrolyte nausea and vomiting. Most of the relevant receptors are imbalance and nutritional deficiencies (Marek, 2003), and excitatory – they induce nausea and vomiting when it can also impact on a patient’s psycho­social well-being. stimulated (Twycross and Back, 1998) (Fig 1). They may become withdrawn, isolated and unable to The vomiting centre, sometimes referred to as a cen- perform their usual activities of daily living. The patient’s tral pattern generator, is located within the reticular for- distress often extends to family members. mation of the brain stem and is thought to coordinate the vomiting process. It lies completely within the blood- brain barrier and receives impulses from the chemore- Learning objectives ceptor trigger zone (CTZ), vestibular apparatus (the part of the internal ear concerned with balance) higher corti- Each week Nursing Times publishes a guided learning article with reflection cal centres and afferent nerve impulses from the periph- points to help you with your CPD. After reading the article you should be able to: ery (primarily via the vagus nerve, but also the glos- sopharyngeal nerve and sympathetic afferents). The vomiting process is coordinated by efferent impulses from l Understand the physiology behind nausea and vomiting; the vomiting centre to the pharynx, larynx, diaphragm, l Know the link between advanced cancer and nausea and vomiting; intercostal muscles and gut. The CTZ is located within the (on the l Be familiar with the assessment of nausea and vomiting; floor of the fourth ventricle in the brain). Although ana- tomically close to the vomiting centre, the CTZ lies partly l Know the different medications that can be used to treat nausea and vomiting; outside the blood-brain barrier and is therefore exposed l Understand the connection between nausea and vomiting and . to various noxious agents borne in the blood and cere-

brospinal fluid – such as , biochemical products and SPL

32 NT 25 January 2005 Vol 101 No 4 www.nursingtimes.net keywords n Cancer care n Nausea n Vomiting

Fig 1. Simplified diagram of the neural emetic pathways References

Dibble, S. et al (2000) Acupressure for Biochemical Toxins/drugs Chemotherapy / Odours nausea: results of a pilot study. disturbance anticipatory Tastes Nursing Forum; 27: 1: 41–47. Sights Dunlop, G.M. (1989) A study of the relative frequency and importance of Dopamine Higher cerebral type 2 D2 5-HT3 intestinal symptoms, and weakness in centres patients with far advanced cancer. Chemoreceptor Palliative Medicine; 4: 37–43. trigger zone CTZ Eckert, R. (2001) Understanding anticipatory nausea. Oncology Nursing Forum; 28: 10, 1553–1558. Motion Chemotherapy Chemotherapy Gastric distension sickness Grond, S. et al (1994) Prevalence and pattern of symptoms in patients with : a prospective evaluation of Vagus nerve 1,635 cancer patients referred to a pain Radiotherapy Sympathetic Inner ear clinic. Journal of Pain and Symptom to the gut Afferents Vestibular disorders Management; 9: 6, 372–382. Glossopharyngeal apparatus nerve Marek, C. (2003) therapy in patients receiving cancer chemotherapy. Oncology Nursing Forum; 30: 2, Intestinal obstruction 259–269.

Marieb, E. (1989) Human Anatomy and Muscarinic Histamine Serotonin Physiology. Menlo Park, CA: Benjamin cholinergic type 1 H1 5-HT2 Cummings.

Vomiting centre

Initiation of vomiting

drugs (Yarbro et al, 1999; Baines, 1988). Neural path- l Does nausea precede vomiting? ways from the CTZ provide the main stimulus to the l Does vomiting relieve nausea? vomiting centre (Allan, 1999; Baines, 1988). l When did the symptoms start? Did they coincide with The vagus nerve provides the connection between the changes in therapy or medication? gut and the vomiting centre (with some stimulation of l Does anything make the symptoms better? the CTZ). Stimulation of the vagus nerve is thought to l Does anything make the symptoms worse? play a key role in nausea and vomiting induced by chem- l What is the effect of any current or past antiemetic otherapy and radiotherapy. therapy including dose, frequency, duration, effect, route The vomiting centre is also stimulated by impulses of administration? from the vestibular apparatus – motion and labyrinthitis l What are the patient’s current medications/therapies? being the most common to induce nausea and vomiting. l Are there upper gastrointestinal symptoms such as dyspepsia, heartburn, fullness or early satiation? Assessment l Is there any abdominal pain or swelling? The choice of treatment for nausea and vomiting requires l What is the patient’s urine output? a thorough assessment of the primary and subsidiary or l Do they have constipation or diarrhoea? concurrent causes, as well as which receptors and neuro- l Are there signs of infection (for example in the chest transmitters are understood to be involved (Box 1). or urinary tract)? It is insufficient to simply record that a patient ‘has l Is the patient drowsy or confused? This article has been double-blind been sick’. Assessment should address questions such as: l What is the condition of the patient’s oral cavity? peer-reviewed. l Does the patient feel nauseous? Ongoing evaluation of symptoms and interventions is For related articles on this subject l Is the patient vomiting? If so, what is the frequency, equally important. Frequent and regular monitoring ena- and links to relevant websites see volume, content, timing? bles the treatment plan to be adjusted as needed. www.nursingtimes.net

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References Pharmacology spectrum of antiemetic properties. It has an antagonistic Occasionally, assessment will reveal a specific cause of action on D2, H1, Ach m and 5-HT2 receptors (Twycross Perdue, C. (2004) The syringe driver – an nausea and vomiting that is treatable (for example and Back, 1998; Baines, 1997). also has aid to delivering symptom control. hypercalcaemia). However, antiemetic therapy is nearly anti­emetic properties, although its mode of action is Nursing Times; 100: 13, 32–35. always necessary for patients with advanced cancer. uncertain. Many antiemetic drugs are available with varying modes Referral to a specialist team is recom- Roscoe, J. et al (2000) Nausea and of action, but none will provide complete control in all mended for patients with advanced cancer whose symp- vomiting remain a significant clinical situations. The three most commonly used antiemetics toms are uncontrolled after 48 hours. problem: trends over time in controlling chemotherapy-induced nausea and in palliative care are , and vomiting in 1,413 patients treated in (Back, 2001; Twycross and Back, 1998). Route of administration community clinical practices. Journal of Metoclopramide affects the myenteric plexus through The three first-line antiemetics used in palliative care can Pain and Symptom Management; its action as a 5-HT4 and D2 antagonist. Its pro­ be given orally and parenterally. Oral administration is 20: 2, 113–121. kinetic effect results in accelerated gastric emptying. At the route of choice but may be a problem for those who: higher doses, metoclopramide antagonises D2 and 5-HT3 l Are unable to swallow – due to dysphagia, frailty, un- Twycross, R. (2004) Anorexia, cachexia, receptors in the CTZ (Yarbro et al, 1999; Baines, 1997). consciousness; nausea and vomiting. Medicine; Metoclopramide is the antiemetic of choice in cases of l Are persistently vomiting; 32: 4, 9–13. gastric stasis and partial gastric obstruction. It is also the l May not be absorbing the drug – this is uncommon first choice antiemetic in chronic, unexplained nausea except in cases of delayed gastric emptying, for example Twycross, R. (1997) Symptom Management in Advanced Cancer. (Twycross, 2004; Back, 2001). with nausea or obstructed gastric outflow; Oxford: Radcliffe Medical Press. Haloperidol is a more potent and more selective D2 l Are reluctant to take oral medication –for example be- antagonist than metoclopramide. It is used when there is cause they are afraid of inducing vomiting. Twycross, R., Back, I. (1998) Nausea thought to be a chemical cause for nausea and vomiting, When the oral route cannot be used, occasional epi- and vomiting in advanced cancer. such as secondary renal failure, hypercalcaemia or drug sodes of nausea and vomiting may be relieved by injec- European Journal of Palliative Care; therapy (Twycross, 2004; Back, 2001). tion. For persistent nausea and vomiting, a continuous 5: 2, 39–45. Cyclizine acts on the vomiting centre and has antihista- subcutaneous infusion via syringe driver is the preferred minic and antimuscarinic properties. It is used when method of administering an antiemetic (Baines, 1997). (1996) Can have Vickers, A. nausea is associated with complete , The syringe driver: specific effects on health? A systematic vestibular disturbance and raised . l Avoids the need for repeated injections; review of acupuncture antiemesis trials. l Journal of the Royal Society of Antimuscarinic drugs such as cyclizine should not be Produces relatively constant systemic levels of medi- Medicine; 89: 303–311. prescribed with a prokinetic such as metoclopramide as cation, avoiding medication peaks (increasing the risk of they have antagonistic properties. side-effects) and troughs (resulting in reduced symptom Yarbro, C.H. et al (1999) Cancer and If a single first-line antiemetic does not provide relief control); Symptom Management. then health care professionals must question whether l Has minimal impact on patient mobility; London: Jones and Bartlett. the cause has been correctly identified. Options include: l Allows medication to be administered over a 24-hour l Changing to an antiemetic that has a different action; period (Perdue, 2004). l Combining antiemetics with complementary action. About one-third of patients with advanced cancer who Chemotherapy experience nausea and vomiting require more than one Nausea and vomiting are common side-effects of chem- antiemetic (Twycross, 1997). If first-line antiemetics fail otherapy. Chemotherapy agents and radiation to the to provide satisfactory relief, adding or substituting a gut are thought to stimulate the enterochromaffin cells second-line antiemetic such as or of the , causing them to release dexamethasone should be considered. 5-HT that binds to the 5-HT3 receptors located on the Levomepromazine is a with a broad vagus nerve. The impulses are carried to the CTZ resulting in the sensation of nausea and the need to vomit (Marek, 2003; Yarbro et al, 1999). Guided reflection Chemotherapy may damage the rapidly dividing cells of the gut leading to breaches in gut wall integrity. Such Use the following points to write a reflection for your PREP portfolio: damage could allow emetogenic toxins to enter the bloodstream (Yarbro et al, 1999). Chemotherapy may l Describe how this article is relevant to your work; also inhibit gastric emptying (Yarbro et al, 1999). Several distinct types of nausea and vomiting have l Summarise the article’s main points about nausea and vomiting in advanced cancer; been associated with chemotherapy: l Acute – occurring within the first 24 hours of treat- l Identify new knowledge about nausea and vomiting you have learnt from this article; ment and related to the release of 5-HT from enterochro- l Consider how you will use this information in your future practice; maffin cells; l Delayed – occurring 24–72 hours after treatment. The l State how you intend to follow up what you have learnt from this article. causal mechanism is unclear but may be related to re- duced gastric motility and gut wall damage;

34 NT 25 January 2005 Vol 101 No 4 www.nursingtimes.net Box 1. causes of nausea and vomiting Patients undergoing chemotherapy will experience in patients with advanced cancer nausea and vomiting to varying degrees. Factors that contribute to the severity of the symptoms include l Drugs (Marek, 2003; Eckert, 2001): l Drugs cause nausea and vomiting in different ways: The chemotherapy agents used and their dosage; l Age – it is more pronounced in younger people; l Gastric irritation – NSAIDs non-steroidal anti- l Gender – females are more prone to chemotherapy- inflammatory drugs, iron supplements, antibiotics; induced nausea and vomiting; l Gastric stasis – , tricyclic antidepressants, l Alcohol intake – a chronic, high alcohol intake reduces ; incidence of chemotherapy-induced nausea and vomiting; l 5-HT3 stimulation – chemotherapy, l Individuals who suffer from may ex- selective serotonin re-uptake inhibitors (SSRIs); perience more severe episodes of nausea and vomiting; l Increased levels of anxiety. l Drugs with an unpleasant taste – docusate sodium (liquid), potassium supplements; Non-pharmacological measures l Excessive amounts of medication at any time. There is a range of non-pharmacological interventions l Radiotherapy – especially on abdomen or head; that may help reduce the frequency and severity of symptoms, enhance the effect of antiemetics and in- l Gastric – gastric stasis, gastric obstruction (partial crease the patient’s sense of control. Dietary measures or complete), ‘squashed stomach syndrome’; may include: l Constipation; l Eating foods cold or at room temperature as they of- l Metabolic – uraemia, hypercalcaemia; ten smell less strongly than hot foods; l Avoiding fatty foods; l Pain; l Eating carbohydrates; l Pharyngeal stimulation – candida infection, l Eating small, frequent meals; tenacious sputum; l Avoiding foods that increase the patient’s nausea; l Psychosomatic factors – , anxiety, anticipatory l Educating family members who, in their desire to ‘do nausea and vomiting, aversion to certain tastes, the right thing’ encourage the patient to eat more than sights and odours; they can comfortably manage. It can be argued that the patient’s favourite food l Vestibular disturbance; should be avoided during episodes of nausea in case it l ; provides a future stimulus for nausea and vomiting, so l Concurrent causes – renal failure, peptic depriving the patient of a pleasurable experience. ulceration, alcohol , gastric infection. Avoiding the sight and smell of food may reduce epi- sodes of nausea. The inpatient should be protected from Sources: Twycross and Back, 1998; Baines, 1997; Twycross, 1997 unpleasant odours, for example from bedside com- modes, episodes of incontinence or malodorous wounds. l Anticipatory – occurring within the 24 hours before Once the patient has finished eating, any remaining food treatment commences. Anticipatory vomiting is related should be quickly cleared away. Any used receptacles to previously poorly tolerated chemotherapy and is less should be removed promptly after episodes of vomiting. common since the introduction of effective antiemetic Occasionally, in cases of complete bowel obstruction regimes. Trigger factors are often those associated with where nausea and vomiting is intractable, the passing of receiving the treatment, such as the journey to the a nasogastric tube or a venting gastrostomy may provide chemotherapy unit, sights and smells or seeing the staff relief (Twycross, 2004). Abdominal paracentesis can ease who administer the chemotherapy (Eckert, 2001). symptoms when nausea and vomiting is associated with 5-HT3 antagonists, for example and gran- tense ascites. isetron, are highly effective antiemetics used to treat Taking too many tablets at once can also induce nau- acute nausea and vomiting induced by chemotherapy. A sea and vomiting in susceptible patients. When prescrib- prokinetic such as metoclopramide has value in the ing, medical staff should work closely with nursing col- treatment of delayed nausea and vomiting. Dexametha- leagues to avoid burdening the patient with excessive sone is used in the treatment of both acute and delayed numbers of tablets at any one time. Mouthwashes should nausea, although the mode of action remains unclear be available after episodes of vomiting. The reassuring (Marek, 2003; Yarbro et al, 1999). presence of a calm, competent and understanding nurse There is no satisfactory treatment for anticipatory nau- should not be underestimated. sea and vomiting, and prevention is important. However, Relaxation and positive imagery may prove beneficial may be tried. Non-pharmacological in reducing the incidence of nausea and vomiting associ- interventions have a particularly important role in antici- ated with anxiety. Acupuncture (Vickers, 1996) and acu- patory nausea. pressure (Dibble et al, 2000) can also be of benefit.n

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