By reading this article and writing a practice profile, you can gain ten continuing education points (CEPs). You have up to a year to send in your practice profile. Guidelines on how to write and submit a profile are featured immediately after the continuing professional development article every week. Managing post-operative nausea and vomiting 47-52 Multiple-choice questions and submission instructions 53 Practice profile assessment guide 54 Practice profile 24 Managing post-operative nausea and vomiting NS95 Jolley S (2001) Managing post-operative nausea and vomiting. Nursing Standard. 15, 40, 47-52. Date of acceptance: February 27 2001. Aims and intended learning outcomes The aim of this article is to provide an overview of the management of post-operative nausea and vomiting, with an emphasis on risk assessment and prophylaxis. After reading this article you should be able to: Describe the effects and complications associated with post-operative nausea and vomiting. Explain which risk factors are associated with post-operative sickness. Discuss the factors that prevent the most effective management of this condition. Understand how to perform risk assessment of patients undergoing surgery. Update your understanding of antiemetics, how they work, and their use in prophylaxis as well as treatment of post-operative sickness. Undertake appropriate nursing care to minimise the effects of post-operative sickness. Introduction Nausea and vomiting are among the most common post-operative complications (Tate and Cook 1996a). Post-operative nausea and vomiting (PONV) affects around one million surgical patients in the UK every year, which equates to about one in three people undergoing an operation (DoH 1990). The percentage of surgical patients affected is higher in some specialties, for example, about 42 per cent of patients undergoing gynaecological procedures experience PONV (Rowbotham 1995). Despite a growing body of background knowledge and research, the management of PONV is inconsistent and disorganised. According to Kenny and Rowbotham (1992):...the continuing high incidence of PONV suggests that the problem may be under-recognised and that methods of treatment and prophylaxis could be improved. This article focuses on work that has been carried out in the gynaecology unit at Queens Medical Centre in Nottingham, which resulted in a 30 per cent reduction of nausea and vomiting and the development of a new protocol for the management of PONV. Although the protocol was developed specifically for gynaecology patients, it could be adapted for use with different groups of patients. Nausea and vomiting Nausea is an unpleasant sensation that commonly precedes vomiting. Problems associated with vomiting are loss of fluid and electrolytes, exhaustion, soreness and patient distress. The vomiting reflex is actually an important defence mechanism for the expulsion of toxins. It is controlled by the emetic, or vomiting centre, in the brain. The vomiting centre receives messages via the nervous system from different sources, including the pharynx, gastrointestinal tract, eye, vestibular apparatus in the ear, respiratory and circulatory systems, testicles and pain receptors. Stimuli are also sent from the cerebral cortex and chemoreceptor trigger zone (CTZ), which is situated in the brainstem. Many of the drugs This article has been supported by an educational grant from GlaxoSmithKline In brief Author Sue Jolley BA, CertEd, RGN, is Research Sister, Gynaecology Unit, Queens Medical Centre, Nottingham. Summary Post-operative nausea and vomiting leads to unnecessary suffering for many surgical patients. Improved nursing management can help prevent and better treat this condition. Key words Nausea Patient assessment Patients: education These key words are based on subject headings from the British Nursing Index. This article has been subject to double-blind review Online archive For related articles visit our online archive at: www.nursing-standard.co.uk and search using the key words above.
Fig 1. Possible mechanisms involved in PONV TIME OUT 2 Who is at greatest risk of PONV? What factors are likely to increase an individual s risk of experiencing this condition? (Kenny and Rowbotham 1992) Box 1. Physical complications of PONV Obstruction of airway Aspiration of vomit, which can lead to aspiration pneumonia Complications following maxillofacial/plastic/ocular surgery Possible wound disruption Raised intracranial pressure in neurosurgical patients Dehydration and electrolyte imbalances Increased pain, discomfort and distress Problems with pain control if opiates are the cause Delay in giving oral analgesia and other medication Exhaustion Interference with nutrition General delay in mobilisation and recovery (Bingham 1993, Ernst 1994, Kapur 1991, Kenny and Rowbotham 1992, Thompson 1992) used in anaesthesia and pain control cause PONV because chemoreceptors in the CTZ monitor substances in the blood and cerebrospinal fluid. The vomiting centre can also be stimulated by disturbance of the gut or oropharynx, movement, pain, hypoxaemia and hypotension. Figure 1 illustrates the interaction of the different mechanisms that can cause PONV. Because many different factors contribute to PONV, it can be difficult to prevent and treat. TIME OUT 1 Why do you think PONV can be a serious problem? What complications might be associated with post-operative sickness? Think about the psychological effects of this condition, as well as the physical ones. Complications of PONV The effects of PONV have been well documented (Bingham 1993, Blinkhorne 1995, Williams 1994). The physical complications associated with PONV are listed in Box 1. As well as medical complications, nausea and vomiting can have psychological effects on patients, such as discomfort and distress; shame and embarrassment; exhaustion; dissatisfaction with the outcome of the operation; and fear of further surgery. Patients might become extremely distressed, which in turn can cause them anxiety about undergoing further surgery (Kapur 1991, NATN 1993). PONV also has cost implications in terms of nursing time, delayed recovery, hospital resources and possible re-operation costs (Blinkhorne 1995, Ernst 1994, Rowbotham 1995). Risk factors Research has examined the risk factors associated with PONV (Rowbotham 1995, Tate and Cook 1996a). Gender plays an important role women are three times more likely than men to experience PONV (Rowbotham 1995). The type of surgical procedure carried out has an effect on the risk of PONV occurring, with gynaecological and abdominal procedures having an increased risk due to disturbance of the gut during the procedure. Figure 2 illustrates the incidence of PONV in different surgical procedures (Rowbotham 1995, Ernst 1994). Other factors likely to increase the risk of PONV include: A previous history of PONV, travel sickness or migraine. Pre- and post-operative starvation time inadequate starvation before an operation is a risk factor for PONV (Kapur 1991), but prolonged fasting can also cause nausea (Kenny and Rowbotham 1992). The optimum time to resume oral intake following surgery can be equally problematic. The type of anaesthetic agent used some of the older intravenous induction agents such as thiopentone are associated with PONV, whereas propofol has a lower incidence of PONV (Tate and Cook 1996a). Inhaled anaesthetic agents, such as nitrous oxide, increase the risk of PONV. Nitrous oxide causes gut distension and pressure on the middle ear, which can both contribute to PONV. The use of opioids for pain relief opioids stimulate the vomiting centre via the CTZ. They also decrease gut motility causing distension. Opioids can increase the sensitivity of the middle ear to movement which can cause nausea in some people. This explains the association with travel sickness. Anxiety either due to previous experience of PONV or because of general fears about a hospital admission, can increase the likelihood of PONV occurring (Bingham 1993, Blinkhorne 1995). This might be because of conditioning or learned responses (Andrews 1999).
Obesity this might be a factor but the cause is not clearly understood. Fat-soluble anaesthetic agents accumulate in adipose tissue and the anaesthetics are slowly released. Therefore, the more fat there is, the longer the side effects will last. There might also be difficulties with lifting and handling a larger person. Emergency surgery often results in PONV because it is not always possible to fast the patient for enough time. Fig 2. Incidence of PONV in surgical procedures TIME OUT 3 PONV is a common but distressing complication for surgical patients. What could be done to improve nursing management of this condition? Background to managing PONV There are several factors to consider in developing a comprehensive management strategy. One way of reducing PONV is by prevention and this depends on a thorough pre-operative assessment of the patient. The use of a risk assessment tool or checklist to identify patients most at risk of PONV has been advocated (Blinkhorne 1995). Predictive factors and constructed scoring systems for PONV risk have been analysed, but these are too complex for everyday use at ward level (Koivuranta et al 1997, Palazzo and Evans 1993). A simple tool for risk assessment would, therefore, be a great asset in managing patients at risk of PONV. Patient expectations are often low with the assumption that PONV is inevitable (Jolley 1999). Nausea and vomiting are considered to be the worst possible symptoms after an operation (Orkin 1992). However, the vast majority of patients are not aware that they can take medication to reduce the likelihood of postoperative sickness occurring (Harmer 1998). Tate and Cook (1996a) reported that only a third of patients tell a member of staff when they feel nauseous. Many patients fear that nothing can be done to alleviate their symptoms and because of this they might delay asking for help (Rowbotham 1995). Patients often do not receive either prophylaxis or the best treatment for PONV (Harmer 1998). A survey carried out by the National Association of Theatre Nurses in 1993 found that only one in three nurses worked in hospitals where administration of antiemetics before surgery was routine, and two thirds thought that (Rowbotham 1995, Ernst 1994) doctors did not consider the problem to be a serious one (NATN 1993). Drugs prescribed are often the doctor s preferred ones rather than the most efficacious (Tate and Cook 1996a). Prescriptions for antiemetics are often to be given as necessary and decisions about administration are left to recovery and ward staff. Without clear guidelines, treatment can be erratic. Although 75 per cent of patients are prescribed an antiemetic, only 56 per cent actually receive any medication (Ernst 1994). The majority of nurses believe that PONV should be prevented (NATN 1993), but nurses understanding of PONV could be a lot better (Tate and Cook 1996b). In the survey by the National Association of Theatre Nurses (1993), only half of the nurses knew that patients having abdominal and gynaecological surgery were more likely to experience sickness. A questionnaire on nurses knowledge of PONV carried out in the gynaecology unit at Queens Medical Centre in Nottingham demonstrated large gaps in knowledge, with only 60 per cent of the nurses questioned giving the correct responses (Jolley 2000a). Improvement in the management of PONV requires three main elements. These are: A clear protocol incorporating a risk assessment tool and guidelines for drug therapy. An education programme for staff and patients to increase knowledge and alter their expectations. A set of standards to monitor and evaluate the care being given.
Box 2. Example of risk assessment tool Risk factor Laparotomy Vaginal operation (hysterectomy/repairs) Laparoscopy History of travel sickness Previous experience of PONV A tick in any yes box means the patient is at high risk. The patient is at low risk if there are no ticks Yes Risk assessment A study was carried out in the gynaecology department in the author s trust, which led to the development, implementation and evaluation of a new protocol for the management of PONV. The first stage in this protocol is patient assessment using a risk assessment tool that was designed following an audit to establish the most significant risk factors. An example of the risk assessment tool used in the gynaecology department is shown in Box 2. In the gynaecology department, because of the high rate of PONV found for some operation groups, patients undergoing a laparotomy, major vaginal operation or laparoscopy are automatically considered high risk. Other patients only become high risk if they have a past history of PONV or travel sickness. The risk assessment tool could be adapted for use in other areas by incorporating the appropriate risk factors, but the same basic principles would apply. Risk assessment should be carried out by nurses, who:...are in an excellent position to identify patients most at risk of PONV (Blinkhorne 1995). After assessment, patient drug cards should be labelled with the patient s risk status before undergoing an operation. TIME OUT 4 Look at the risk assessment tool in Box 2. Think about how you might adapt this tool for use in the area where you work. What risk factors are important to the patients you encounter? (Some research and audit would need to be carried out before you could implement the tool for everyday use). An assessment of patient risk factors can also help in planning patient care. For example, the amount of time a patient is fasted pre-operatively needs to be planned so that it is not too long. The ward environment should also be considered so that, ideally, the patient at risk of PONV is positioned away from any strong smells, such as food or chemicals, with privacy if needed. The patient should be included in any planning as communication and reassurance will help alleviate anxiety. Drug therapy Four main neurotransmitters are involved in sending stimuli to the chemoreceptor emetic trigger zone (CTZ) and vomiting centre in the medulla. These are: Dopamine. Histamine. Acetylcholine. 5-Hydroxytryptamine 3 (5HT 3 ). Different types of antiemetic drugs work by affecting different neurotransmitter receptor sites (Tate and Cook 1996b): Antidopaminergics these drugs act on the CTZ and are all useful in relieving nausea and vomiting associated with chemotherapy, radiotherapy, surgery and toxins, but not motion sickness. Examples are phenothiazine, metoclopramide, droperidol and domperidone. These all have serious Parkinsonian-type side effects. It should be noted that metoclopramide also hastens gastric emptying and should not be used after gastrointestinal surgery or in cases of intestinal obstruction. Antihistamines antihistamines act on the vomiting centre, CTZ and middle ear. They are good for treating motion sickness and are not contraindicated when there might be intestinal obstruction. Many antihistamines have been used in the management of motion sickness, but only cyclizine has been developed for the treatment of PONV. All antihistamines can cause drowsiness. Anticholinergics these work on the vomiting centre and are also good for motion sickness. An example is hyoscine. However, the side effects include dry mouth, drowsiness and urinary retention so the use of anticholinergics has declined with the development of less irritant anaesthetics. 5HT 3 anatagonists this group of drugs was developed to treat nausea and vomiting associated with chemotherapy. They work on the CTZ and were found to be equally effective for PONV. They are indicated if the gut has been manipulated and if anaesthetic/opioid drugs are the cause of sickness. An example is ondansetron. These antiemetics only have mild side effects such as headaches and constipation. Research by anaesthetists has examined how well different antiemetics work, both for prophylaxis and treatment. Ideally, the cause of vomiting should always be established and blindly administering antiemetic therapy is not appropriate (Williams 1994). However, because the exact cause of PONV is not always clear, evidence supports using combined therapies, which means antiemetics from different groups, including the 5HT 3 receptor antagonists (Ernst 1994, Kapur 1991, Malins et al 1994, Thompson 1992). It is, therefore, important that nurses understand the different modes of
actions so that the right drugs are combined. Two drugs from the same group, such as phenothiazine and metoclopramide, should be avoided. If one failed, it is likely that another also will, and there is an increased risk of side effects. Since the implementation of the protocol in the author s department, standardised guidelines are used for prescribing antiemetic drugs. Following risk assessment by a nurse, usually in the pre-admissions unit or on the ward, all low risk patients are given intravenous (IV) cyclizine (50mg) prophylactically in theatre and high risk patients are given IV cyclizine as well as ondansetron (4mg). These drugs were chosen because they can be given intravenously and have a proven efficacy rate for PONV (Vickers 1999). The same drugs are then used postoperatively. Patients are allowed a second dose of ondansetron after 30 minutes so all patients suffering with PONV in the immediate postoperative period can have nurse-administered antiemetics. Following this, the prescription of the antiemetics, as required, is on a standardised label. All drugs are given intravenously. In rare cases where further support might be needed, nurses can contact the anaesthetist or the hospital s acute pain service. TIME OUT 5 Which antiemetics are used in your workplace and what guidelines exist for administration? Are you aware of their mode of action and possible side effects? Find out this information and incorporate it into a patient information leaflet on PONV. Drug interventions for PONV do not always work. When this happens, you should always check that there is adequate pain relief, hydration, oxygenation and maintenance of blood pressure. You should encourage only slow and smooth patient movements. Most importantly, you should offer support, sympathy and reassurance. There are also three non-pharmacological treatments that might be considered. These include acupressure, such as pressure bands, botanical remedies that are usually based on ginger and aromatherapy using peppermint oil (Tate and Cook 1996b). Education It is important for nurses involved in the management of PONV, as well as theatre staff and anaesthetists, to have a good general knowledge of the issues involved (Williams 1994). Carrying out a staff education programme is one way of ensuring that all staff understand PONV and are aware of nursing guidelines on caring for patients. Emphasis should be placed on the importance of treating PONV promptly once reported:...appropriate nursing care can help prevent episodes of emesis and minimise the impact on patients when they occur (Tate and Cook 1996b). It is also important to keep documentation, especially of vomiting episodes, for maintaining and monitoring standards. Patient education is important (Orkin 1992, Williams 1994). Patients must be actively involved in their care to achieve effective management of PONV (Tate and Cook 1996b). Making patient information leaflets on PONV available before or on admission can increase patient satisfaction with the information they receive and help alleviate anxiety (Jolley 2000b). All patients undergoing surgical procedures should be provided with information about treatment and reassurance concerning PONV. The main message to convey is that patients should not suffer silently, but should tell nurses immediately so that PONV can be treated effectively. TIME OUT 6 Mrs Jones is booked in for a laparotomy. She has previously experienced post-operative sickness and is anxious about having the operation because of her past experience. How would you alleviate her fears and what would her nursing care be? Nursing guidelines Sample nursing guidelines for management of PONV are as follows: Prior to or on admission Carry out a preoperative risk assessment for each patient. Developing or using an appropriate risk assessment tool would help to achieve this. Inform the relevant staff (doctors and anaesthetists) so patients can be prescribed prophylactic treatment if relevant. If patients are at risk of PONV, inform them that they will be given appropriate medication, thus reducing anxiety and increasing confidence. Discuss information about PONV and what to expect, and consider providing an information leaflet. Provide information about admission and all procedures to relieve general anxiety, which can contribute to the risk of PONV. Following surgery Avoid any sudden
movements. Move patients slowly and smoothly. Discourage them from sitting up too quickly following surgery and monitor for hypotension. Ensure patients are well hydrated and offer them mouthwash if necessary. If there is no evidence of gut distension (based on the type of surgery, observation of abdomen and presence of bowel sounds), oral intake can be commenced two hours after surgery. Start fluid intake slowly, commencing with sips only. Do not withhold oral fluids longer than necessary. If any problems are evident, delay oral intake for at least eight hours, or longer if necessary. Ensure patients have adequate pain control. Monitor for any sign of nausea and record on the patient s chart and encourage them to report any nausea immediately it is experienced. When nausea or vomiting is reported Once nausea or vomiting is reported, it must be treated promptly following a prescribed regimen. Always monitor the effectiveness of any medication given. If it is not successful, try an alternative antiemetic. Encourage patients to take deep breaths to reduce the sensation of nausea. Give privacy and support patients who vomit often need reassurance that there is no damage to their operation site. Measure and record any vomiting that occurs; encourage the patient to rinse his or her mouth afterwards. If vomiting persists or is difficult to control, medical staff should be informed. Monitoring care It is necessary to monitor how well PONV is managed. Setting standards is important so that performance can be monitored and targets for improvements set:...although most centres now have quality standards for many aspects of patient care, few have developed standards for the control of PONV (Ernst 1994). This seems to be an ongoing problem (Dobson et al 1999). Standards for PONV should be twofold: relating both to the incidence of PONV and to patients satisfaction with the care they receive. Regular audits can be used to determine whether standards are achieved and maintained. Good patient record-keeping is important for audit purposes. Conclusion The use of routine risk assessment, standardised prescribing of prophylactic antiemetics and efficient protocols to improve the management of PONV have been suggested previously by Dobson et al (1999). This article describes how it can be achieved in practice. An interdisciplinary and comprehensive approach was important in the success introducing a PONV protocol into the gynaecology department where it was carried out. It is hoped that others will be able to build on this work to help different groups of surgical patients TIME OUT 7 Now that you have completed the article, you might like to think about writing a practice profile. Guidelines to help you are on page 56. REFERENCES Andrews P (1999) Towards an understanding of the mechanism of PONV. In Strunin L et al (Eds) The Effective Management of London, Aesculapius Medical Press. Bingham K (1993) Postoperative nausea and vomiting. British Journal of Theatre Nursing. 3, 6, 4-6. Blinkhorne K (1995) Prepared for a smooth recovery? Nursing Times. 91, 28, 42-44. Department of Health (1990) Statistical Bulletin (October). London, HMSO. Dobson F et al (1999) Improving clinical outcome from the management of PONV: the developing role of the anaesthetist, pharmacist and multidisciplinary team. In Strunin L et al (Eds) The Effective Management of London, Aesculapius Medical Press. Ernst E (1994) The Economics of Quality Care. Postoperative Nausea and Vomiting. Cookham, Direct Publication Solutions. Harmer M (1998) The Challenge of Uxbridge, Glaxo Wellcome. Jolley S (2000a) Post-operative nausea and vomiting: a survey of nurses knowledge. Nursing Standard. 14, 23, 32-34. Jolley S (2000b) Patient information on post-operative sickness. Nursing Standard. 14, 49, 32-34. Jolley S (1999) Let s get positive about postoperative nausea and vomiting. British Journal of Theatre Nursing. 9, 10, 450-451. Kapur P (1991) Editorial: the big little problem. Anaesthesia and Analgesia. 73, 3, 243-245. Kenny G, Rowbotham D (Eds) (1992) London, Synergy Medical Education. Koivuranta M (1997) Postoperative Nausea and Vomiting. Oulu, Oulu University Press. Malins A et al (1994) Nausea and vomiting after gynaecological laparoscopy: comparison of premedication with oral ondansetron, metoclopramide and placebo. British Journal of Anaesthesia. 72, 2, 231-233. National Association of Theatre Nurses (1993) Postoperative Nausea and Vomiting: Report on the Size and Impact of the Problem for the Nurse. Cookham, Direct Publishing Solutions. Orkin K (1992) What do patients want? Preferences for immediate postoperative recovery. Anesthesia and Analgesia. 74, 5225. Palazzo M, Evans R (1993) Logistic regression analysis of fixed patient factors for postoperative sickness: a model for risk assessment. British Journal of Anaesthesia. 70, 2, 135-140. Rowbotham D (1995) Recognising risk factors. Nursing Times. 91, 28, 44-46. Tate S, Cook H (1996a) Postoperative nausea and vomiting 1: physiology and aetiology. British Journal of Theatre Nursing. 5, 16, 962-966. Tate S, Cook H (1996b) Postoperative nausea and vomiting 2: management and treatment. British Journal of Theatre Nursing. 5, 17, 1032-1039. Thompson J (1992) Postoperative nausea and vomiting. British Journal of Theatre Nursing. 2, 7, 22-24. Vickers A (1999) Poor clinical outcome from management of PONV: review of theatre-to-ward management following major surgery and hospital-to-home management following day surgery. In Strunin et al (Eds) The Effective Management of Postoperative Nausea and Vomiting. London, Aesculapius Medical Press. Williams C (1994) Causes and management of nausea and vomiting. Nursing Times. 90, 44, 38-41.