The 2014 consensus guidelines for the management of postoperative nausea and vomiting: a leapfrog towards a postoperative nausea and vomiting-free hospital

Postoperative nausea and vomiting: is the big little problem becoming a smaller little problem?

Postoperative nausea and vomiting (PONV) has been identified as a big (very frequently encountered) little (not linked to life-threatening outcomes) problem. Traditional drugs (dexamethasone, droperidol or similar drugs, serotonin receptor antagonists) each have significant but limited effect, leading to an increasing use of combination therapies. High-risk patients, often identified through use of risk scoring systems, remain with a significant residual risk despite combining up to three traditional drugs. A recent correspondence in this Journal proposes the use of up to five anti-emetic drugs to further minimise the risk. This disruptive strategy was supported by favourable initial results, absence of side-effects and lower acquisition costs of the added new drugs (aprepitant and palonosetron) because of their recent loss of patent protection. These results are provocative and hypothesis generating, but need confirmation and do not warrant immediate changes in clinical practice. The next steps will also necessitate wider implementation of protocols protecting patients from PONV and a search for additional drugs and techniques aimed at treating established PONV.

Postoperative/postdischarge nausea and vomiting: evidence-based prevention and treatment

PURPOSE OF REVIEW

Postoperative/postdischarge nausea and vomiting (PONV/PDNV) remains a relevant issue in perioperative care. Especially in outpatient surgery, PONV can prevent discharge or lead to unplanned readmission.

RECENT FINDINGS

Evidence on prophylaxis and treatment of PONV is growing, but implementation remains poor.

SUMMARY

A liberal, universal PONV management is now endorsed by the guidelines. Specific evidence concerning prevention and (at-home) treatment of PDNV is still scarce.

Efficacy of evidence-based institutional protocol for prevention of postoperative nausea and vomiting: A prospective observational study

BACKGROUND

Postoperative nausea and vomiting (PONV) is the second most common complaint in the postoperative period, often resulting in increased post anaesthesia care unit (PACU) and hospital stay. Translation of knowledge into consistent practice was considered a major gap. Hence, the present study was undertaken to test the efficacy of locally developed evidence-based institutional protocol for prevention of PONV.

METHODS

Phase I consisted of determining the baseline incidence of PONV before introduction of the institutional protocol for PONV prophylaxis. In phase II, educational sessions for anaesthesiologists for PONV prevention and treatment were conducted, after which an institutional protocol was introduced. In phase III, this protocol was implemented, and the incidence of PONV was recorded using the same methodology as in phase I. The rate of adherence to the institutional protocol was also recorded.

RESULTS

The incidence of postoperative nausea (PON) dropped significantly from 32.5% in phase I to 20% in phase III (p = 0.033). Similarly, the incidence of postoperative vomiting (POV) decreased from 20.5% in phase I to 9.1% in phase III (p = 0.016). Of all anaesthesiologists, 78.18% were noted to adhere to the protocol in phase III. Incidence of PON and POV was significantly less in patients in whom PONV prophylaxis was administered in adherence to protocol (8.3% vs 57.7%, p < 0.001; 3.6% vs 26.9%, p < 0.001, respectively).

CONCLUSION

Evidence-based institutional protocols are effective in significantly reducing the incidence of PONV in adults undergoing noncardiac surgery under anaesthesia.

CLINICAL TRIAL NUMBER AND REGISTRY URL

The trial was registered with Clinical Trials Registry of India (http:/ctri.nic.in) (CTRI/2015/12/006432).

Isoflurane not at the expense of postoperative nausea and vomiting in cardiac anesthesia - an observational study

OBJECTIVES

Inhalative anesthesia is of common use, but is generally known to potentiate postoperative nausea and vomiting (PONV). With an internal change of anesthesia regimen from total intravenous anesthesia (TIVA) to isoflurane (in terms of myocardial protection) in cardiac anesthesia a higher incidence of PONV was to be expected. Therefore, we evaluated the incidence of PONV after the simultaneous implementation of PONV prophylaxis.

METHODS

The incidence of PONV, prospectively assessed in 197 cardiac surgery patients (68 y ± 10.4, 66.5% male) having isoflurane plus dual PONV prophylaxis with dexamethasone and droperidol, was compared with previous data of 190 controls (67 y ± 9.6, 71% male) having TIVA without and with single or dual PONV prophylaxis (n = 64 dexamethasone and droperidol, n = 25 dexamethasone, n = 101 only TIVA), and the Apfel-scoring (0-4 depending on PONV-risk). DRKS00014275. Statistics: Chi²-test, p < .05 (Bonferroni).

RESULTS

The incidence of PONV under isoflurane with antiemetic prophylaxis was 20.8% (95% confidence interval (CI) 15.4; 27.4) compared to 30.5% (95%CI 24; 37.6) under TIVA (p = .029; dexamethasone and droperidol 23.4% (95%CI 13.8; 35.7); dexamethasone 32% (95%CI 14.9; 53.5); only TIVA 34.7% (95%CI 25.5; 44.8)), but was not lower in high-risk patients than predicted according to Apfel-scoring 4 (71.4 vs. 78%).

CONCLUSION

In cardiac anesthesia, the use of isoflurane is not at the expense of PONV when using a risk-independent two-drug-prophylaxis. It is even beneficial resulting surprisingly in a lower incidence of PONV than under TIVA unless with and without prophylaxis. Patients with the highest risk for PONV and receiving isoflurane should receive a third antiemetic prophylactic drug.

Oral mosapride can provide additional anti-emetic efficacy following total joint arthroplasty under general anesthesia: a randomized, double-blinded clinical trial

Background

We sought to determine (1) whether the addition of prophylactic oral mosapride to a protocol including dexamethasone and ondansetron further reduces postoperative nausea and vomiting (PONV) compared with ondansetron alone or the combination of both; (2) whether preemptive application of oral mosapride provides additional clinical benefits for bowel function and appetite, thus improving functional recovery.

Methods

We randomized 240 patients undergoing total hip and knee arthroplasty to receive placebo (Control, n = 80), dexamethasone (10 mg) before anesthesia induction (Dexa, n = 82), or dexamethasone (10 mg) before anesthesia induction as well as oral mosapride (5 mg) before and after surgery (Mosa+Dexa, n = 78). Patients were assessed at 0–6, 6–12, 12–24, and 24–48 h postoperatively. Primary outcomes were incidence and severity of PONV as well as complete response. Secondary outcomes were appetite, time until first defecation and ambulation, patient satisfaction score, and length of hospital stay.

Results

Mosa+Dexa patients showed significantly lower incidence of nausea at 6–12 h (3.8%) and over the entire evaluation period (6.4%), as well as a higher rate of complete response (89.7%) than other patients. Mosa+Dexa patients required less time to achieve first defecation and ambulation, they were hospitalized for shorter time, and they were more satisfied with clinical care.

Conclusion

Addition of oral mosapride further reduced incidence of PONV, especially postoperative nausea, during 6–12 h postoperatively. Moreover, preemptive application of oral mosapride can further improve appetite, bowel function, ambulation and length of hospital stay.

Trial registration

The study protocol was registered at the Chinese Clinical Trial Registry (ChiCTR1800015896), prospectively registered on 27/04/2018.

Acupuncture PC6 for postoperative nausea and vomiting at different times: A protocol for systematic review and meta analysis

BACKGROUND

Postoperative nausea and vomiting (PONV) is a condition that commonly following anesthesia and surgery, antiemetics can lead to some side effects in treating PONV. Acupuncture PC6(Neiguan) has been widely used in the prevention and treatment of postoperative nausea and vomiting. However, there still exists controversy towards its effectiveness, appropriate, and effective intervention time. We, therefore, design this meta-analysis to assess the effectiveness and confirm the optimal time of acupuncture PC6 point for PONV.

METHODS

The following electronic databases will be searched from their inception to April 2020, including PubMed, Cochrane Library, EMBASE, Web of Science, WHO International Clinical Trials Registry Platform, Chinese National Knowledge Infrastructure, WanFang Database, Chinese Biomedical Literature Database, the Chongqing VIP Chinese Science, and Technology Periodical Database. All randomized controlled trials in English or Chinese involving acupuncture PC6 for patients with PONV will be included. Two reviewers will independently responsible for the data extraction, study selection, risk of bias assessment and assessment of study quality. The primary outcome was the number of postoperative nausea, postoperative vomiting and PONV during 0 to 6 hours and after 6 hours of the postoperatively. The secondary outcome is the number of people with side effects and the use of rescue therapy. The meta-analysis will be conducted using RevMan V.5.3.5 statistical software.

RESULTS

This systematic review will evaluate the efficacy and appropriateness time of acupuncture PC6 in the treatment of PONV.

CONCLUSION

This study will provide high-quality current evidence of the effectiveness and optimal time of acupuncture PC6 point for the patient with PONV.

ETHICS AND DISSEMINATION

Ethical approval is not required; this review will not involve individuals' information. The results will be published in a peer-reviewed publication or disseminated in relevant conferences.

INPLASY REGISTRATION NUMBER

DOI 10.37766/inplasy2020.4.0012.

Risk-adapted strategy or universal multimodal approach for PONV prophylaxis?

The issue of postoperative nausea and vomiting (PONV) remains important in surgical practice, contributing to patient distress, slower recovery, and increased use of healthcare resources. Many surgical patients report it to be a worse problem than pain. Numerous findings of research indicate that PONV significantly affects patients' well-being and is among the important determinants of patient satisfaction with perioperative care. Numerous investigations have confirmed the efficacy of combining pharmacological interventions indicating that PONV is a clinical complication that is in principle avoidable. Nonetheless, PONV continues to be bothersome for too many patients. Thus, perhaps the biggest challenge across the field is to achieve a uniformly high standard of PONV management using the currently available resources. Although a risk-adapted approach has been advocated in the past, the current trend incorporated in clinical guidelines support a more liberal approach of multimodal antiemetic prevention. The current article emphasizes pros and cons of the various approaches to PONV prophylaxis and depicts most promising strategies to achieve a "PONV-free hospital."

Unplanned readmission after outpatient laparoscopic cholecystectomy

BACKGROUND

Readmission after surgery has been considered as a measure of quality of hospital and surgical care. This study aims to investigate unplanned readmission after laparoscopic cholecystectomy.

METHODS

The NSQIP database was used to investigate 30 days unplanned readmission after laparoscopic cholecystectomy. Multivariate analysis was used to identify predictors of readmission.

RESULTS

We found a total of 117,248 patients who underwent outpatient laparoscopic cholecystectomy during 2014-2016. Of these 3315 (2.8%) had unplanned readmission. Overall, 90% of readmitted patients were discharged after one day of hospitalization. Pain (14.07%) followed by unspecified symptoms including fever, nausea, vomiting, ileus was the most common reason for readmission. After adjustment, factors such as renal failure on dialysis (AOR: 2.26, P < 0.01), discharge to a facility (AOR: 1.93, P < 0.01), and steroid use for chronic condition (AOR: 1.51, P < 0.01), were associated with unplanned readmission.

CONCLUSION

Overall, 2.8% of the patients undergoing outpatient laparoscopic cholecystectomy are readmitted to the hospital. Most of such patients are discharged after one day of hospitalization. Unspecified symptoms such as pain and vomiting were the most common reasons for readmission. Readmission strongly influences patients' comorbid factors and it is not a reliable measurement of quality of hospital and surgical care.

A pharmacological profile of intravenous amisulpride for the treatment of postoperative nausea and vomiting

INTRODUCTION

The issue of postoperative nausea and vomiting (PONV) remains important in surgical practice, contributing to patient distress, slower recovery, and increased use of healthcare resources. Many surgical patients report it to be a worse problem than the pain. New antiemetics of different classes are still needed to help manage PONV effectively, especially the treatment of established PONV after the failure of common prophylactic antiemetics such as 5-HT₃-antagonists and corticosteroids. Intravenous amisulpride, a drug with a long history of safe use in oral form as an antipsychotic, has recently been approved in the US (trade name: Barhemsys) as an intravenous antiemetic for the prevention and treatment of PONV.

AREAS COVERED

This review article summarizes the published data on the clinical pharmacology, safety, and efficacy of intravenous amisulpride as an antiemetic, supplemented by published data on oral amisulpride, where relevant to the intravenous form. Literature was obtained via the PubMed search terms 'intravenous amisulpride' and 'amisulpride AND safety.' Both primary and secondary pharmacology are covered, along with clinical pharmacokinetics (distribution, metabolism, and excretion). The review of clinical safety and efficacy includes data from four studies in the prevention of PONV, two in the treatment of PONV and two investigating effects on the QT interval of the electrocardiogram in healthy volunteers.

EXPERT OPINION

Given the importance of sufficient PONV prevention for patients and the healthcare system, the availability of intravenous amisulpride is helpful, restoring the dopamine-antagonist class as a potential mainstay in both combination prophylaxis and treatment.

Prevention of Opioid-Induced Nausea and Vomiting During Treatment of Moderate to Severe Acute Pain: A Randomized Placebo-Controlled Trial Comparing CL-108 (Hydrocodone 7.5 mg/Acetaminophen 325 mg/Rapid-Release, Low-Dose Promethazine 12.5 mg) with Conventional Hydrocodone 7.5 mg/Acetaminophen 325 mg

OBJECTIVES

To evaluate the prevention of opioid-induced nausea and vomiting (OINV) and the relief of moderate to severe acute pain by CL-108, a novel drug combining a low-dose antiemetic (rapid-release promethazine 12.5 mg) with hydrocodone 7.5 mg/acetaminophen 325 mg (HC/APAP) was used.

METHODS

This was a multicenter, randomized, double-blind, placebo- and active-controlled multidose study. After surgical extraction of two or more impacted third molar teeth (including at least one mandibular impaction), 466 patients with moderate to severe pain (measured on a categorical pain intensity scale [PI-CAT]) were randomized to CL-108, HC/APAP, or placebo. Over the next 24 hours, patients used the PI-CAT to assess pain at regular intervals whereas nausea, vomiting, and other opioid-related side effects were also assessed prospectively. Study medications were taken every four to six hours as needed; supplemental rescue analgesic and antiemetic medications were permitted. Co-primary end points were the incidence of OINV and the time-weighted sum of pain intensity differences over 24 hours (SPID24).

RESULTS

Relative to HC/APAP treatment alone, CL-108 treatment reduced OINV by 64% (P < 0.001). Treatment with CL-108 significantly reduced pain intensity compared with placebo (SPID24 = 16.2 vs 3.5, P < 0.001). There were no unexpected or serious adverse events.

CONCLUSIONS

CL-108 is a safe and effective combination analgesic/antiemetic for the prevention of OINV during treatment of moderate to severe acute pain.

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.

Adverse side effects of dexamethasone in surgical patients

BACKGROUND

In the perioperative period, dexamethasone is widely and effectively used for prophylaxis of postoperative nausea and vomiting (PONV), for pain management, and to facilitate early discharge after ambulatory surgery.Long-term treatment with steroids has many side effects, such as adrenal insufficiency, increased infection risk, hyperglycaemia, high blood pressure, osteoporosis, and development of diabetes mellitus. However, whether a single steroid load during surgery has negative effects during the postoperative period has not yet been studied.

OBJECTIVES

To assess the effects of a steroid load of dexamethasone on postoperative systemic or wound infection, delayed wound healing, and blood glucose change in adult surgical patients (with planned subgroup analysis of patients with and without diabetes).

SEARCH METHODS

We searched MEDLINE, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL), in the Cochrane Library, and the Web of Science for relevant articles on 29 January 2018. We searched without language or date restriction two clinical trial registries to identify ongoing studies, and we handsearched the reference lists of relevant publications to identify all eligible trials.

SELECTION CRITERIA

We searched for randomized controlled trials comparing an incidental steroid load of dexamethasone versus a control intervention for adult patients undergoing surgery. We required that studies include a follow-up of 30 days for proper assessment of the number of postoperative infections, delayed wound healing, and the glycaemic response.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened studies for eligibility, extracted data from relevant studies, and assessed all included studies for bias. We resolved differences by discussion and pooled included studies in a meta-analysis. We calculated Peto odds ratios (ORs) for dichotomous outcomes and mean differences (MDs) for continuous outcomes. Our primary outcomes were postoperative systemic or wound infection, delayed wound healing, and glycaemic response within 24 hours. We created a funnel plot for the primary outcome postoperative (wound or systemic) infection. We used GRADE to assess the quality of evidence for each outcome.

MAIN RESULTS

We included in the meta-analysis 37 studies that included adults undergoing a large variety of surgical procedures (i.e. abdominal surgery, cardiac surgery, neurosurgery, and orthopaedic surgery). We excluded one previously included study, as this study was recently retracted. Age range of participants was 18 to 80 years. There is probably little or no difference in the risk of postoperative (wound or systemic) infection with dexamethasone compared with no treatment, placebo, or active control (ramosetron, ondansetron, or tropisetron) (Peto OR 1.01, 95% confidence interval (CI) 0.80 to 1.27; 4603 participants, 26 studies; I² = 32%; moderate-quality evidence). The effects of dexamethasone on delayed wound healing are unclear because the wide confidence interval includes both meaningful benefit and harm (Peto OR 0.99, 95% CI 0.28 to 3.43; 1072 participants, eight studies; I² = 0%; low-quality evidence). Dexamethasone may produce a mild increase in glucose levels among participants without diabetes during the first 12 hours after surgery (MD 13 mg/dL, 95% CI 6 to 21; 10 studies; 595 participants; I² = 50%; low-quality evidence). We identified two studies reporting on glycaemic response after dexamethasone in participants with diabetes within 24 hours after surgery (MD 32 mg/dL, 95% CI 15 to 49; 74 participants; I² = 0%; very low-quality evidence).

AUTHORS' CONCLUSIONS

A single dose of dexamethasone probably does not increase the risk for postoperative infection. It is uncertain whether dexamethasone has an effect on delayed wound healing in the general surgical population owing to imprecision in trial results. Participants with increased risk for delayed wound healing (e.g. participants with diabetes, those taking immunosuppressive drugs) were not included in the randomized studies reporting on delayed wound healing included in this meta-analysis; therefore our findings should be extrapolated to the clinical setting with caution. Furthermore, one has to keep in mind that dexamethasone induces a mild increase in glucose. For patients with diabetes, very limited evidence suggests a more pronounced increase in glucose. Whether this influences wound healing in a clinically relevant way remains to be established. Once assessed, the two studies awaiting classification and three that are ongoing may alter the conclusions of this review.

Adverse side effects of dexamethasone in surgical patients

BACKGROUND

In the perioperative period, dexamethasone is widely and effectively used for prophylaxis of postoperative nausea and vomiting (PONV), for pain management, and to facilitate early discharge after ambulatory surgery.Long-term treatment with steroids has many side effects, such as adrenal insufficiency, increased infection risk, hyperglycaemia, high blood pressure, osteoporosis, and development of diabetes mellitus. However, whether a single steroid load during surgery has negative effects during the postoperative period has not yet been studied.

OBJECTIVES

To assess the effects of a steroid load of dexamethasone on postoperative systemic or wound infection, delayed wound healing, and blood glucose change in adult surgical patients (with planned subgroup analysis of patients with and without diabetes).

SEARCH METHODS

We searched MEDLINE, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL), in the Cochrane Library, and the Web of Science for relevant articles on 29 January 2018. We searched without language or date restriction two clinical trial registries to identify ongoing studies, and we handsearched the reference lists of relevant publications to identify all eligible trials.

SELECTION CRITERIA

We searched for randomized controlled trials comparing an incidental steroid load of dexamethasone versus a control intervention for adult patients undergoing surgery. We required that studies include a follow-up of 30 days for proper assessment of the number of postoperative infections, delayed wound healing, and the glycaemic response.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened studies for eligibility, extracted data from relevant studies, and assessed all included studies for bias. We resolved differences by discussion and pooled included studies in a meta-analysis. We calculated Peto odds ratios (ORs) for dichotomous outcomes and mean differences (MDs) for continuous outcomes. Our primary outcomes were postoperative systemic or wound infection, delayed wound healing, and glycaemic response within 24 hours. We created a funnel plot for the primary outcome postoperative (wound or systemic) infection. We used GRADE to assess the quality of evidence for each outcome.

MAIN RESULTS

We included in the meta-analysis 38 studies that included adults undergoing a large variety of surgical procedures (i.e. abdominal surgery, cardiac surgery, neurosurgery, and orthopaedic surgery). Age range of participants was 18 to 80 years. There is probably little or no difference in the risk of postoperative (wound or systemic) infection with dexamethasone compared with no treatment, placebo, or active control (ramosetron, ondansetron, or tropisetron) (Peto OR 1.01, 95% confidence interval (CI) 0.80 to 1.27; 4931 participants, 27 studies; I² = 27%; moderate-quality evidence). The effects of dexamethasone on delayed wound healing are unclear because the wide confidence interval includes both meaningful benefit and harm (Peto OR 0.99, 95% CI 0.28 to 3.43; 1072 participants, eight studies; I² = 0%; low-quality evidence). Dexamethasone may produce a mild increase in glucose levels among participants without diabetes during the first 12 hours after surgery (MD 13 mg/dL, 95% CI 6 to 21; 10 studies; 595 participants; I² = 50%; low-quality evidence). We identified two studies reporting on glycaemic response after dexamethasone in participants with diabetes within 24 hours after surgery (MD 32 mg/dL, 95% CI 15 to 49; 74 participants; I² = 0%; very low-quality evidence).

AUTHORS' CONCLUSIONS

A single dose of dexamethasone probably does not increase the risk for postoperative infection. It is uncertain whether dexamethasone has an effect on delayed wound healing in the general surgical population owing to imprecision in trial results. Participants with increased risk for delayed wound healing (e.g. participants with diabetes, those taking immunosuppressive drugs) were not included in the randomized studies reporting on delayed wound healing included in this meta-analysis; therefore our findings should be extrapolated to the clinical setting with caution. Furthermore, one has to keep in mind that dexamethasone induces a mild increase in glucose. For patients with diabetes, very limited evidence suggests a more pronounced increase in glucose. Whether this influences wound healing in a clinically relevant way remains to be established. Once assessed, the three studies awaiting classification and two that are ongoing may alter the conclusions of this review.

Combination of gabapentin and ramosetron for the prevention of postoperative nausea and vomiting after gynecologic laparoscopic surgery: a prospective randomized comparative study

Background

As a drug originally introduced for its anticonvulsant effects, gabapentin has been recently shown to be effective in the treatment of nausea and vomiting in various clinical settings. This study compared the antiemetic efficacy of oral gabapentin, intravenous ramosetron and gabapentin plus ramosetron in patients receiving fentanyl-based patient-controlled analgesia after laparoscopic gynecologic surgery.

Methods

One hundred and thirty two patients undergoing laparoscopic gynecologic surgery under general anesthesia were allocated randomly into three groups: group G received 300 mg oral gabapentin 1 h before anesthesia, group R received 0.3 mg intravenous ramosetron at the end of surgery, and group GR received a combination of 300 mg oral gabapentin 1 h before anesthesia and 0.3 mg intravenous ramosetron at the end of surgery. Postoperative nausea, retching, vomiting, rescue antiemetic drug use, pain, rescue analgesic requirements and adverse effects were assessed at 0–2, 2–24 and 24–48 h after surgery. Postoperative nausea and vomiting (PONV) was defined as the presence of nausea, retching or vomiting.

Results

The incidence of complete response (no PONV and no rescue antiemetics up to 48 h postoperatively) was significantly higher in group GR (26/40, 65%) than group G (16/40, 40%; P = 0.025) and group R (18/44, 41%; P = 0.027), whereas there was no significant difference between group G and group R (P = 0.932). There were no significant between-group differences in the incidence of emetic episodes, use of rescue antiemetics, severe emesis, use of rescue analgesics or any adverse effects. Postoperative pain scores were also similar among groups.

Conclusions

The combination with gabapentin and ramosetron is superior to either drug alone for prevention of PONV after laparoscopic gynecologic surgery.

Trial registration

ClinicalTrials.gov NCT02617121, registered November 25, 2015.

Postoperative nausea and vomiting: physiopathology, risk factors, prophylaxis and treatment

Recognising the importance of the prevention and early treatment of postoperative nausea and vomiting (PONV) is essential to avoid postoperative complications, improve patient satisfaction and enable the development of major outpatient surgery and fast-track surgery. The topic of PONV might seem to have become stagnant, but we are moving forward. New concepts and problems like post-discharge nausea and vomiting, new risk factors and new drugs are appearing. However, there continue to be mistaken notions about PONV, such as the association between PONV and post-anaesthesia care unit stays, or assuming that it is a risk factore characteristic of the patient, anaesthesia or surgery when it is not. Perhaps, now is the moment to tackle PONV in a different manner, implementing guidelines and going for more aggressive prophylaxis in some groups of patients. We present an extensive review of this topic.

Sources of Placebo-Induced Relief From Nausea: The Role of Instruction and Conditioning

OBJECTIVES

It is well documented that expectancies alter the nauseous response. However, the lack of integration in research examining sources of expectancy has limited our understanding of how expectancies are formed and, consequently, our ability to intervene. The present study explored the role of both instructions and conditioning in placebo-induced relief from nausea.

METHODS

The study used a 2 × 2 between-subjects design with instruction and conditioning as factors with 56 healthy volunteers. The instruction manipulation involved randomizing participants to receive information that a sham treatment (a peppermint essence vapor) would reduce nausea or no such instructions. The conditioning manipulation involved further randomizing participants to have the first administration of this sham treatment paired with a surreptitious reduction in galvanic vestibular stimulation (GVS) intensity or no prior pairing. Nausea was induced through GVS. On test, all groups received the same level of GVS with the sham treatment present.

RESULTS

On test, participants who received instruction had significantly lower nauseous response scores than those who did not (F(1,46) = 6.71, p = .013), and those who received conditioning also reported less nausea than those who did not (F(1,46) = 5.20, p = .027), with the interaction between the two not reaching statistical significance (F(1,46) = 2.33, p = .13).

CONCLUSIONS

These findings indicate that placebo responding in nausea can be induced both through positive instructions and as little as one pairing of a treatment with a reduction in nausea, as well as their combination. This suggests that using placebo effects to complement antiemetic therapy may offer an important method of further reducing nausea in the clinic.

Ultrasound-Assisted Thoracic Paravertebral Block Reduces Intraoperative Opioid Requirement and Improves Analgesia after Breast Cancer Surgery: A Randomized, Controlled, Single-Center Trial

OBJECTIVES

The contribution of ultrasound-assisted thoracic paravertebral block to postoperative analgesia remains unclear. We compared the effect of a combination of ultrasound assisted-thoracic paravertebral block and propofol general anesthesia with opioid and sevoflurane general anesthesia on volatile anesthetic, propofol and opioid consumption, and postoperative pain in patients having breast cancer surgery.

METHODS

Patients undergoing breast cancer surgery were randomly assigned to ultrasound-assisted paravertebral block with propofol general anesthesia (PPA group, n = 121) or fentanyl with sevoflurane general anesthesia (GA group, n = 126). Volatile anesthetic, propofol and opioid consumption, and postoperative pain intensity were compared between the groups using noninferiority and superiority tests.

RESULTS

Patients in the PPA group required less sevoflurane than those in the GA group (median [interquartile range] of 0 [0, 0] vs. 0.4 [0.3, 0.6] minimum alveolar concentration [MAC]-hours), less intraoperative fentanyl requirements (100 [50, 100] vs. 250 [200, 300]μg,), less intense postoperative pain (median visual analog scale score 2 [1, 3.5] vs. 3 [2, 4.5]), but more propofol (median 529 [424, 672] vs. 100 [100, 130] mg). Noninferiority was detected for all four outcomes; one-tailed superiority tests for each outcome were highly significant at P<0.001 in the expected directions.

CONCLUSIONS

The combination of propofol anesthesia with ultrasound-assisted paravertebral block reduces intraoperative volatile anesthetic and opioid requirements, and results in less post operative pain in patients undergoing breast cancer surgery.

TRIAL REGISTRATION

ClinicalTrial.gov NCT00418457.