[Tropisetron for prevention of postoperative nausea and vomiting: a quantitative systematic review]

Pharmacologic interventions for postoperative nausea and vomiting after thyroidectomy: A systematic review and network meta-analysis

Objective

To determine the effectiveness of pharmacologic interventions for preventing postoperative nausea and vomiting (PONV) in patients undergoing thyroidectomy.

Design

Systematic review and network meta-analysis (NMA).

Data sources

MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Google Scholar.

Eligibility criteria, participants, and interventions

Randomized clinical trials that investigated the efficacy of pharmacologic interventions in preventing PONV in patients undergoing thyroidectomy were included. The primary endpoints were the incidences of postoperative nausea and vomiting (PONV), postoperative nausea (PON), postoperative vomiting (POV), use of rescue antiemetics, and incidence of complete response in the overall postoperative phases. The secondary endpoints were the same parameters assessed in the early, middle, and late postoperative phases. The surface under the cumulative ranking curve (SUCRA) values and rankograms were used to present the hierarchy of pharmacologic interventions.

Results

Twenty-six studies (n = 3,467 patients) that investigated 17 different pharmacologic interventions were included. According to the SUCRA values, the incidence of PONV among the overall postoperative phases was lowest with propofol alone (16.1%), followed by palonosetron (27.5%), and with tropisetron (28.7%). The incidence of PON among the overall postoperative phases was lowest with propofol alone (11.8%), followed by tropisetron and propofol combination (14%), and ramosetron and dexamethasone combination (18.0%). The incidence of POV among the overall postoperative phases was lowest with tropisetron and propofol combination (2.2%), followed by ramosetron and dexamethasone combination (23.2%), and tropisetron alone (37.3%). The least usage of rescue antiemetics among the overall postoperative phases and the highest complete response was observed with tropisetron and propofol combination (3.9% and 96.6%, respectively).

Conclusion

Propofol and tropisetron alone and in combination, and the ramosetron and dexamethasone combination effectively prevented PONV, PON, POV in patients undergoing thyroidectomy, with some heterogeneity observed in this NMA of full-text reports. Their use minimized the need for rescue antiemetics and enhanced the complete response.

Trial registration number

CRD42018100002.

Postoperative Nausea and Vomiting in Pediatric Patients

Postoperative nausea and vomiting (PONV), postoperative vomiting (POV), post-discharge nausea and vomiting (PDNV), and opioid-induced nausea and vomiting (OINV) continue to be causes of pediatric morbidity, delay in discharge, and unplanned hospital admission. Research on the pathophysiology, risk assessment, and therapy for PDNV, OINV and pain therapy options in children has received increased attention. Multimodal pain management with the use of perioperative regional and opioid-sparing analgesia has helped decrease nausea and vomiting. Two common emetogenic surgical procedures in children are adenotonsillectomy and strabismus repair. Although PONV risk factors differ between adults and children, the approach to decrease baseline risk is similar. As PONV and POV are frequent in children, antiemetic prophylaxis should be considered for those at risk. A multimodal approach for antiemetic and pain therapy involves preoperative risk evaluation and stratification, antiemetic prophylaxis, and pain management with opioid-sparing medications and regional anesthesia. Useful antiemetics include dexamethasone and serotonin 5-hydroxytryptamine-3 (5-HT3) receptor antagonists such as ondansetron. Multimodal combination prophylactic therapy using two or three antiemetics from different drug classes and propofol total intravenous anesthesia should be considered for children at high PONV risk. "Enhanced recovery after surgery" protocols include a multimodal approach with preoperative preparation, adequate intravenous fluid hydration, opioid-sparing analgesia, and prophylactic antiemetics. PONV guidelines and management algorithms help provide effective postoperative care for pediatric patients.

Stability of butorphanol-tropisetron mixtures in 0.9% sodium chloride injection for patient-controlled analgesia use

Tropisetron is an adjuvant for butorphanol used in intravenous patient-controlled analgesia (PCA) and has been reported to provide superior pain control. It is efficacious in reducing the incidence of postoperative nausea and vomiting. However, this admixture is not available commercially and stability data applicable to hospital practice are limited. This study aimed to describe the drug compounding and evaluates the long-term (up to 14 days) stability of butorphanol and tropisetron in 0.9% sodium chloride injection for PCA use.In this study, commercial solutions of butorphanol tartrate and tropisetron hydrochloride were combined and further diluted with 0.9% sodium chloride injection to final concentrations of butorphanol tartrate 0.08 mg/mL and tropisetron hydrochloride 0.05 mg/mL. The polyolefin bags and glass bottles were stored at 4°C and 25°C for up to 14 days. The drug stabilities were determined by visual inspection, pH measurement, and high-pressure liquid chromatography assay of drug concentrations.The data obtained for admixtures prepared and stored at temperatures of 25°C and 4°C show the drugs have maintained at least 98% of the initial concentration. All solutions remained clear and colorless over the 14-day period, and the pH value did not change significantly.The results indicate that admixtures of butorphanol tartrate 0.08 mg/mL and tropisetron hydrochloride 0.05 mg/mL in 0.9% sodium chloride injection solution were stable for 14 days when stored in polyolefin bags or glass bottles at 4°C and 25°C and protected from light. The infusion is feasible for manufacturing in pharmacy aseptic units and can be stored for up to 14 days for routine use in PCA infusions.

Postoperative nausea and vomiting in pediatric anesthesia

PURPOSE OF REVIEW

Postoperative nausea and vomiting (PONV) has a high incidence in children and requires prophylactic and therapeutic strategies.

RECENT FINDINGS

PONV can be reduced by the avoidance of nitrous oxide, volatile anesthetics, and the reduction of postoperative opioids. The use of dexamethasone, 5-HT3 antagonists, or droperidol alone is potent, but combinations are even more effective to reduce PONV. Droperidol has a Food and Drug Administration warning. Hence, dexamethasone and 5-HT3 antagonists should be preferred as prophylactic drugs. It is further reasonable to adapt PONV prophylaxis to different risk levels. Prolonged surgery time, inpatients, types of surgery (e.g. strabismus and ear-nose-throat surgery), and patients with PONV in history should be treated as high risk, whereas short procedures and outpatients are to be treated as low risk.

SUMMARY

Concluding from the existing guidelines and data on the handling of PONV in children at least 3 years, the following recommendations are given: outpatients undergoing small procedures should receive a single prophylaxis, outpatients at high risk a double prophylaxis, inpatients with surgery time of more than 30 min and use of postoperative opioids should get double prophylaxis, and inpatients receiving a high-risk surgical procedure or with other risk factors a triple prophylaxis (two drugs and total intravenous anesthesia). Dimenhydrinate can be used as a second choice, whereas droperidol and metoclopramide can only be recommended as rescue therapy.

Efficacy of palonosetron versus ramosetron on preventing opioid-based analgesia-related nausea and vomiting after lumbar spinal surgery: a prospective, randomized, and double-blind trial

STUDY DESIGN

A prospective, randomized, and double-blind study.

OBJECTIVE

To compare the efficacy of ramosetron and palonosetron on preventing postoperative nausea and vomiting (PONV) associated with opioid-based intravenous patient-controlled analgesia (IV-PCAopioid) after lumbar spinal surgery.

SUMMARY OF BACKGROUND DATA

IV-PCAopioid, an effective method to control pain after lumbar spinal surgery, accompanies PONV. Ramosetron and palonosetron are novel 5-hydroxytryptamine 3 antagonists known to have longer action duration and higher receptor affinity than their congeners, whereas their relative efficacy has not been validated yet.

METHODS

One hundred ninety-six patients were randomly and evenly allocated to receive either 0.3 mg of ramosetron or 0.075 mg of palonosetron 10 minutes before the end of operation. Ramosetron or palonosetron were also added to the IV-PCAopioid, which was continuously infused for 48 hours postoperatively. The incidence and intensity of PONV were serially assessed for 72 hours postoperatively. Intensity of pain, volume of IV-PCAopioid consumption, use of rescue analgesics and antiemetics, and adverse events were also assessed.

RESULTS

The overall incidence of PONV was lower in the ramosetron group than the palonosetron group (50% vs. 67%, P = 0.014) without any intergroup difference in the incidence of vomiting. Nausea intensity scores were also lower until 6 (P = 0.041) and 24 hour (P = 0.026) postoperatively in the ramosetron group than the palonosetron group. Pain intensity scores were significantly lower in the ramosetron group than the palonosetron group for 72 hours postoperatively.

CONCLUSION

Ramosetron was superior to palonosetron in term of reducing the incidence and severity of nausea associated with IV-PCAopioid after lumbar spinal surgery. This favorable influence of ramosetron on PONV was translated to significant postoperative pain reduction compared with palonosetron.

LEVEL OF EVIDENCE

1.

Consensus guidelines for the management of postoperative nausea and vomiting

The present guidelines are the most recent data on postoperative nausea and vomiting (PONV) and an update on the 2 previous sets of guidelines published in 2003 and 2007. These guidelines were compiled by a multidisciplinary international panel of individuals with interest and expertise in PONV under the auspices of the Society for Ambulatory Anesthesia. The panel members critically and systematically evaluated the current medical literature on PONV to provide an evidence-based reference tool for the management of adults and children who are undergoing surgery and are at increased risk for PONV. These guidelines identify patients at risk for PONV in adults and children; recommend approaches for reducing baseline risks for PONV; identify the most effective antiemetic single therapy and combination therapy regimens for PONV prophylaxis, including nonpharmacologic approaches; recommend strategies for treatment of PONV when it occurs; provide an algorithm for the management of individuals at increased risk for PONV as well as steps to ensure PONV prevention and treatment are implemented in the clinical setting.

Prevention and control of postoperative nausea and vomiting in post-craniotomy patients

Postoperative nausea and vomiting (PONV) are the most frequent side-effects in the postoperative period, impairing subjective well-being and having economic impact due to delayed discharge. However, emetic symptoms can also cause major medical complications, and post-craniotomy patients may be at an increased risk. A review and critical appraisal of the existing literature on PONV in post-craniotomy patients, and a comparison of these findings with the current knowledge on PONV in the general surgical population, leads to the following conclusions: (1) Despite the lack of a documented case of harm caused by retching or vomiting in a post-craniotomy patient, the potential risk caused by arterial hypertension and high intra-abdominal/intra-thoracic pressure leading to high intracranial pressure, forces to avoid PONV in these patients. (2) There is unclarity about a specifically increased (or decreased) risk for PONV in post-craniotomy patients compared with other surgical procedures. (3) The decision whether or not to administer an antiemetic should not be based primarily on risk scores for PONV but on the likelihood for potential catastrophic consequences of PONV. If such a risk cannot be ruled out, a multimodal antiemetic approach should be considered regardless of the individual risk. (4) Randomized controlled trials with antiemetics in post-craniotomy patients are limited with respect to sample size and methodological quality. This also impacts upon the meaning of meta-analyses performed with trials that showed marked heterogeneity and inconclusive results. (5) No studies on the treatment of established PONV are available. This highlights the need to transfer knowledge about PONV treatment from other surgical procedures. (6) Despite the possibility that PONV in post-craniotomy patients can be triggered by specific conditions (e.g. surgery near the area postrema at the floor of the fourth ventricle with the vomiting centre located nearby), recommendations based on trials in post-craniotomy patients may be flawed. Thus, general knowledge on prevention and treatment of PONV must adopted for craniotomy settings.

[Nausea and vomiting in the postoperative phase. Expert- and evidence-based recommendations for prophylaxis and therapy]

There are no consensus guidelines for the management of postoperative nausea and vomiting (PONV) in German speaking countries. This meeting was intended to develop such guidelines on which individual health care facilities can derive their specific standard operating procedures (SOPs). Anesthesiologists reviewed published literature on key topics which were subsequently discussed during two meetings. It was emphasized that recommendations were based on the best available evidence. The clinical relevance of individual risk factors should be viewed with caution since even well proven risk factors, such as the history of PONV, do not allow the identification of patients at risk for PONV with a satisfactory sensitivity or specificity. A more useful approach is the use of simplified risk scores which consider the presence of several risk factors simultaneously. Most individual antiemetic interventions for the prevention of PONV have comparable efficacy with a relative risk reduction of about 30%. This appears to be true for total intravenous anesthesia (TIVA) as well as for dexamethasone and other antiemetics; assuming a sufficiently high, adequate and equipotent dosage which should be weight-adjusted in children. As the relative risk reduction is context independent and similar between the interventions, the absolute risk reduction of prophylactic interventions is mainly dependent on the patient's individual baseline risk. Prophylaxis is thus rarely warranted in patients at low risk, generally needed in patients with a moderate risk and should include a multimodal approach in patients at high risk for PONV. Therapeutic interventions of PONV should be administered promptly using an antiemetic which has not been used before. The group suggests algorithms where prophylactic interventions are mainly dependent on the patient's risk for PONV. These algorithms should provide evidence-based guidelines allowing the development of SOPs/policies which take local circumstances into account.

Management of postoperative nausea and vomiting in children

Postoperative nausea and vomiting (PONV) continues to be a frequent and important cause of morbidity in children. Postoperative vomiting (POV) is more commonly studied in children than postoperative nausea because of a child's inability to effectively express distress after experiencing nausea. POV is problematic in children and is one of the leading postoperative complaints from parents and the leading cause of readmission to the hospital. POV occurs twice as frequently in children as in adults, increasing until puberty and then decreasing to adult incidence rates. Gender differences are not seen before puberty. POV remains a main cause of morbidity in children because severe vomiting can be associated with dehydration, postoperative bleeding, pulmonary aspiration, and wound dehiscence. While children have an increased potential for dehydration and the resulting physiologic impairments, other associated results such as a delay in hospital discharge or an overnight or longer hospital admission also must be considered. The two most common emetogenic surgical procedures evaluated in children are strabismus repair and adenotonsillectomy. The approach to the management of PONV and POV in children is similar to that in adults. However, as the rate of POV is more frequent in children than in adults, more children are candidates for antiemetic prophylaxis. The management approach is multifactorial and involves proper preoperative preparation, risk stratification, rational selection of antiemetic prophylaxis, choice of anesthesia technique, and a plan for postoperative antiemetic therapy. It is important to identify children at moderate-to-high risk for POV as prophylactic antiemetic therapy is useful in these children. Antiemetics of choice for POV in children include dexamethasone, dimenhydrinate, perphenazine, ondansetron, dolasetron, granisetron, and tropisetron. The serotonin (5-hydroxytryptamine; 5-HT(3)) antagonists are the antiemetic drugs of first choice for POV prophylaxis in children because as a group they have greater efficacy for preventing vomiting than nausea. The 5-HT(3) antagonists can be effectively combined with dexamethasone with an increase in efficacy. If possible, regional anesthesia should be considered. For those undergoing general anesthesia, the baseline POV risk should be reduced. Children at moderate-to-high PONV risk should receive combination therapy with two or three prophylactic antiemetics from different antiemetic drug classes. Reference to and the use of PONV guidelines and management algorithms help improve cost-effective postoperative care.

Anti-emetic prophylaxis with oral tropisetron and/or dexamethasone

BACKGROUND

The corticosteroid dexamethasone and the serotonine3 -antagonist tropisetron are both effective drugs for the prophylaxis of post-operative nausea and vomiting (PONV) when given intravenously. The aim of this trial was to evaluate the oral use of both drugs as part of a routine oral premedication and to compare their single and combined effectiveness.

MATERIALS AND METHODS

In this randomized, placebo-controlled, double-blind study, 320 inpatients with a moderate-high risk of PONV (> or = 40% according to two validated risk scores) received an oral premedication 1-2 h pre-operatively with placebo, a fixed dose of tropisetron 5 mg, dexamethasone 8 mg, or a combination of both drugs. A standardized general anaesthesia was performed, including benzodiazepine premedication, propofol, rocuronium, desflurane in air/O2, fentanyl or sufentanil followed by a continuous infusion of remifentanil. Post-operative analgesia and anti-emetic rescue medication were standardized. The main outcome measures were the severity of PONV within the first 24 h (rated by a standardized scoring algorithm). The incidence of PONV was used as the secondary outcome.

RESULTS

Data from 310 patients were analyzed. The mean severity score in the placebo-, tropisetron-, dexamethasone- and the combined-groups was 1.37, 0.8, 0.8 and 0.38, respectively. The incidence of PONV of any severity was 59.2%, 37.5%, 40% and 22.8%, respectively. The reduction of the incidence and the severity of PONV were statistically significant with all three interventions. Results from additional analyses suggested that both drugs were equally effective and that there was a simple additive effect of tropisetron and dexamethasone compared with placebo.

CONCLUSION

Oral tropisetron and dexamethasone were both equally effective in reducing the severity and incidence of post-operative nausea and vomiting. The latter could be reduced by approximately 35% in a population of moderate-high risk for PONV. Both drugs had an additive effect. However, even in the combination group there still remained an unacceptably high incidence of PONV of more than 20%. This highlighted the need for a multimodal anti-emetic approach in high-risk patients and the importance of treatment of PONV.

PONV: a problem of inhalational anaesthesia?

Even nowadays every third or fourth patient suffers from postoperative nausea and vomiting (PONV) after general anaesthesia with volatile anaesthetics. There is now strong evidence that volatile anaesthetics are emetogenic and that there are no meaningful differences between halothane, enflurane, isoflurane, sevoflurane, and desflurane in this respect. However, when propofol is substituted for volatile anaesthetics the risk for PONV is reduced by only about one fifth, indicating that there are other even more important causes for PONV following general anaesthesia. A main causative factor might be the use of perioperative opioids, but their impact--relative to other factors including volatile anaesthetics--has never been quantified. Patient-specific risk factors have also been shown to be clinically relevant; they are therefore included in the calculation of simplified risk scores that allow prediction of a patient's risk independent of the type of surgery. Although controversial, the well-known different incidences following certain types of surgery are most likely caused by patient-specific and anaesthesia-related risk factors. There is a common consensus that prophylaxis with anti-emetic strategies is rarely justified when the risk of PONV is low, while it is warranted in case of imminent medical risk associated with vomiting or in a patient with a high risk for PONV. A recently published large multicentre trial of factorial design, IMPACT, has demonstrated that various anti-emetic strategies are associated with a very similar and constant relative reduction rate of about 25-30% and that the main predictor for the efficacy of prophylaxis is the patient's risk for PONV. Interestingly, all anti-emetics (dexamethasone, droperidol and ondansetron) work independently, so that their combined benefit can be derived directly from the single effects. The effectiveness of the anti-emetics was also independent of a variety of risk factors, including volatile anaesthetics. This means that any anti-emetic prophylaxis for PONV induced by volatile anaesthetics is equally effective. Of course, the most logical approach for prevention would be the omission of volatile anaesthetics and nitrous oxide using a total intravenous anaesthesia with propofol. However, since volatile anaesthetics are probably not the most important risk factors, it might be even better--if appropriate--to avoid general anaesthesia by using a regional, opioid-free anaesthesia if PONV is a serious problem.

Selective serotonin 5-HT3 receptor antagonists for postoperative nausea and vomiting: are they all the same?

Selective serotonin 5-HT(3) receptor antagonists have proven safe and effective for the management of postoperative nausea and vomiting. Dolasetron, granisetron, ondansetron and tropisetron selectively and competitively bind to 5-HT(3) receptors, blocking serotonin binding at vagal afferents in the gut and in the regions of the CNS involved in emesis, including the chemoreceptor trigger zone and the nucleus tractus solitarii. Despite their shared mechanism of action, 5-HT(3) receptor antagonists have different chemical structures and exhibit differences in receptor binding affinity, dose response and duration of effect. Furthermore, although dolasetron, granisetron, ondansetron and tropisetron are all extensively metabolised by the cytochrome P450 (CYP) system, different components of this system predominate in the metabolism of each of these agents. Hence, although these agents are considered equally effective in the overall population, their pharmacokinetic and pharmacodynamic differences may explain the variability in individual responses to these drugs. This review discusses the pharmacological profiles of dolasetron, granisetron, ondansetron and tropisetron, and the clinical implications of differences in their profiles.

Strategies for postoperative nausea and vomiting

Significant improvement towards a better control of postoperative nausea and vomiting have been achieved in recent years. Today, we understand better who is likely to vomit or to be nauseous after surgery. Significant amounts of the huge literature on anti-emetic interventions have been systematically reviewed, critically appraised and quantitatively synthesized. Thus, we know what anti-emetic interventions work, and how well they work, and we know their adverse effect profile. We also know which interventions have no worthwhile efficacy. A rational approach to postoperative nausea and vomiting includes three steps: identification of patients at risk, keeping the baseline risk low, and prophylactic administration of anti-emetics in those patients who are most likely to need them. For patients who are identified as high-risk patients, all measurements should be simultaneously initiated (multimodal anti-emesis).

Evidence-based management of postoperative nausea and vomiting: a review

PURPOSE

To provide evidence-based guidelines for the prophylaxis and treatment of postoperative nausea and vomiting (PONV).

SOURCE

Literature from randomized controlled trials, systematic reviews, logistic regression analyses and expert opinion in the management of PONV.

PRINCIPAL FINDINGS

The etiology of PONV is multifactorial. Patient, anesthesia, and surgery related risk factors have been identified. Universal PONV prophylaxis is not cost-effective. Identification of patients at high-risk of PONV allows targeting prophylaxis to those who will benefit most from it. No prophylaxis is needed for patients at low risk for PONV. For patients at moderate risk for PONV, prophylaxis using a single antiemetic or a combination of two agents should be considered. Double and triple antiemetic combinations should be considered for patients at high risk for PONV. Furthermore, a multimodal approach should be adopted incorporating steps to keep the baseline risk of PONV low. The optimum cost-effective approach to the management of PONV will differ between an ambulatory centre and an inpatient hospital setting. For the treatment of established PONV in patients who failed prophylaxis, patients should not receive a repeat dose of the prophylactic antiemetic. Rather, a drug acting at a different receptor should be used. Beyond six hours after surgery, patients can be treated with any of the agents used for prophylaxis, except dexamethasone and transdermal scopolamine.

CONCLUSION

PONV are common after anesthesia and surgery. We provided evidence-based guidelines for the management of this problem based on the available literature.

[Prediction of postoperative nausea and vomiting using an artificial neural network]

OBJECTIVE

Postoperative nausea and vomiting (PONV) are still frequent side-effects after general anaesthesia. These unpleasant symptoms for the patients can be sufficiently reduced using a multimodal antiemetic approach. However, these efforts should be restricted to risk patients for PONV. Thus, predictive models are required to identify these patients before surgery. So far all risk scores to predict PONV are based on results of logistic regression analysis. Artificial neural networks (ANN) can also be used for prediction since they can take into account complex and non-linear relationships between predictive variables and the dependent item. This study presents the development of an ANN to predict PONV and compares its performance with two established simplified risk scores (Apfel's and Koivuranta's scores).

METHODS

The development of the ANN was based on data from 1,764 patients undergoing elective surgical procedures under balanced anaesthesia. The ANN was trained with 1,364 datasets and a further 400 were used for supervising the learning process. One of the 49 ANNs showing the best predictive performance was compared with the established risk scores with respect to practicability, discrimination (by means of the area under a receiver operating characteristics curve) and calibration properties (by means of a weighted linear regression between the predicted and the actual incidences of PONV).

RESULTS

The ANN tested showed a statistically significant ( p<0.0001) and clinically relevant higher discriminating power (0.74; 95% confidence interval: 0.70-0.78) than the Apfel score (0.66; 95% CI: 0.61-0.71) or Koivuranta's score (0.69; 95% CI: 0.65-0.74). Furthermore, the agreement between the actual incidences of PONV and those predicted by the ANN was also better and near to an ideal fit, represented by the equation y=1.0x+0. The equations for the calibration curves were: KNN y=1.11x+0, Apfel y=0.71x+1, Koivuranta 0.86x-5.

CONCLUSION

The improved predictive accuracy achieved by the ANN is clinically relevant. However, the disadvantages of this system prevail because a computer is required for risk calculation. Thus, we still recommend the use of one of the simplified risk scores for clinical practice.

Impact of a multimodal anti-emetic prophylaxis on patient satisfaction in high-risk patients for postoperative nausea and vomiting

Postoperative nausea and vomiting (PONV) are frequent and unpleasant symptoms. This prospective study aimed to assess the efficacy of a multimodal approach to prevent PONV, and patient satisfaction using the willingness-to-pay method. Two validated risk scores were applied to forecast the individual risk for PONV in 900 consecutive patients of whom 108 were identified as high-risk patients (predicted risk: 79-87%). High-risk patients received multimodal anti-emetic prophylaxis: total intravenous anaesthesia with propofol, high fractional inspired oxygen (80%), omission of nitrous oxide, dexamethasone 8 mg, haloperidol 10 microg.kg(-1), and tropisetron 2 mg. Of the remaining patients with low or moderate risk for PONV, a random sample of 71 females received balanced propofol-desflurane anaesthesia without prophylactic anti-emetics. All patients were interviewed 2 and 24 h after surgery for occurrence of nausea and vomiting. Patient satisfaction was measured using the willingness-to-pay method. The incidence of PONV (95%-confidence interval) in the control-group was 41% (29-51%), slightly lower than predicted by the risk scores (53-57%). The multimodal anti-emetic approach reduced the predicted risk (79-87%) in the high risk-group to 7% (3-14%). This was associated with a high willingness-to-pay median (25th/75th percentile) of 84 UK pounds (33-184 UK pounds) in the multimodal anti-emetic group compared to 14 UK pounds (4-30 UK pounds) in the control group. A multimodal anti-emetic approach can considerably reduce the incidence of PONV in high-risk patients and is associated with a high patient satisfaction as measured by the willingness-to-pay method.