Intravenous dolasetron and ondansetron in prevention of postoperative nausea and vomiting: a multicenter, double-blind, placebo-controlled study

Is Prevention of Postoperative Vomiting Surgery Dependent? A Retrospective Cohort Study of Total Knee Arthroplasty

The study of postoperative nausea and vomiting (PONV) has been ongoing since the early days of general anesthesia. The search for risk factors of PONV and the development of new agents to treat PONV are the two main strategies to combat the adverse side effects of general anesthesia. Female sex, non-smoking status, a history of PONV/motion sickness, and postoperative opioid use are the four independent risk factors for PONV derived after a series of prospective studies, evidence-based systematic reviews, and meta-analyses. The two frequently asked questions that arise ask whether risk factors apply to different clinical settings and whether prevention measures of PONV can be surgery dependent. We conducted a comprehensive review of 665 patients who underwent primary total knee arthroplasty (TKA) between January and December 2019. As nausea is subjective and its measurement is not standardized, postoperative vomiting (POV) was used as a study endpoint. The exclusion criteria were desflurane anesthesia, spinal anesthesia, anesthesia without bispectral index monitoring, and day surgery. Three well-recognized risk factors, consisting of body weight, sevoflurane consumption, and postoperative opioid consumption, were not considered as independent risk factors of POV, while female sex, preoperative adductor canal block (ACB), and dexamethasone were identified as being so in this study. The risk of POV in the female sex was 2.49 times that in the male sex; however, when dexamethasone was used, this risk was reduced by >40% compared with no antiemetic use, and by >50% when patients received preoperative ACB compared with those without the block. The clinical characteristics of our TKA patients—female dominance, old age, and their fairly constant body weights that were distinct from those of other surgical patients—suggested that age may play a crucial role in determining the relative contributions of the different risk factors of POV. We concluded that risk factors of POV are dependent on clinical settings. Based on these results, it is reasonable to speculate that a surgery-dependent plan for the prevention of POV is feasible for patients in similar clinical settings.

Risk Factors of Postoperative Vomiting in the Eye of "Real-World Evidence"-Modifiable and Clinical Setting-Dependent Risk Factors in Surgical Trauma Patients

Numerous studies on postoperative nausea and vomiting (PONV) have been carried out since the early days of contemporary surgery. The incidence of PONV has been greatly reduced in recent years and new drugs for PONV keep evolving in the market; however, a substantial number of patients are still under the threat of PONV. Female gender, non-smokers, a history of PONV/motion sickness, and postoperative opioid use are four well-recognized risk factors of PONV. Many potential risk factors reported in previous studies were not consistently presented as predictors for PONV. Two questions then arise; are risk factors clinical setting dependent and are risk factors modifiable? We attempted to answer the questions through a comprehensive review of perioperative records of surgical patients from the Trauma Department of our hospital. As nausea is subjective and no standard is applicable for its measurement, postoperative vomiting (POV) was used as an endpoint in this study. To the best of our knowledge, this is the first study to address the POV issue in surgical trauma patients. A total of 855 patients were enrolled in this study after excluding age below 20 years old, total intravenous anesthesia, desflurane anesthesia, or records with missing data. Our results showed that female gender (OR 4.89) is the strongest predicting factor, followed by a less potent predicting factor—more intraoperative opioid consumption (OR 1.07)—which favor more POV. More intraoperative crystalloid supply (OR 0.71) and a higher body weight (OR 0.9) favor less POV. Other potential risk factors did not reach statistical significance in this study as independent risk factors. Our results also showed that when the intraoperative crystalloid infusion rate is greater than 4 mL/kg/h (OR 0.20), it favors a lower rate of POV; when intraoperative opioid consumption is greater than 12 mg morphine equivalents, MME (OR 1.87), it favors a higher rate of POV. We concluded that dominance of any independent risk factor over other risk factors depends on how individual factors interact with the clinical setting. Some risk factors could be modified, and a cut-off value could be derived to facilitate a better plan for POV prevention.

Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network meta-analysis

BACKGROUND

Postoperative nausea and vomiting (PONV) is a common adverse effect of anaesthesia and surgery. Up to 80% of patients may be affected. These outcomes are a major cause of patient dissatisfaction and may lead to prolonged hospital stay and higher costs of care along with more severe complications. Many antiemetic drugs are available for prophylaxis. They have various mechanisms of action and side effects, but there is still uncertainty about which drugs are most effective with the fewest side effects.

OBJECTIVES

• To compare the efficacy and safety of different prophylactic pharmacologic interventions (antiemetic drugs) against no treatment, against placebo, or against each other (as monotherapy or combination prophylaxis) for prevention of postoperative nausea and vomiting in adults undergoing any type of surgery under general anaesthesia • To generate a clinically useful ranking of antiemetic drugs (monotherapy and combination prophylaxis) based on efficacy and safety • To identify the best dose or dose range of antiemetic drugs in terms of efficacy and safety SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP), ClinicalTrials.gov, and reference lists of relevant systematic reviews. The first search was performed in November 2017 and was updated in April 2020. In the update of the search, 39 eligible studies were found that were not included in the analysis (listed as awaiting classification).

SELECTION CRITERIA

Randomized controlled trials (RCTs) comparing effectiveness or side effects of single antiemetic drugs in any dose or combination against each other or against an inactive control in adults undergoing any type of surgery under general anaesthesia. All antiemetic drugs belonged to one of the following substance classes: 5-HT₃ receptor antagonists, D₂ receptor antagonists, NK₁ receptor antagonists, corticosteroids, antihistamines, and anticholinergics. No language restrictions were applied. Abstract publications were excluded.

DATA COLLECTION AND ANALYSIS

A review team of 11 authors independently assessed trials for inclusion and risk of bias and subsequently extracted data. We performed pair-wise meta-analyses for drugs of direct interest (amisulpride, aprepitant, casopitant, dexamethasone, dimenhydrinate, dolasetron, droperidol, fosaprepitant, granisetron, haloperidol, meclizine, methylprednisolone, metoclopramide, ondansetron, palonosetron, perphenazine, promethazine, ramosetron, rolapitant, scopolamine, and tropisetron) compared to placebo (inactive control). We performed network meta-analyses (NMAs) to estimate the relative effects and ranking (with placebo as reference) of all available single drugs and combinations. Primary outcomes were vomiting within 24 hours postoperatively, serious adverse events (SAEs), and any adverse event (AE). Secondary outcomes were drug class-specific side effects (e.g. headache), mortality, early and late vomiting, nausea, and complete response. We performed subgroup network meta-analysis with dose of drugs as a moderator variable using dose ranges based on previous consensus recommendations. We assessed certainty of evidence of NMA treatment effects for all primary outcomes and drug class-specific side effects according to GRADE (CINeMA, Confidence in Network Meta-Analysis). We restricted GRADE assessment to single drugs of direct interest compared to placebo.

MAIN RESULTS

We included 585 studies (97,516 randomized participants). Most of these studies were small (median sample size of 100); they were published between 1965 and 2017 and were primarily conducted in Asia (51%), Europe (25%), and North America (16%). Mean age of the overall population was 42 years. Most participants were women (83%), had American Society of Anesthesiologists (ASA) physical status I and II (70%), received perioperative opioids (88%), and underwent gynaecologic (32%) or gastrointestinal surgery (19%) under general anaesthesia using volatile anaesthetics (88%). In this review, 44 single drugs and 51 drug combinations were compared. Most studies investigated only single drugs (72%) and included an inactive control arm (66%). The three most investigated single drugs in this review were ondansetron (246 studies), dexamethasone (120 studies), and droperidol (97 studies). Almost all studies (89%) reported at least one efficacy outcome relevant for this review. However, only 56% reported at least one relevant safety outcome. Altogether, 157 studies (27%) were assessed as having overall low risk of bias, 101 studies (17%) overall high risk of bias, and 327 studies (56%) overall unclear risk of bias. Vomiting within 24 hours postoperatively Relative effects from NMA for vomiting within 24 hours (282 RCTs, 50,812 participants, 28 single drugs, and 36 drug combinations) suggest that 29 out of 36 drug combinations and 10 out of 28 single drugs showed a clinically important benefit (defined as the upper end of the 95% confidence interval (CI) below a risk ratio (RR) of 0.8) compared to placebo. Combinations of drugs were generally more effective than single drugs in preventing vomiting. However, single NK₁ receptor antagonists showed treatment effects similar to most of the drug combinations. High-certainty evidence suggests that the following single drugs reduce vomiting (ordered by decreasing efficacy): aprepitant (RR 0.26, 95% CI 0.18 to 0.38, high certainty, rank 3/28 of single drugs); ramosetron (RR 0.44, 95% CI 0.32 to 0.59, high certainty, rank 5/28); granisetron (RR 0.45, 95% CI 0.38 to 0.54, high certainty, rank 6/28); dexamethasone (RR 0.51, 95% CI 0.44 to 0.57, high certainty, rank 8/28); and ondansetron (RR 0.55, 95% CI 0.51 to 0.60, high certainty, rank 13/28). Moderate-certainty evidence suggests that the following single drugs probably reduce vomiting: fosaprepitant (RR 0.06, 95% CI 0.02 to 0.21, moderate certainty, rank 1/28) and droperidol (RR 0.61, 95% CI 0.54 to 0.69, moderate certainty, rank 20/28). Recommended and high doses of granisetron, dexamethasone, ondansetron, and droperidol showed clinically important benefit, but low doses showed no clinically important benefit. Aprepitant was used mainly at high doses, ramosetron at recommended doses, and fosaprepitant at doses of 150 mg (with no dose recommendation available). Frequency of SAEs Twenty-eight RCTs were included in the NMA for SAEs (10,766 participants, 13 single drugs, and eight drug combinations). The certainty of evidence for SAEs when using one of the best and most reliable anti-vomiting drugs (aprepitant, ramosetron, granisetron, dexamethasone, ondansetron, and droperidol compared to placebo) ranged from very low to low. Droperidol (RR 0.88, 95% CI 0.08 to 9.71, low certainty, rank 6/13) may reduce SAEs. We are uncertain about the effects of aprepitant (RR 1.39, 95% CI 0.26 to 7.36, very low certainty, rank 11/13), ramosetron (RR 0.89, 95% CI 0.05 to 15.74, very low certainty, rank 7/13), granisetron (RR 1.21, 95% CI 0.11 to 13.15, very low certainty, rank 10/13), dexamethasone (RR 1.16, 95% CI 0.28 to 4.85, very low certainty, rank 9/13), and ondansetron (RR 1.62, 95% CI 0.32 to 8.10, very low certainty, rank 12/13). No studies reporting SAEs were available for fosaprepitant. Frequency of any AE Sixty-one RCTs were included in the NMA for any AE (19,423 participants, 15 single drugs, and 11 drug combinations). The certainty of evidence for any AE when using one of the best and most reliable anti-vomiting drugs (aprepitant, ramosetron, granisetron, dexamethasone, ondansetron, and droperidol compared to placebo) ranged from very low to moderate. Granisetron (RR 0.92, 95% CI 0.80 to 1.05, moderate certainty, rank 7/15) probably has no or little effect on any AE. Dexamethasone (RR 0.77, 95% CI 0.55 to 1.08, low certainty, rank 2/15) and droperidol (RR 0.89, 95% CI 0.81 to 0.98, low certainty, rank 6/15) may reduce any AE. Ondansetron (RR 0.95, 95% CI 0.88 to 1.01, low certainty, rank 9/15) may have little or no effect on any AE. We are uncertain about the effects of aprepitant (RR 0.87, 95% CI 0.78 to 0.97, very low certainty, rank 3/15) and ramosetron (RR 1.00, 95% CI 0.65 to 1.54, very low certainty, rank 11/15) on any AE. No studies reporting any AE were available for fosaprepitant. Class-specific side effects For class-specific side effects (headache, constipation, wound infection, extrapyramidal symptoms, sedation, arrhythmia, and QT prolongation) of relevant substances, the certainty of evidence for the best and most reliable anti-vomiting drugs mostly ranged from very low to low. Exceptions were that ondansetron probably increases headache (RR 1.16, 95% CI 1.06 to 1.28, moderate certainty, rank 18/23) and probably reduces sedation (RR 0.87, 95% CI 0.79 to 0.96, moderate certainty, rank 5/24) compared to placebo. The latter effect is limited to recommended and high doses of ondansetron. Droperidol probably reduces headache (RR 0.76, 95% CI 0.67 to 0.86, moderate certainty, rank 5/23) compared to placebo. We have high-certainty evidence that dexamethasone (RR 1.00, 95% CI 0.91 to 1.09, high certainty, rank 16/24) has no effect on sedation compared to placebo. No studies assessed substance class-specific side effects for fosaprepitant. Direction and magnitude of network effect estimates together with level of evidence certainty are graphically summarized for all pre-defined GRADE-relevant outcomes and all drugs of direct interest compared to placebo in http://doi.org/10.5281/zenodo.4066353.

AUTHORS' CONCLUSIONS

We found high-certainty evidence that five single drugs (aprepitant, ramosetron, granisetron, dexamethasone, and ondansetron) reduce vomiting, and moderate-certainty evidence that two other single drugs (fosaprepitant and droperidol) probably reduce vomiting, compared to placebo. Four of the six substance classes (5-HT₃ receptor antagonists, D₂ receptor antagonists, NK₁ receptor antagonists, and corticosteroids) were thus represented by at least one drug with important benefit for prevention of vomiting. Combinations of drugs were generally more effective than the corresponding single drugs in preventing vomiting. NK₁ receptor antagonists were the most effective drug class and had comparable efficacy to most of the drug combinations. 5-HT₃ receptor antagonists were the best studied substance class. For most of the single drugs of direct interest, we found only very low to low certainty evidence for safety outcomes such as occurrence of SAEs, any AE, and substance class-specific side effects. Recommended and high doses of granisetron, dexamethasone, ondansetron, and droperidol were more effective than low doses for prevention of vomiting. Dose dependency of side effects was rarely found due to the limited number of studies, except for the less sedating effect of recommended and high doses of ondansetron. The results of the review are transferable mainly to patients at higher risk of nausea and vomiting (i.e. healthy women undergoing inhalational anaesthesia and receiving perioperative opioids). Overall study quality was limited, but certainty assessments of effect estimates consider this limitation. No further efficacy studies are needed as there is evidence of moderate to high certainty for seven single drugs with relevant benefit for prevention of vomiting. However, additional studies are needed to investigate potential side effects of these drugs and to examine higher-risk patient populations (e.g. individuals with diabetes and heart disease).

WITHDRAWN: Drugs for preventing postoperative nausea and vomiting

BACKGROUND

Drugs can prevent postoperative nausea and vomiting, but their relative efficacies and side effects have not been compared within one systematic review.

OBJECTIVES

The objective of this review was to assess the prevention of postoperative nausea and vomiting by drugs and the development of any side effects.

SEARCH METHODS

We searched The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 2, 2004), MEDLINE (January 1966 to May 2004), EMBASE (January 1985 to May 2004), CINAHL (1982 to May 2004), AMED (1985 to May 2004), SIGLE (to May 2004), ISI WOS (to May 2004), LILAC (to May 2004) and INGENTA bibliographies.

SELECTION CRITERIA

We included randomized controlled trials that compared a drug with placebo or another drug, or compared doses or timing of administration, that reported postoperative nausea or vomiting as an outcome.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted outcome data.

MAIN RESULTS

We included 737 studies involving 103,237 people. Compared to placebo, eight drugs prevented postoperative nausea and vomiting: droperidol, metoclopramide, ondansetron, tropisetron, dolasetron, dexamethasone, cyclizine and granisetron. Publication bias makes evidence for differences among these drugs unreliable. The relative risks (RR) versus placebo varied between 0.60 and 0.80, depending upon the drug and outcome. Evidence for side effects was sparse: droperidol was sedative (RR 1.32) and headache was more common after ondansetron (RR 1.16).

AUTHORS' CONCLUSIONS

Either nausea or vomiting is reported to affect, at most, 80 out of 100 people after surgery. If all 100 of these people are given one of the listed drugs, about 28 would benefit and 72 would not. Nausea and vomiting are usually less common and, therefore, drugs are less useful. For 100 people, of whom 30 would vomit or feel sick after surgery if given placebo, 10 people would benefit from a drug and 90 would not. Between one to five patients out of every 100 people may experience a mild side effect, such as sedation or headache, when given an antiemetic drug. Collaborative research should focus on determining whether antiemetic drugs cause more severe, probably rare, side effects. Further comparison of the antiemetic effect of one drug versus another is not a research priority.

Prevention of Postoperative Nausea and Vomiting

Objective:

To review the literature on the prevention of postoperative nausea and vomiting (PONV) in adults.

Data Sources:

Literature retrieval was accessed through MEDLINE (1966–December 2006) using the terms postoperative nausea and vomiting, prevention and treatment. Article references were hand-searched for additional relevant articles and abstracts.

Study Selection And Data Extraction:

All studies published in English were evaluated. Those dealing with prevention and treatment of PONV in adults were included in the review.

Data Synthesis:

Evidence suggests that providing prophylactic antiemetic medications in high-risk surgical patients is warranted. 5-HT3 receptor antagonists are widely used, with no one agent being clearly superior. However, studies have shown other types of agents to ho more cost-effective.

Conclusions:

The first step in the prevention of PONV is assessment and reduction of risk factors. Although nonpharmacologic therapies may play a role in the treatment of PONV, the mainstay of therapy for PONV is pharmacologic modalities. Patients at moderate to high risk for PONV need prophylactic antiemetic therapy. High-risk patients may require combination therapy with 2 or 3 agents from different antiemetic classes. Rescue antiemetic therapy is needed by patients who actually develop PONV. The agents of choice in such cases should be from antiemetic classes different from those used for prophylaxis of PONV.

Comparative safety of serotonin (5-HT3) receptor antagonists in patients undergoing surgery: a systematic review and network meta-analysis

BACKGROUND

Serotonin (5-HT3) receptor antagonists are commonly used to decrease nausea and vomiting for surgery patients, but these agents may be harmful. We conducted a systematic review on the comparative safety of 5-HT3 receptor antagonists.

METHODS

Searches were done in MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials to identify studies comparing 5-HT3 receptor antagonists with each other, placebo, and/or other antiemetic agents for patients undergoing surgical procedures. Screening search results, data abstraction, and risk of bias assessment were conducted by two reviewers independently. Random-effects pairwise meta-analysis and network meta-analysis (NMA) were conducted. PROSPERO registry number: CRD42013003564.

RESULTS

Overall, 120 studies and 27,787 patients were included after screening of 7,608 citations and 1,014 full-text articles. Significantly more patients receiving granisetron plus dexamethasone experienced an arrhythmia relative to placebo (odds ratio (OR) 2.96, 95 % confidence interval (CI) 1.11-7.94), ondansetron (OR 3.23, 95 % CI 1.17-8.95), dolasetron (OR 4.37, 95 % CI 1.51-12.62), tropisetron (OR 3.27, 95 % CI 1.02-10.43), and ondansetron plus dexamethasone (OR 5.75, 95 % CI 1.71-19.34) in a NMA including 31 randomized clinical trials (RCTs) and 6,623 patients of all ages. No statistically significant differences in delirium frequency were observed across all treatment comparisons in a NMA including 18 RCTs and 3,652 patients.

CONCLUSION

Granisetron plus dexamethasone increases the risk of arrhythmia.

Ondansetron: a review of pharmacokinetics and clinical experience in postoperative nausea and vomiting

INTRODUCTION

Postoperative nausea and vomiting (PONV) is associated with poor patient satisfaction and delayed recovery after general anesthesia. Multiple neurotransmitters are involved in the mediation of PONV but despite the introduction of new antiemetics, no completely effective drug exists for its prevention or treatment.

AREAS COVERED

This review provides a detailed description of ondansetron's chemistry, pharmacokinetics, pharmacodynamics, toxicity and a brief review of clinical trials involving ondansetron and the management of PONV. We searched reviews, meta-analysis and randomized controlled trials (Medline, Embase and article reference lists).

EXPERT OPINION

According to current literature, administering ondansetron 4 mg i.v. near the end of surgery provides sufficient protection against PONV in low- and moderate-risk patients, comparable to traditional antiemetics such as antihistamines and droperidol. High-risk patients require a multimodal approach since one quarter of them will not respond to monotherapy. In the future, transdermal formulation or formulations for nasal or buccal delivery will be available. The development of non-racemic mixture consisting of R-ondansetron would enhance the safety profile and probably the efficacy too.

A network meta-analysis on the efficacy of serotonin type 3 receptor antagonists used in adults during the first 24 hours for postoperative nausea and vomiting prophylaxis

BACKGROUND

The serotonin type 3 receptor antagonists (5-HT(3) antagonists) ondansetron, granisetron, tropisetron, and dolasetron are potential prophylactic agents for patients with mild to moderate risk of postoperative nausea and vomiting (PONV). A few trials have been conducted to compare the efficacy among 2 to 3 of these 4 agents. However, the comparative efficacy of all four 5-HT(3) antagonists has not yet been quantitatively investigated.

OBJECTIVE

The goal of this study was to investigate whether the 5-HT(3) antagonists--ondansetron, granisetron, tropisetron, and dolasetron-differ in efficacy when used for the prevention of PONV.

METHODS

PubMed and the Cochrane Library were searched for randomized controlled, double-blind studies measuring efficacy in terms of PONV prophylaxis. A Bayesian meta-analysis was conducted using published studies of 5-HT(3) antagonists for PONV prophylaxis. The odds of patients with no PONV and postoperative vomiting (POV) within each study arm 24 hours after surgery were the primary indices of drug efficacy. Data were extracted and analyzed via indirect comparisons using random effects Bayesian models in WinBUGS version 1.4.3.

RESULTS

A total of 85 studies were identified, representing 15,269 patients. The results indicate that granisetron was significantly better than ondansetron (odds ratio [OR] = 1.53 [95% credible interval (CI), 1.15-2.00]) and dolasetron (OR = 1.67 [95% CI, 1.12-2.38]) in preventing PONV. Four antiemetic drugs had comparable efficacy in terms of preventing POV: granisetron showed similar efficacy compared with ondansetron (OR = 1.49 [95% CI, 0.90-2.43]), tropisetron (OR = 1.69 [95% CI, 0.92-3.13]), and dolasetron (OR = 1.32 [95% CI, 0.71-2.38]). Ondansetron exhibited comparable efficacy compared with tropisetron (OR = 1.14 [95% CI, 0.66-1.96]) and dolasetron (OR = 0.88 [95% CI, 0.51-1.47]). Tropisetron and dolasetron were also similar in efficacy (OR = 0.78 [95% CI, 0.40-1.45]). All 5-HT(3) antagonists were statistically significantly better at preventing PONV or POV than placebo.

CONCLUSIONS

With respect to PONV prophylaxis, granisetron was significantly better than ondansetron and dolasetron; ondansetron, tropisetron, and dolasetron exhibited similar efficacy. With respect to POV prophylaxis, ondansetron, granisetron, tropisetron, and dolasetron seemed to have comparable efficacy.

Antiemetic prophylaxis in thyroid surgery: a randomized, double-blind comparison of three 5-HT3 agents

PURPOSE

The aim of this double-blind randomized study was to compare the antiemetic efficacy of three 5-hydroxytryptamine type 3 antagonists in terms of the incidence and intensity of postoperative nausea and vomiting (PONV) in a homogenous group of female patients undergoing thyroidectomy.

METHODS

The study cohort consisted of 203 American Society of Anesthesiologists PS I-II female patients randomized into four groups to receive at induction of anesthesia an intravenous (IV) bolus of 5 ml solution of one of the following: normal saline (placebo), granisetron 3 mg, ondansetron 4 mg, or tropisetron 5 mg. Nausea and vomiting were evaluated at five time points: during the first hour in the postanesthesia care unit (PACU) and 6, 12, 18, and 24 h postoperatively. Nausea intensity was measured using a visual analogue scale score (0-10).

RESULTS

Patients in the placebo group displayed a high incidence of nausea in the PACU and at 6, 12, and 18 h postoperatively (44, 60, 50, and 34%, respectively) and of vomiting (26, 42, 30 and 10%). The administration of granisetron reduced significantly the incidence of nausea at 6, 12, and 18 h (26, 18, and 2%, respectively) and vomiting at 6 and 12 h (10 and 6%, respectively). Ondansetron reduced significantly the incidence of nausea and vomiting only at 6 h postoperatively (28 and 12%, respectively). The administration of tropisetron did not affect the incidence of PONV compared to placebo.

CONCLUSION

Among the female patients of this study undergoing thyroid surgery, granisetron 3 mg provided the best prophylaxis from PONV. Ondansetron 4 mg was equally effective, but its action lasted only 6 h, whereas tropisetron 5 mg was found ineffective.

Use of the visual analog scale to rate and monitor severity of nausea in the emergency department

OBJECTIVES

The objective was to describe the association between verbal descriptors of nausea severity and visual analog scale (VAS) ratings in an undifferentiated emergency department (ED) population and to calculate the minimum clinically significant difference (MCSD) in VAS rating of nausea severity in this population.

METHODS

A prospective observational study was conducted at three EDs on a convenience sample of stable, consenting adult patients presenting with nausea as part of their symptom complex. Data included demographics, adjectival description of nausea severity (none, mild, moderate, or severe), and VAS rating (standard 100-mm line) at enrollment, 30 minutes, and 60 minutes. At 30 and 60 minutes they were also asked to describe any change in nausea severity from the previous rating ("a lot less,""a little less,""the same,""a little more,""a lot more"). The MCSD was defined as the average VAS change when a patient reported "a little less" or "a little more" nausea.

RESULTS

A total of 247 patients provided 693 matched adjectival ratings and VAS scores. Median age was 45 years, and 100 (40%) were male. The median VAS measures for none, mild, moderate, and severe nausea were 2, 23, 53, and 83 mm, respectively. VAS distributions in the verbal categories were statistically different from each other (Spearman rank correlation coefficient = 0.90; p < 0.0001). The MCSD was 22 mm (95% CI = 20 to 24 mm).

CONCLUSIONS

There is very good correlation between verbal descriptors of nausea and VAS ratings. The MCSD for VAS nausea ratings in an ED population is 22 mm.

Management of postoperative vomiting in pediatric patients

PURPOSE OF REVIEW

Postoperative vomiting remains a common complication of general anesthesia and occurs more frequently in children than adults. Prophylactic antiemetics have limited efficacy and have a potential for side effects. The new 5 HT3 antagonists are effective but expensive, while the older less expensive drugs such as droperidol have come under disrepute because of the potential for serious, life-threatening, cardiac arrhythmias. This review examines the literature to aid practicing anesthesiologists in the choice of patient who will benefit from prophylactic antiemetics.

RECENT FINDINGS

In this review we discuss the factors associated with postoperative vomiting that are and are not under the control of the anesthesiologist. The Consensus Panel recommendations for reducing the risks of postoperative vomiting and for the rational use of prophylactic antiemetics in selected cases are reviewed. The controversy over the 'black box warning' on the use of droperidol is discussed. Finally, the evidence supports the importance of choosing a drug from another class for rescue therapy when prophylaxis with one drug has failed.

SUMMARY

Anesthesiologists should practice evidence-based medicine in reducing the common anesthetic complication of postoperative vomiting by an individualized approach that balances the choice of drugs with the expected risk of postoperative vomiting for cost-effective management.

Drugs for preventing postoperative nausea and vomiting

BACKGROUND

Drugs can prevent postoperative nausea and vomiting, but their relative efficacies and side effects have not been compared within one systematic review.

OBJECTIVES

The objective of this review was to assess the prevention of postoperative nausea and vomiting by drugs and the development of any side effects.

SEARCH STRATEGY

We searched The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 2, 2004), MEDLINE (January 1966 to May 2004), EMBASE (January 1985 to May 2004), CINAHL (1982 to May 2004), AMED (1985 to May 2004), SIGLE (to May 2004), ISI WOS (to May 2004), LILAC (to May 2004) and INGENTA bibliographies.

SELECTION CRITERIA

We included randomized controlled trials that compared a drug with placebo or another drug, or compared doses or timing of administration, that reported postoperative nausea or vomiting as an outcome.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted outcome data.

MAIN RESULTS

We included 737 studies involving 103,237 people. Compared to placebo, eight drugs prevented postoperative nausea and vomiting: droperidol, metoclopramide, ondansetron, tropisetron, dolasetron, dexamethasone, cyclizine and granisetron. Publication bias makes evidence for differences among these drugs unreliable. The relative risks (RR) versus placebo varied between 0.60 and 0.80, depending upon the drug and outcome. Evidence for side effects was sparse: droperidol was sedative (RR 1.32) and headache was more common after ondansetron (RR 1.16).

AUTHORS' CONCLUSIONS

Either nausea or vomiting is reported to affect, at most, 80 out of 100 people after surgery. If all 100 of these people are given one of the listed drugs, about 28 would benefit and 72 would not. Nausea and vomiting are usually less common and, therefore, drugs are less useful. For 100 people, of whom 30 would vomit or feel sick after surgery if given placebo, 10 people would benefit from a drug and 90 would not. Between one to five patients out of every 100 people may experience a mild side effect, such as sedation or headache, when given an antiemetic drug. Collaborative research should focus on determining whether antiemetic drugs cause more severe, probably rare, side effects. Further comparison of the antiemetic effect of one drug versus another is not a research priority.

Meta-analysis of the use of rescue antiemetics following PONV prophylactic failure with 5-HT3 antagonist/dexamethasone versus single-agent therapies

OBJECTIVE

To assess the use of rescue antiemetic medication following 5-HT3 receptor antagonist (5-HT3RA) plus dexamethasone therapy versus monotherapy with a 5-HT3RA for prophylaxis of postoperative nausea and vomiting (PONV).

DATA SOURCES

Reports of randomized, controlled trials were identified via a MEDLINE search (1966-September 2005) using the key terms ondansetron, dolasetron, tropisetron, granisetron, 5-HT3, PONV, vomiting, emesis, and nausea.

STUDY SELECTION AND DATA EXTRACTION

Randomized, controlled trials of adult populations that had treatment arms comparing 5-HT3RA/dexamethasone combination therapy with 5-HT3RA or dexamethasone monotherapies versus placebo or 5-HT3RA versus dexamethasone or placebo were selected for analysis. Another criterion was that a proportion of patients required rescue medication 48 hours or less following surgery.

DATA SYNTHESIS

Odds ratios (ORs) with 95% confidence interval were calculated to determine incidence rates for use of rescue medications within early (0-6 h), late (6-24 h), and overall (0-24 or 48 h) postoperative periods. Overall effect sizes were calculated by pooling ORs within fixed and random effects models.

CONCLUSIONS

Prophylaxis with 5-HT3RA/dexamethasone was associated with lower use of rescue antiemetics than 5-HT3RA (OR(pooled) = 0.48; 95% CI 0.29 to 0.77) or dexamethasone (OR(pooled) = 0.26; 95% CI 0.12-0.57) monotherapy during the overall postoperative period. Insufficient data were available to assess rescue use during early or late postoperative periods. It appears that patients at high risk of PONV who are treated prophylactically with combination 5-HT3RA/dexamethasone therapy are overall less likely to require rescue medication than if treated with 5-HT3RAs or dexamethasone alone. Additional large prospective studies are needed to determine the optimal regimen and timing of administration of prophylactic antiemetic therapy for different surgical populations.

Prophylactic intravenous ondansetron and dolasetron in intrathecal morphine-induced pruritus: a randomized, double-blinded, placebo-controlled study

Pruritus is the most common side effect of intrathecal morphine for postoperative pain relief. Activation of central 5-hydroxytryptamine subtype 3 (5-HT3) receptors is one of its possible mechanisms. The role of 5-HT3 antagonists in the prevention of pruritus has not been clearly established. In a prospective, randomized, double-blind, placebo-controlled study, we evaluated the efficacy of prophylactic administration of ondansetron and dolasetron for the prevention of intrathecal morphine-induced pruritus. The patients were randomized into 3 groups to receive either 4 mg ondansetron IV (group O, n = 35), 12.5 mg dolasetron IV (group D, n = 35) or 5 mL placebo (group P, n = 35) 30 min before administration of spinal anesthesia with 10 to 17.5 mg of 0.5% hyperbaric bupivacaine and 0.25 mg of morphine for urologic, orthopedic, or vascular surgery. Patients were evaluated for incidence and severity of pruritus at arrival to the postanesthesia care unit and at 2, 4, 8, and 24 h postoperatively. The incidence and severity of pruritus was significantly less frequent in the ondansetron and dolasetron groups compared with placebo (34%, 20%, and 66% respectively, P < 0.01). Patients who received 5-HT3 antagonist reported significantly less total severity of pruritus compared with placebo during the first 8 h and the severe pruritus was observed only in patients within P group (P group: 4 of 35; 11%, O or D group: 0 of 35; 0%, P < 0.05). We conclude that the prophylactic use of ondansetron and dolasetron helps to reduce the incidence and severity of intrathecal morphine-induced pruritus.

Prevention and treatment of postoperative nausea and vomiting

PURPOSE

The physiology, risk factors, and prevention and treatment of postoperative nausea and vomiting (PONV) are discussed.

SUMMARY

Factors to consider when determining a patient's risk for PONV include sex, history of PONV, history of motion sickness, smoking status, duration of anesthesia, use of opioids, and type of surgery. Receptors that, when activated, can cause nausea or vomiting or both include dopamine type 2, serotonin type 3, histamine type 1, and muscarinic cholinergic type 1 receptors. Patients at moderate to high risk for PONV benefit from the administration of a prophylactic antiemetic agent that blocks one or more of these receptors. Effective agents include transdermal scopolamine, prochlorperazine, promethazine, droperidol, ondansetron, dolasetron, granisetron, and dexamethasone. In high-risk patients, combining two or more antiemetics with different mechanisms of action has been shown to be more effective than using a single agent. In addition to administering a prophylactic antiemetic, it is important to reduce the patient's risk by considering regional anesthesia, considering inducing and maintaining general anesthesia with propofol, ensuring good intravenous hydration, avoiding hypotension, and providing effective analgesia. If PONV occurs in the immediate postoperative period, it is best treated with an antiemetic agent from a pharmacologic class different from that of the prophylactic agent.

CONCLUSION

Prophylactic antiemetic therapy for PONV is effective, but combinations of agents may be necessary for high-risk patients. Nonpharmacologic strategies are also important.

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.

Timing of administration of dolasetron affects dose necessary to prevent postoperative nausea and vomiting

STUDY OBJECTIVE

To determine if the timing of administration affects the dose of dolasetron necessary to prevent postoperative nausea and vomiting (PONV).

DESIGN

Pooled data from 8 randomized, multicenter, double-blind, placebo-controlled studies with common endpoints.

SETTING

University hospital.

PATIENTS

A total of 4,587 ASA physical status I, II, and III patients, including 4,124 females undergoing primarily gynecologic procedures and 463 males undergoing various procedures (i.e., thyroidectomy or orthopedic, ophthalmologic, urologic, ENT, or laparoscopic surgery).

INTERVENTIONS

Balanced general anesthesia was used during all procedures. Patients received a dose of dolasetron either for prevention of PONV (25 or 50 mg IV at induction; 25, 50, 100, or 200 mg orally 1 to 2 hours pre-induction; or 12.5, 25, 50, or 100 mg IV at end of anesthesia) or for treatment of PONV (12.5, 25, 50, or 100 mg IV). One PONV prevention study had an ondansetron (comparator) group.

MEASUREMENTS

Outcome measures over a 24-hour study period included complete response (defined as no vomiting/retching and no need for rescue medication), percentage of patients without nausea [defined as nausea visual analog scale (VAS) score < 5 mm], and maximum nausea according to VAS score.

MAIN RESULTS

A 12.5-mg IV dose of dolasetron resulted in a complete response rate that was statistically significantly higher than placebo and comparable to higher dolasetron doses (25 mg to 100 mg IV) when administered either near the end of anesthesia for prevention of PONV or at the onset of symptoms for treatment of PONV. In contrast, when administered at induction of anesthesia, a statistically significant treatment response was observed with dolasetron 50 mg IV, but not at a lower dose.

CONCLUSIONS

When dosed near the end of anesthesia, a 12.5 mg IV dose of dolasetron was comparable to higher doses administered at or before induction of anesthesia.

The efficacy of the 5-HT3 receptor antagonists combined with droperidol for PONV prophylaxis is similar to their combination with dexamethasone. A meta-analysis of randomized controlled trials

PURPOSE

The aim of this quantitative systematic review is to compare the efficacy and side effects of combining one of the 5-HT(3) receptor antagonists (5-HT) with droperidol or dexamethasone for postoperative nausea and vomiting (PONV) prophylaxis.

METHODS

We performed a systematic search (Medline, Embase, and the Cochrane Library) for randomized controlled trials that compared the antiemetic efficacy of combining one of the 5-HT with droperidol or dexamethasone vs 5-HT alone. Relevant endpoints were prevention of early (0 to 6 hr), and overall (0 to 24 hr) PONV, and side effects. The articles that could meet the inclusion criteria were scored for inclusion and methodological validity using the three-item, five-point, Oxford-scale. Relative risk and numbers needed-to-treat with 95% confidence intervals were calculated for each combination vs 5-HT alone. The two combinations were then indirectly compared. A random effects model was used.

RESULTS

We considered 41 trials for analysis but subsequently excluded eight. Thirty-three trials with data from 3,447 patients were analyzed. Except for early nausea with the 5-HT plus droperidol, both combinations were significantly more effective than 5-HT in preventing early and overall PONV. There was no difference in antiemetic efficacy between the two combinations. The incidence of commonly reported side effects was also similar in the two combination groups.

CONCLUSION

We conclude that there is no statistically significant difference in antiemetic efficacy or side effects profile when one of the 5-HT is combined with either droperidol or dexamethasone and that both combination regimens are significantly more effective than 5-HT alone.

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.

Randomized, double-blind trial of dolasetron versus droperidol for prophylaxis of postoperative nausea and vomiting in patients undergoing TRAM flap breast reconstruction surgery

Clinical observation indicates that patients undergoing transverse rectus abdominus musculocutaneous (TRAM) flap breast reconstruction surgery frequently experience postoperative nausea and/or vomiting (PONV). No controlled trials have evaluated the role of pharmacologic prophylaxis of PONV in this population. A prospective randomized, double-blinded, active-controlled trial comparing intraoperative intravenous droperidol 1 mg with dolasetron 50 mg was conducted. Seventy-one patients were included in the intention-to-treat analysis. The incidence of the primary end point of PONV within 24 hours after surgery was 81.8% versus 78.9% for droperidol and dolasetron, respectively (p = 0.8). No significant differences were detected in the time to onset of PONV, incidence of severe nausea or emesis, or incidence of emesis alone. Time to rescue antiemetic use was longer in the droperidol group (7.1 vs. 1.3 hours, p = 0.002). Adverse effects were similar between the two groups. No PONV-related complications occurred during the trial period. The incidence of PONV in TRAM flap breast reconstruction surgery patients remains high despite prophylactic intraoperative antiemetic administration.

Electrocardiographic and cardiovascular effects of the 5-hydroxytryptamine3 receptor antagonists

OBJECTIVE

To review the electrocardiographic (ECG) and cardiovascular effects of 5-hydroxytryptamine(3) (5-HT(3)) receptor antagonists preclinically, in healthy volunteers, and in patients undergoing chemotherapy or surgery.

DATA SOURCES

A MEDLINE search was performed of clinical trials and preclinical data published between 1963 and December 2002 assessing the ECG and cardiovascular effects of 5-HT(3) receptor antagonists, supplemented with reviews and secondary sources.

STUDY SELECTION AND DATA EXTRACTION

All of the articles identified were evaluated and all information deemed relevant was included in this review.

DATA SYNTHESIS

There are no clinically relevant differences in efficacy and safety among the available 5-HT(3) receptor antagonists for prevention and treatment of chemotherapy-induced and postoperative nausea and vomiting. As a class, they have well-defined electrophysiologic activity. Changes in ECG parameters (PR, QRS, QT, QTc, JT intervals) are small, reversible, clinically insignificant, and independent of the patient population studied, and patients are asymptomatic during these changes. ECG changes are most prominent 1-2 hours after a dose of dolasetron, ondansetron, and granisetron and return to baseline within 24 hours. Clinically important adverse cardiovascular events associated with these changes are rare. No serious cardiac events (including torsade de pointes) arising from ECG interval changes have been attributed to 5-HT(3) receptor antagonist use.

CONCLUSIONS

Clinical data demonstrate that ECG interval changes are a class effect of the 5-HT(3) receptor antagonists. Theoretical concern regarding cardiovascular adverse events with these agents is not supported by clinical experience. The significant benefits of these agents outweigh the theoretical small risk of meaningful cardiovascular events.

A comparison of the costs and efficacy of ondansetron and dolasetron in the prophylaxis of postoperative vomiting in pediatric patients undergoing ambulatory surgery

Postoperative vomiting (POV) after ambulatory surgery remains a major problem. We designed this study to determine the smallest dose of dolasetron equivalent to the Food and Drug Administration approved dose of ondansetron 100 micro g/kg IV, for the prophylaxis of POV in children undergoing surgery. In this double-blinded controlled study, 204 healthy ASA I-II children aged 2-12 yr, undergoing superficial ambulatory (day-case) surgery, were randomized to receive either ondansetron 100 micro g/kg IV, or dolasetron 45, 175, 350, or 700 micro g/kg IV during a standardized perioperative regimen. The primary end-point was the incidence of complete response, defined as the absence of POV symptoms. Costs were calculated from the perspective of the hospital using a previously described model. The incidence of early (0-6 h) and 24-h emesis was more frequent in the dolasetron 45 micro g/kg group compared with the dolasetron 350 and 700 micro g/kg groups and with the ondansetron group. Repeated POV occurred more often when dolasetron was used in a dose <350 micro g/kg. There were no significant differences in emesis rates between the dolasetron 175, 350, and 700 micro g/kg groups or between these groups and the ondansetron 100 micro g/kg group. The smallest dose of dolasetron with acceptable equivalent efficacy and patient satisfaction scores to ondansetron 100 micro g/kg was 350 micro g/kg. Institutional costs for managing POV were less with dolasetron 350 micro g/kg than with ondansetron.

IMPLICATIONS

This randomized double-blinded dose-ranging study concluded that dolasetron, 350 micro g/kg IV, was the smallest dose that provided acceptable equivalent efficacy and patient satisfaction scores to ondansetron, 100 micro g/kg IV, for the prophylaxis of postoperative vomiting in children undergoing outpatient surgery. However, with this dose, the costs to the institution for managing postoperative vomiting were less.

Pharmacotherapy of postoperative nausea and vomiting

Postoperative nausea and vomiting (PONV) are two of the most common and unpleasant side effects following anaesthesia and surgery. Despite the development of new anti-emetics and a vast amount of published research, PONV continues to be a problem, especially in high-risk patients. Recent interest has focused on the use of a combination of agents, acting on different receptors and the adoption of a multimodal approach to tackle this problem. The search for the most cost-effective strategy has also been a major goal. This article will discuss the risk factors and physiology of PONV, currently available therapies, the use of a multimodal approach and the cost-effectiveness of PONV management. Finally, recommendations for the prophylaxis and treatment of PONV will be discussed.

[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.

The efficacy and cost-effectiveness of prophylactic 5-hydroxytryptamine3 receptor antagonists: tropisetron, ondansetron and dolasetron

There are currently three 5-hydroxytryptamine3 (5-HT3) receptor antagonists available in Australia. In this randomized, double-blind, parallel group study the prophylactic antiemetic effect of a single dose of tropisetron 2 mg, ondansetron 4 mg or dolasetron 12.5 mg was compared after major gynaecological surgery. One hundred and eighteen patients (group T n = 42; group O n = 36; group D n = 40) were evaluated for nausea, vomiting, recovery characteristics and satisfaction for 24 hours postoperatively. A cost-effectiveness analysis was performed. Rescue antiemetic, prochlorperazine 12.5 mg i.m., was given if vomiting occurred more than 10 minutes after arrival in the recovery room. If prochlorperazine was ineffective one hour after administration, droperidol 1 mg i.v. was given. There were no significant differences between groups for the incidence of vomiting during consecutive epochs until 24 hours postoperatively or overall (57%, 75% and 72.5% for groups T, O and D respectively, P = 0.18). The incidence and number of rescue antiementic treatments for nausea or vomiting were similar. The incidence of nausea and the overall and interval nausea scores were similar except for lower "worst nausea" score in group T between 12 and 18 hours (P = 0.02). Recovery times, satisfaction and cost per patient did not differ between groups. We conclude that the risk of postoperative nausea and vomiting remained high in this setting despite 5-HT3 receptor antagonist prophylaxis and that the choice between these agents should be based on the lowest available acquisition cost.

Dolasetron prophylaxis reduces nausea and postanaesthesia recovery time after remifentanil infusion during monitored anaesthesia care for extracorporeal shock wave lithotripsy

BACKGROUND

Remifentanil is used as an analgesic for different procedures performed during monitored anaesthesia care. Opioid-induced nausea and vomiting can be troublesome.

METHODS

This prospective, randomized, double-blind study was performed to evaluate the efficacy of prophylaxis with dolasetron in reducing the frequency of postoperative nausea and duration of discharge time. Forty urological patients, undergoing elective ambulatory extracorporeal shock wave lithotripsy (ESWL) received randomly either dolasetron 12.5 mg i.v. (Group 1) or placebo (Group 2) 10 min before a patient-adapted continuous infusion of remifentanil 0.15-0.4 micro g kg(-1) min(-1) was administered. Frequency and intensity (VAS 0-100 mm) of nausea, retching, and vomiting were assessed by patients and blinded investigators during and after the procedure.

RESULTS

Patient characteristics, baseline values, duration of ESWL, and total dose of remifentanil did not differ between groups. The frequency (Group 1/Group 2; 20/55%; P<0.05) and mean (SD) maximal intensity [15 (9)/45 (14) mm; P<0.05] of nausea during 24 h was significantly reduced after dolasetron and discharge times in Group 1 were less than Group 2 [22 (14)/45 (28) min; P<0.05].

Dolasetron, but not metoclopramide prevents nausea and vomiting in patients undergoing laparoscopic cholecystectomy

PURPOSE

Postoperative nausea and vomiting (PONV) is one of the most frequent complications of general anesthesia. The aim of the study was to compare the antiemetic efficacy of dolasetron and metoclopramide after inhalational or i.v. anesthesia (IVA).

METHODS

In a randomized, placebo-controlled, double-blinded trial we evaluated the efficacy of 12.5 mg dolasetron i.v. and 20 mg metoclopramide (MCP) i.v. in preventing PONV in 387 patients (ASA I-III) undergoing laparoscopic cholecystectomy. Patients were allocated randomly to one of three main groups: Group D (n = 129) received 12.5 mg dolasetron i.v., Group MCP (n = 129) 20 mg MCP i.v., and Group C (n = 129) saline as placebo i.v. Using a multifactorial study design, one third of each main group (n = 43) was further randomized to receive either general anesthesia with desflurane, isoflurane or IVA with propofol and remifentanil. PONV, postoperative piritramide and droperidol consumption were documented.

RESULTS

Independent from the anesthesia regimen chosen, dolasetron reduced PONV (19%) significantly compared to MCP (45%) and placebo (46%). Furthermore we could show a significant difference in the incidence of PONV between IVA (28%) and isoflurane (46%), but not in comparison to desflurane (36%). Patients receiving IVA had a higher postoperative piritramide consumption compared to the two other groups.

CONCLUSIONS

The results of our study suggest that dolasetron was more effective than MCP and placebo in preventing PONV. This action is independent of the anesthetic technique used.

Ondansetron and dolasetron provide equivalent postoperative vomiting control after ambulatory tonsillectomy in dexamethasone-pretreated children

In this prospective, randomized, double-blinded, placebo-controlled study, we compared the incidence of emesis and 48-h recovery profiles after a single dose of preoperative ondansetron versus dolasetron in dexamethasone-pretreated children undergoing ambulatory tonsillectomy. One-hundred-forty-nine children, 2-12 yr old, ASA physical status I and II, completed the study. All children received standardized perioperative care, including premedication, surgical and anesthetic techniques, IV fluids, analgesics, and rescue antiemetic medications. Patients were randomized to receive ondansetron 0.15 mg/kg, maximum 4 mg (Group 1); dolasetron 0.5 mg/kg, maximum 25 mg (Group 2); or saline placebo (Group 3) IV before the initiation of surgery. In addition, all patients received dexamethasone 1 mg/kg (maximum 25 mg). Rescue antiemetics were administered for two or more episodes of retching/vomiting. The incidence of retching/vomiting before home discharge did not differ between the ondansetron and dolasetron groups and was significantly less frequent compared with the placebo group (10%, Group 1; 8%, Group 2; 30%, Group 3). Similar results were obtained at 24-48 h after discharge (6%, Groups 1 and 2; 18%, Group 3). The need for rescue antiemetics administered after the second retching/vomiting episode was significantly less in Groups 1 (4%) and 2 (6%) compared with Group 3 (22%) before home discharge. The complete response rate, defined as no retching/vomiting and no antiemetic for 48 h, was significantly increased in Groups 1 (76%) and 2 (74%) compared with Group 3 (44%). The antiemetic efficacy of prophylactic ondansetron and dolasetron was comparable in dexamethasone-pretreated children undergoing ambulatory tonsillectomy.

IMPLICATIONS

The efficacy of a single dose of prophylactic ondansetron versus dolasetron in conjunction with dexamethasone was studied on posttonsillectomy retching/vomiting and 48-h recovery in children 2-12 yr old. Compared with placebo, ondansetron and dolasetron produced comparable reductions in the incidence of retching/vomiting and the need for rescue antiemetics.

Postoperative Nausea and Vomiting: An Overview

Despite new technology and pharmacological agents, postoperative nausea and vomiting continues to have a 20% to 30% occurrence rate. New antiemetic drugs and improved anesthetic techniques have decreased the incidence of anesthesia-induced postoperative nausea and vomiting. Patient characteristics and surgical factors are now largely responsible for postoperative emesis. Postoperative nausea and vomiting can lead to serious complications such as aspiration, dehydration, electrolyte disturbances, and disruption of the incision site. Postoperative nausea and vomiting leads to increased direct and indirect costs and may be associated with patients' dissatisfaction with the surgical experience. Nonpharmacological and pharmacological treatments, including new antiemetic drugs, have decreased the incidence of postoperative nausea and vomiting. However, clinical trials are needed to determine the most suitable treatments for the most common causes of postoperative nausea and vomiting.

Influence of standardized orders on postoperative nausea and vomiting after gynecologic surgery

OBJECTIVE

The risk of postoperative nausea and vomiting (PONV) after gynecologic surgery remains high, despite effective prophylactic medications. Thus, the objectives of this study were to determine whether standardized orders for the prophylaxis and treatment of PONV in gynecologic surgery patients (1) reduce PONV occurrence, (2) reduce total costs, and (3) influence the choice of medications used for PONV prophylaxis and treatment.

METHODS

A retrospective design was employed in which a random sample of 200 patients was selected from each of the two 6-month phases before (pre) and after (post) the implementation of standardized orders for PONV prophylaxis and treatment. The primary outcome was the occurrence of any PONV episode. Logistic regression was used to adjust for potential confounding factors. All costs were in 1999 Canadian dollars (Canadian dollar = US$0.673 in 1999).

RESULTS

Characteristics were similar except for surgical and anesthesia length between phases. The proportion of patients who received PONV prophylaxis increased from 31% (pre) to 47% (post; p = 0.002). There was a reduction in the risk of a PONV event in the post-phase (odds ratio [OR] 0.67, 95% CI 0.67 to 0.97; p = 0.04). The risk of PONV was significantly reduced with the administration of prophylactic medications (OR 0.46, 95% CI 0.46 to 0.67; p = 0.001). There was a reduction in the mean number of PONV episodes in the post-phase (1.47 events) versus the pre-phase (1.81 events; p = 0.02). A reduction in mean PONV management costs was observed in the post-phase ($8.31, SD +/- 8.50) compared with the pre-phase ($10.23, SD +/- 8.25; p = 0.02). For mean prophylactic costs, these were significantly higher in the postimplementation phase compared with the preimplementation phase ($1.64, SD +/- 3.36 vs. $0.91, SD +/- 2.43; p = 0.013). For mean total PONV costs (prophylaxis plus management costs), there was a nonsignificant reduction in the postimplementation phase compared with the preimplementation phase ($9.95, SD +/- 9.20 vs. $11.15, SD +/- 8.51, respectively; p = 0.18). Univariate sensitivity analyses revealed that the economic results were sensitive to several parameters.

CONCLUSIONS

The implementation of preprinted order forms for PONV prophylaxis and treatment appears to be an effective and economically attractive strategy.

Impact of antiemetic selection on postoperative nausea and vomiting and patient satisfaction

STUDY OBJECTIVE

To determine the impact of antiemetic selection on postoperative nausea and vomiting (PONV) and patient satisfaction after ambulatory surgery.

DESIGN

Prospective, observational study.

SETTING

Ambulatory surgery center in an academic medical center.

PATIENTS

Five hundred fifty-four consecutive patients undergoing ambulatory surgical procedures of any kind.

INTERVENTION

Data on antiemetic utilization, occurrence of PONV, and patient satisfaction were collected perioperatively. Multiple regression analyses for antiemetic choice were performed.

MEASUREMENTS AND MAIN RESULTS

Prophylactic antiemetic therapy was administered to 292 (52.7%) patients, most often with droperidol (200 patients), metoclopramide (134), or dexamethasone (55). Forty-one (7.4%) patients had an episode of emesis in the postanesthesia care unit. Choice of antiemetic was not a significant predictor of PONV. Patient satisfaction for all patients was 9.5 on a 10-point scale, with no agent more or less successful than any other.

CONCLUSION

As choice of antiemetic drug given for prophylaxis had little impact on clinical outcome or patient satisfaction, traditional agents should form the core of antiemetics used for PONV prophylaxis in ambulatory surgery patients.

The effect of timing of dolasetron administration on its efficacy as a prophylactic antiemetic in the ambulatory setting

Dolasetron (12.5 mg IV) is effective in both preventing and treating postoperative nausea and vomiting (PONV) after ambulatory surgery. However, the optimal timing of dolasetron administration and its effect on the patient's quality of life after discharge have not been established. One-hundred-five healthy, consenting women undergoing gynecologic laparoscopic procedures with a standardized general anesthetic technique were enrolled in this randomized, double-blinded study. Group 1 received dolasetron 12.5 mg IV 10-15 min before the induction of anesthesia; Group 2 received dolasetron 12.5 mg IV at the end of the laparoscopy (79 +/- 48 min later than Group 1); and Group 3 received dolasetron 12.5 mg IV at the end of anesthesia (93 +/- 52 min later than Group 1). The incidence of PONV, complete responses (defined as no emetic episodes and no rescue medication within the 24-h period after anesthesia), recovery profiles, and patient satisfaction were recorded. In the postanesthesia care unit and during the 24-h follow-up period, the incidence of nausea and vomiting, as well as the need for rescue antiemetics, did not differ significantly among the three groups. The percentages of patients with complete responses to the study drug within the first postoperative 24 h were also similar in all three groups (55%, 59%, and 52% for Groups 1, 2, and 3, respectively). The early and intermediate recovery profiles, including resumption of a normal diet and patient satisfaction with the control of PONV, were not different among the three study groups. Dolasetron 12.5 mg IV administered before the induction of anesthesia is as effective as dolasetron given at the end of laparoscopy or at the end of anesthesia in preventing PONV after outpatient laparoscopy.

IMPLICATIONS

The timing of dolasetron administration appears to have little effect on its efficacy when administered as a prophylactic antiemetic in the ambulatory setting.

Efficacy of single-dose intravenous dolasetron versus ondansetron in the prevention of postoperative nausea and vomiting

BACKGROUND

Postoperative nausea and vomiting (PONV) is a significant problem in surgical patients. The 5-hydroxytryptamine3-receptor antagonists ondansetron, dolasetron, and granisetron are being used to prevent PONV and avoid the adverse events associated with traditional antiemetics such as antihistaminic agents, anticholinergic agents, and dopamine antagonists.

OBJECTIVE

Because practitioners have taken widely differing approaches to the selection and dosing of agents in this class, this retrospective study assessed the relative efficacy of i.v. dolasetron and ondansetron in preventing PONV when used according to their approved labeling.

METHODS

The medical charts of patients who underwent total abdominal hysterectomy or laparoscopic cholecystectomy and received either dolasetron 12.5 mg or ondansetron 4 mg were reviewed. Efficacy was assessed based on the number of episodes of PONV and time to the occurrence of PONV in the 24 hours after surgery.

RESULTS

Of 75 medical records reviewed, 59 met the criteria for inclusion in the efficacy analysis. There were no statistically significant between-group differences in demographic or baseline clinical characteristics. The majority of patients were obese (body mass index > or = 27 kg/m2), had no history of either PONV or motion sickness, and underwent total abdominal hysterectomy. PONV occurred in 11 of 25 (44%) patients receiving dolasetron and 18 of 34 (53%) patients receiving ondansetron. Four patients receiving dolasetron experienced PONV in the first 2 hours after surgery, compared with 7 patients receiving ondansetron.

CONCLUSION

There were no significant differences in efficacy between single doses of i.v. dolasetron 12.5 mg and i.v. ondansetron 4 mg in the prevention of PONV.

5-HT3 receptor antagonists vs traditional agents for the prophylaxis of postoperative nausea and vomiting

PURPOSE

Numerous antiemetics have been studied for the prevention of postoperative nausea and vomiting (PONV) including traditional agents (metoclopramide, perphenazine, prochlorperazine, cyclizine and droperidol) and the 5-HT3 receptor antagonists (ondansetron, dolasetron, granisetron and tropisetron). The results have been divergent and inconsistent. The purpose of this quantitative systematic review was to evaluate the effectiveness of 5HT3 receptor antagonists compared to traditional antiemetics for the prevention of PONV METHODS: A systematic search of the English language literature using computerized MEDLINE, EMBASE, and Pre-MEDLINE databases from 1966 to October 1999 and a manual search of references from retrieved articles were performed. Individual efficacy and adverse effect data was extracted from each of the studies according to a predefined protocol. The summary odds ratios were calculated using the Dersimonian and Laird method under a random effects model.

RESULTS

A total of 41 trials met our pre-defined inclusion criteria and were included in our analysis. Results in the 32 studies examining PONV indicated a 46% reduction in the odds of PONV in the 5-HT3-treated group (0.54 [95% CI 0.42-0.71], P < 0.001). Evaluation of PONV by traditional antiemetic agent demonstrated a 39% reduction compared with droperidol (0.61 [95% CI 0.42-0.89], P < 0.001) and a 56% reduction compared with metoclopramide (0.44 [95% CI 0.31-0.62], P < 0.001). Results in the 34 studies examining vomiting indicated a 38% reduction in the odds of vomiting in the 5-HT3-treated group (0.62 [95% CI 0.48-0.81], P < 0.001).

CONCLUSIONS

The 5-HT3 receptor antagonists are superior to traditional antiemetic agents for the prevention of PONV and vomiting. The reduction in the odds of PONV and vomiting is significant in the overall analysis and the subgroup analyses comparing 5-HT3 receptor antagonists with droperidol and metoclopramide.

A comparison of the costs and efficacy of ondansetron versus dolasetron for antiemetic prophylaxis

The optimal dose and timing of 5-HT(3) antagonist administration for prophylaxis against postoperative nausea and vomiting (PONV) remains controversial. Although 5-HT(3) antagonists seem to be most effective when administered near the end of surgery, there are no data on the comparative efficacy or costs associated with the 5-HT(3) antagonists dolasetron and ondansetron when administered at the end of the operation. In this double-blinded study, 200 outpatients undergoing otolaryngologic procedures with a standardized general anesthetic received 4 (O4) or 8 mg (O8) of ondansetron or 12.5 (D12.5) or 25 mg (D25) of dolasetron IV within 30 min before the end of surgery. A blinded observer recorded the emetic episodes, maximum nausea score, recovery room resource and drug use, nursing time spent managing PONV, times to achieve discharge criteria from the Phase 1 and 2 recovery units, postdischarge emesis, and patient satisfaction. Total costs were calculated by using the perspective of a free-standing surgicenter. There were no differences in patient demographics, incidence of PONV, need for rescue medications, time spent in the recovery areas, unanticipated hospital admissions, or patient satisfaction among the four treatment groups. The mean total costs (95% confidence intervals) to prevent PONV in one patient were lowest in the D12.5 group: $23.89 (17.18-28.79) vs $37.81 (30.29-45.32), $33.91 (28.92-39.35), and $75.18 (61.13-89.24) for D25, O4, and O8, respectively. Excluding nursing labor costs did not alter this finding: $18.51 (14.18-22.85), $34.77 (28.03-41.49), $31.77 (28. 92-39.35), and $71.76 (58.17-85.35) for D12.5, D25, O4, and O8, respectively. We conclude that 12.5 mg of dolasetron IV is more cost effective than 4 mg of ondansetron IV for preventing PONV after otolaryngologic surgery and is associated with similar patient satisfaction.

IMPLICATIONS

When administered at the end of surgery, 12.5 mg of dolasetron IV is as effective as 25 mg of dolasetron IV, 4 mg of ondansetron IV, and 8 mg of ondansetron IV in preventing emetic symptoms after otolaryngologic surgery and was associated with similar patient satisfaction at a reduced cost. There were no differences in the antiemetic efficacy of the 4 and 8 mg doses of ondansetron.

Pooled analysis of three large clinical trials to determine the optimal dose of dolasetron mesylate needed to prevent postoperative nausea and vomiting. The Dolasetron Prophylaxis Study Group

STUDY OBJECTIVE

To identify the maximally effective dolasetron dose (i.e., maximum efficacy with minimum adverse events) for prevention of postoperative nausea and vomiting (PONV) using the statistical power generated in a pooled patient sample from three large, nearly identical clinical trials.

DESIGN

Three randomized, multicenter, placebo-controlled, double-blinded trials.

SETTING

Trials 1, 2, and 3 enrolled patients at 10, 25, and 17 hospitals and/or surgical centers, respectively.

PATIENTS

A total of 1,946 ASA physical status, I, II, and III patients. Trials 1 and 2 enrolled only female patients (n = 916) undergoing gynecologic surgery. Trial three enrolled 722 females (approximately 70% gynecologic surgeries) and 308 males (approximately 46% orthopedic surgeries) undergoing a variety of surgical procedures.

INTERVENTIONS

All surgical procedures used balanced general anesthesia. Patients received 12.5, 25, 50, or 100 mg of the antiemetic, dolasetron, near the end of anesthesia.

MEASUREMENTS AND MAIN RESULTS

Efficacy endpoints were identical and measured for 24 hours: complete response (no vomiting or rescue medication) and maximum nausea, reported using a 100-mm visual analog scale (VAS). Safety was assessed using adverse event reports, laboratory and electrocardiographic data, and vital signs. All four dolasetron doses produced significant increases in complete response and decreases in maximum VAS nausea compared with placebo (p < 0.01). No increased efficacy was observed with dolasetron doses higher than 12.5 mg. Safety was similar between each dolasetron dose and placebo.

CONCLUSION

Dolasetron 12.5 mg, given near the end of anesthesia, is the maximally effective dose studied for preventing postoperative nausea and vomiting.

Prevention and treatment of postoperative nausea and vomiting

Pain, nausea and vomiting are frequently listed by patients as their most important perioperative concerns. With the change in emphasis from an inpatient to outpatient hospital and office-based medical/surgical environment, there has been increased interest in the 'big little problem' of postoperative nausea and vomiting (PONV). Currently, the overall incidence of PONV is estimated to be 25 to 30%, with severe, intractable PONV estimated to occur in approximately 0.18% of all patients undergoing surgery. PONV can lead to delayed postanaesthesia care unit (PACU) recovery room discharge and unanticipated hospital admission, thereby increasing medical costs. The aetiology and consequences of PONV are complex and multifactorial, with patient-, medical- and surgery-related factors. A thorough understanding of these factors, as well as the neuropharmacology of multiple emetic receptors [dopaminergic, muscarinic, cholinergic, opioid, histamine, serotonin (5-hydroxy-tryptamine; 5-HT)] and physiology [cranial nerves VIII (acoustic-vestibular), IX (glossopharyngeal) and X (vagus), gastrointestinal reflex] relating to PONV are necessary to most effectively manage PONV. Commonly used older, traditional antiemetics for PONV include the anticholinergics (scopolamine), phenothiazines (promethazine), antihistamines (diphenhydramine), butyrophenones (droperidol) and benzamides (metoclopramide). These antiemetics have adverse effects such as dry mouth, sedation, hypotension, extrapyramidal symptoms, dystonic effects and restlessness. The newest class of antiemetics used for the prevention and treatment of PONV are the serotonin receptor antagonists (ondansetron, granisetron, tropisetron, dolasetron). These antiemetics do not have the adverse effects of the older, traditional antiemetics. Headache and dizziness are the main adverse effects of the serotonin receptor antagonists in the dosages used for PONV. The serotonin receptor antagonists have improved antiemetic effectiveness but are not as completely efficacious for PONV as they are for chemotherapy-induced nausea and vomiting. Older, traditional antiemetics (such as droperidol) compare favourably with the serotonin receptor antagonists regarding efficacy for PONV prevention. Combination antiemetic therapy improves efficacy for PONV prevention and treatment. In the difficult-to-treat PONV patient (as in the chemotherapy patient), suppression of numerous emetogenic peripheral stimuli and central neuroemetic receptors may be necessary. This multimodal PONV management approach includes use of: (i) multiple different antiemetic medications (double or triple combination antiemetic therapy acting at different neuroreceptor sites); (ii) less emetogenic anaesthesia techniques; (iii) adequate intravenous hydration; and (iv) adequate pain control.

Systematic review of ondansetron for the prevention and treatment of postoperative nausea and vomiting in adults

OBJECTIVES

To determine the efficacy and safety of ondansetron for the prevention and treatment of postoperative nausea and vomiting (PONV) in adults.

DESIGN

Systematic review of published double-blind randomised controlled trials.

DATA SOURCES

Twenty seven trials from 1990 to July 1998 retrieved from a systematic literature search (Medline, Cinahl, Embase, Cochrane Library, reference lists, hand searching of anaesthetic journals, & provided manufacturer information); restricted to English language.

MAIN OUTCOME MEASURES

Estimation of efficacy (incidence of complete absence of nausea or other outcome measure as defined by the authors) at 24 hours.

RESULTS

Seven double-blind randomised controlled trials with 1,623 patients studied intravenous ondansetron 1 mg, 4 mg, or 8 mg for the treatment of postoperative nausea and vomiting (PONV). Four mg, compared with metoclopramide 10 mg, produced higher patient satisfaction scores and an increased incidence of freedom from nausea at 24 hours. Further studies are required to compare the safety, efficacy and dose response with other anti-emetics at 24 hours. Twenty double-blind randomised controlled trials with 4,364 patients studied intravenous and oral administration of ondansetron 1 mg, 4 mg, and 8 mg for the prevention of postoperative nausea and vomiting. There appears to be no significant difference between droperidol (0.625 mg, 1 mg or 1.25 mg) i.v. and ondansetron 4 mg in efficacy and incidence of side effects. Compared with metoclopramide, ondansetron produced less nausea but the incidence of vomiting was the same at 24 hours.

CONCLUSIONS

Further PONV could be prevented with ondansetron 4 mg compared with placebo and metoclopramide 10 mg. Further studies are required to compare ondansetron with other anti-emetics for the treatment of PONV. For prophylaxis of PONV ondansetron 4 mg appears to be equal to low dose droperidol in efficacy and the incidence of side effects, and superior to metoclopramide. Ondansetron should perhaps be limited to second line treatment in view of patient satisfaction, efficacy and cost when compared with droperidol.