Intrathecal Dexamethasone and Dexmedetomidine as Adjuncts to Bupivacaine in Elective Cesarean Section: A Case Series.

The purpose of this study was to investigate whether the combination of intrathecal dexamethasone and dexmedetomidine in combination with bupivacaine in spinal anesthesia is effective for reducing nausea, vomiting, shivering, and pain. A retrospective review of records was used to examine the outcomes of patients undergoing cesarean delivery under spinal anesthesia with dexamethasone, dexmedetomidine, and bupivacaine. The records of 11 consecutive patients who underwent cesarean delivery under spinal anesthesia with intrathecal dexamethasone and dexmedetomidine in combination with bupivacaine were evaluated. Data collected included patient demographics, medications and fluids administered, presence of nausea, vomiting, shivering, intraoperative breakthrough pain, and postoperative pain. There were no reported complications related to the administration of intrathecal dexamethasone and dexmedetomidine in combination with bupivacaine in this case series of patients. No patients required treatment for intraoperative vomiting, shivering, or breakthrough pain. One patient required opioid pain medication postoperatively. This case series demonstrates that the administration of intrathecal dexamethasone and dexmedetomidine in combination with bupivacaine for patients undergoing elective cesarean section appears to be safe and offers some advantages as to traditional methods of intrathecal delivery for this surgical procedure.

Comparison of laparoscopic-guided versus ultrasound-guided TAP block in laparoscopic cholecystectomy.

INTRODUCTION: Transversus abdominis plane (TAP) block is a widely used anesthetic technique of the abdominal wall, where ultrasound guidance is considered the gold standard. In this study, we aimed to compare the effectiveness of laparoscopic-assisted TAP (LTAP) block with ultrasound-assisted TAP (UTAP) block for post-operative pain, nausea, vomiting, duration of the block, and bowel function. MATERIALS AND METHODS: This study included 60 patients who were randomly assigned to two groups to undergo either the LTAP or UTAP block technique after laparoscopic cholecystectomy. The time taken for administering the block, post-operative nausea and vomiting, post-operative pain, respiratory rate, bowel movements, and analgesia requirements were reported. RESULTS: The time taken for the LTAP block was shorter (p < 0.001). Post-operative mean tramadol consumption, paracetamol consumption, and analgesic requirement were comparable between the two groups (p = 0.76, p = 0.513, and p = 0.26, respectively). The visual analog scale at 6, 24, and 48 h was statistically not significant (p = 0.632, p = 0.802, and p = 0.173, respectively). Nausea with vomiting and the necessity of an antiemetic medication was lower in the UTAP group (p = 0.004 and p = 0.009, respectively). CONCLUSION: The LTAP block is an easy and fast technique to perform in patients as an alternative method where ultrasound guidance or an anesthesiologist is not available.

ANTECEDENTES: El bloqueo del plano transverso del abdomen (TAP) es una técnica anestésica de la pared abdominal ampliamente utilizada, en la cual la guía ecográfica se considera el método de referencia. OBJETIVO: Comparar la efectividad del bloqueo TAP asistido por laparoscopia (LTAP) con el bloqueo TAP asistido por ultrasonido (UTAP) para el dolor posoperatorio, las náuseas y los vómitos, y la función intestinal. MÉTODO: El estudio incluyó 60 pacientes que fueron asignados aleatoriamente a dos grupos para someterse a la técnica de bloqueo LTAP o UTAP después de una colecistectomía laparoscópica. Se informaron el tiempo de administración del bloqueo, las náuseas y los vómitos posoperatorios, el dolor posoperatorio, la frecuencia respiratoria, las evacuaciones y los requerimientos de analgesia. RESULTADOS: El tiempo de bloqueo LTAP fue menor (p < 0.001). El consumo medio de tramadol, el consumo de paracetamol y el requerimiento de analgésicos posoperatorios fueron comparables entre los dos grupos (p = 0.76, p = 0.513 y p = 0.26, respectivamente). El dolor en la escala analógica visual a las 6, 24 y 48 horas no fue estadísticamente significativo (p = 0.632, p = 0.802 y p = 0.173, respectivamente). CONCLUSIONES: El bloqueo PATL es una técnica fácil y rápida de realizar en pacientes como método alternativo cuando no se dispone de guía ecográfica o anestesióloga.

Auricular Acupressure in Relieving PONV and Promoting Gastrointestinal Function Recovery in Females After Laparoscopic Sleeve Gastrectomy: A Prospective Randomized Controlled Trial.

BACKGROUND: The role of current pharmacological treatment after laparoscopic sleeve gastrectomy (LSG) is limited. The incidence of postoperative nausea and vomiting (PONV) after LSG remains high. Auricular acupressure (AA) is believed to relieve PONV after laparoscopic surgeries, but its role in patients with obesity after LSG has yet to be confirmed. METHODS: Ninety-five female patients who underwent LSG were randomized into two groups: AA combined with conventional anti-nausea medication (AA group, 47 patients) or conventional anti-nausea medication group (control group, 48 patients). Index of nausea and vomiting and retching (INVR) scores, postoperative anti-vomiting medication use, time of first anus exhausting, time of first fluid intake, and time of first to get out of bed were collected within 48 h after surgery. RESULTS: Demographic data of patients in both groups were balanced and comparable. INVR score (F = 7.505, P = 0.007), vomiting score (F = 11.903, P = 0.001), and retching score (F = 12.098, P = 0.001) were significantly lower in the AA group than that in the control group within 48 h postoperatively. Use of metoclopramide was significantly less in the AA group than in the control group (4.7 [5.5]) vs. 8.8 [7.6], P = 0.004); time to first anus exhausting was significantly less in the AA group than in the control group (17.50 [6.00] vs. 20.42 [8.62], P = 0.020). CONCLUSIONS: AA combined with conventional anti-vomiting agents can alleviate PONV in female patients after LSG, and AA can promote gastrointestinal exhaustion. TRIAL REGISTRATION: The trial has been registered in the Chinese Clinical Trial Registry (ChiCTR) with the registration no. ChiCTR2100047381 on June 13, 2021.

Effect of intraoperative and/or postoperative esketamine administration on preventing postpartum depression: A systematic review and meta-analysis.

This systematic review and meta-analysis aimed to evaluate the impact of intraoperative and/or postoperative esketamine application on the prevention of postpartum depression (PPD). PubMed, Embase, and Web of Science were thoroughly searched for eligible randomized controlled trials (RCTs) regarding the application of esketamine for postnatal depression prevention. Nine RCTs including 1277 participants were involved in the final analysis. It was found that intraoperative and/or postoperative administration of esketamine significantly reduced the PPD incidence and the Edinburgh Postnatal Depression Scores in the early postoperative period. Meanwhile, esketamine lowered the occurrence of postoperative nausea and vomiting with no influence on other psychiatric symptoms.

Analysis of influencing factors and construction of prediction model for postoperative nausea and vomiting in patients undergoing laparoscopic sleeve gastrectomy: a single-center retrospective cohort study.

BACKGROUND: With the increasing number of bariatric surgeries, the high incidence of postoperative nausea and vomiting (PONV) associated with this surgery has also gradually attracted attention. Among the common bariatric surgery methods, patients undergoing sleeve gastrectomy (SG) have the highest incidence of nausea and vomiting. The mechanism of occurrence of PONV is very complex. This study aims to explore the influencing factors of PONV in patients undergoing laparoscopic sleeve gastrectomy (LSG) and construct a nomogram prediction model based on these factors. METHODS: With the approval of the Ethics Committee, the electronic medical records of patients who underwent LSG from July 2022 to May 2023 were collected retrospectively. RESULTS: A total of 114 patients with complete medical records who underwent LSG from July 2022 to May 2023 were included in this study. Among them, 46 patients developed PONV, resulting in a PONV incidence rate of 40.4%. Multivariate logistic regression analysis revealed that female gender, the use of inhalation anesthesia, and operation time ≥ 120 min were risk factors for PONV in LSG. Additionally, the use of more than two kinds of antiemetic drugs was identified as a protective factor. Based on these factors, a nomogram model was constructed. CONCLUSION: PONV in patients undergoing LSG is related to gender, type of anesthesia, duration of surgery, and combination therapy with antiemetic drugs. The nomogram prediction model constructed in this study demonstrates high accuracy and discrimination in predicting the occurrence of PONV in patients undergoing LSG.

Comparative efficacy of prophylactic protocols in reducing perioperative nausea and vomiting during video-assisted thoracoscopic radical resection of lung cancer.

Lung cancer, a global mortality leader, often necessitates Video-Assisted Thoracoscopic (VATS) surgery. However, post-operative nausea and vomiting (PONV) is common, highlighting a need for effective management and prevention strategies in this context. A retrospective case-control study at Fujian Medical University Union Hospital evaluated patients undergoing VATS radical resection of lung cancer between May and September 2022. Patients were categorized based on PONV prevention methods, and data encompassing demographics, surgical history, and postoperative adverse events s were analyzed to assess the association between prophylactic protocols and PONV incidence. The Netupitant and Palonosetron Hydrochloride (NEPA) group showed a significant reduction in PONV occurrences post-surgery compared to Ondansetron (ONDA) and Control groups, emphasizing NEPA's efficacy in alleviating PONV symptoms (P < 0.05). Furthermore, following VATS radical resection of lung cancer, NEPA markedly reduced the intensity of PONV symptoms in patients. Both univariate and multivariate logistic analyses corroborated that NEPA independently reduces PONV risk, with its protective effect also apparent in susceptible populations like females and non-smokers. NEPA utilization markedly reduced both the incidence and severity of PONV in patients undergoing VATS radical resection of lung cancer, serving as an independent protective factor in mitigating PONV risk post-surgery.

Effect of converting from propofol to remimazolam with flumazenil reversal on recovery from anesthesia in outpatients with mental disabilities: a randomized controlled trial.

BACKGROUND: General anesthesia is often necessary for dental treatment of outpatients with mental disabilities. Rapid recovery and effective management of postoperative nausea and vomiting (PONV) are critical for outpatients. This study aimed to investigate the effect of transitioning from propofol to remimazolam with flumazenil reversal administered toward the end of surgery during propofol-based total intravenous anesthesia (TIVA) on recovery. METHODS: Adults with mental disabilities scheduled to undergo dental treatment were randomly assigned to receive either propofol-based TIVA (Group P) or propofol-remimazolam-based TIVA with flumazenil reversal (Group PR). Propofol was replaced with remimazolam 1 h before the end of surgery in Group PR; moreover, 0.5 mg of flumazenil was administered after the neuromuscular blockade reversal agent. The primary outcome was the duration of stay in the post-anesthesia care unit (PACU). The secondary outcomes included time to eye-opening, time to extubation, occurrence of PONV, and quality of recovery. RESULTS: Fifty-four patients were included in this study. The duration of stay in the PACU in Group PR was significantly shorter than that in Group P (mean difference, 8.7 min; confidence interval [95% CI], 3.3-14.2; P = 0.002). Group PR exhibited a shorter time to eye opening (mean difference, 5.4 min; 95% CI, 3.3-8.1; P < 0.001) and time to extubation (mean difference, 5.5 min; 95% CI, 3.6-7.9; P < 0.001) than Group P. Neither group required the administration of rescue analgesics, and the incidence of PONV was not reported. CONCLUSIONS: Transitioning from propofol to remimazolam 1 h before the end of surgery followed by flumazenil reversal reduced the duration of stay in the PACU and the time to eye opening and extubation without affecting the incidence of PONV and quality of recovery. TRIAL REGISTRATION NUMBER: Clinical Research Information Service (KCT0007794), Clinical trial first registration date: 12/10/2022.

Commonly used antiemetics for prophylaxis of postoperative nausea and vomiting after Caesarean delivery with neuraxial morphine: a network meta-analysis.

BACKGROUND: Dopamine antagonists, 5-HT3 antagonists, and dexamethasone are frequently used in obstetrics to prevent postoperative nausea and vomiting (PONV). However, the superiority of any drug class is yet to be established. This network meta-analysis aimed to compare the efficacy of these antiemetics for PONV prophylaxis in women receiving neuraxial morphine for Caesarean delivery. METHODS: We searched PubMed, Embase, CENTRAL, Web of Science, and Wanfang Data for eligible randomised controlled trials. Primary outcomes were the incidences of postoperative nausea (PON) and postoperative vomiting (POV) within 24 h after surgery. We used a Bayesian random-effects model and calculated odds ratios with 95% credible intervals for dichotomous data. We performed sensitivity and subgroup analyses for primary outcomes. RESULTS: A total of 33 studies with 4238 women were included. In the primary analyses of all women, 5-HT3 antagonists, dopamine antagonists, dexamethasone, and 5-HT3 antagonists plus dexamethasone significantly reduced PON and POV compared with placebo, and 5-HT3 antagonists plus dexamethasone were more effective than monotherapy. In the subgroup analyses, similar results were seen in women receiving epidural morphine or intrathecal morphine alone but not in women receiving intrathecal morphine with fentanyl or sufentanil. However, most included studies had some concerns or a high risk of bias, and the overall certainty of the evidence was low or very low. CONCLUSIONS: Combined 5-HT3 antagonists plus dexamethasone are more effective than monotherapy in preventing PONV associated with neuraxial morphine after Caesarean delivery. Future studies are needed to determine the role of prophylactic antiemetics in women receiving intrathecal morphine and lipophilic opioids. SYSTEMATIC REVIEW PROTOCOL: PROSPERO CRD42023454602.

Effect of S-Ketamine on Postoperative Nausea and Vomiting in Patients Undergoing Video-Assisted Thoracic Surgery: A Randomized Controlled Trial.

Purpose: Postoperative nausea and vomiting (PONV) frequently occur in patients after surgery. In this study, the authors investigated whether perioperative S-ketamine infusion could decrease the incidence of PONV in patients undergoing video-assisted thoracoscopic surgery (VATS) lobectomy. Patients and Methods: This prospective, randomized, double-blinded, controlled study was conducted a total of 420 patients from September 2021 to May 2023 at Xuzhou Central Hospital in China, who underwent elective VATS lobectomy under general anesthesia with tracheal intubation. The patients were randomly assigned to either the S-ketamine group or the control group. The S-ketamine group received a bolus injection of 0.5 mg/kg S-ketamine and an intraoperative continuous infusion of S-ketamine at a rate of 0.25 mg/kg/h. The control group received an equivalent volume of saline. All patients were equipped with patient-controlled intravenous analgesia (PCIA), with a continuous infusion rate of 0.03 mg/kg/h S-ketamine in the S-ketamine group or 0.03 µg/kg/h sufentanil in the control group. The primary outcome was the incidence of PONV. Secondary outcomes included perioperative opioid consumption, hemodynamics, postoperative pain, and adverse events. Results: The incidence of PONV in the S-ketamine group (9.7%) was significantly lower than in the control group (30.5%). Analysis of perioperative opioid usage revealed that remifentanil usage was 40.0% lower in the S-ketamine group compared to the control group (1414.8 µg vs 2358.2 µg), while sufentanil consumption was 75.2% lower (33.1 µg vs 133.6 µg). The S-ketamine group demonstrated better maintenance of hemodynamic stability. Additionally, the visual analogue scale (VAS) scores on postoperative day 1 (POD-1) and postoperative day 3 (POD-3) were significantly lower in the S-ketamine group. Finally, no statistically significant difference in other postoperative adverse reactions was observed between the two groups. Conclusion: The results of this trial indicate that perioperative S-ketamine infusion can effectively reduce the incidence of PONV in patients undergoing VATS lobectomy.

Comparison of prophylaxis strategy for postoperative nausea and vomiting and its incidence before and after the implementation of 5-hydroxytryptamine 3 in surgical setting: a single-center, retrospective study.

PURPOSE: To investigate the association between adherence to guideline-recommended risk-based postoperative nausea and vomiting (PONV) prophylaxis, the antiemetics used for PONV prophylaxis, and the incidence of PONV in patients who were underwent general anesthesia before and after 5-HT3 receptor antagonists became available. METHODS: Patients (≥ 20 years old) who were extubated after scheduled surgery and returned to general wards between January 2021 and February 2022 and between June 2022 and July 2023 were included. Risk factors included age < 50, female, motion sickness, nonsmoker, surgical factors, and postoperative opioid use. Two and three or more prophylaxis were recommended for patients with one or two and three or more risk factors, respectively. The primary outcome was the number of patients who received adequate prophylaxis, and the secondary outcomes were antiemetic agents used during anesthesia and the incidence of PONV on postoperative days 0 and 1. PONV was defined as documented PONV or rescue antiemetic administration. RESULTS: From January 2021 to February 2022 and from June 2022 to July 2023, 2342 and 2682 patients were included, respectively. Before ondansetron became available, more D2 receptor antagonists were used (p < 0.001), and after ondansetron became available, both ondansetron (p < 0.001) and propofol (p < 0.001) were given more frequently. Before and after ondansetron became available, the number of patients with adequate prophylaxis was 3.7% and 9.2%, respectively (p < 0.001), and the incidence of PONV on postoperative days 0 and 1 was 44.6% and 44.0%, respectively (p = 0.67). CONCLUSION: The availability of ondansetron increased the number of patients with adequate PONV prophylaxis, but did not decrease the incidence of PONV.

Intraoperative Brainstem Auditory Evoked Potentials and Postoperative Nausea and Vomiting After Microvascular Decompression.

BACKGROUND: We performed this study to investigate the effect of intraoperative brainstem auditory evoked potential (IBAEP) changes on the development of postoperative nausea and vomiting (PONV) after microvascular decompression (MVD) for neurovascular cross compression. METHODS: A total of 373 consecutive cases were treated with MVD. The use of rescue antiemetics after surgery was used as an objective indicator of PONV. IBAEP monitoring was routinely performed in all. RESULTS: The use of rescue antiemetics was significantly associated with female sex (OR = 3.427; 95% CI, 2.077-5.654; P < 0.001), PCA use (OR = 3.333; 95% CI, 1.861-5.104; P < 0.001), and operation time (OR = 1.017; 95% CI, 1.008-1.026; P < 0.001). A Wave V peak delay of more than 1.0 milliseconds showed a significant relation with the use of rescue antiemetics (OR = 1.787; 95% CI, 1.114-2.867; P = 0.016) and a strong significant relation with the use of rescue antiemetics more than 5 times (OR = 2.426; 95% CI, 1.372-4.290; P = 0.002). CONCLUSIONS: A wave V peak delay of more than 1.0 milliseconds might have value as a predictor of PONV after MVD. More detailed neurophysiological studies will identify the exact pathophysiology underlying PONV after MVD.

Quadratus lumborum block vs. transversus abdominis plane block for postoperative pain control in patients with nephrectomy: A systematic review and network meta-analysis.

STUDY OBJECTIVE: This systematic review and network meta-analysis aimed to compare the analgesic efficacy of transversus abdominis plane block (TAPB) and quadratus lumborum block (QLB) on nephrectomy. DESIGN: Systematic review and network meta-analysis. PATIENTS: Patients undergoing nephrectomy. INTERVENTIONS: TAPB and QLB for postoperative analgesia. MEASUREMENTS: The primary outcome was 24 h morphine-equivalent consumptions after surgery. Secondary outcomes included postoperative pain scores, postoperative opioid consumption, postoperative rescue analgesia, postoperative nausea and vomiting (PONV), length of hospital stay after surgery, and patient satisfaction. MAIN RESULTS: Fourteen studies involving 883 patients were included. Seven studies compared TAPB to control, six studies compared QLB to control, and one study compared TAPB to QLB. For direct meta-analysis of the post-surgical 24 h morphine-equivalent consumption, QLB was lower than control (mean difference [95%CI]: -18.16 [-28.96, -7.37]; I2 = 88%; p = 0.001), while there was no difference between TAPB and control (mean difference [95%CI]: -8.34 [-17.84, 1.17]; I2 = 88%; p = 0.09). Network meta-analysis showed similar findings that QLB was ranked as the best anesthetic technique for reducing postoperative 24 h opioid consumption (p-score = 0.854). Moreover, in direct meta-analysis, as compared to control, the time of first postoperative rescue analgesia was prolonged after QLB (mean difference [95%CI]: 165.00 [128.99, 201.01]; p < 0.00001), but not TAPB (mean difference [95%CI]: 296.82 [-91.92, 685.55]; p = 0.13). Meanwhile, QLB can effectively reduce opioid usages at intraoperative period, as well as at postoperative 6 h and 48 h, while TAPB can only reduce opioid consumption at 6 h after surgery. As compared to control, both TAPB and QLB exhibited the reduction in PONV and pain scores at post-surgical some timepoints. Also, QLB (mean difference [95%CI]: -0.29 [-0.49, -0.08]; p = 0.006) but not TAPB (mean difference [95%CI]: 0.60 [-0.25, 1.45]; p = 0.17) exhibited the shorter postoperative length of hospital stay than control. CONCLUSIONS: QLB is more likely to be effective in reducing postoperative opioid use than TAPB, whereas both of them are superior to control with regard to the reduction in postoperative pain intensity and PONV. TRIAL REGISTRATION: PROSPERO identifier: CRD42022358464.

Randomized clinical trial of continuous transversus thoracis muscle plane block for patients undergoing open heart valve replacement surgery.

The optimal analgesia regimen after open cardiac surgery is unclear. The aim of this study was to investigate the beneficial effects of continuous transversus thoracis muscle plane (TTMP) blocks initiated before surgery on open cardiac surgery outcomes. A group of 110 patients were randomly allocated to either receive bilateral continuous TTMP blocks (TTP group) or no nerve block (SAL group). The primary endpoint was post-operative pain at 4, 8, 16, 24, 48 and 72 h after extubation at rest and exercise. The secondary outcome measures included analgesia requirements (sufentanil and flurbiprofen axetil administration), time to extubation, incidence of reintubation, length of stay in the ICU, incidence of post-operative nausea and vomiting (PONV), time until return of bowel function, time to mobilization, urinary catheter removal and length of hospital stay. The length of stay in the ICU and length of hospital stay were significantly longer in the SAL group than in the TTP group. NRS scores at rest and exercise were significantly lower in the TTP group than in the SAL group at all time points. The TTP group required significantly less intraoperative and post-operative sufentanil and post-operative dynastat consumption than the SAL group. Time to extubation, time to first flatus, time until mobilization and time until urinary catheter removal were significantly earlier in the TTP group than in the SAL group. The incidence of PONV was significantly lower in the TTP group. Bilateral continuous TTMP blocks provide effective analgesia and accelerate recovery in patients undergoing open heart valve replacement surgery.

Olanzapine as a prophylactic antiemetic for preventing postoperative nausea and vomiting after general anesthesia: A systematic review and meta-analysis.

BACKGROUND: The antiemetic effectiveness of olanzapine, as a prophylactic off-label antiemetic drug, for Postoperative Nausea and Vomiting (PONV) is unknown. In this systematic review and meta-analysis, the authors evaluate the efficacy and side effects of olanzapine as a prophylactic antiemetic in adult patients who undergo general anesthesia and assess adverse effects. METHODS: A systematic search was done on electronic bibliographic databases in July 2023. Randomized controlled trials of olanzapine as a prophylactic antiemetic for PONV in adults who underwent general anesthesia were included. The authors excluded non-RCTs and retracted studies. The authors set no date of publication or language limits. The outcomes were the incidence of PONV within 24 h postoperatively and the safety of olanzapine. The risk of bias was assessed according to the tool suggested by the National Heart, Lung, and Blood Institute. RESULTS: Meta-analysis included 446 adult patients. Olanzapine reduced on average 38 % the incidence of PONV. The estimated risk ratio (95 % CI) of olanzapine versus control was 0.62 (0.42-0.90), p = 0.010, I2 = 67 %. In the subgroup meta-analysis, doses of olanzapine (10 mg) reduced on average 49 % of the incidence of PONV (RR = 0.51 [0.34-0.77], p = 0.001, I2 = 31 %). CONCLUSIONS: This systematic review with meta-analysis indicated that olanzapine as a prophylactic antiemetic alone or combined with other antiemetic agents reduced the incidence of postoperative nausea and vomiting. However, this conclusion must be presented with some degree of uncertainty due to the small number of studies included. There was a lack of any evidence to draw conclusions on side effects.

Prevention of postoperative nausea and vomiting after orthognathic surgery: a scoping review.

INTRODUCTION: Postoperative nausea and vomiting (PONV) is one of the most common adverse events following orthognathic surgery. It's a distressing feeling for patients and continues to be the cause of postoperative complications such as bleeding, delayed healing, and wound infection. This scoping review aims to identify effective PONV prophylaxis strategies during orthognathic surgery that have emerged in the past 15 years. METHODS: We searched Pubmed, Cochrane Controlled Register of Trials, and Embase from 2008 to May 2023. Studies meeting the following criteria were eligible for inclusion: (1) recruited patients undergo any orthognathic surgery; (2) evaluated any pharmacologic or non-pharmacologic method to prevent PONV. Studies meeting the following criteria were excluded: (1) case series, review papers, or retrospective studies; (2) did not report our prespecified outcomes. RESULTS: Twenty-one studies were included in this review. Pharmacological methods for PONV prevention include ondansetron and dexamethasone (3 studies), peripheral nerve block technique (4 studies), dexmedetomidine (1 study), pregabalin (2 studies), nefopam (2 studies), remifentanil (1 study), propofol (2 studies), and penehyclidine (1 study). Non-pharmacologic methods include capsicum plaster (1 study), throat packs (2 studies) and gastric aspiration (2 studies). CONCLUSIONS: Based on current evidence, we conclude that prophylactic antiemetics like dexamethasone, ondansetron, and penehyclidine are the first defense against PONV. Multimodal analgesia with nerve block techniques and non-opioid analgesics should be considered due to their notable opioid-sparing and PONV preventive effect. For the non-pharmacological methods, throat packs are not recommended for routine use because of their poor effect and serious complications. More prospective RCTs are required to confirm whether gastric aspiration can prevent PONV effectively for patients undergoing orthognathic surgery.