The prophylactic antiemetic efficacy of prochlorperazine and ondansetron in nasal septal surgery: a randomized double-blind comparison

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).

The Relationship Between the Preoperative Neutrophil-to-Lymphocyte Ratio and Postoperative Nausea and Vomiting in Patients Undergoing Septorhinoplasty Surgery

BACKGROUND

Postoperative nausea and vomiting (PONV) is one of the most common complications during the postoperative period. In the literature, there are many factors associated with PONV risk, but it is claimed that inflammation increases this risk. The neutrophil-to-lymphocyte ratio (NLR) is a cheap parameter to use in the diagnosis and follow-up of systemic inflammatory diseases. In this study, we aimed to investigate whether the preoperative NLR was a marker for PONV and to determine its relation with antiemetic use.

METHODS

Eighty patients who were planned to undergo elective septorhinoplasty and were in ASA I-II were prospectively included in the study. The NLR value was calculated by dividing the number of neutrophils by the number of lymphocytes obtained from the preoperative complete blood count. The patients were divided into two groups of 40 patients: patients with an NLR < 2 (group 1) and patients with an NLR > 2 (group 2). Nausea and vomiting during the first 24 h in the recovery room and in the related clinic and antiemetic requirement were recorded.

RESULTS

The rate of nausea-vomiting in the recovery room and in the postoperative 24-h period in group 1 was significantly lower than in group 2 (p < 0.05). The rate of use of antiemetics in the recovery room and in the postoperative 24-h period in group 1 was significantly lower than in group 2 (p < 0.05).

CONCLUSION

NLR values above 2 calculated in the preoperative period may be an indicator of PONV risk. Antiemetic prophylaxis may be given according to this value.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these evidence-based medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Perioperative Analgesia for Patients Undergoing Septoplasty and Rhinoplasty: An Evidence-Based Review

OBJECTIVES/HYPOTHESIS

Opioid misuse and diversion is a pressing topic in today's healthcare environment. The objective of this study was to conduct a review of non-opioid perioperative analgesic regimens following septoplasty, rhinoplasty, and septorhinoplasty.

STUDY DESIGN

Evidence-based systematic review.

METHODS

PubMed, MEDLINE, Cochrane Library, and Embase databases were reviewed for articles related to perioperative analgesic use in septoplasty, rhinoplasty, and septorhinoplasty. Quality of studies were assessed via the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) criteria, Jadad scores, and the Cochrane bias tool. Patient demographic data and clinical outcomes, including medication type, dose, administration time, pain scores, and adverse events, were obtained from included studies. Summary tables detailing the benefits and harms of each investigated regimen are included.

RESULTS

Thirty-seven studies met inclusion criteria for this evidence-based review. The quality of the studies was determined to be of moderate quality based off of GRADE standardized criteria with a mean Jadad score of 3.1. A preponderance of evidence showed reduced perioperative pain scores and rescue analgesic requirements, supporting the use of local anesthetics for analgesic control. Nonsteroidal anti-inflammatory drugs (NSAIDs) demonstrated similar decreased visual analog scores and postoperative analgesic demand; however, increased adverse events in this class warrant caution.

CONCLUSIONS

Contemporary literature supports the use of NSAIDs, gabapentin, local anesthetics, and α-agonists as effective perioperative analgesic opioid alternatives for septoplasty and septorhinoplasty. Local anesthetic use is a cost-effective option resulting in decreased postoperative pain scores and rescue analgesic requirements. Further large-scale, multi-institutional, controlled studies are needed to provide definitive recommendations.

LEVEL OF EVIDENCE

NA Laryngoscope, 129:E200-E212, 2019.

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.

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.

Effect of pharyngeal packing during nasal surgery on postoperative nausea and vomiting

OBJECTIVE

The aim of this study was to evaluate the efficacy of pharyngeal packing in reducing postoperative nausea and vomiting (PONV) after nasal surgery by taking into consideration the surgery types.

STUDY DESIGN

A prospective, randomized, controlled trial.

SETTING

A tertiary referral center.

SUBJECTS AND METHODS

After the study was approved by the local ethics committee, this study was conducted in the Otorhinolaryngology clinic with the collaboration of the Anesthesiology clinic. The development of PONV within 24 hours after surgery was evaluated in patients who were applied a pharyngeal pack (Group 1) or not (Group 2) during nasal surgery.

RESULTS

There were 104 adult patients for routine nasal surgery included in the current study, yielding 100 (group 1, n = 50; group 2, n = 50) evaluable subjects. No significant difference was found in the incidence of PONV between the two groups at two (P = 0.41), four (P = 0.54), eight (P = 0.51), and 24 hours. According to surgery type, the incidence of PONV after two hours was 71 percent in septorhinoplasty, 68 percent in endoscopic sinus surgery, and 50 percent in septoplasty; after four hours it was 59 percent in septorhinoplasty, 53 percent in endoscopic sinus surgery, and 37 percent in septoplasty; and after eight hours it was 35 percent in septorhinoplasty, 39 percent in endoscopic sinus surgery, and 21 percent in septoplasty. PONV was not seen at 24 hours. Compared to the septoplasty group for which pharyngeal packing was used, significantly lower rates of PONV at four and eight hours were found in the septoplasty group in which pharyngeal packing was not used (P = 0.02).

CONCLUSION

Pharyngeal packing in nasal surgery has no impact on PONV.

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.

Dimenhydrinate and metoclopramide alone or in combination for prophylaxis of PONV

PURPOSE

Dimenhydrinate and metoclopramide are inexpensive antiemetic drugs. Metoclopramide, especially, has been studied extensively in the past, but there are no studies on the combination of both drugs for prevention of postoperative nausea and vomiting (PONV).

METHODS

One hundred and sixty male inpatients undergoing endonasal surgery were randomized to receive one of four antiemetic regimens in a double-blind manner: placebo, 1 mg x kg(-1) dimenhydrinate, 0.3 mg x kg(-1) metoclopramide, or the combination of both drugs was administered after induction of anesthesia. Patients received a second dose of these drugs six hours after the first administration to mitigate their short half-life. Standardized general anesthesia included benzodiazepine premedication, propofol, desflurane in N2O/O2 vecuronium, and a continuous infusion of remifentanil. Postoperative analgesia and antiemetic rescue medication were standardized. Episodes of vomiting, retching, nausea, and the need for additional antiemetics were recorded for 24 hr. The incidences of PONV were analyzed with Fisher's Exact test and the severity of PONV (rated by a standardized scoring algorithm) with the Jonckheere-Terpestra-test.

RESULTS

The incidence of patients free from PONV was 62.5% in the placebo-group and increased to 72.5% in the metoclopramide-group (P = 0.54), 75.0% in the dimenhydrinate-group (P = 0.34), and 85.0% in the combination- group (P = 0.025). In the latter group, the severity of PONV was reduced compared with placebo treatment (P = 0.017; Jonckheere-Terpestra-test).

CONCLUSION

Dimenhydrinate and metoclopramide were ineffective in reducing the incidence and the severity of PONV. Their combination reduced the incidence of PONV compared with placebo.

Prochlorperazine versus promethazine for uncomplicated nausea and vomiting in the emergency department: a randomized, double-blind clinical trial

STUDY OBJECTIVE

Nausea and vomiting related to gastritis or gastroenteritis are common complaints in the emergency department. The most effective antiemetic agent is yet undetermined. This study was conducted to compare the efficacy of prochlorperazine versus promethazine for uncomplicated nausea and vomiting in the ED.

METHODS

The study was a randomized, double-blind comparison of prochlorperazine (Compazine) and promethazine (Phenergan) for acute ED treatment of gastritis or gastroenteritis. We studied patients 18 years or older with presumed uncomplicated gastritis or gastroenteritis who presented to 2 academic EDs. Patients were randomly assigned to receive either prochlorperazine, 10 mg intravenously, or promethazine, 25 mg intravenously. Visual analog scale readings of patient comfort were obtained at baseline and at 30- and 60-minute intervals. The primary endpoint was degree of relief at 30 and 60 minutes. Secondary endpoints were time to complete relief, need for further antiemetic medication (treatment failures), and side effects. Statistical analysis was performed using the Mann-Whitney U test for nonparametric analysis and repeated-measures analysis of variance (ANOVA).

RESULTS

Eighty-four patients were enrolled in the study; 42 received prochlorperazine and 42 received promethazine. There were no differences in demographics in the 2 groups. At baseline (time 0), there was no difference in symptoms (P =.23). At 30 and 60 minutes after receiving medication, prochlorperazine worked significantly better than promethazine (P =.004 and P <.001 using nonparametric analysis). Using repeated-measures ANOVA, there was a significant difference in symptoms over time for both groups (P <.001) and a significant difference in prochlorperazine versus promethazine (P =.002). Time to complete relief was significantly shorter with prochlorperazine (P =.021). There were significantly fewer treatment failures with prochlorperazine (P =.03, 9.5% versus 31%; difference 21%, 95% confidence interval 5 to 38). There was no difference in incidence of extrapyramidal effects. Prochlorperazine caused significantly fewer complaints of sleepiness (P =.002, 38% versus 71%; difference 33%, 95% confidence interval 13 to 53; P =.002).

CONCLUSION

Prochlorperazine works significantly better than promethazine for relieving symptoms of nausea and vomiting more quickly and completely in ED patients with uncomplicated nausea and vomiting.

Attitudes to oral feeding following caesarean section

In order to evaluate postoperative nutrition in women who have undergone Caesarean section, we conducted a national survey. Questionnaires were sent to 100 randomly selected obstetric units in the UK, and were completed and returned by senior midwives. We found that that only 21.5% of units had a departmental policy concerning feeding after Caesarean section. Midwives decided when women could eat and drink in the majority of obstetric units (78.5%), often without the help of guidelines. The period of postoperative starvation was found to vary greatly, from < 1 h in some units to > 24 h in others. We suggest that all obstetric units should produce guidelines in order to rationalise postoperative feeding for women following Caesarean section.

Prevention or treatment of postoperative vomiting using ondansetron? A mathematical assessment

STUDY OBJECTIVES

To assess the effectiveness of ondansetron versus placebo when used as prophylaxis of postoperative vomiting compared to its use for the treatment of established postoperative vomiting.

DATA SOURCES

All prospectively randomized controlled trials, identified using the MEDLINE database and which had been included in two previously published meta-analyses.

MEASUREMENTS AND MAIN RESULTS

The effectiveness of ondansetron (1, 4, and 8 mg) used for prevention (28 studies) or treatment (two studies) of postoperative vomiting was compared using odds ratios and number needed to treat (NNT) scores. NNT values were extrapolated to a similar incidence of vomiting in the placebo groups. The effectiveness equivalence between both meta-analyses was compared by assessing the degree of coincidence between the respective 95% confidence intervals (CI). The 1-mg dose was superior in treatment than in prophylaxis, odds ratios (95% CI): 2.73 (1.81-4.11) versus 1.34 (1.04-1.74), respectively (p < 0.05), although this difference did not reach statistical significance when the NNT values were compared. For the 4-mg dose, a near congruence was observed in the odds ratios; 3.34 (2.22-5.03) versus 2.61 (2.24-3.05) as well as in the NNT values: 3.90 (2.97-5.78) versus 3.40 (2.93-4.07). For the 8-mg dose, there were equivalent NNT values: 4.10 (3.08-6.23) versus 4.08 (3.28-5.43), and with respect to the odds ratios: 3.18 (2.11-4.81) versus 2.42 (1.95-2.99). The differences were not statistically significant.

CONCLUSIONS

For the usual doses recommended for postoperative emesis, there was equivalent effectiveness of ondansetron whether administered as prophylaxis or as a treatment of established vomiting.

Ondansetron in the prophylaxis of postoperative vomiting: a meta-analysis

STUDY OBJECTIVES

To assess the efficacy of ondansetron and the incidence of headache when used as prophylaxis for postoperative vomiting.

DATA SOURCES

Studies were identified using MEDLINE (January 1990 to July 1997) with the key words: "vomiting," "ondansetron," and "surgery" and/or "anesthesia."

STUDY SELECTION

All prospectively randomized trials in which ondansetron and placebo had been administered for prevention of postoperative vomiting.

DATA EXTRACTION

Data on patient numbers, gender and ages, drug dosage, outcomes (incidence of vomiting and incidence of headache), time of outcome (up to 8 hrs or up to 48 hrs postoperatively), and baseline risk for vomiting according to type of surgical intervention were extracted.

MAIN RESULTS

48 trials involving 12,078 patients (10,390 adults and 1688 children) met the selection criteria. No evidence was found that the drug became more effective at doses larger than 4 mg. The dose of 8 mg was not statistically demonstrated to be superior (p = 0.558), while that of 1 mg was barely effective. The meta-analysis indicated that when the incidence of vomiting is elevated (e.g., the combined average of the placebo groups of 48%), on the statistical (i.e., hypothetical) grounds of six patients being treated with 4 mg of ondansetron, one will not vomit due to the treatment and, of the rest, two patients would have vomited despite the treatment and three patients would not have vomited anyway. The overall incidence of headache was 7.05% in ondansetron groups versus 6.16% in placebo groups.

CONCLUSIONS

While ondansetron is an effective antiemetic with minimal adverse effects, the data obtained on the numbers needed to be treated calculation for prophylaxis of postoperative vomiting should be considered in future cost-effective strategies of postoperative management.