Possibilities and limitations in the pharmacological management of postoperative nausea and vomiting

The incidence of postoperative nausea and vomiting (PONV) after a standard anaesthetic technique consisting of inhalational anaesthetics and opioids and no PONV prophylaxis is up to 30%. Being one of the most common complaints following surgery under general anaesthesia, it is not surprising that PONV is a considerable cause of dissatisfaction with recovery from anaesthesia and remains one of the most commonly used items in surveys assessing patient satisfaction with the perioperative period and in scoring systems for the quality of recovery following anaesthesia. The weakest link in the chain from research to patient benefit is the implementation of well proven strategies. Rather than simply following existing consensus guidelines, anaesthesiologists should critically assess whether the algorithms introduced produce the desired effect. Risk-adapted strategies may work, but recent implementation studies suggest that compliance with these algorithms may be poor and that high-risk patients often do not receive appropriate antiemetic prophylaxis. Multimodal prevention may represent a more simple approach and, thus, a more reliable strategy to reduce the incidence of PONV. Such an approach would circumvent the inherent weaknesses of the need to undertake a risk assessment for each individual patient. Anaesthesiologists need to know about the new agents available to manage PONV, such as the NK1-antagonists or the newer 5-HT3 antagonists, but should not forget the traditional and well established antiemetics that are valuable components in the current portfolio. The low cost of most of the currently available antiemetics and the low incidence of side-effects suggests that a liberal antiemetic prophylaxis regimen is a meaningful option in order to eliminate or substantially reduce the 'big little problem'.     

Postoperative nausea and vomiting

Numerous pathophysiological mechanisms are known to cause nausea or vomiting but their role for postoperative nausea and vomiting (PONV) is not quite clear. Volatile anesthetics, nitrous oxide and opioids appear to be the most important causes for PONV. Female gender, non-smoking and a history of motion sickness and PONV are the most important patient specific risk factors. With these risk factors an objective risks assessment is achievable as a good rational basis for a risk dependent antiemetic approach: When the risk is low, moderate, or high, the use of none, a single or a combination of prophylactic antiemetic interventions seems to be justified. Performing a total intravenous anesthesia (Ti.v.A) with propofol is a reasonable prophylactic approach, but does not solve the problem satisfactorily alone if the risk is very high, reducing the risk of PONV only by 30%. This is comparable to the reduction rate of antiemetics, such as serotonin antagonist, dexamethasone and droperidol. It must be stressed that metoclopramide is ineffective. Data from IMPACT indicate that prophylaxis is not very effective if the patients risk is low. At a moderate risk the use of Ti.v.A or an antiemetic is reasonable and only a (very) high risk justifies the combination of several prophylactic antiemetic interventions. For the treatment of PONV an antiemetic should be chosen which has not been used prophylactically. The necessary doses are usually a quarter of those needed for prophylaxis.     

Oral ondansetron,tropisetron or metoclopramide to prevent postoperative nausea and vomiting: a comparison in high-risk patients undergoing thyroid or parathyroid surgery

BACKGROUND: Oral antiemetic prophylaxis may be a practical alternative to intravenous administration. Intravenous ondansetron and tropisetron prevent postoperative nausea and vomiting (PONV) at least as efficiently as traditional antiemetics, droperidol and metoclopramide. We tested the hypothesis that the incidence of PONV after oral ondansetron or tropisetron prophylaxis is lower compared with metoclopramide among high-risk patients. METHODS: In a prospective, double-blind study we studied 179 high-risk patients who received either ondansetron 16 mg, tropisetron 5 mg, or metoclopramide 10 mg orally 1 h before the operation. A standard general anesthetic technique and postoperative analgesia were used. The incidence of PONV and the need for rescue antiemetic medication was recorded for 24 h. RESULTS: In the postanesthesia care unit, the incidence of PONV was lower after premedication with tropisetron compared with ondansetron and metoclopramide (15%, 32% and 39%, respectively). The incidence of PONV during 0-24 h was the same in each group (68%, 58% and 75% in the ondansetron, tropisetron and metoclopramide group, respectively), but the incidence of vomiting was significantly lower after ondansetron (34%) and tropisetron (22%) prophylaxis compared with metoclopramide (53%). The need for additional antiemetics was significantly lower after tropisetron prophylaxis compared with metoclopramide. Patient satisfaction was significantly higher after tropisetron than after metoclopramide. CONCLUSIONS: In the initial period, the incidence of PONV was lower after premedication with oral tropisetron than after ondansetron or metoclopramide. Considering the entire 24-h postoperative period, the incidence of PONV was the same after all three premedications, but the incidence of vomiting was lower after oral ondansetron and tropisetron than after metoclopramide.     

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.     

Postoperative Übelkeit und Erbrechen

Numerous pathophysiological mechanisms are known to cause nausea or vomiting but their role for postoperative nausea and vomiting (PONV) is not quite clear. Volatile anesthetics, nitrous oxide and opioids appear to be the most important causes for PONV. Female gender, non-smoking and a history of motion sickness and PONV are the most important patient specific risk factors. With these risk factors an objective risk assessment is achievable as a good rational basis for a risk dependent antiemetic approach: When the risk is low, moderate, or high, the use of none, a single or a combination of prophylactic antiemetic interventions seems to be justified. Performing a total intravenous anesthesia (TIVA) with propofol is a reasonable prophylactic approach, but does not solve the problem satisfactorily alone if the risk is very high, reducing the risk of PONV only by 30%. This is comparable to the reduction rate of antiemetics, such as serotonin antagonists, dexamethasone and droperidol. It must be stressed that metoclopramide is ineffective. Data from IMPACT indicate that prophylaxis is not very effective if the patients risk is low. At a moderate risk the use of TIVA or an antiemetic is reasonable and only a (very) high risk justifies the combination of several prophylactic antiemetic interventions. For the treatment of PONV an antiemetic should be chosen which has not been used prophylactically. The necessary doses are usually a quarter of those needed for prophylaxis.     

A risk adapted approach reduces the overall institutional incidence of postoperative nausea and vomiting

PURPOSE: Routine prophylactic antiemetic treatment of surgical patients appears justified only in case of an increased risk of postoperative nausea and vomiting (PONV). The objective of this investigation was to assess the feasibility and efficacy of a dichotomized risk score adapted management of PONV based on ondansetron prophylaxis and treatment with respect to the overall institutional rate of PONV. METHODS: After estimating the individual PONV risk by a simplified score, 162 adult patients scheduled for elective surgery received either 4 mg ondansetron intravenously (two to four risk factors = high-risk) or no prophylaxis (zero to one risk factor = low-risk). For antiemetic treatment ondansetron was given intravenously and orally. Incidence of PONV was recorded during the first 24 hr after recovery. RESULTS: Data from 159 subjects were analyzed with 44 patients classified as low-risk and 115 patients classified as high-risk. Nine low-risk and 58 high-risk patients experienced PONV. The expected institutional PONV incidence of 47% was reduced to 36%. Treatment with ondansetron was necessary in seven low-risk and 37 high-risk patients with a complete response rate of 71% (low-risk) and 43% (high-risk). CONCLUSION: Providing antiemetic prophylaxis with ondansetron to high-risk patients strictly based on a simplified risk score can reduce the overall institutional rate of PONV. However, classifying patients into two groups while using ondansetron as the single antiemetic in the high-risk group appears to be of limited efficacy as the incidence of PONV in high-risk patients is still double that of low-risk patients.     

The effectiveness of rescue antiemetics after failure of prophylaxis with ondansetron or droperidol: a preliminary report

STUDY OBJECTIVES: To compare the effectiveness of treating established postoperative nausea and vomiting (PONV) with an antiemetic acting at a different receptor with that of treating PONV with the antiemetic used for prophylaxis. DESIGN: Analysis of data collected in a previously published randomized, double-blind, placebo-controlled study. SETTING: Outpatient surgical procedures from 50 institutions in North America. PATIENTS: Patients (N = 2061) undergoing outpatient surgical procedures planned to last no more than 2 hours. INTERVENTIONS: Patients were randomized to receive ondansetron 4 mg, droperidol 1.25, droperidol 0.625 mg, or placebo. In the postoperative anesthesia care unit, patients who developed PONV received rescue antiemetics at the discretion of the attending anesthesiologist. The following antiemetics were used for rescue: ondansetron 4 mg, droperidol 0.625 to 1.25 mg, metoclopramide 10 mg, promethazine 6.25 to 25 mg, and dimenhydrinate 25 to 50 mg. MEASUREMENTS: The complete response rate (no nausea, no emesis, and no need for further rescue) after administration of the rescue antiemetic in patients with established PONV was calculated. The complete response rate after administration of each of the different rescue antiemetics was compared with that after administration of the same antiemetic used for PONV prophylaxis. MAIN RESULTS: In patients who failed prophylaxis with ondansetron 4 mg, the complete response rate was significantly higher (P = .02) after rescue with promethazine 6.25 to 25 mg (78%) than after rescue with ondansetron 4 mg (46%). In patients who failed prophylaxis with droperidol 0.625 and 1.25 mg, the complete response rate was significantly higher after rescue with promethazine 6.25 to 25 mg (77%; P = .02) and dimenhydrinate 25 to 50 mg (78%; P = .04) than after rescue with droperidol 0.625 to 1.25 mg (56%). CONCLUSION: In patients who failed prophylaxis with ondansetron or droperidol, promethazine was significantly more effective than the agent used for prophylaxis for the treatment of PONV. In patients who failed prophylaxis with droperidol, dimenhydrinate was also more effective than droperidol for the treatment of established PONV in the postoperative anesthesia care unit.     

Postoperative nausea and vomiting in adult patients

OBJECTIVE: Identifying risk factors and predictive models for Postoperative Nausea and Vomiting (PONV) and developing antiemetic guidelines for its prevention and treatment. DATA SOURCES: Medline (1997-2002) searches, using "postoperative nausea and vomiting" [MESH], complemented by handsearch. STUDY SELECTION AND DATA EXTRACTION: Published randomised controlled trials, systematic reviews and multivariable analysis of large cohort studies were evaluated. DATA SYNTHESIS: Avoiding PONV seems to be one of the highest priority for most patients. Its most important risk factors are volatile anaesthetics and opioids. If these are given to susceptible patients such as female, those with previous history of PONV or motion sickness and non-smoker, this is likely to result in PONV. For patients receiving volatile anaesthesia, simplified risk scores are available to estimate the individual risk of PONV. Patients at high risk for PONV may benefit from a multimodal approach which involves a) lowering the baseline risk (e.g. by total intravenous anaesthesia with propofol) with b) prophylactically given antiemetics such as droperidol, dexamethasone and serotonin antagonists, alone or in combination. In these selected patients, antiemetics are cost effective. CONCLUSIONS: A strategy to prevent and treat PONV should depend on the individuals risk. However, its clinical usefulness and economic implications needs to be validated.     

Management of postoperative nausea and vomiting in ambulatory surgery

The management of PONV has improved significantly over the years but remains a frequent occurrence in postoperative patients. Evaluation of individual patient risk and the consideration for prophylactic antiemetic in high-risk populations should reduce these unpleasant symptoms and help direct appropriate clinical strategies. Treatment following failure of prophylactic antiemetic therapy requires knowledge of previously used antiemetics and the time of their administration.     

现有止吐措施的效果：一项对高风险患者的前瞻性研究

背景在这项前瞻性的多中心观察研究中,我们评估了手术后恶心、呕吐（PONV）的发生率和持续时间,评估了对高危患者预防性和补救性使用止吐剂的效果,并且在美国麻醉医师协会（ASA）和美国围麻醉护士学会（ASPAN）指南的基础上确定了基于人口数量的止吐剂作用。方法选择拟行择期腹腔镜手术和大型整形手术且具有两项以上Apfel PONV危险因素的患者作用研究对象（女性,既住有PONV或者晕动病痛电,不吸烟）。记录手术后的72小时内由于PONV所导致的止吐剂的使用、呕吐的发怍次数、恶心的严重程度以硬功能性干预等临床资料。完全有效（CR）定义为无呕吐且未进行补救性药物治疗,完全控制定义为CR且无中、重度恶心。同时分析ASA和ASPAN指南的依从性（相对未遵守者）PONV治疗效果。结果由于使用止吐剂数量不同．大约有18％～40％的患者发生手术后呕吐。补救性药物治疗的发生率（45％）与中、重度恶心的发生率（47％）以及因呕吐症状而进行功能性干预的比例（44％）近拟、预防性使用3种或以上止吐剂的患者相对于预防性使用少于1种止吐剂的患者总体上有更好的预后．尽管遵守了最近编写的PONV治疗指南,CR依旧小于70％（ASA：69％;ASPAN：63％）。在3天的研究时间内,完全控制率比CR率低10％。结论在可能会发展为PONV的患者中,预防性使用3种或以上的止吐剂在72小时内对呕吐有很大的正面影响．虽然遵守编写的PONV治疗指南改善了患者的预后,仍然有30％以上的高危患者发生手术后呕吐和生理功能紊乱。     

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.     

Übelkeit und Erbrechen in der postoperativen Phase

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.     

Multimodal antiemetic management prevents early postoperative vomiting after outpatient laparoscopy

Because no completely effective antiemetic exists for the prevention of postoperative nausea and vomiting (PONV), we hypothesize that a multimodal approach to management of PONV may reduce both vomiting and the need for rescue antiemetics in high-risk patients. After IRB approval, women undergoing outpatient laparoscopy were randomized to one of three groups. Group I (n = 60) was managed by using a predefined multimodal clinical care algorithm. Patients undergoing the same surgical procedure who received a standard balanced outpatient anesthetic with ondansetron 4 mg (Group II, n = 42) or placebo (Group III, n = 37) prophylaxis were chosen to establish baseline incidence of nausea and vomiting. None of the Group I patients vomited before discharge, compared with 7% in Group II (P = 0.07) and 22% in Group III (P = 0.0003). However, one patient (2%) in Group I required treatment for symptoms in the postanesthesia care unit, compared with 24% in Group II (P<0.0001) and 41% in Group III (P< 0.0001). Time to discharge-ready was significantly shorter in Group I (128, 118-139 min; mean, 95% confidence interval) versus Group II (162, 145-181 min; P = 0.0015) and Group III (192, 166-222 min; P = 0.0001). Patient satisfaction with control of PONV was not different between Group I and Group II. Return to normal daily activity and overall satisfaction were not different among groups. Multimodal management resulted in a 98% complete response rate and a 0% incidence of vomiting before discharge; however, this improvement did not result in an increased level of patient satisfaction when compared with routine monotherapy prophylaxis. We conclude that both multimodal management and routine monotherapy antiemetic prophylaxis resulted in an increased level of patient satisfaction than symptomatic treatment in this high-risk population.     

Postoperative nausea and vomiting

Postoperative nausea and vomiting (PONV) is a major cause of morbidity and patient discomfort. Many patients fear vomiting as much as, if not more than pain.PONV may also have an economic impact. In day-case surgery, PONV may result in delayed discharge or even overnight admission. On average, 30% of surgical patients suffer PONV symptoms but after day-case gynaecological laparoscopic surgery the incidence exceeds 50%.In the last decades, a vast amount of research has been performed in this area and new antiemetic drugs and interventions have been introduced. However, no ‘gold standard’ antiemetic intervention has been found and the incidence of PONV is still significant. The mechanism of stimulation of emesis and the factors incriminated in the development of PONV are discussed. The impact of these factors on PONV and the calculation of risk scores are presented. The antiemetic drugs as well as the non-pharmacological techniques used for prophylaxis and treatment of PONV are also reviewed.     

Multimodal therapies for postoperative nausea and vomiting, and pain

Postoperative nausea and vomiting (PONV) and pain are two of the major concerns for patients presenting for surgery. The causes of PONV are multifactorial and can largely be categorized as patient risk factors, anaesthetic technique, and surgical procedure. Antiemetics work on several different receptor sites to prevent or treat PONV. This is probably why numerous studies have now demonstrated that using more than one antiemetic is usually more effective and results in fewer side-effects than simply increasing the dose of a single antiemetic. A multimodal approach to PONV should not be limited to drug therapy alone but should involve a holistic approach starting before operation and continuing intraoperatively with risk reduction strategies to which are added prophylactic antiemetics according to the assessed patient risk for PONV. With the increasing understanding of the pathophysiology of acute pain, especially the occurrence of peripheral and central hypersensitization, it is unlikely that a single drug or intervention is sufficiently broad in its action to be adequately effective, especially with moderate or greater pain. Although morphine and its congeners are usually the foundation of pain management regimens, as their dose increases so does the incidence of side-effects. Thus, the approach for the management of acute postoperative pain is to use multiple drugs or modalities (e.g. regional anaesthesia) to maximize pain relief and reduce side-effects.     

Antiemetic Prophylaxis for Office-based Surgery: Are the 5-HT3 Receptor Antagonists Beneficial?

Background: Office-based surgery has become increasingly popular because of its cost-saving potential. However, the occurrence of postoperative nausea and vomiting (PONV) can delay patient discharge. Prophylaxis using a combination of antiemetic drugs has been suggested as an effective strategy for minimizing PONV. The authors designed this randomized, double-blinded, placebo-controlled study to assess the efficacy of ondansetron and dolasetron when administered in combination with droperidol and dexamethasone for routine antiemetic prophylaxis against PONV in the office-based surgery setting.

Methods: Following institutional review board approval, 135 consenting outpatients with American Society of Anesthesiologists physical status I-III who were undergoing superficial surgical procedures lasting 20-40 min were randomly assigned to one of three antiemetic treatment groups. Propofol was administered for induction of anesthesia, followed by 2-4% desflurane with 67% nitrous oxide in oxygen. Desflurane was subsequently adjusted to maintain a clinically adequate depth of anesthesia with an electroencephalographic Bispectral Index value between 50 and 60. All patients received 0.625 mg intravenous droperidol and 4 mg intravenous dexamethasone after induction of anesthesia. The study medication, containing normal saline (control), 12.5 mg intravenous dolasetron, or 4 mg intravenous ondansetron, was administered prior to the end of surgery. All patients received local anesthetics at the incisional site and 30 mg intravenous ketolorac to minimize postoperative pain. Recovery profiles, incidence of PONV, requirement for rescue antiemetic drugs, complete response rates, and patient satisfaction were assessed.

Results: The recovery times to patient orientation, oral intake, ambulation, and actual discharge did not differ among the three groups. The incidence of PONV, nausea scores, and requirement for rescue antiemetics were also similar in all three groups during the 24-h study period. In addition, the complete response rates to the prophylactic antiemetics (96-98%) and percentages of very satisfied patients (93-98%) were equally high in all three groups. However, the antiemetic drug acquisition costs were US $2.50, $15.50, and $18.50 in the control, dolasetron, and ondansetron groups, respectively.     

Tumor lysis associated with dexamethasone use in a child with leukemia

Postoperative nausea and vomiting (PONV) occurs in every third patient undergoing general anesthesia without PONV prophylaxis. Antiemetic prophylaxis with dexamethasone is commonly used in patients at moderate risk. We present a case in which PONV prophylaxis with a single dose of dexamethasone led to tumor lysis in a patient with acute leukemia. In case of a cancer patient at moderate risk for PONV, the anesthesiologist should contact the oncologist first, or use other antiemetic drugs such as antiserotoninergic agents for PONV prophylaxis.     

Antiemetic prophylaxis for office-based surgery: are the 5-HT3 receptor antagonists beneficial?

BACKGROUND: Office-based surgery has become increasingly popular because of its cost-saving potential. However, the occurrence of postoperative nausea and vomiting (PONV) can delay patient discharge. Prophylaxis using a combination of antiemetic drugs has been suggested as an effective strategy for minimizing PONV. The authors designed this randomized, double-blinded, placebo-controlled study to assess the efficacy of ondansetron and dolasetron when administered in combination with droperidol and dexamethasone for routine antiemetic prophylaxis against PONV in the office-based surgery setting. METHODS: Following institutional review board approval, 135 consenting outpatients with American Society of Anesthesiologists physical status I-III who were undergoing superficial surgical procedures lasting 20-40 min were randomly assigned to one of three antiemetic treatment groups. Propofol was administered for induction of anesthesia, followed by 2-4% desflurane with 67% nitrous oxide in oxygen. Desflurane was subsequently adjusted to maintain a clinically adequate depth of anesthesia with an electroencephalographic Bispectral Index value between 50 and 60. All patients received 0.625 mg intravenous droperidol and 4 mg intravenous dexamethasone after induction of anesthesia. The study medication, containing normal saline (control), 12.5 mg intravenous dolasetron, or 4 mg intravenous ondansetron, was administered prior to the end of surgery. All patients received local anesthetics at the incisional site and 30 mg intravenous ketolorac to minimize postoperative pain. Recovery profiles, incidence of PONV, requirement for rescue antiemetic drugs, complete response rates, and patient satisfaction were assessed. RESULTS: The recovery times to patient orientation, oral intake, ambulation, and actual discharge did not differ among the three groups. The incidence of PONV, nausea scores, and requirement for rescue antiemetics were also similar in all three groups during the 24-h study period. In addition, the complete response rates to the prophylactic antiemetics (96-98%) and percentages of very satisfied patients (93-98%) were equally high in all three groups. However, the antiemetic drug acquisition costs were US $2.50, $15.50, and $18.50 in the control, dolasetron, and ondansetron groups, respectively. CONCLUSION: The addition of dolasetron (12.5 mg) or ondansetron (4 mg) failed to improve the antiemetic efficacy of droperidol (0.625 mg intravenous) and dexamethasone (4 mg intravenous) when they were used for routine prophylaxis in the office-based surgery setting.     

Postoperative nausea and emesis

Watcha and White [51] have made recommendations for antiemetic therapy and prophylaxis based on published peer-reviewed studies. They range from no prophylaxis for patients at low risk to "multimodal" antiemetic therapy for those at the highest risk (Fig. 1) [10]. Recommendations for rescue therapy of breakthrough PONV are also provided. With this approach, it should be possible [figure: see text] to individualize prophylaxis and rescue therapy to achieve an optimal cost-effective management strategy for this uncomfortable postoperative complication.