Supplemental perioperative intravenous crystalloids for postoperative nausea and vomiting

The incidences of nausea and vomiting after general anesthesia with remimazolam versus sevoflurane: a prospective randomized controlled trial

BACKGROUND

Postoperative nausea and vomiting (PONV) refers to nausea and vomiting that occurs within 24-h after surgery or in the post-anesthesia care unit (PACU). Previous studies have reported that the use of remimazolam, a newer benzodiazepine (BDZ) hypnotic, for anesthesia results in less PONV. In this study, we compared the rate of PONV between sevoflurane and remimazolam after general anesthesia.

METHODS

In this prospective randomized controlled trial, participants aged 20-80 years who underwent elective laparoscopic cholecystectomy or hemicolectomy were randomized to either the remimazolam or sevoflurane group. The primary outcome was PONV incidence for 24-h after surgery. Secondary outcomes comprised of PONV at 30-min post-surgery, postoperative additional antiemetic use, and Quality of Recovery-15 (QOR-15) score at 24-h postoperatively.

RESULTS

Forty patients were enrolled in the study. The remimazolam group exhibited significantly lower rates of PONV for 24-h after surgery than did the sevoflurane group (remimazolam group vs. sevoflurane group; 5% vs. 45%, P = 0.003, respectively). The use of dexamethasone, a rescue antiemetic administered within 24 h of surgery, was substantially lower in the remimazolam group than in the sevoflurane group (0% in remimazolam vs. 30% in sevoflurane, P = 0.020). The QOR-15 score at 24-h after surgery showed no significant difference between the two groups.

CONCLUSIONS

Compared to sevoflurane, opting for remimazolam as an intraoperative hypnotic may decrease the incidence of PONV and reduce antiemetic use for 24 h after laparoscopic surgery.

Pathogenetic justification of digestive tract dysfunction correction to reduce the risk of ventricular extrasystoles after coronary bypass grafting

Introduction

In heart pathology, abdominal pathology is often detected, but due attention has not been paid to this issue, and algorithms for predicting, preventing, and correcting the coefficient of endothelial dysfunction (CED) after coronary artery bypass grafting (CABG) with the use of artificial circulation (AC) have not been developed.

Aim

To substantiate the pathogenetic expediency of correction of postoperative intestinal paresis after coronary artery bypass grafting for the prevention of functional cardiac complications.

Material and methods

147 men were divided into 2 groups. Statistical processing of the obtained data was performed using Windows Microsoft Excel software and parametric methods of variational statistics, and the reliability of differences was determined using Student's formula and table.

Results

It was found that in group II, after coronary artery bypass grafting, the clinical symptoms of intestinal dysfunction were significantly less (p = 0.019), and the recovery of defecation was significantly faster (p = 0.033) than in group I. After coronary artery bypass grafting, the frequency of high-grade extrasystoles in group II was significantly lower than in group I (p = 0.033).

Conclusions

The application of the digestive tract dysfunction correction program is pathogenetically justified because it provides a reduction in the frequency of intestinal paresis and hence a reduction in the frequency of development of ventricular extrasystoles of high gradations after coronary artery bypass grafting.

Enhanced recovery protocols for ambulatory surgery

INTRODUCTION

In the United States, ambulatory surgeries account for up to 87% of all surgical procedures. (1) It was estimated that 19.2 million ambulatory surgeries were performed in 2018 (https://www.hcup-us.ahrq.gov/reports/statbriefs/sb287-Ambulatory-Surgery-Overview-2019.pdf). Cataract procedures and musculoskeletal surgeries are the most common surgical interventions performed in ambulatory centers. However, more complex surgical interventions, such as sleeve gastrectomies, oncological, and spine surgeries, and even arthroplasties are routinely performed as day cases or in a model of an ambulatory extended recovery. (2-5) The ambulatory surgery centers industry has grown since 2017 by 1.1% per year and reached a market size of $31.2 billion. According to the Ambulatory Surgery Center Association, there is a potential to save $57.6 billion in Medicare costs over the next decade (https://www.ibisworld.com/industry-statistics/market-size/ambulatory-surgery-centers-united-states/). These data suggest an expected rise in the volume of ambulatory (same day) or extended ambulatory (23 h) surgeries in coming years. Similar increases are also observed in other countries. For example, 75% of elective surgeries are performed as same-day surgery in the United Kingdom. (6) To reduce costs and improve the quality of care after those more complex procedures, ambulatory surgery centers have started implementing patient-centered, high-quality, value-based practices. To achieve those goals, Enhanced Recovery After Surgery (ERAS) protocols have been implemented to reduce the length of stay, decrease costs, increase patients' satisfaction, and transform clinical practices. The ERAS fundamentals for ambulatory surgery are based on five pillars, including (1) preoperative patient counseling, education, and optimization; (2) multimodal and opioid-sparing analgesia; (3) nausea and vomiting, wound infection, and venous thromboembolism prophylaxis; (4) maintenance of euvolemia; and (5) encouragement of early mobility. Those pillars rely on interdisciplinary teamwork led by anesthesiologists, surgery-specific workgroups, and safety culture. (2) Research shows that a team of ambulatory anesthesiologists is crucial in improving postoperative nausea and vomiting (PONV) and pain control. (7) This review will summarize the current evidence on the elements and clinical importance of implementing ERAS protocol for ambulatory surgery.

Patient-reported nausea after implementation of an enhanced recovery after surgery protocol for gynae-oncology patients

OBJECTIVES

This study aimed to analyze the adherence to strategies to prevent post-operative nausea and vomiting after implementation of an enhanced recovery after surgery (ERAS) protocol for gynae-oncology patients. Patient-reported nausea before and after ERAS was also studied.

METHODS

This prospective observational study included all patients undergoing laparotomy for a suspicious pelvic mass or confirmed advanced ovarian cancer before (pre-ERAS) and after the implementation of ERAS (post-ERAS) at Oslo University Hospital, Norway. Patients were a priori stratified according to the planned extent of surgery into two cohorts (Cohort 1: Surgery of advanced disease; Cohort 2: Surgery for a suspicious pelvic tumor). Clinical data including baseline characteristics and outcome data were prospectively collected.

RESULTS

A total of 439 patients were included, 243 pre-ERAS and 196 post-ERAS. At baseline, 27% of the patients reported any grade of nausea. In the post-ERAS cohort, statistically significantly more patients received double post-operative nausea and vomiting prophylaxis (64% pre-ERAS vs 84% post-ERAS, p<0.0001). There was no difference in the need for rescue medication (82% pre-ERAS vs 79% post-ERAS; p=0.17) and no statistically significant difference between pre- and post-ERAS or between the surgical cohorts in patient-reported nausea of any grade on day 2. Patients who reported none/mild nausea on day 2 had significantly less peri-operative fluid administered during surgery than those who reported moderate or severe nausea (median 12.5 mL/kg/hour vs 16.5 mL/kg/hour, p=0.045) but, in multivariable analysis, fluid management did not remain significantly associated with nausea.

CONCLUSION

Implementation of an ERAS protocol increased the adherence to post-operative nausea and vomiting prevention guidelines. Nausea, both before and after laparotomy, remains an unmet clinical need of gynae-oncology patients also in an ERAS program. Patient-reported outcome measures warrant further investigation in the evaluation of ERAS.

Postdischarge nausea and vomiting (PDNV) in children: A review and observational study

Postdischarge nausea and vomiting (PDNV) cause substantial pediatric morbidity with potentially serious postoperative complications. However, few studies have addressed PDNV prevention and treatment in pediatric patients. Here we searched the literature and processed it in a narrative review describing PDNV incidence, risk factors, and management in pediatric patients.. A successful strategy for reducing PDNV considers both the pharmacokinetics of the antiemetic agents and the principle of multimodal prophylaxis, utilizing agents of different pharmacologic classes. Since many highly effective antiemetic agents have relatively short half-lives, a different approach must be used to prevent PDNV. A combination of oral and intravenous medications with longer half-lives, such as palonosetron or aprepitant, can be used. In addition, we designed a prospective observational study with the primary objective of determining PDNV incidence. In our study group of 205 children, the overall PDNV incidence was 14.6% (30 of 205), including 21 children suffering from nausea and 9 suffering from vomiting.

Intraoperative pleth variability index-based fluid management therapy and gastrointestinal surgical outcomes in elderly patients: a randomised controlled trial

BACKGROUND

Intraoperative goal-directed fluid therapy (GDFT) has been reported to reduce postoperative complications of patients undergoing major abdominal surgery. The clinical benefits of pleth variability index (PVI)-directed fluid management for gastrointestinal (GI) surgical patients remain unclear. Therefore, this study aimed to evaluate the impact of PVI-directed GDFT on GI surgical outcomes in elderly patients.

METHODS

This randomised controlled trial was conducted in two university teaching hospitals from November 2017 to December 2020. In total, 220 older adults undergoing GI surgery were randomised to the GDFT or conventional fluid therapy (CFT) group (n = 110 each). The primary outcome was a composite of complications within 30 postoperative days. The secondary outcomes were cardiopulmonary complications, time to first flatus, postoperative nausea and vomiting, and postoperative length of stay.

RESULTS

The total volumes of fluid administered were less in the GDFT group than in the CFT group (2.075 L versus [vs.] 2.5 L, P = 0.008). In intention-to-treat analysis, there was no difference in overall complications between the CFT group (41.3%) and GDFT group (43.0%) (odds ratio [OR] = 0.935; 95% confidence interval [CI], 0.541-1.615; P = 0.809). The proportion of cardiopulmonary complications was higher in the CFT group than in the GDFT group (19.2% vs. 8.4%; OR = 2.593, 95% CI, 1.120-5.999; P = 0.022). No other differences were identified between the two groups.

CONCLUSIONS

Among elderly patients undergoing GI surgery, intraoperative GDFT based on the simple and non-invasive PVI did not reduce the occurrence of composite postoperative complications but was associated with a lower cardiopulmonary complication rate than usual fluid management.

TRIAL REGISTRATION

This trial was registered with the Chinese Clinical Trial Registry (ChiCTR-TRC-17012220) on 1 August 2017.

Development and assessment of novel machine learning models to predict the probability of postoperative nausea and vomiting for patient-controlled analgesia

Postoperative nausea and vomiting (PONV) can lead to various postoperative complications. The risk assessment model of PONV is helpful in guiding treatment and reducing the incidence of PONV, whereas the published models of PONV do not have a high accuracy rate. This study aimed to collect data from patients in Sichuan Provincial People's Hospital to develop models for predicting PONV based on machine learning algorithms, and to evaluate the predictive performance of the models using the area under the receiver characteristic curve (AUC), accuracy, precision, recall rate, F1 value and area under the precision-recall curve (AUPRC). The AUC (0.947) of our best machine learning model was significantly higher than that of the past models. The best of these models was used for external validation on patients from Chengdu First People's Hospital, and the AUC was 0.821. The contributions of variables were also interpreted using SHapley Additive ExPlanation (SHAP). A history of motion sickness and/or PONV, sex, weight, history of surgery, infusion volume, intraoperative urine volume, age, BMI, height, and PCA_3.0 were the top ten most important variables for the model. The machine learning models of PONV provided a good preoperative prediction of PONV for intravenous patient-controlled analgesia.

Postoperative Vomiting Following Laparoscopic Cholecystectomy Is Associated with Intraoperative Fluid Administration: A Retrospective Cohort Study

Potential risk factors for postoperative vomiting (POV) are important for daily anesthesia practice. To identify the risk factors associated with POV we retrospectively reviewed 553 adult patients who underwent scheduled simple laparoscopic cholecystectomy under sevoflurane-based general anesthesia between January and December 2018. Patients who experienced POV were predominantly women, had lower body weight, and higher ASA (American Society of Anesthesiologists) physical status. The POV group showed female sex predominance, lower body weight, and higher ASA physical status, with a significant difference when compared with the non-POV group. In univariate analysis, female sex and Apfel scores of 2, 3, and 4 were associated with a higher POV incidence. Age > 70 years, higher body weight, and ASA physical status III were associated with a lower POV incidence. In multivariate logistic regression, sex, age, Apfel score, and intraoperative crystalloid infusion rate were POV predictive factors. Receiver operating characteristic analysis showed a negative association between the intraoperative crystalloid infusion rate and POV occurrence with an area under the curve of 0.73 (p = 0.001). The cutoff intraoperative crystalloid infusion rate was 2 mL/kg/h with 82% sensitivity and 49% specificity (≥2 mL/kg/h was associated with a lower POV incidence vs. <2 mL/kg/h (OR, 95% CI; 0.52 [0.33–0.83])). To decrease POV in these patients, identifying high-risk factors and an intraoperative crystalloid administration of ≥2 mL/kg/h should be considered in patients undergoing LC under sevoflurane-based general anesthesia.

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.

Prevention and Treatment of Postoperative Nausea and Vomiting (PONV): A Review of Current Recommendations and Emerging Therapies

Postoperative nausea and vomiting is one of the most frequent adverse events after surgery and anesthesia. It is distressing for the patient and can lead to other postoperative complications. Management of PONV involves a framework of risk assessment, multimodal risk reduction, and prophylactic measures, as well as prompt rescue treatment. There has been a significant paradigm shift in the approach towards PONV prevention. There have also been several emerging therapeutic options for PONV prophylaxis and treatment. In this review, we will discuss the up-to-date PONV management guidelines and highlight novel therapeutic options which have emerged in the last few years.

The use of intravenous lidocaine for postoperative pain and recovery: international consensus statement on efficacy and safety

Intravenous lidocaine is used widely for its effect on postoperative pain and recovery but it can be, and has been, fatal when used inappropriately and incorrectly. The risk-benefit ratio of i.v. lidocaine varies with type of surgery and with patient factors such as comorbidity (including pre-existing chronic pain). This consensus statement aims to address three questions. First, does i.v. lidocaine effectively reduce postoperative pain and facilitate recovery? Second, is i.v. lidocaine safe? Third, does the fact that i.v. lidocaine is not licensed for this indication affect its use? We suggest that i.v. lidocaine should be regarded as a 'high-risk' medicine. Individual anaesthetists may feel that, in selected patients, i.v. lidocaine may be beneficial as part of a multimodal peri-operative pain management strategy. This approach should be approved by hospital medication governance systems, and the individual clinical decision should be made with properly informed consent from the patient concerned. If i.v. lidocaine is used, we recommend an initial dose of no more than 1.5 mg.kg^-1 , calculated using the patient's ideal body weight and given as an infusion over 10 min. Thereafter, an infusion of no more than 1.5 mg.kg^-1 .h^-1 for no longer than 24 h is recommended, subject to review and re-assessment. Intravenous lidocaine should not be used at the same time as, or within the period of action of, other local anaesthetic interventions. This includes not starting i.v. lidocaine within 4 h after any nerve block, and not performing any nerve block until 4 h after discontinuing an i.v. lidocaine infusion.

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).

Risk of postoperative nausea and vomiting in hip and knee arthroplasty: a prospective cohort study after spinal anaesthesia including intrathecal morphine

BACKGROUND

The overall risk of postoperative nausea and vomiting after general anaesthesia is approximately 30% even with prophylactic medications. Studies exploring the risk after regional anaesthesia including intrathecal morphine are limited but indicate that intrathecal morphine is highly emetogenic and is additive to the PONV risk associated with other forms of anaesthesia. The aim of this observational study was to investigate the risk of PONV after spinal blockade combined with intrathecal morphine and to explore associations with patient and perioperative factors, including given PONV-prophylaxis. We hypothesized that a large number of patients in a clinical setting receive less prophylaxis than the recommendations in guidelines (suboptimal prophylaxis), leading to a higher risk for PONV compared to those receiving adequate PONV prophylaxis.

METHODS

The study was conducted as a prospective observational cohort study regarding PONV in patients undergoing hip/knee replacement under spinal anaesthesia including intrathecal morphine. Patients were included at a county hospital in Sweden during April-November 2013 (n = 59) and September 2014-June 2015 (n = 40). One hundred eight patients entered the study with 99 patients analysed in the final cohort. Patients were followed the first three postoperative days with a questionnaire regarding PONV and peri- and postoperative data was collected. PONV risk is presented as the proportion of patients (%) with PONV and was related to the level of perioperative PONV-prophylaxis (suboptimal/optimal). Univariate analysis was used to analyse factors associated with PONV.

RESULTS

Forty-six patients (46%) experienced PONV during the 3-day study period whereof 36 patients (36%) until noon the first day after the procedure. 19/27 patients (70%) that received suboptimal PONV-prophylaxis experienced PONV compared to 27/72 (38%) that received optimal PONV-prophylaxis (p = 0.015). Further, female gender and/or a history of motion sickness were associated with an increased PONV-risk.

CONCLUSIONS

There was a high risk for PONV after spinal anaesthesia including morphine. PONV risk was associated with the level of prophylaxis and with known risk factors for PONV. Our findings suggest that a more liberal use of PONV prophylaxis might be motivated.

Management strategies for the treatment and prevention of postoperative/postdischarge nausea and vomiting: an updated review

Postoperative nausea and vomiting (PONV) and postdischarge nausea and vomiting (PDNV) remain common and distressing complications following surgery. The routine use of opioid analgesics for perioperative pain management is a major contributing factor to both PONV and PDNV after surgery. PONV and PDNV can delay discharge from the hospital or surgicenter, delay the return to normal activities of daily living after discharge home, and increase medical costs. The high incidence of PONV and PDNV has persisted despite the introduction of many new antiemetic drugs (and more aggressive use of antiemetic prophylaxis) over the last two decades as a result of growth in minimally invasive ambulatory surgery and the increased emphasis on earlier mobilization and discharge after both minor and major surgical procedures (e.g. enhanced recovery protocols). Pharmacologic management of PONV should be tailored to the patient’s risk level using the validated PONV and PDNV risk-scoring systems to encourage cost-effective practices and minimize the potential for adverse side effects due to drug interactions in the perioperative period. A combination of prophylactic antiemetic drugs with different mechanisms of action should be administered to patients with moderate to high risk of developing PONV. In addition to utilizing prophylactic antiemetic drugs, the management of perioperative pain using opioid-sparing multimodal analgesic techniques is critically important for achieving an enhanced recovery after surgery. In conclusion, the utilization of strategies to reduce the baseline risk of PONV (e.g. adequate hydration and the use of nonpharmacologic antiemetic and opioid-sparing analgesic techniques) and implementing multimodal antiemetic and analgesic regimens will reduce the likelihood of patients developing PONV and PDNV after surgery.

Supplemental perioperative intravenous crystalloids for postoperative nausea and vomiting

BACKGROUND

Postoperative nausea and vomiting (PONV) is a common complication following general anaesthesia. It may be associated with patient dissatisfaction, increased costs of treatment, and unintended admission to hospital.Supplemental intravenous crystalloid administration in the perioperative period may be a simple intervention to prevent PONV.

OBJECTIVES

To assess whether supplemental intravenous crystalloid administration prevents PONV in patients undergoing surgical procedures under general anaesthesia.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 7), MEDLINE (1946 to August 2018), Embase (1947 to August 2018), and the Cumulative Index of Nursing and Allied Health Literature (CINAHL; 1971 to August 2018). We searched clinical trials registers for ongoing or unpublished completed studies (August 2018), handsearched three major journals (British Journal of Anaesthesia, European Journal of Anaesthesiology, and Anesthesiology; August 2018), and conducted backward and forward citation searching of relevant articles.

SELECTION CRITERIA

We included randomized controlled trials of participants older than six months undergoing surgical procedures under general anaesthesia and given supplemental perioperative intravenous crystalloids, defined as a volume larger than that received by a comparator group, to prevent PONV.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures described by Cochrane.

MAIN RESULTS

We included 41 studies (4224 participants). Participants underwent ambulatory or short length of stay surgical procedures, and were predominantly American Society of Anesthesiology (ASA) class I or II. There is one study awaiting classification and three ongoing studies. All studies took place in surgical centres, and were conducted in geographically diverse settings. Risk of bias was generally unclear across all domains.Supplemental intravenous crystalloid administration probably reduces the cumulative risk of postoperative nausea (PON) (risk ratio (RR) 0.62, 95% confidence interval (CI) 0.51 to 0.75; 18 studies; 1766 participants; moderate-certainty evidence). When the postoperative period was divided into early (first six hours postoperatively) and late (at the time point closest to or including 24 hours postoperatively) time points, the intervention reduced the risk of early PON (RR 0.67, 95% CI 0.58 to 0.78; 20 studies; 2310 participants; moderate-certainty evidence) and late PON (RR 0.47, 95% CI 0.32 to 0.69; 17 studies; 1682 participants; moderate-certainty evidence).Supplemental intravenous crystalloid administration probably reduces the risk of postoperative vomiting (POV) (RR 0.50, 95% CI 0.40 to 0.63; 20 studies; 1970 participants; moderate-certainty evidence). The intervention specifically reduced both early POV (RR 0.56, 95% CI 0.41 to 0.76; 19 studies; 1998 participants; moderate-certainty evidence) and late POV (RR 0.48, 95% CI 0.29 to 0.79; 15 studies; 1403 participants; moderate-certainty evidence).Supplemental intravenous crystalloid administration probably reduces the need for pharmacologic treatment of PONV (RR 0.62, 95% CI 0.51 to 0.76; 23 studies; 2416 participants; moderate-certainty evidence).The effect of supplemental intravenous crystalloid administration on the risk of unplanned postoperative admission to hospital is unclear (RR 1.05, 95% CI 0.77 to 1.43; 3 studies; 235 participants; low-certainty evidence).No studies reported serious adverse events that may occur following supplemental perioperative intravenous crystalloid administration (i.e. admission to high-dependency unit, postoperative cardiac or respiratory complication, or death).

AUTHORS' CONCLUSIONS

There is moderate-certainty evidence that supplemental perioperative intravenous crystalloid administration reduces PON and POV, in ASA class I to II patients receiving general anaesthesia for ambulatory or short length of stay surgical procedures. The intervention probably also reduces the risk of pharmacologic treatment for PONV. The effect of the intervention on the risk of unintended postoperative admission to hospital is unclear. The risk of serious adverse events resulting from supplemental perioperative intravenous crystalloid administration is unknown as no studies reported this outcome. The one study awaiting classification may alter the conclusions of the review once assessed.