Applicability of risk scores for postoperative nausea and vomiting in adults to paediatric patients

[Comparison of different prediction models for the occurrence of nausea and vomiting in the postoperative phase : A systematic qualitative comparison based on prospectively defined quality indicators]

BACKGROUND

Various prognostic prediction models exist for evaluating the risk of nausea and vomiting in the postoperative period (PONV). So far, no systematic comparison of these prognostic scores is available.

METHOD

A systematic literature search was carried out in seven medical databases to find publications on prognostic PONV models. Identified scores were assessed against prospectively defined quality criteria, including generalizability, validation and clinical relevance of the models.

RESULTS

The literature search revealed 62 relevant publications with a total of 81,834 patients which could be assigned to 8 prognostic models. The simplified Apfel score performed best, primarily because it was extensively validated. The Van den Bosch score and Sinclair score tied for second place. The simplified Koivuranta score was in third place.

CONCLUSION

The qualitative analysis highlights the strengths and weaknesses of each prediction system based on predetermined standardized quality criteria.

Is PONV still a problem in pediatric surgery: a prospective study of what children tell us

Background

Postoperative nausea and vomiting (PONV) is an unpleasant complication after surgery that commonly co-occurs with pain. Considering the high prevalence among pediatric patients, it is important to explore the main risk factors leading to PONV in order to optimize treatment strategies. The objectives of this study are as follows: (1) to determine the prevalence of PONV on the day of surgery by conducting interviews with pediatric patients, (2) to assess PONV prevalence in the recovery room and on the ward by analyzing nursing records, and (3) to collect information on PONV risk factors on the day of surgery and the following postoperative days. We wanted to investigate real-life scenarios rather than relying on artificially designed studies.

Methods

A prospective analysis [according to STrengthening the Reporting of OBservational studies in Epidemiology (STROBE) guidelines] of PONV on the day of surgery and the following postoperative days was conducted by evaluating demographic and procedural parameters, as well as conducting interviews with the children under study. A total of 626 children and adolescents, ranging in age from 4 to 18 years, were interviewed on the ward following their surgery. The interviews were conducted using a questionnaire, as children aged 4 and above can participate in an outcome-based survey.

Results

On the day of surgery, several multivariable independent predictors were identified for PONV. The type of surgery was found to be a significant factor (p = 0.040) with the highest odds ratio (OR) in patients with procedural investigations [OR 5.9, 95% confidence interval (CI): 1.8-19.2], followed by abdominal surgery (OR 3.1, 95% CI: 0.9-11.1) when inguinal surgery was used as the reference category. In addition, the study identified several predictors, including the amount of fentanyl administered during anesthesia (µg/kg body weight) (OR 1.4, 95% CI: 1.1-1.8), intraoperative use of piritramide (OR 2.6, 95% CI: 1.5-4.4) and diclofenac (OR 2.0, 95% CI: 1. 3-3.1), opioid administration in the recovery room (OR 3.0, 95% CI: 1.9-4.7), and piritramide use on the ward (OR 4.5, 95% CI: 1.7-11.6).

Conclusions

The main risk factors for PONV include the intraoperative administration of opioids during the recovery room stay and at the ward, the intraoperative use of non-opioids (diclofenac), and the specific type of surgical procedure. Real-life data demonstrated that in clinical praxis, there is a gap between the adherence to established guidelines and the use of antiemetic prophylaxis in surgeries that are generally not associated with a high PONV prevalence. Further efforts are needed to improve the existing procedures and thus improve the overall outcome.

Effects of a Preoperative Carbohydrate Load on Postoperative Recovery in Children: A Randomised, Double-Blind, Placebo-Controlled Trial

BACKGROUND

Nausea and vomiting are common causes for prolonged postoperative length of hospital stay (LOS) in children. A preoperative carbohydrate load may reduce postoperative nausea and vomiting by improving the perioperative metabolic state. The aim of this study was to determine if a preoperative carbohydrate-containing drink would lead to an improvement in the perioperative metabolic state and consequently reduce the incidence of postoperative nausea, vomiting and LOS in children undergoing day-case surgical procedures.

METHOD

Randomised, double-blind, placebo-controlled trial involving children aged 4 to 16-years undergoing day-case surgical procedures. Patients were randomised to receive a carbohydrate-containing drink or a placebo. During the induction of anaesthesia, a venous blood gas, and blood glucose and ketone levels were measured. Postoperatively, the incidence of nausea, vomiting, and LOS were documented.

RESULTS

120 patients were randomised with 119/120 (99.2%) undergoing analysis. Blood glucose level was higher in the carbohydrate group; 5.4 mmol/L [3.3-9.4] versus 4.9 mmol/L [3.6-6.5] (p = 0.01). Blood ketone level was lower in the carbohydrate group; 0.2 mmol/L versus 0.3 mmol/L (p = 0.003). The incidence of nausea and vomiting was not different (p > 0.9 and p = 0.8, respectively). LOS in the carbohydrate group was 26 min shorter than the placebo group (p = 0.02).

CONCLUSION

Although a preoperative carbohydrate load may provide a more stable metabolic state at the induction of anaesthesia, we did not find a reduction in postoperative nausea and vomiting. A preoperative carbohydrate load has also minimal effects on the postoperative LOS.

TYPE OF STUDY

Randomised clinical trial.

LEVEL OF EVIDENCE

I.

The Impact of Different Antiemetics on the Nausea in Early Postoperative Period After Laparoscopic Holecystectomy

Postoperative nausea and vomiting (PONV) is a patient-important outcome; patients often rate PONV as worse than postoperative pain. This clinical study was aimed to asses the efficiency of standard aniemetics administration separately or in combination in prevention of PONV in patients who underwent to the same surgical procedure - laparoscopic cholecystectomy. Also, this article could provide a novel information about the best choice for prevention and treatment of PONV. This study included 87 patients divided into four groups according to the postoperative phramacological treatment: First group was control group without treatment, Second group was group of patients with ondasetron treatment in postoperative period, Third group was group of patients with ondasetron+dexamethasone treatment, and fourth group was group of patients with dexamethasone treatment in postoperative period for nausea. PONV was distributed in Ondansetron+Dexamethasone group in the lowest percent (4.5%), which means that this conbination of antiemetics was very effective. Than, Dexamethasone group was in relation with low incidence of PONV (14.3%), and after that were Ondansetron and Control groups. Also smokers and males has lower incidence of PONV, especially in combination with Ondansetron+Dexamethasone treatment.

The incidence of PONV is lower in male smokers patients who were underwent to combination of two antiemetics, ondansetron and dexamethasone compared to monotherapy and female non-smokers. Preventive strategies for PONV must include risk stratification followed by prophylactic approach and also testing the newer antiemetics. Because of the high incidence of postoperative nausea and vomiting as a patient-important outcome, the preventive strategies should be considered as serious condition which requires multimodal approach.

Statistical Development and Validation of Clinical Prediction Models

SUMMARY

Clinical prediction models in anesthesia and surgery research have many clinical applications including preoperative risk stratification with implications for clinical utility in decision-making, resource utilization, and costs. It is imperative that predictive algorithms and multivariable models are validated in a suitable and comprehensive way in order to establish the robustness of the model in terms of accuracy, predictive ability, reliability, and generalizability. The purpose of this article is to educate anesthesia researchers at an introductory level on important statistical concepts involved with development and validation of multivariable prediction models for a binary outcome. Methods covered include assessments of discrimination and calibration through internal and external validation. An anesthesia research publication is examined to illustrate the process and presentation of multivariable prediction model development and validation for a binary outcome. Properly assessing the statistical and clinical validity of a multivariable prediction model is essential for reassuring the generalizability and reproducibility of the published tool.

Polymorphisms of 5-hydroxytryptamine receptor type 3B gene and clinical characteristics for vomiting after breast surgery in chinese han female population

WHAT IS KNOWN AND OBJECTIVE

The 5-hydroxytryptamine type 3B receptor (HTR3B) is involved in postoperative vomiting. We aimed to investigate whether genomic variations of rs1176744 and rs1672717 in HTR3B are associated with postoperative vomiting (POV) in the Chinese Han female population after surgery.

METHODS

Five hundred and sixty-eight female patients classified as ASA I-II undergoing breast surgery under standard general anaesthesia were enrolled in the study. Episodes of POV in the first 24 h after surgery were recorded. Targeted single nucleotide polymorphisms (SNPs) in the HTR3B gene were identified by genotyping using the SNPscan^TM technique. Univariate and multivariate analyses were conducted to investigate the association between SNPs and POV.

RESULTS

We eventually analysed 407 subjects undergoing breast surgery under general anaesthesia. Of these, 104(25.6%) patients suffered POV within 24 h after surgery. In the multivariate logistic regression analysis, we found that age≥50 years (p = 0.012) and longer duration of surgery (p = 0.019) were independent risk factors for POV. Simultaneously, in the dominant model of rs1672717, compared with the AA genotype, GG+GA carriers suffered more POV (OR=1.669, p = 0.038). However, the use of atropine reduced the incidence of POV in our study (p = 0.019).

WHAT IS NEW AND CONCLUSION

Our investigation demonstrated that polymorphism of rs1672717 (HTR3B) may be a genetic risk factor for developing POV.

TRIAL REGISTRATION

clinicaltrials.gov identifier: NCT03705026.

Postoperative Nausea and Vomiting in Pediatric Patients

Postoperative nausea and vomiting (PONV), postoperative vomiting (POV), post-discharge nausea and vomiting (PDNV), and opioid-induced nausea and vomiting (OINV) continue to be causes of pediatric morbidity, delay in discharge, and unplanned hospital admission. Research on the pathophysiology, risk assessment, and therapy for PDNV, OINV and pain therapy options in children has received increased attention. Multimodal pain management with the use of perioperative regional and opioid-sparing analgesia has helped decrease nausea and vomiting. Two common emetogenic surgical procedures in children are adenotonsillectomy and strabismus repair. Although PONV risk factors differ between adults and children, the approach to decrease baseline risk is similar. As PONV and POV are frequent in children, antiemetic prophylaxis should be considered for those at risk. A multimodal approach for antiemetic and pain therapy involves preoperative risk evaluation and stratification, antiemetic prophylaxis, and pain management with opioid-sparing medications and regional anesthesia. Useful antiemetics include dexamethasone and serotonin 5-hydroxytryptamine-3 (5-HT3) receptor antagonists such as ondansetron. Multimodal combination prophylactic therapy using two or three antiemetics from different drug classes and propofol total intravenous anesthesia should be considered for children at high PONV risk. "Enhanced recovery after surgery" protocols include a multimodal approach with preoperative preparation, adequate intravenous fluid hydration, opioid-sparing analgesia, and prophylactic antiemetics. PONV guidelines and management algorithms help provide effective postoperative care for pediatric patients.

Incidence of postoperative vomiting in pediatric population undergoing anesthesia: a prospective cohort study

Introduction: Postoperative nausea and vomiting are frequent adverse effects of anesthesia and surgery. Impact is greater in pediatric populations compared to adults and the reported incidences are heterogeneous. Objective: To describe the incidence of postoperative vomiting in a pediatric population and to identify associated risk factors. Materials and methods: This prospective cohort study included 190 children aged 3 to 12 years undergoing surgery and anesthesia in a maternal and child health clinic in Bucaramanga (Colombia). The main outcome variable was postoperative vomiting. Data were analyzed using bivariate, multivariate analysis and logistic regression to assess the associated risk factors. Results: The overall incidence of postoperative vomiting was 18.95% (95% CI: 13.32 - 24.57), with a higher incidence at home vs. hospital (12.63% vs. 9.47%). After adjustment, associated risk factors were anesthesia time longer than 45 minutes (OR: 2.33; 95% CI: 1.10-4.90) and postoperative use of opioids (OR: 4.17; 95% IC: 1.65-10.5). The incidence of postoperative vomiting was higher in patients who underwent emergency surgery. Conclusion: This is the first study in Colombia that evaluates the incidence of postoperative vomiting in children. The incidence in our pediatric population is within the ranges reported worldwide. Associated risk factors were anesthesia time longer than 45 minutes and postoperative use of opioids. Further research is required in order to study emergency surgery as a potential risk factor.

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.

Postoperative Nausea and Vomiting in Paediatric Anaesthesia

Postoperative nausea and vomiting (PONV) is a common complication in paediatric anaesthesia and is a source of significant morbidity. Various independent risk factors have been implicated in the development of paediatric PONV, including higher pain scores postoperatively, the use of opioids for pain management and the use of volatile anaesthetics for the maintenance of anaesthesia. This review of the current literature regarding the prevention and treatment of paediatric PONV is based on a search of the PubMed database, which identified published clinical trials, systematic reviews and meta-analyses. While the occurrence of PONV in many cases is difficult to avoid entirely, the risk can be mitigated by the use of multimodal nonopioid analgesic regimens, total intravenous drugs in favour of volatile anaesthetics and an appropriate regimen of prophylactic pharmacotherapy. Frequently administered drug classes for the prevention of PONV include corticosteroids, 5HT3 antagonists and anticholinergics. The clinical use of the findings in the literature may help to reduce the occurrence of PONV in children. In this review, we provide comprehensive and updated information on the risk factors contributing the occurrence of PONV in children, outline the current opinion on the drugs that are commonly used for management and provide an overview of the guidelines that are used to help establish the prophylaxis and treatment of paediatric PONV.

An exploratory study of the relationship between postoperative nausea and vomiting and postdischarge nausea and vomiting in children undergoing ambulatory surgery

BACKGROUND

The factors contributing to postoperative nausea and vomiting in children have been identified, but there have been no reported studies that have studied pediatric postdischarge nausea and vomiting.

AIMS

This preliminary study aimed to identify  the factors affecting postdischarge nausea and vomiting in ambulatory children, specifically whether postoperative nausea and vomiting factors are contributory.

METHODS

One hundred and twenty-two pediatric patients aged 5-10 years undergoing elective ambulatory surgery participated in this institution-approved study. After obtaining written parental consent and patient assent when indicated, child self-ratings of nausea and pain were completed preoperatively and at discharge, and for 3 days postdischarge. Questionnaires were returned by mail, with a 64% return rate. Using stepwise logistic regression with backward elimination, three separate analyses were undertaken to predict the following outcomes: nausea present in recovery, nausea present on postoperative day 1, and emesis on day of surgery.

RESULTS

Nearly half (47%) of our cohort experienced nausea at the time of discharge; 11% had emesis on day of surgery. On postoperative day 1, there was a 15% incidence of nausea with a 3% incidence of emesis. In the multiple logistic regression analyses, nausea at discharge was predicted by male gender (odds ratio 2.5, 95% CI: 1.0-6.2) and the presence of pain on discharge (odds ratio 3.0, 95% CI: 1.0-9.2). Emesis on day of surgery was predicted by the presence of nausea at discharge (odds ratio 16.9, 95% CI: 1.8-159.3) and having a family history of nausea/vomiting (odds ratio 8.3, 95% CI: 1.6-43.4). The presence of nausea on postoperative day 1 was predicted only by the presence of nausea on discharge (odds ratio 3.7, 95% CI: 1.2-11.1).

CONCLUSION

Our preliminary data indicate that postoperative nausea and vomiting may persist into the postdischarge period and pain may be a contributing factor.

Useful pharmacodynamic endpoints in children: selection, measurement, and next steps

Pharmacodynamic (PD) endpoints are essential for establishing the benefit-to-risk ratio for therapeutic interventions in children and neonates. This article discusses the selection of an appropriate measure of response, the PD endpoint, which is a critical methodological step in designing pediatric efficacy and safety studies. We provide an overview of existing guidance on the choice of PD endpoints in pediatric clinical research. We identified several considerations relevant to the selection and measurement of PD endpoints in pediatric clinical trials, including the use of biomarkers, modeling, compliance, scoring systems, and validated measurement tools. To be useful, PD endpoints in children need to be clinically relevant, responsive to both treatment and/or disease progression, reproducible, and reliable. In most pediatric disease areas, this requires significant validation efforts. We propose a minimal set of criteria for useful PD endpoint selection and measurement. We conclude that, given the current heterogeneity of pediatric PD endpoint definitions and measurements, both across and within defined disease areas, there is an acute need for internationally agreed, validated, and condition-specific pediatric PD endpoints that consider the needs of all stakeholders, including healthcare providers, policy makers, patients, and families.

Revisiting the applicability of adult early post-operative nausea and vomiting risk factors for the paediatric patient: A prospective study using cotinine levels in children undergoing adenotonsillectomies

Background and Aims:

Post-operative vomiting (POV) in children remains a significant clinical problem. This prospective study aims to investigate the applicability of well-established adult early post-operative nausea and vomiting (PONV) risk factors on paediatric POV after adenotonsillectomies under regulated anaesthetic conditions.

Methods:

After Institutional Review Board approval, 213 children aged 3–10-year-old were enrolled. The participants had pre-operative questionnaires completed, followed protocolised anaesthetic plans and had saliva analysed for cotinine. The primary outcomes were POV as correlated with age, gender, family or personal history of PONV, motion sickness history, opioid use, surgical time, anaesthetic time and environmental tobacco smoke (ETS) exposure, as assessed by cotinine levels and questionnaire reports. Data on analgesics, antiemetics and POV incidence before post-anaesthesia care unit discharge were collected. Statistical analysis was done through multiple logistic regression.

Results:

A total of 200 patients finalised the study. Early POV occurred in 32%. Family history of PONV (odds ratio [OR] = 5.3, P < 0.01) and motion sickness history (OR = 4.4, P = 0.02) were highly significant risk factors. Age reached borderline statistical significance (OR = 1.4, P = 0.05). None of the other factors reached statistical significance.

Conclusion:

Early POV occurs frequently in paediatric patients undergoing adenotonsillectomies. In this paediatric-aged group, the incidence of POV was affected by the family history of PONV, and history of motion sickness. Age, female gender, opioid use, surgical and anaesthetic times did not affect the incidence of POV. ETS exposure, as assessed by cotinine levels and questionnaire reports, had no protective effect on early paediatric POV.

Incidence of postoperative nausea and vomiting following gynecological laparoscopy: A comparison of standard anesthetic technique and propofol infusion

OBJECTIVE

To determine the safety, efficacy, and feasibility of propofol-based anesthesia in gynecological laparoscopies in reducing incidences of postoperative nausea and vomiting compared to a standard anesthesia using thiopentone/isoflurane.

DESIGN

Randomized single-blind (for anesthesia techniques used) and double-blind (for postoperative assessment) controlled trial.

SETTING

Operation theater, postanesthesia recovery room, teaching hospital.

PATIENTS

Sixty ASA (American Society of Anesthesiologists) I and II female patients (aged 20-60 years) scheduled for gynecological laparoscopy were included in the study.

INTERVENTIONS

Patients in Group A received standard anesthesia with thiopentone for induction and maintenance with isoflurane-fentanyl, and those in Group B received propofol for induction and maintenance along with fentanyl. All patients received nitrous oxide, vecuronium, and neostigmine/glycopyrrolate. No patient received elective preemptive antiemetic, but patients did receive it after more than one episode of vomiting.

MEASUREMENTS

Assessment for incidence of postoperative nausea and vomiting as well as other recovery parameters were carried out over a period of 24 hours.

MAIN RESULTS

Six patients (20%) in Group A and seven patients (23.3%) in Group B experienced nausea. Two patients (6.66%) in Group B had vomiting versus 12 (40%) in Group A (p<0.05). Overall, the incidence of emesis was 60% and 30% in Groups A and B, respectively (p<0.05). All patients in Group B had significantly faster recovery compared with those in Group A. No patient had any overt cardiorespiratory complications.

CONCLUSION

Propofol-based anesthesia was associated with significantly less postoperative vomiting and faster recovery compared to standard anesthesia in patients undergoing gynecological laparoscopy.

Effect of sevoflurane anesthesia on the comprehensive mRNA expression profile of the mouse hippocampus

Postoperative nausea and vomiting (PONV) is a common complication after general anesthesia. Recent studies suggested that the hippocampus is involved in PONV. Hypothesising that hippocampal dopaminergic neurons are related to PONV, we examined the comprehensive mRNA profile of the hippocampus, using a sevoflurane-treated mouse model to confirm this. This study was conducted after approval from our institutional animal ethics committee, the Animal Research Center of Sapporo Medical University School of Medicine (project number: 12-033). Eight mice were assigned to two groups: a naïve group and a sevoflurane group (Sev group). In the Sev group, four mice were anesthetised with 3.5% sevoflurane for 1 hour. Subsequently, mRNA was isolated from their hippocampal cells and RNA sequencing was performed on an Illumina HiSeq 2500 platform. Mapping of the quality-controlled, filtered paired-end reads to mouse genomes and quantification of the expression levels of each gene were performed using R software. The Rtn4rl2 gene that encodes the Nogo receptor was the most up-regulated gene in the present study. The expression levels of dopamine receptor genes and the tachykinin gene were increased by sevoflurane exposure, while the genes related to serotonin receptors were not altered by sevoflurane exposure. The expression levels of LIM-homeodomain-related genes were highly down-regulated by sevoflurane. These findings suggest that sevoflurane exposure induces dopaminergic stimulation of hippocampal neurons and triggers PONV, while neuronal inflammation caused by LIM-homeodomain-related genes is down-regulated by sevoflurane.

Transparent Reporting of a multivariable prediction model for Individual Prognosis or Diagnosis (TRIPOD): explanation and elaboration

The TRIPOD (Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis) Statement includes a 22-item checklist, which aims to improve the reporting of studies developing, validating, or updating a prediction model, whether for diagnostic or prognostic purposes. The TRIPOD Statement aims to improve the transparency of the reporting of a prediction model study regardless of the study methods used. This explanation and elaboration document describes the rationale; clarifies the meaning of each item; and discusses why transparent reporting is important, with a view to assessing risk of bias and clinical usefulness of the prediction model. Each checklist item of the TRIPOD Statement is explained in detail and accompanied by published examples of good reporting. The document also provides a valuable reference of issues to consider when designing, conducting, and analyzing prediction model studies. To aid the editorial process and help peer reviewers and, ultimately, readers and systematic reviewers of prediction model studies, it is recommended that authors include a completed checklist in their submission. The TRIPOD checklist can also be downloaded from www.tripod-statement.org.

Postoperative nausea and vomiting in pediatric anesthesia

PURPOSE OF REVIEW

Postoperative nausea and vomiting (PONV) has a high incidence in children and requires prophylactic and therapeutic strategies.

RECENT FINDINGS

PONV can be reduced by the avoidance of nitrous oxide, volatile anesthetics, and the reduction of postoperative opioids. The use of dexamethasone, 5-HT3 antagonists, or droperidol alone is potent, but combinations are even more effective to reduce PONV. Droperidol has a Food and Drug Administration warning. Hence, dexamethasone and 5-HT3 antagonists should be preferred as prophylactic drugs. It is further reasonable to adapt PONV prophylaxis to different risk levels. Prolonged surgery time, inpatients, types of surgery (e.g. strabismus and ear-nose-throat surgery), and patients with PONV in history should be treated as high risk, whereas short procedures and outpatients are to be treated as low risk.

SUMMARY

Concluding from the existing guidelines and data on the handling of PONV in children at least 3 years, the following recommendations are given: outpatients undergoing small procedures should receive a single prophylaxis, outpatients at high risk a double prophylaxis, inpatients with surgery time of more than 30 min and use of postoperative opioids should get double prophylaxis, and inpatients receiving a high-risk surgical procedure or with other risk factors a triple prophylaxis (two drugs and total intravenous anesthesia). Dimenhydrinate can be used as a second choice, whereas droperidol and metoclopramide can only be recommended as rescue therapy.

Development and validation of a risk score to predict the probability of postoperative vomiting in pediatric patients: the VPOP score

BACKGROUND

Few data are available in the literature on risk factors for postoperative vomiting (POV) in children.

OBJECTIVE

The aim of the study was to establish independent risk factors for POV and to construct a pediatric specific risk score to predict POV in children.

METHODS

Characteristics of 2392 children operated under general anesthesia were recorded. The dataset was randomly split into an evaluation set (n = 1761), analyzed with a multivariate analysis including logistic regression and backward stepwise procedure, and a validation set (n = 450), used to confirm the accuracy of prediction using the area under the receiver operating characteristic curve (ROCAUC ), to optimize sensitivity and specificity.

RESULTS

The overall incidence of POV was 24.1%. Five independent risk factors were identified: stratified age (>3 and <6 or >13 years: adjusted OR 2.46 [95% CI 1.75-3.45]; ≥6 and ≤13 years: aOR 3.09 [95% CI 2.23-4.29]), duration of anesthesia (aOR 1.44 [95% IC 1.06-1.96]), surgery at risk (aOR 2.13 [95% IC 1.49-3.06]), predisposition to POV (aOR 1.81 [95% CI 1.43-2.31]), and multiple opioids doses (aOR 2.76 [95% CI 2.06-3.70], P < 0.001). A simplified score was created, ranging from 0 to 6 points. Respective incidences of POV were 5%, 6%, 13%, 21%, 36%, 48%, and 52% when the risk score ranged from 0 to 6. The model yielded a ROCAUC of 0.73 [95% CI 0.67-0.78] when applied to the validation dataset.

CONCLUSIONS

Independent risk factors for POV were identified and used to create a new score to predict which children are at high risk of POV.

Strategies for preventing side effects of systemic opioid in postoperative pediatric patients

BACKGROUND AND OBJECTIVES

Opioid is the gold standard for treating moderate-to-severe pain in pediatric patients. However, its undesirable side effects lead to unsatisfied postoperative pain management outcome (Pediatr Anesth, 17, 2007, 756). The most commonly reported opioid-related side effects are vomiting (40%), pruritus (20-60%) (Anesthesiology, 77, 1992, 162; Drugs, 67, 2007, 2323), and constipation (15-90%) (Int J Clin Pract, 61, 2007, 1181). The potential life-threatening adverse event, respiratory depression, is less common (0.0013%) (Pediatr Anesth, 20, 2010, 119). The aim of this review was to evaluate prevention strategies that have been shown to decrease opioid side effects in pediatric patients during the postoperative period.

METHODS

Literature searches were conducted from 1984 to February 2013. Meta-analysis, systematic review, and randomized, placebo-controlled studies were obtained from PubMed and the Cochrane Library. The medical subject heading (MeSH) terms were opioid analgesics, adverse effects, pediatrics, children, side effects, and postoperative pain.

RESULTS AND CONCLUSION

Data from 62 studies were reviewed. The strategies that could effectively prevent and reduce opioid side effects in pediatric patients during the postoperative period included minimizing the amount of opioid consumption by a multimodal approach, opioid titration, using local anesthetic techniques and providing the specific prophylaxis for each side effect.

No Superiority of Granisetron Over Metoclopramide in Prevention of Post-operative Nausea and Vomiting: A Randomized Clinical Trial

PURPOSE

Post-operative nausea and vomiting (PONV) is considered as one of the most disturbing sequels of surgeries under general anesthesia, which if not controlled appropriately increases post-operative morbidity, nursing burden, and general healthcare costs. In this study, we compared granisetron with its brand Kytril(®) and also with metoclopramide regarding PONV management.

METHODS

A total of 180 obstetrics and gynecology patients who underwent surgeries under general anesthesia participated in this prospective study at the Dr. Shariati Teaching Hospital, Tehran, Iran. The patients were randomly assigned to single-dose generic granisetron (40 mcg/kg), Kytril(®) (40 mcg/kg), or metoclopramide (0.2 mg/kg) at the end of the surgery. Two episodes of emetic symptoms (nausea and vomiting) were recorded by a gynecologist who had no knowledge of which treatment each patient had received. This gynecologist observed the patients at three different intervals: 0-6, 6-12, and 12-18 h post-surgery.

RESULTS

One hundred and thirty-seven patients (76.1 %) underwent hysterectomy and 40 patients (22.2 %) underwent myomectomy. Each group consisted of 60 patients (33 %). The incidence of vomiting in the first 6, 12, and 18 h post-surgery was 22, 15.2, and 13.3 % for granisetron; 18.6, 10, and 8.3 % for Kytril; and 22, 11.9, and 5 % for generic metoclopramide, respectively. There was no significant difference in the incidence of PONV with any of these agents.

CONCLUSIONS

All three anti-nausea and vomiting agents, granisetron, its brand (Kytril), and generic metoclopramide, have a similar effect to manage PONV in obstetrics and gynecological surgeries. Trial registration This trial is registered with www.irct.ir, number IRCT201010134927N1.

Postoperative vomiting in pediatric oncologic patients: prediction by a fuzzy logic model

OBJECTIVE

To report a fuzzy logic mathematical model to predict postoperative vomiting (POV) in pediatric oncologic patients and compare with preexisting scores.

BACKGROUND

Although POV has a high incidence in children and may decrease parental satisfaction after surgeries, there is only one specific score that predicts POV in children: the Eberhart's score. In this study, we report a fuzzy model that intends to predict the probability of POV in pediatric oncologic patients. Fuzzy logic is a mathematical theory that recognizes more than simple true and false values and takes into account levels of continuous variables such as age or duration of the surgery. The fuzzy model tries to account for subjectiveness in the variables.

METHODS

Preoperative potential risk factors for POV in 198 children (0-19 year old) with malignancies were collected and analyzed. Data analysis was performed with the chi-square test and logistic regression to evaluate probable risk factors for POV. A system based on fuzzy logic was developed with the risk factors found in the logistic regression, and a computational interface was created to calculate the probability of POV.

RESULTS

The model showed a good performance in predicting POV. After the analysis, the model was compared with Eberhart's score in the same population and showed a better performance.

CONCLUSIONS

The fuzzy score can predict the chance of POV in children with cancer with good accuracy, allowing better planning for postoperative prophylaxis of vomiting. The computational interface is available for free download at the internet and is very easy to use.

Prophylaxis of postoperative nausea and vomiting in adolescent patients: a review with emphasis on combination of fixed-dose ondansetron and transdermal scopolamine

Postoperative nausea and vomiting (PONV) is a relatively common occurrence (20–30%) that delays discharge and, if persistent, can lead to serious complications. The incidence of PONV is a function of patient characteristics, the type and duration of surgery, the type of anesthesia, and the choice of pre-, intra-, and postoperative pharmacotherapy. There are no completely effective antiemetic agents for this condition, but recommendations for treatment strategies are separately available for pediatric and adult patients. Left unclear is whether adolescents should be guided by the pediatric or the adult recommendations. We review the developmental physiology of the relevant physiological factors (absorption, distribution, metabolism, and elimination). We also review the clinical evidence regarding the safety and efficacy of a fixed-dose combination of ondansetron (4 mg, i.v.) and transdermal scopolamine (1.5 mg).

Nausea and vomiting after surgery under general anesthesia: an evidence-based review concerning risk assessment, prevention, and treatment

BACKGROUND

The German-language recommendations for the management of postoperative nausea and vomiting (PONV) have been revised by an expert committee. Major aspects of this revision are presented here in the form of an evidence-based review article.

METHODS

The literature was systematically reviewed with the goal of revising the existing recommendations. New evidence-based recommendations for the management of PONV were developed, approved by consensus, and graded according to the scheme of the Scottish Intercollegiate Guidelines Network (SIGN).

RESULTS

The relevant risk factors for PONV include female sex, nonsmoker status, prior history of PONV, motion sickness, use of opioids during and after surgery, use of inhalational anesthetics and nitrous oxide, and the duration of anesthesia. PONV scoring systems provide a rough assessment of risk that can serve as the basis for a risk-adapted approach. Risk-adapted prophylaxis, however, has not been shown to provide any greater benefit than fixed (combination) prophylaxis, and PONV risk scores have inherent limitations; thus, fixed prophylaxis may be advantageous. Whichever of these two approaches to manage PONV is chosen, high-risk patients must be given multimodal prophylaxis, involving both the avoidance of known risk factors and the application of multiple validated and effective antiemetic interventions. PONV should be treated as soon as it arises, to minimize patient discomfort, the risk of medical complications, and the costs involved.

CONCLUSION

PONV lowers patient satisfaction but is treatable. The effective, evidence-based measures of preventing and treating it should be implemented in routine practice.

Prognostic models and risk scores: can we accurately predict postoperative nausea and vomiting in children after craniotomy?

Postoperative nausea and vomiting (PONV) is a problem for many children after craniotomy. Prognostic models and risk scores help identify who is at risk for an adverse event such as PONV to help guide clinical care. The purpose of this article is to assess whether an existing prognostic model or risk score can predict PONV in children after craniotomy. The concepts of transportability, calibration, and discrimination are presented to identify what is required to have a valid tool for clinical use. Although previous work may inform clinical practice and guide future research, existing prognostic models and risk scores do not appear to be options for predicting PONV in children undergoing craniotomy. However, until risk factors are further delineated, followed by the development and validation of prognostic models and risk scores that include children after craniotomy, clinical judgment in the context of current research may serve as a guide for clinical care in this population.

[Nausea and vomiting in the postoperative phase. Expert- and evidence-based recommendations for prophylaxis and therapy]

There are no consensus guidelines for the management of postoperative nausea and vomiting (PONV) in German speaking countries. This meeting was intended to develop such guidelines on which individual health care facilities can derive their specific standard operating procedures (SOPs). Anesthesiologists reviewed published literature on key topics which were subsequently discussed during two meetings. It was emphasized that recommendations were based on the best available evidence. The clinical relevance of individual risk factors should be viewed with caution since even well proven risk factors, such as the history of PONV, do not allow the identification of patients at risk for PONV with a satisfactory sensitivity or specificity. A more useful approach is the use of simplified risk scores which consider the presence of several risk factors simultaneously. Most individual antiemetic interventions for the prevention of PONV have comparable efficacy with a relative risk reduction of about 30%. This appears to be true for total intravenous anesthesia (TIVA) as well as for dexamethasone and other antiemetics; assuming a sufficiently high, adequate and equipotent dosage which should be weight-adjusted in children. As the relative risk reduction is context independent and similar between the interventions, the absolute risk reduction of prophylactic interventions is mainly dependent on the patient's individual baseline risk. Prophylaxis is thus rarely warranted in patients at low risk, generally needed in patients with a moderate risk and should include a multimodal approach in patients at high risk for PONV. Therapeutic interventions of PONV should be administered promptly using an antiemetic which has not been used before. The group suggests algorithms where prophylactic interventions are mainly dependent on the patient's risk for PONV. These algorithms should provide evidence-based guidelines allowing the development of SOPs/policies which take local circumstances into account.

Mechanisms underlying postoperative nausea and vomiting and neurotransmitter receptor antagonist-based pharmacotherapy

Postoperative nausea and vomiting (PONV) is one of the most common and distressing complications following surgery, and understanding the mechanism(s) underlying PONV is essential to providing optimal prophylaxis and/or treatment of PONV. The knowledge base of PONV physiology has significantly expanded over the past decade. This article reviews the risk factors for the development of PONV and the mechanisms of action of pharmacological agents (including antagonists of serotonin 5-HT(3), dopaminergic D(2), histamine H(1), muscarinic cholinergic, opioid and neurokinin NK(1) receptors) for the management (i.e. prophylaxis and treatment) of PONV. NK(1) receptor antagonists, with their unique mechanism of action, are a particularly promising area of research as they appear to be efficacious in preventing PONV during both the early and the late postoperative periods. A successful PONV management strategy includes: (i) identifying patients at risk; (ii) keeping the baseline risk low; and (iii) using a combination of antiemetics acting on different receptors in moderate- to high-risk patients.

Klinische Pharmakologie

The rule of three describes three steps which are needed for an optimal control of postoperative nausea and vomiting (PONV). Firstly, patients at high risk of PONV need to be identified. Knowledge about predictive factors may help to identify patients who may best profit from prophylaxis and those where prophylaxis is not worthwhile since the baseline risk is too low. Secondly, for high-risk patients a low emetogenic anaesthesia technique should be chosen, and thirdly, these patients should additionally receive a prophylactic antiemetic cocktail. At present, butyrophenones (e.g. droperidol), 5-HT(3) receptor antagonists ("setrons") and steroids (e.g. dexamethasone) are the most rational choices for the antiemetic cocktail. Although there is strong evidence that there is an additive effect when these antiemetics are combined, economic constraints may influence the number of antiemetics that are eventually chosen. Identification of high-risk patients remains the most difficult part of the rule of three. Risk scores have been proposed and have been widely implemented in clinical practice. The sensitivity and specificity of such scores, however, remain particularly unsatisfactory. Unless more reliable risk scores are developed, aggressive treatment of established PONV symptoms may be more useful and more cost-effective than prophylaxis for many patients.

[Prevention and treatment of postoperative nausea and vomiting in children. An evidence-based approach]

Significant improvement towards an efficacious control of postoperative nausea and vomiting (PONV) has taken place recently. These improvements may be summarised using the "rule of three". That rule describes a pragmatic and rational approach of PONV control. First, identify the patient at risk using predictive factors. Second, modify the anaesthesia technique to keep the baseline risk as low as possible. Third, administer antiemetics rationally, considering their degree of efficacy, their risk, and their potential additive effects. Despite considerable research efforts, identifying the patient at high risk of PONV remains a difficult task. However, today, we understand the degree of efficacy, dose-responsiveness, and adverse effects of most antiemetics. None of those molecules should be regarded as being universally efficacious, there is no gold standard, and, when used alone, their degree of efficacy is limited. Thus, they should be combined for improved efficacy. Among the most promising molecules are butyrophenones (droperidol, haloperidol), 5-HT(3) receptor antagonists (ondansetron, dolasetron, tropisetron, granisetron), and steroids (for instance, dexamethasone). The lack of relevant paediatric PONV data remains a major drawback and is highly unsatisfactory. Hopefully, future research will further improve the control of PONV not only in adults but also in children.

Motion sickness as a predictor of postoperative vomiting in children aged 1-16 years

BACKGROUND

Motion sickness (MS) may be a risk factor for postoperative vomiting (POV), but its independent predictive value in children is not known.

METHODS

A convenience sample of 70 consecutive patients aged 1-16 years scheduled for elective surgery were questioned, a history of MS was sought and patients were observed for the subsequent development of POV.

RESULTS

The overall incidence of POV was 29%. Fourteen children (20%) had a history of MS; MS-positive children were more likely to vomit than those who were MS-negative (P < 0.01). The type of surgery, use of opioids or prophylactic antiemetics did not differ significantly between the groups. The sensitivity of MS as a predictor of POV is 45% and the specificity 90%, giving a positive predictive value of 64.3% and a negative predictive value of 80.4%.

CONCLUSION

Motion sickness is associated with POV in this group of children, but its positive predictive value is fairly low.

Risk Factors for Postoperative Nausea and Vomiting

Knowledge of postoperative nausea and vomiting (PONV) risk factors allows anesthesiologists to optimize the use of prophylactic regimens. Modern PONV risk research began in the 1990s with publication of studies using logistic regression analysis to simultaneously identify multiple independent PONV predictors and publication of meta-analyses and systematic reviews. This literature shows that female gender post-puberty, nonsmoking status, history of PONV or motion sickness, childhood after infancy and younger adulthood, increasing duration of surgery, and use of volatile anesthetics, nitrous oxide, large-dose neostigmine, or intraoperative or postoperative opioids are well established PONV risk factors. Possible risk factors include history of migraine, history of PONV or motion sickness in a child's parent or sibling, better ASA physical status, intense preoperative anxiety, certain ethnicities or surgery types, decreased perioperative fluids, crystalloid versus colloid administration, increasing duration of anesthesia, general versus regional anesthesia or sedation, balanced versus total IV anesthesia, and use of longer-acting versus shorter-acting opioids. Early-phase menstruation, obesity and lack of supplemental oxygen are disproved risk factors. Current risk scoring systems have approximately 55%-80% accuracy in predicting which patient groups will suffer PONV. Further research examining genetic and under-investigated clinical patient characteristics as potential risk factors, and involving outpatients and children, should improve predictive systems.

PONV: a problem of inhalational anaesthesia?

Even nowadays every third or fourth patient suffers from postoperative nausea and vomiting (PONV) after general anaesthesia with volatile anaesthetics. There is now strong evidence that volatile anaesthetics are emetogenic and that there are no meaningful differences between halothane, enflurane, isoflurane, sevoflurane, and desflurane in this respect. However, when propofol is substituted for volatile anaesthetics the risk for PONV is reduced by only about one fifth, indicating that there are other even more important causes for PONV following general anaesthesia. A main causative factor might be the use of perioperative opioids, but their impact--relative to other factors including volatile anaesthetics--has never been quantified. Patient-specific risk factors have also been shown to be clinically relevant; they are therefore included in the calculation of simplified risk scores that allow prediction of a patient's risk independent of the type of surgery. Although controversial, the well-known different incidences following certain types of surgery are most likely caused by patient-specific and anaesthesia-related risk factors. There is a common consensus that prophylaxis with anti-emetic strategies is rarely justified when the risk of PONV is low, while it is warranted in case of imminent medical risk associated with vomiting or in a patient with a high risk for PONV. A recently published large multicentre trial of factorial design, IMPACT, has demonstrated that various anti-emetic strategies are associated with a very similar and constant relative reduction rate of about 25-30% and that the main predictor for the efficacy of prophylaxis is the patient's risk for PONV. Interestingly, all anti-emetics (dexamethasone, droperidol and ondansetron) work independently, so that their combined benefit can be derived directly from the single effects. The effectiveness of the anti-emetics was also independent of a variety of risk factors, including volatile anaesthetics. This means that any anti-emetic prophylaxis for PONV induced by volatile anaesthetics is equally effective. Of course, the most logical approach for prevention would be the omission of volatile anaesthetics and nitrous oxide using a total intravenous anaesthesia with propofol. However, since volatile anaesthetics are probably not the most important risk factors, it might be even better--if appropriate--to avoid general anaesthesia by using a regional, opioid-free anaesthesia if PONV is a serious problem.