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

Pyridoxine Prevents Postoperative Nausea and Vomiting in Gynecologic Laparoscopic Surgery: A Double-blind Randomized Controlled Trial

BACKGROUND

Postoperative nausea and vomiting are common complications after gynecologic laparoscopic surgery. Pyridoxine has been recommended as a first-line drug to prevent and treat nausea and vomiting during pregnancy; however, its efficacy in preventing postoperative nausea and vomiting remains unclear.

METHODS

Patients of 18 to 65 yr old who received elective gynecologic laparoscopic surgery under general anesthesia were randomized into either the pyridoxine group or the control group. The pyridoxine group received 0.2 g of vitamin B 6 before anesthesia induction, and the control group received normal saline intravenously. Both groups received a similar regimen of combined intravenous and inhalation general anesthesia. All patients received dexamethasone (intravenous) after anesthesia induction and ondansetron (intravenous) before surgery completion. Postoperative nausea and vomiting occurrence was recorded according to the patients' self-reported data. Other clinical data were collected from hospital system, and concentrations of blood interleukin-6 and substance P were measured by enzyme-linked immunosorbent assay.

RESULTS

A total of 442 patients were screened, and 240 patients were equally randomized to the pyridoxine or control group. The incidence of postoperative nausea and vomiting was statistically significant lower in the pyridoxine group than in the control group (16.7% [20 of 120] vs . 35.8% [43 of 120]; relative risk = 0.47 [95% CI, 0.29 to 0.74]; absolute risk reduction = 0.20 [95% CI, 0.08 to 0.30]; P = 0.001), and pyridoxine decreased the incidence of postoperative nausea (12.5% [15 of 120] vs . 35% [42 of 120]; relative risk = 0.36 [95% CI, 0.21 to 0.61]; absolute risk reduction = 0.23 [95% CI, 0.12 to 0.33]; P < 0.001). There were no statistical differences in postoperative vomiting, time to the first postoperative nausea and vomiting occurrence, pain, serum interleukin-6 and substance P, and leukocyte and neutrophil counts.

CONCLUSIONS

In this single-center randomized trial, pyridoxine plus dexamethasone and ondansetron reduced the incidence of postoperative nausea and vomiting in patients undergoing elective gynecologic laparoscopic surgery under general anesthesia. These findings need to be validated in multicenter studies in diverse populations to ensure generalizability.

Increased Postoperative Opioid Consumption in the Presence of Coadministration of 5-Hydroxytryptamine Type 3 Antagonists with Acetaminophen: A Hospital Registry Study

BACKGROUND

Acetaminophen and 5-hydroxytryptamine type 3 (5-HT3) receptor antagonists are administered as standard prophylaxes for postoperative pain, nausea, and vomiting. Preclinical studies, however, suggest that 5-HT3 antagonists may compromise acetaminophen's analgesic effect. This hospital registry study investigates whether 5-HT3 antagonists mitigate the analgesic effect of prophylactic acetaminophen in a perioperative setting.

METHODS

This study included 55,016 adult patients undergoing general anesthesia for ambulatory procedures at a tertiary healthcare center in Massachusetts from 2015 to 2022. Using binary exposure variables and a comprehensive selection of preplanned patient- and procedure-related covariates for confounder control, the authors investigated whether intraoperative 5-HT3 antagonists affected the association between pre- or intraoperative acetaminophen and postoperative opioid consumption, gauged by opioid dose in milligram oral morphine equivalents (OME) administered in the postanesthesia care unit. A multivariable, zero-inflated negative binomial regression model was applied.

RESULTS

A total of 3,166 patients (5.8%) received only acetaminophen, 15,438 (28.1%) only 5-HT3 antagonists, 31,850 (57.9%) both drugs, and 4,562 (8.3%) neither drug. The median postanesthesia care unit opioid dose was 7.5 mg OME (interquartile range, 7.5 to 14.3 mg OME) among 16,640 of 55,016 (30.2%) patients who received opioids, and the mean opioid dose was 3.2 mg OME across all patients (maximum cumulative dose, 20.4 mg OME). Acetaminophen administration was associated with a -5.5% (95% CI, -9.6 to -1.4%; P = 0.009; adjusted absolute difference, -0.19 mg OME; 95% CI, -0.33 to -0.05; P = 0.009) reduction in opioid consumption among patients who did not receive a 5-HT3 antagonist, while there was no effect in patients who received a 5-HT3 antagonist (adjusted absolute difference, 0.00 mg OME; 95% CI, -0.06 to 0.05; P = 0.93; P for interaction = 0.013).

CONCLUSIONS

A dose-dependent association of pre- or intraoperative acetaminophen with decreased postoperative opioid consumption was not observed when 5-HT3 antagonists were coadministered, suggesting that physicians might consider reserving 5-HT3 antagonists as rescue medication for postoperative nausea or vomiting when acetaminophen is administered for pain prophylaxis.

EDITOR’S PERSPECTIVE

Postoperative nausea and vomiting at Landspitali: A prospective study

BACKGROUND

In the last decade, anaesthesia practice has changed at Landspitali, where the majority of patients now receive antiemetic prophylaxis, and the use of total intravenous anaesthesia is the dominant mode for maintenance of anaesthesia. The aim of this study was to assess the incidence of postoperative nausea and vomiting (PONV) in a prospective way, the use of PONV prophylaxis, and clinical risk factors associated with PONV during this era.

METHODS

A prospective cohort study using a convenience sample of 438 patients ≥18 years old admitted to the postoperative care unit (PACU) after elective or emergency operations in May-July 2022 at Landspitali University Hospital in Iceland. Patients answered questionnaires in the PACU and 24 h after discharge from PACU.

RESULTS

The incidence of self-reported moderate/severe nausea (5/10 or higher on NRS) in PACU was 4% and 3% on postoperative day 1. A total of 91% of delivered anaesthetics were with intravenous medications only, and 82% of patients received at least one prophylactic medication for PONV. When asked to rate the worst nausea experienced, this was described as moderate/severe by 7% in PACU and 17% on postoperative day 1. Risk factors associated with PONV were female gender (OR 1.90, 95% CI 1.04-3.53) and a history of motion sickness or PONV (2.74, 1.51-4.94), but increasing age was protective (0.83 per decade, 0.71-0.98). Despite a more liberal administration of antiemetics, patients with more risk factors per Apfel PONV risk classification had a higher incidence of PONV.

CONCLUSION

The incidence of PONV is generally low in this diverse surgical population where anaesthesia is mostly maintained with total intravenous anaesthesia and PONV prophylaxis is common. PONV remains a predictable complication following anaesthesia, suggesting further improvement in its prevention is possible.

Penehyclidine for Prevention of Postoperative Nausea and Vomiting in Patients Undergoing Gynecological Laparoscopic Surgery Under Combined Intravenous and Inhalation Anesthesia: A Randomized, Double-Blind, Placebo-Controlled Trial

Purpose

We designed this study to investigate the effect of intravenous use of penehyclidine on postoperative nausea and vomiting (PONV) after gynecological laparoscopic surgery.

Patients and Methods

Ninety-two Women Patients (Aged ≥ 18) Scheduled for Elective Gynecologic Laparoscopy Were Enrolled in the Current Study. Patients Were Equally Randomized Assigned Into Penehyclidine group (PHC group: received a bolus of penehyclidine 10 μg/kg during the induction of anesthesia, then followed by a continuous infusion of 10 μg/kg penehyclidine at a fixed rate of 2.0 mL/h in postoperative intravenous analgesia pump over 48h, 0.5 mg upper limit respectively) or Control group (received 0.9% saline in replace of penehyclidine at the same time points). The primary outcome measure was the incidence of postoperative nausea and vomiting in the postanesthesia care unit and ward area. Quality of Recovery-15 (QoR-15) scores and general comfort questionnaire (GCQ) scores were assessed on postoperative day (POD) 1, 2.

Results

Patients between two groups had comparable baseline characteristics. Compared with the Control group, the incidence and severity of PONV, postoperative nausea (PON), and postoperative vomiting (POV) were significantly lower in the PHC group at 2h (PONV: P = 0.002, P = 0.004, respectively; PON: P = 0.018, P = 0.038, respectively; POV: P = 0.011, P = 0.072, respectively), 24h (PONV: P = 0.003, P = 0.001, respectively; PON: P = 0.010, P = 0.032, respectively; POV: P = 0.006, P = 0.044, respectively), and 48h (PONV: P = 0.003, P = 0.002, respectively; PON: P = 0.007, P = 0.019, respectively; POV: P = 0.002, P = 0.013, respectively) after surgery. The QoR-15 and GCQ scores of the PHC group were significantly higher than those of the Control group at POD 1, 2 (P < 0.001; P < 0.001, respectively).

Conclusion

Our findings suggest that perioperative intravenous application of penehyclidine can effectively prevent postoperative nausea and vomiting in gynecological laparoscopic surgery patients and improve postoperative recovery.

Enhanced recovery pathways for head and neck surgery with free tissue transfer reconstruction

The enhanced recovery after surgery (ERAS) pathway is designed to facilitate recovery after surgery by packaging evidence-based protocols specific to each aspect of the perioperative period, including the preoperative, intraoperative, postoperative, and post-discharge periods. The ERAS pathway, which was originally developed for use with colonic resection, is now being expanded to include a variety of surgical procedures, and the ERAS Society has published a consensus review of the ERAS pathway for head and neck surgery with free tissue transfer reconstruction (HNS-FTTR). The ERAS pathway for HNS-FTTR consists of various important protocols, including early postoperative mobilization, early postoperative enteral nutrition, abolition of preoperative fasting, preoperative enteral fluid loading, multimodal pain management, and prevention of postoperative nausea and vomiting. In recent years, meta-analyses investigating the utility of the ERAS pathway in head and neck cancer surgery have also been presented, and all reports showed that the length of the postoperative hospital stay was reduced by the implementation of the ERAS pathway. The ERAS pathway is now gaining traction in the field of head and neck surgery; however, the details of its efficacy remain uncertain. We believe the future direction will require research focused on improving the quality of postoperative patient recovery and patient satisfaction. It will be important to use patient-reported outcomes to determine whether the ERAS pathway is actually beneficial.

The risk factors of postoperative nausea and vomiting in patients undergoing laparoscopic sleeve gastrectomy and laparoscopic distal gastrectomy: a propensity score matching analysis

Postoperative nausea and vomiting (PONV) is a common side effect after laparoscopic surgery. The aim of the study is to investigate the variables that could predict PONV in patients who underwent laparoscopic gastrectomy. We divided patients who underwent laparoscopic gastrectomy into PONV and No-PONV groups. Propensity score matching (PSM) was applied to adjust confounding factors for further validation, and ordinal logistic regression analysis was used to identify predictors for PONV. In the ordinal logistic regression analysis, the preoperative neutrophil-to-lymphocyte ratio (NLR) (odds ratio [OR]: 3.19, 95% confidence interval [CI]: 1.38-7.38; p < 0.01) was identified as an independent risk factor for the presence of PONV and a predictor of the severity of PONV (OR: 3.44, 95% CI: 1.67-5.20; p < 0.01) in 94 PSM patients. Besides, NLR was positively correlated with the PONV score (r = 0.534, p < 0.001). In the receiver-operating characteristic (ROC) curve analysis, an NLR with an optimal cutoff value of 1.59 predicted severe PONV with a sensitivity of 72% and specificity of 81%. The NLR was an independent risk factor for the presence of PONV, and a high NLR tends to be positively associated with the severity of PONV after laparoscopic gastrectomy.

Effectiveness of neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios in predicting the incidence of nausea and vomiting after total knee arthroplasty in patients with hemophilia A

Objective

To investigate the ability of preoperative neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) to predict postoperative nausea and vomiting (PONV) after total knee arthroplasty (TKA).

Methods

The clinical data of 108 male patients with hemophilia A who underwent TKA an our institution were collected and analyzed. Confounding factors were adjusted by propensity score matching. The best cutoffs of the NLR and PLR were determined by the area under the receiver operating characteristic curve (ROC). The predictive ability of these indexes was assessed by measuring the sensitivity, specificity, and positive and negative likelihood ratios.

Results

There were significant differences in the use of antiemetics (p = 0.036) and the incidence of nausea (p < 0.001) and vomiting (p = 0.006) between the two groups (NLR <2 and ≥2). An increase in preoperative NLR was an independent risk factor for PONV in patients with hemophilia A (p < 0.05). ROC analysis showed that NLR significantly predicted the occurrence of PONV (cutoff value: 2.20, ROC: 0.711, p < 0.001). In turn, the PLR did not strongly predict PONV.

Conclusions

The NLR is an independent risk factor for PONV in patients with hemophilia A and can significantly predict this event. Thus, follow-up monitoring is essential for these patients.

Include or not to include conference abstracts in systematic reviews? Lessons learned from a large Cochrane network meta-analysis including 585 trials

BACKGROUND

Systematic reviews attempt to gather all available evidence. Controversy exists regarding effort and benefit of including study results presented at conferences only. We recently published a Cochrane network meta-analysis (NMA) including 585 randomized controlled trials comparing drugs for prevention of postoperative nausea and vomiting (PONV). Studies published as conference abstracts only were excluded. This study aimed to include all eligible studies published as abstracts only, assessing their added value regarding reporting quality and effect on the review's interpretation.

METHODS

Conference abstracts were searched in the review's excluded studies and conference proceedings of anaesthesiologic societies. We assessed their reporting quality regarding review's eligibility criteria, Cochrane 'risk of bias' assessment tool 1.0, and adherence to CONSORT (Consolidated Standards of Reporting Trials) for abstracts. Abstracts were included in sensitivity NMA, and impact on the NMA structure was investigated.

RESULTS

We identified 90 abstracts. A total of 14% (13/90) were eligible. A total of 86% (77/90) are awaiting classification due to insufficient reporting of review's eligibility criteria. In abstracts awaiting classification, sufficient information was missing on standardization of anaesthesia in 71% (55/77), age of participants in 56% (43/77), and outcome details in 46% (36/77). A total of 73% (66/90) of abstracts lacked sufficient information on 15/25 data extraction items. Reported study characteristics of abstracts were comparable to included studies of the review. A total of 62% (56/90) of abstract trials were assessed as overall high risk of bias due to poor reporting. Median adherence to CONSORT for abstracts was 24% (IQR, 18 to 29%). Six of the 13 eligible abstracts reported relevant outcome data in sufficient detail for NMA on seven outcomes of the Cochrane review. Inclusion of abstracts did not substantially change the network structure, network effect estimates, ranking of treatments, or the conclusion. Certainty of evidence for headache on palonosetron use was upgraded from very low to low.

CONCLUSIONS

Most conference abstracts on PONV were insufficiently reported regarding review's narrow inclusion criteria and could not be included in NMA. The resource-intensive search and evaluation of abstracts did not substantially extent the full-text evidence base of the review, given the few adequately reported abstracts. Conferences should oblige authors to adhere to CONSORT for abstracts.

Effects of Ramosetron on Nausea and Vomiting Following Spinal Surgery: A Meta-Analysis

BACKGROUND

Spinal surgery is associated with severe pain within the first few days after surgery. Opioids are commonly used to control postoperative pain, but these can lead to postoperative nausea and vomiting (PONV). Therefore, use of more effective and better-tolerated agents would be beneficial for these patients. Serotonin receptor antagonists, such as ramosetron, have been used to reduce PONV in patients receiving anesthesia.

OBJECTIVE

We conducted a meta-analysis of published randomized controlled trials (RCTs) to compare the efficacy and tolerance of ramosetron to prevent PONV after spinal surgery.

METHODS

Medline, Embase, Cochrane Library, and Science Citation Index databases were systematically searched for relevant RCT articles published between January 1979 and November 2020. Full text articles restricted to English language that described RCTs comparing the use of ramosetron with other serotonin antagonists to treat PONV following spinal surgery in adult patients were considered for meta-analysis. Two reviewers independently performed study selection, quality assessment, and data extraction of all articles. Differences were resolved by a third reviewer.

RESULTS

The search identified 88 potentially relevant articles, of which only 3 met our selection criteria. Study drugs were administered at the end of spinal surgery in all 3 included articles. The meta-analysis revealed that ramosetron (0.3 mg) reduced the pain score (mean difference = -0.66; 95% CI -1.02 to -0.30), lowered the risk of PONV (risk ratio = 0.86; 95% CI, 0.76-0.97), and postoperative vomiting (risk ratio = 0.32; 95% CI, 0.17-0.60), and limited the use of rescue antiemetics (risk ratio = 0.66; 95% CI, 0.45-0.96) after spinal surgery. However, there were no significant differences in the incidence of postoperative nausea, the use of rescue pain medications, the number of rescue analgesics required, and the risk of discontinuation of patient-controlled analgesia between ramosetron and palonosetron (0.075 mg) or ondansetron (4 mg). There were no statistically significant differences in the risk of adverse events among the 3 medications.

CONCLUSIONS

This meta-analysis of 3 RCTs showed that ramosetron reduced the risk of PONV and POV, limited the use of rescue antiemetics, reduced the postoperative pain score, and did not increase the risk of discontinuing patient-controlled analgesia compared with palonosetron or ondansetron after spinal surgery in 3 RCTs. Therefore, this meta-analysis indicates that ramosetron is an effective and well tolerated antiemetic that can be used to prevent PONV following spinal surgery in adult patients. PROSPERO identifier: CRD42020223596 (Curr Ther Res Clin Exp. 2022; 83:XXX-XXX)© 2022 Elsevier HS Journals, Inc.

Drugs for preventing postoperative nausea and vomiting in adults after general anesthesia: An abridged Cochrane network meta-analysis

OBJECTIVE

In this abridged version of the recently published Cochrane review on antiemetic drugs, we summarize its most important findings and discuss the challenges and the time needed to prepare what is now the largest Cochrane review with network meta-analysis in terms of the number of included studies and pages in its full printed form.

METHODS

We conducted a systematic review with network meta-analyses to compare and rank single antiemetic drugs and their combinations belonging to 5HT₃-, D₂-, NK₁-receptor antagonists, corticosteroids, antihistamines, and anticholinergics used to prevent postoperative nausea and vomiting in adults after general anesthesia.

RESULTS

585 studies (97 516 participants) testing 44 single drugs and 51 drug combinations were included. The studies' overall risk of bias was assessed as low in only 27% of the studies. In 282 studies, 29 out of 36 drug combinations and 10 out of 28 single drugs lowered the risk of vomiting at least 20% compared to placebo. In the ranking of treatments, combinations of drugs were generally more effective than single drugs. Single NK₁ receptor antagonists were as effective as other drug combinations. Of the 10 effective single drugs, certainty of evidence was high for aprepitant, ramosetron, granisetron, dexamethasone, and ondansetron, while moderate for fosaprepitant and droperidol. For serious adverse events (SAEs), any adverse event (AE), and drug-class specific side effects evidence for intervention effects was mostly not convincing.

CONCLUSIONS

There is high or moderate evidence for at least seven single drugs preventing postoperative vomiting. However, there is still considerable lack of evidence regarding safety aspects that does warrant investigation.

A Fast and Validated HPLC Method for the Simultaneous Analysis of Five 5-HT3 Receptor Antagonists via the Quantitative Analysis of Multicomponents by a Single Marker

In this study, a new strategy for the simultaneous quantization of five serotonin 5-hydroxytryptamine receptor antagonists—ondansetron, azasetron, ramosetron, granisetron, and tropisetron—either in infusion samples or in injection dosage form was first established based on high-performance liquid chromatography combined with a quantitative analysis of multiple components by a single marker. The quantitative analysis of multicomponents by a single marker method was conducted with ondansetron as an internal reference substance and performed using relative retention time and ultraviolet spectral similarity as the double indicator. The quantitative analysis of the 5-HT₃ receptor antagonists was calculated and investigated based on the relative correction factors. Chromatographic separation was achieved using a C₁₈ column (150 mm × 4.6 mm, 5.0 μm), and the mobile phase was composed of acetonitrile-0.05 mol·L⁻¹ potassium dihydrogen phosphate (pH 4.0) (25 : 75) at a flow rate of 1.0 mL·min⁻¹ and detection wavelengths of 307 nm (ondansetron, azasetron, ramosetron), 302 nm (granisetron), and 285 nm (tropisetron). In addition, the accuracy of the quantitative analysis of multicomponents by a single marker method was compared with an external standard method, and no significant difference was observed between the two methods. The established method is rapid, is easy, and does not require many reference substances, and it can been successfully applied as part of the quality control of the five 5-HT₃ receptor antagonists in their injection dosage form and infusion sample drugs in hospitals.

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

Postoperative nausea and vomiting is a common adverse effect of anaesthesia. Although dozens of different anti-emetics are available for clinical practice, there is currently no comparative ranking of efficacy and safety of these drugs to inform clinical practice. We performed a systematic review with network meta-analyses to compare, and rank in terms of efficacy and safety, single anti-emetic drugs and their combinations, including 5-hydroxytryptamine₃ , dopamine-2 and neurokinin-1 receptor antagonists; corticosteroids; antihistamines; and anticholinergics used to prevent postoperative nausea and vomiting in adults after general anaesthesia. We systematically searched for placebo-controlled and head-to-head randomised controlled trials up to November 2017 (updated in April 2020). We assessed how trustworthy the evidence was using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) and Confidence In Network Meta-Analysis (CINeMA) approaches for vomiting within 24 h postoperatively, serious adverse events, any adverse event and drug class-specific side-effects. We included 585 trials (97,516 participants, 83% women) testing 44 single drugs and 51 drug combinations. The studies' overall risk of bias was assessed as low in only 27% of the studies. In 282 trials, 29 out of 36 drug combinations and 10 out of 28 single drugs lowered the risk of vomiting at least 20% compared with placebo. In the ranking of treatments, combinations of drugs were generally more effective than single drugs. Single neurokinin-1 receptor antagonists were as effective as other drug combinations. Out of the 10 effective single drugs, certainty of evidence was high for aprepitant, with risk ratio (95%CI) 0.26 (0.18-0.38); ramosetron, 0.44 (0.32-0.59); granisetron, 0.45 (0.38-0.54); dexamethasone, 0.51 (0.44-0.57); and ondansetron, 0.55 (0.51-0.60). It was moderate for fosaprepitant, 0.06 (0.02-0.21) and droperidol, 0.61 (0.54-0.69). Granisetron and amisulpride are likely to have little or no increase in any adverse event compared with placebo, while dimenhydrinate and scopolamine may increase the number of patients with any adverse event compared with placebo. So far, there is no convincing evidence that other single drugs effect the incidence of serious, or any, adverse events when compared with placebo. Among drug class specific side-effects, evidence for single drugs is mostly not convincing. There is convincing evidence regarding the prophylactic effect of at least seven single drugs for postoperative vomiting such that future studies investigating these drugs will probably not change the estimated beneficial effect. However, there is still considerable lack of evidence regarding safety aspects that does warrant investigation.

What is the ideal combination antiemetic regimen?

Postoperative nausea and vomiting (PONV) and post-discharge nausea and vomiting (PDNV) are frequent unpleasant complaints that patients and clinicians report after surgery. PONV and PDNV have been associated with postoperative complications and hospital discharge delays. Despite the extensive evidence describing the use of several regimens in different surgical populations, the ideal regimen has not been established. Several antiemetic drugs have been evaluated in more than 1000 clinical controlled trials for management of this complex emetogenic pathway, including the 5-hydroxytryptamine (5-HT₃) receptor antagonists, dopamine receptor antagonists, neurokinin-type receptor antagonists, antihistaminics, anticholinergics, and corticosteroids, with the 5-HT₃ receptor antagonists being the most commonly used for PONV prophylaxis. Because of the complex emetogenic pathway and multifactorial etiology of PONV, a multimodal approach using two or more drugs that act at different neuro-receptor sites is suggested in patients with one or more risk factors to successfully address PONV and reduce its incidence. Nevertheless, the most studied regimens in randomized clinical trials (RCTs) are the combination of serotonin 5-HT3 receptor antagonists with dexamethasone or dopamine receptor antagonists (droperidol). Therefore, the safest and more effective combination regimen appears to be the use of serotonin 5-HT3 receptor antagonist antiemetic drugs with dexamethasone.

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).

A Single Prophylactic Dose of Ondansetron Given at Cessation of Postoperative Propofol Sedation Decreases Postoperative Nausea and Vomiting in Cardiac Surgery Patients: A Randomized Controlled Trial

BACKGROUND

Postoperative nausea and vomiting (PONV) is a common occurrence after cardiac surgery. However, in contrast to other surgical populations, routine PONV prophylaxis is not a standard of care in cardiac surgery. We hypothesized that routine administration of a single prophylactic dose of ondansetron (4 mg) at the time of stopping postoperative propofol sedation before extubation in the cardiac surgery intensive care unit would decrease the incidence of PONV.

METHODS

With institutional human ethics board approval and written informed consent, we conducted a randomized controlled trial in patients ≥19 years of age with no history of PONV undergoing elective or urgent cardiac surgery procedures requiring cardiopulmonary bypass. The primary outcome was the incidence of PONV in the first 24 hours postextubation, compared by the χ test. Secondary outcomes included the incidence and times to first dose of rescue antiemetic treatment administration, the incidence of headaches, and the incidence of ventricular arrhythmias.

RESULTS

PONV within the first 24 hours postextubation occurred in 33 of 77 patients (43%) in the ondansetron group versus 50 of 82 patients (61%) in the placebo group (relative risk, 0.70 [95% confidence interval {CI}, 0.51-0.95]; absolute risk difference, -18% [95% CI, -33 to -2]; number needed to treat, 5.5 [95% CI, 3.0-58.4]; χ test, P = .022). Kaplan-Meier "survival" analysis of the times to first rescue antiemetic treatment administration over 24 hours indicated that patients in the ondansetron group fared better than those in the placebo group (log-rank [Mantel-Cox] test; P = .028). Overall, 32 of 77 patients (42%) in the ondansetron group received rescue antiemetic treatment over the first 24 hours postextubation versus 47 of 82 patients (57%) in the placebo group (relative risk, 0.73 [95% CI, 0.52-1.00]; absolute risk difference, -16% [95% CI, -31 to 1]); P = .047. There were no significant differences between the groups in the incidence of postoperative headache (ondansetron group, 5 of 77 patients [6%] versus placebo group, 4 of 82 patients [5%]; Fisher exact test; P = .740) or ventricular arrhythmias (ondansetron group, 2 of 77 patients [3%] versus placebo group, 4 of 82 patients [5%]; P = .68).

CONCLUSIONS

These findings support the routine administration of ondansetron prophylaxis at the time of discontinuation of postoperative propofol sedation before extubation in patients following cardiac surgery. Further research is warranted to optimize PONV prophylaxis in cardiac surgery patients.

Simultaneous Determination of Dexamethasone, Ondansetron, Granisetron, Tropisetron, and Azasetron in Infusion Samples by HPLC with DAD Detection

A simple and rapid high-performance liquid chromatography with diode array detector (HPLC-DAD) method has been developed and validated for simultaneous quantification of five antiemetic agents in infusion samples: dexamethasone, ondansetron, granisetron, tropisetron, and azasetron. The chromatographic separation was achieved on a Phenomenex C₁₈ column (4.6 mm × 150 mm, 5 μm) using acetonitrile-50 mM KH₂PO₄ buffer-triethylamine (25 : 74 : 1; v/v; pH 4.0). Flow rate was 1.0 mL/min with a column temperature of 30°C. Validation of the method was made in terms of specificity, linearity, accuracy, and intra- and interday precision, as well as quantification and detection limits. The developed method can be used in the laboratory to routinely quantify dexamethasone, ondansetron, granisetron, tropisetron, and azasetron simultaneously and to evaluate the physicochemical stability of referred drugs in mixtures for endovenous use.

Stability of tramadol with three 5-HT3 receptor antagonists in polyolefin bags for patient-controlled delivery systems

Background

Mixing 5-hydroxytryptamine-3 (5-HT₃) receptor antagonists with patient-controlled analgesia (PCA) solutions of tramadol has been shown to decrease the incidence of nausea and vomiting associated with the use of tramadol PCA for postoperative pain. However, such mixtures are not commercially available, and the stability of the drug combinations has not been duly studied. The study aimed to evaluate the stability of tramadol with three 5-HT₃ receptor antagonists in 0.9% sodium chloride injection for PCA administration.

Materials and methods

Test samples were prepared by adding 1,000 mg tramadol hydrochloride, 8 mg ondansetron hydrochloride, and 6 mg granisetron hydrochloride or 5 mg tropisetron hydrochloride to 100 mL of 0.9% sodium chloride injection in polyolefin bags. The samples were prepared in triplicates, stored at either 25°C or 4°C for 14 days, and assessed using the following compatibility parameters: precipitation, cloudiness, discoloration, and pH. Chemical stability was also determined using a validated high-pressure liquid chromatography method.

Results

All of the mixtures were clear and colorless throughout the initial observation period. No change in the concentration of tramadol hydrochloride occurred with any of the 5-HT₃ receptor antagonists during the 14 days. Similarly, little or no loss of the 5-HT₃ receptor antagonists occurred over the 14-day period.

Conclusion

Our results suggest that mixtures of tramadol hydrochloride, ondansetron hydrochloride, granisetron hydrochloride, or tropisetron hydrochloride in 0.9% sodium chloride injection were physically and chemically stable for 14 days when stored in polyolefin bags at both 4°C and 25°C.

Efficacy of palonosetron in postoperative nausea and vomiting (PONV)-a meta-analysis

INTRODUCTION

Palonosetron is a second-generation 5-HT3 receptor antagonist with proposed higher efficacy and sustained action for prophylaxis of postoperative nausea and vomiting (PONV).

METHODS

Randomized controlled trials involving adult population undergoing elective surgery under general anesthesia comparing palonosetron to placebo, ramosetron, granisetron, and ondansetron were included. Data were extracted for vomiting incidence (VI), complete response (no nausea/vomiting; Complete Response [CR]), and rescue antiemetic need. This was categorized as early phase (24 hours postoperative for ramosetron and 6 hours for rest) and delayed phase (48 hours for ramosetron and 24 hours for rest). VI and CR were used as markers of drug efficacy. Any adverse effects were evaluated.

RESULTS

Twenty-two trials (4 with 3 groups) were included (comparing palonosetron to placebo in 5, ramosetron in 5, granisetron in 4, and ondansetron in 12 subgroups). Palonosetron demonstrated statistical superiority over placebo for VI and CR, both early/delayed PONV prevention. For delayed phase, palonosetron surpassed ramosetron in all 3 variables; however, none of the variables attained statistical significance during early phase. In early phase, palonosetron had better VI and CR than did granisetron; however, variables other than CR (better for palonosetron) failed to achieve statistical significance for delayed phase. All 3 outcomes were significantly better for palonosetron compared with ondansetron in delayed phase, but statistical superiority could only be demonstrated for VI in early phase. Being inconsistently documented across trials, nausea scores could not be evaluated.

CONCLUSION

Palonosetron is as safe as and more effective than placebo, ramosetron, granisetron, and ondansetron in preventing delayed PONV. For early PONV, it has higher efficacy over placebo, granisetron, and ondansetron.

Incompatibilities of lornoxicam with 4 antiemetic medications in polyolefin bags during simulated intravenous administration

The administration of drugs by patient-controlled analgesia (PCA) is routinely practiced for the management of postoperative pain. It is common for 2 or more drugs to be combined in PCA solutions. The combination of analgesics and antiemetic agents is frequently required. Unfortunately, the compatibility and stability of lornoxicam and antiemetic agents, such as droperidol, ondansetrone, granisetron, and tropisetron, has not been determined. The aim of this study was to evaluate the compatibility and stability of solutions containing lornoxicam with the 4 antiemetic agents in combination for PCA administration.In our study, test samples were prepared in triplicate by adding 40 mg lornoxicam and 5 mg droperidol, 8 mg ondansetron, 6 mg granisetron, or 5 mg tropisetron to 100-mL polyolefin bags of sodium chloride 0.9% and stored at 25 °C. The analgesic mixture samples were visually inspected for precipitation, cloudiness, and discoloration at each sampling interval. Drug concentrations were determined using high-performance liquid chromatographic (HPLC) analysis.No loss of lornoxicam occurred with any of the 4 antiemetic agents tested for up to 48 hours. However, the contents of droperidol, ondansetron, granisetron, and tropisetron were significant loss >48 hours. After storage of 4.0 to 48.0 hours, the presence of a slight precipitate was observed in all the injection combinations.The results indicate that combinations of lornoxicam with droperidol, ondansetrone, granisetron, or tropisetron in infusion solution during simulated intravenous PCA administration were incompatibility when stored protected from light at 25 °C.

Barriers and facilitators to uptake of systematic reviews by policy makers and health care managers: a scoping review

BACKGROUND

We completed a scoping review on the barriers and facilitators to use of systematic reviews by health care managers and policy makers, including consideration of format and content, to develop recommendations for systematic review authors and to inform research efforts to develop and test formats for systematic reviews that may optimise their uptake.

METHODS

We used the Arksey and O'Malley approach for our scoping review. Electronic databases (e.g., MEDLINE, EMBASE, PsycInfo) were searched from inception until September 2014. Any study that identified barriers or facilitators (including format and content features) to uptake of systematic reviews by health care managers and policy makers/analysts was eligible for inclusion. Two reviewers independently screened the literature results and abstracted data from the relevant studies. The identified barriers and facilitators were charted using a barriers and facilitators taxonomy for implementing clinical practice guidelines by clinicians.

RESULTS

We identified useful information for authors of systematic reviews to inform their preparation of reviews including providing one-page summaries with key messages, tailored to the relevant audience. Moreover, partnerships between researchers and policy makers/managers to facilitate the conduct and use of systematic reviews should be considered to enhance relevance of reviews and thereby influence uptake.

CONCLUSIONS

Systematic review authors can consider our results when publishing their systematic reviews. These strategies should be rigorously evaluated to determine impact on use of reviews in decision-making.

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.