Impact of Preoperative Gum Chewing on Postoperative Anti-Emetic Use in Robot-Assisted Laparoscopic Surgery for Benign Ovarian Masses: A Prospective, Single-Blinded Randomized Controlled Trial

Background and Objectives: Postoperative nausea and vomiting (PONV) is a common issue for females undergoing gynecological surgeries, including those assisted by robotic systems. Despite available prophylactic measures, the incidence of PONV remains high, negatively impacting recovery and increasing healthcare costs. This study evaluates whether preoperative gum chewing reduces the need for anti-emetic drugs in females undergoing robot-assisted laparoscopic surgery for benign ovarian mass. Materials and Methods: This prospective, single-blinded, randomized controlled trial enrolled 92 adult females scheduled for robot-assisted laparoscopic surgery to treat benign ovarian mass. Following exclusions, the remaining participants were randomly assigned to either a gum-chewing group or a no-gum-chewing group. The gum-chewing group chewed sugar-free gum for 15 min in the holding area before surgery. The primary outcome measured was the need for anti-emetics to control PONV during the first hour in the post-anesthesia care unit (PACU). Secondary outcomes included the number of anti-emetic requests. No preemptive anti-emetics were administered during surgery. Results: Out of the initial 92 patients, 88 were included in the final analysis, with 44 in each group. The incidence of PONV requiring anti-emetics in the PACU was significantly lower in the gum-chewing group (79.5%) compared to the no-gum-chewing group (95.5%). Additionally, the number of anti-emetic requests was higher in the no-gum-chewing group. No postoperative complications such as tooth or jaw pain/injury or gastric content regurgitation were reported. Conclusions: Preoperative gum chewing for 15 min immediately before surgery significantly reduced the incidence of PONV in females undergoing robot-assisted laparoscopic surgery for benign ovarian mass. This simple, non-pharmacological intervention improved patient comfort and reduced the need for anti-emetic medications without any adverse effects. Further studies are needed to confirm these findings and to develop guidelines for incorporating preoperative gum chewing into clinical practice.

The efficacy of gastric aspiration in reducing postoperative vomiting after oral and maxillofacial surgery: A meta-analysis

BACKGROUND

Gastric aspiration is applied in oral and maxillofacial procedures to reduce postoperative vomiting (POV), yet its clinical benefit remains largely uncertain. Our study aimed to determine the role of gastric aspiration in the amelioration of POV by a meta-analysis.

METHODS

With adherence to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, global recognized databases, including PubMed, Embase, and Cochrane Central, were searched to obtain randomized controlled trials (RCTs) investigating the effects of gastric aspiration in oral and maxillofacial surgery. The incidence and the number of episodes of POV and the frequency of rescue antiemetic use were extracted as parametric data for pooled estimation. Funnel plots and Egger's test were utilized to assess bias. The recommendation of evidence was rated by the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system.

RESULTS

After detailed evaluation, 5 RCTs containing 274 participants were eventually included. The results of pooled estimation indicated that gastric aspiration could not reduce the incidence of POV (risk ratio [95% CI] = 0.94 [0.73, 1.21], P = .621), the number of episodes of POV (standard mean difference [95% CI] = -0.13 [-0.45, 0.19], P = .431) or the frequency of rescue antiemetic use (RR [95% CI] = 0.86 [0.49, 1.52], P = .609). No publication bias was detected by the funnel plot and Egger test. The overall recommendation of evidence was rated low regarding each outcome.

CONCLUSION

Based on current evidence, gastric aspiration is not recommended for oral and maxillofacial surgery. Meanwhile, more large-scale high-quality RCTs are needed.

Enhanced recovery protocols for ambulatory surgery

INTRODUCTION

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

Variation in prescribing for the prevention of postoperative nausea, vomiting, and pain following abdominal surgery: A retrospective study

Background and Aims

Adequate postoperative analgesia and prevention of post-op nausea and vomiting (PONV) are core components of modern day anaesthesia and peri-operative care. As well as contributing to overall morbidity, postoperative pain and PONV are frequently cited as one of the most unpleasant and distressing aspects of surgery for patients. Variation in healthcare delivery is known to exist but has often been poorly described. A first step to understanding the consequences of variation is to describe the extent of variation. We aimed to assess variation in pharmacological strategies to prevent postoperative pain, nausea and vomiting in patients undergoing elective major abdominal surgery at a tertiary hospital in Perth, Western Australia, over a three-month period.

Methods

Retrospective cross-sectional study.

Results

We observed considerable variation in prescribing of postoperative analgesia and PONV prophylaxis and suggest that despite adequate evidence based guidelines, they are often overlooked in practice.

Conclusion

Measurement of the consequences of variation requires randomised clinical trials that evaluate differences in outcome and cost, associated with the strategies that exist within the spectrum of variation.

Risk factors for postoperative nausea and vomiting in patients of orthognathic surgery according to the initial onset time: a cross-sectional study

Background

A high incidence (40-73%) of postoperative nausea and vomiting (PONV) has been reported following orthognathic surgery, and various risk factors have been associated with it. Identifying PONV risk factors based on initial onset time will help establish preventive measures. This study aimed to identify factors that are significantly related to PONV based on the initial onset time after orthognathic surgery.

Methods

This study included 590 patients who underwent orthognathic surgery. Multivariate logistic regression analysis was performed to identify the risk factors that are significantly related to PONV. The objective variables were classified into three categories: no PONV, early PONV (initial onset time: 0-2 h after anesthesia), and late PONV (initial onset time: 2-24 h after anesthesia). The explanatory variables included relevant risk factors for PONV, as considered in previous studies.

Results

Total intravenous anesthesia with propofol was a significant depressant factor for early PONV (adjusted odds ratio [aOR] = 0.340, 95% confidence interval [CI] = 0.209-0.555) and late PONV (aOR = 0.535, 95% CI = 0.352-0.814). The administration of a combination of intraoperative antiemetics (vs. no administration) significantly reduced the risk of early PONV (aOR = 0.464, 95% CI = 0.230-0.961). Female sex and young age were significant risk factors for late PONV (aOR = 1.492, 95% CI = 1.170-1.925 and unit aOR = 1.033, 95% CI = 1.010-1.057, respectively).

Conclusion

We identified factors that are significantly related to PONV based on the initial onset time after orthognathic surgery. Total intravenous anesthesia with propofol significantly reduced the risk of PONV not only in the early period (0-2 h after anesthesia) but also in the late period (2-24 h after anesthesia).

Effect of individualized treatment strategy on postoperative nausea and vomiting in gynaecological laparoscopic surgery: a double-blind, randomized, controlled trial

BACKGROUND

Postoperative nausea and vomiting (PONV) have always been a concern of clinicians and may increase medical costs for patients. Consensus guidelines recommend using multiple antiemetics with different mechanisms as prophylaxis in patients at high risk of PONV. Individualized risk scores for nausea and vomiting and individualized treatment strategies are feasible. This study evaluated the effect of individualized treatment strategies on postoperative nausea and vomiting after laparoscopic gynaecological operations.

METHODS

This was a double-blind, randomized, controlled trial. A total of 119 adult patients who underwent gynaecological laparoscopic surgery under general anaesthesia were randomly divided into an individualized treatment group or a control group, with the individualized treatment group receiving individualized prevention according to a preoperative risk score of nausea and vomiting and the control group receiving no individualized prevention. Vomiting, retching, nausea, and use of rescue medication were all recorded for 24 h after the operation. The primary outcome variable was complete response, defined as no emesis or the use of rescue medication 24 h postoperatively.

RESULTS

The complete response rate was higher in the individualized treatment group (56.7%) than in the control group (23.7%) (95% CI, 0.01-0.27; P < 0.001). The incidences of emesis (18.3% vs. 44.1%, P = 0.002) were significantly lower in the individualized treatment group than in the control group. There were no differences in any nausea (26.7% vs. 33.9%, P = 0.391) or rescue medication use (6.7% vs. 8.5%, P = 0.743). Adverse events and laboratory and electrocardiogram abnormalities occurred no more frequently in the individualized treatment group than in the control group.

CONCLUSION

In conclusion, this single-centre, double-blind, randomized study suggests that an individualized PONV prophylactic treatment strategy based on the number of PONV risk factors could be a safe and effective regimen to reduce the incidence of PONV in adult patients undergoing laparoscopic gynaecological surgery.

Evaluation of Complication Development in General Surgery Patients Admitted to the Post Anesthesia Care Unit

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Effect of anaesthetic depth on primary postoperative ileus after laparoscopic colorectal surgery: protocol for and preliminary data from a prospective, randomised, controlled trial

INTRODUCTION

Primary postoperative ileus is one of the principal factors affecting in-hospital recovery after colorectal surgery. Research on the relationship between anaesthetic depth and perioperative outcomes has been attracting growing attention. However, the impact of anaesthetic depth on the recovery of gastrointestinal function after surgery is unclear. We aimed to conduct a single-centre, prospective, randomised, controlled trial to explore the effect of anaesthetic depth on primary postoperative ileus after laparoscopic colorectal surgery.

METHODS AND ANALYSIS

In this single-centre, prospective, patient-blinded and assessor-blinded, parallel, randomised, controlled trial, a total of 854 American Society of Anesthesiologists physical status I-III patients, aged between 18 and 65 years and scheduled for laparoscopic colorectal surgery lasting ≥2 hours, will be randomly assigned to deep anaesthesia group (Bispectral Index (BIS) 30-40) or light anaesthesia group (BIS 45-55). The primary outcome is primary postoperative ileus during the hospital stay. Secondary outcomes were time to gastrointestinal function recovery, another defined postoperative ileus, 15-item quality of recovery score, length of postoperative stay, postoperative 30-day complications and serum concentrations of intestinal fatty acid-binding protein at 6 hours after surgery.

ETHICS AND DISSEMINATION

The protocol was approved by Medical Ethics Committee of Nanfang Hospital, Southern Medical University (Approval number: NFEC-2018-107) prior to recruitment. All participants will provide written informed consent before randomisation. Findings of the trial will be disseminated through peer-reviewed journals and scientific conferences.

TRIAL REGISTRATION NUMBER

ChiCTR1800018725.

Genetic Susceptibility Toward Nausea and Vomiting in Surgical Patients

Postoperative nausea and vomiting (PONV) are frequently occurring adverse effects following surgical procedures. Despite predictive risk scores and a pallet of prophylactic antiemetic treatments, it is still estimated to affect around 30% of the patients, reducing their well-being and increasing the burden of post-operative care. The aim of the current study was to characterize selected genetic risk factors of PONV to improve the identification of at risk patients. We genotyped 601 patients followed during the first 24 h after surgery for PONV symptoms in the absence of any antiemetic prophylaxis. These patients were recruited in the frame of a randomized, placebo controlled clinical study aiming to test the efficacy of dexamethasone as a treatment of established PONV. We examined the impact of selected single nucleotide polymorphisms (SNPs) located around 13 different genes and the predicted activity of 6 liver drug metabolizing enzymes from the cytochromes P450 family (CYP) on the occurrence and recurrence of PONV. Our genetic study confirms the importance of genetic variations in the type 3B serotonin receptor in the occurrence of PONV. Our modelling shows that integration of rs3782025 genotype in preoperative risk assessments may help improve the targeting of antiemetic prophylaxis towards patients at risk of PONV.

Preoperative reflux or regurgitation symptoms are independent predictors of postoperative nausea and vomiting (PONV) in patients undergoing bariatric surgery: a propensity score matching analysis

BACKGROUND

Postoperative nausea and vomiting (PONV) is common side effect after gastrointestinal surgery. It causses discomfort, increase risk of incision disruption, bleeding and airway blockage. This study aimed to investigate the incidence and severity of PONV and determine whether preoperative reflux or regurgitation symptoms influence PONV in patients undergoing bariatric surgery.

METHODS

Patients with obesity underwent laparoscopic sleeve gastrectomy (LSG) and laparoscopic Roux-en-Y gastric bypass (LRYGB) in our center between January 2016 and December 2018 were divided into PONV and NoPONV group and analyzed retrospectively. PONV and postoperative pain visual analogue scale (VAS) were analyzed after surgery. A 1:1 propensity score matching (PSM) method was performed, and multivariable logistic regression analyses were used to identify predictors for PONV.

RESULTS

There were 483 patients enrolled, with a mean age of 30.19 ± 9.96 years, and 134 pairs of matched patients were selected from PONV group and NoPONV group after PSM. PONV occurred in 288 (59.6%) patients after bariatric surgery (77.4% after LSG vs 21.5% after LRYGB, p < 0.001). In PONV group, 210 (72.9%) were female, preoperative reflux or regurgitation symptoms were 128 (33.6%). Multivariable analysis found that preoperative reflux or regurgitation symptoms were independent risk factors for PONV after LSG, with an OR of 2.78 (95% CI: 1.12-6.93, p = 0.028).

CONCLUSIONS

Incidence of PONV after bariatric surgery is high. For the first time, this study valued preoperative reflux or regurgitation symptoms as risk factors that may promote PONV after bariatric surgery. Patients with preoperative symptoms undergoing LSG have a higher risk of PONV, so these patients should be carefully evaluated for the feasibility of LSG before surgery.

The association of nitrous oxide on length of stay in the postanesthesia care unit: a retrospective observational study

PURPOSE

To assess whether intraoperative use of nitrous oxide (N₂O) as an adjunct to general anesthesia is associated with a shorter length of stay in the postanesthesia care unit (PACU).

METHODS

We analyzed data from adult patients who underwent non-cardiothoracic surgery under general anesthesia between May 2008 and December 2018. We assessed the association between intraoperative low- and high-dose N₂O and PACU length of stay.

RESULTS

A total of 148,284 patients were included in the primary analysis. After adjusting for a priori defined confounders, a high dose of N₂O significantly decreased PACU length of stay, with a calculated difference of -9.1 min (95% confidence interval [CI], -10.5 to -7.7; P < 0.001). Patients who received high-dose N₂O had a lower incidence of both short- and prolonged-duration of intraoperative hypotension (adjusted odds ratio [aOR], 0.85; 95% CI, 0.83 to 0.88; P < 0.001 and aOR, 0.76; 95% CI, 0.73 to 0.80; P < 0.001, respectively) and received a lower total intraoperative vasopressor dose (-0.04 mg of norepinephrine equivalents; 95% CI, -0.06 to -0.01; P = 0.01). The effect of high-dose N₂O on PACU length of stay was modified by surgical complexity (adjusted absolute difference: -26.1 min; 95% CI, -29.2 to -23.1; P < 0.001; P for interaction < 0.001), and most pronounced in patients who underwent complex surgery and received intraoperative antiemetic therapy (adjusted absolute difference: -38.9 min; 95% CI, -43.1 to -34.6; P < 0.001; P for interaction < 0.001).

CONCLUSIONS

Nitrous oxide was dose-dependently associated with a decreased PACU length of stay. The effect was clinically relevant (> 30 min difference) in patients who underwent complex surgical procedures and received intraoperative antiemetic therapy.

The Effect of Intraoperative Body Temperature on Postoperative Nausea and Vomiting in Pediatric Patients

PURPOSE

Pediatric patients are at greater risk for both perioperative hypothermia and postoperative nausea and vomiting (PONV). The primary aim of this study was to investigate whether there is a relationship between intraoperative body temperature and PONV in children undergoing anesthesia. The secondary aim was to investigate the relationship between PONV and intraoperative fentanyl use, age and duration of operation.

DESIGN

A prospective cohort study METHODS: The study included 80 children who were undergoing lower abdominal surgery. Body temperature was monitored after routine preoperative preparation and standard induction. Analgesic and antiemetic requirements and the presence of nausea and vomiting were assessed postoperatively on the 30th minute and the 6th, 12th and 24th hour.

FINDINGS

The children with or without PONV were compared. At the postoperative 6th hour, the incidence of nausea was statistically significant in the children with a mean body temperature below 36°C (P = 0.044; P < 0.05). The mean duration of the surgery was statistically significant longer in the children with PONV (P = 0.001; P = 0.004; P <0.05). Mean body temperature was not statistically significant when comparing children with and without vomiting(P > 0.05).

CONCLUSION

While a body temperature below 36°C increases the incidence of postoperative nausea, it does not cause an increase in the incidence of vomiting. A long operation time in pediatric patients causes an increase in the incidence of PONV. Although not statistically significant, PONV is encountered more than twice as much in patients receiving intraoperative fentanyl administration.

Factors Associated with Chemotherapy Induced Nausea in Cancer Patients: A Case-Control Study

Background: Chemotherapy-induced nausea (CIN) is one of the most common and uncomfortable symptoms in cancer patients, and different factors can be associated with it. Objectives: This study aimed to determine different factors associated with CIN in cancer patients. Methods: A total of 144 cancer patients were selected by convenience sampling. The patients at acute phase of chemotherapy were assigned to case group (n = 58) if they had nausea or to control group (n = 86) if they did not have nausea. The patients' data were collected using a researcher-made questionnaire including items on potential factors for CIN through interviews with the patients and according to their medical records. Logistic regression models were used to conduct data analysis, and the correlations in question were expressed as odds ratio (OR) at 95% confidence interval (CI). Results: The results showed that the chance of nausea increased by 6.4, 2.4, 1.2, and 1.5 times in case of expected nausea, pain, carbohydrate intake, and smelling a specific odor, respectively. The increasing nausea-inducing effect of drugs led to increased chance of post-chemotherapy nausea (OR = 2.366). Conclusions: Having pain, expecting nausea, carbohydrate intake, smelling a certain odor, and high emetogenic potential of chemotherapy are effective in the development of CIN.

An analysis of the management and incidence of postoperative nausea and vomiting

BACKGROUND

Postoperative nausea and vomiting significantly increases recovery time, reduces patient satisfaction, and increases time to discharge. Consensus guidelines for the management of postoperative nausea and vomiting highlight effective methods for prophylaxis and treatment. Implications of adherence to these guidelines include both improved patient outcomes and reduced healthcare costs.

OBJECTIVE

This study aimed to assess the incidence, contributing factors, and current prescribing practices for prophylaxis and treatment of postoperative nausea and vomiting.

METHODS

Electronic medical records were assessed for adult patients who had an elective gastrointestinal or gynaecologic surgical procedure over a one-year period. Patient demographics and perioperative data were collected to assess risk factors and the incidence of postoperative nausea and vomiting. The appropriateness of prophylaxis and treatment was assessed according to current guidelines.

RESULTS

The incidence of postoperative nausea and vomiting was consistent with previously noted findings. The average time spent under anaesthesia was significantly higher in patients who experienced postoperative nausea and vomiting. Appropriate evidence-based rescue therapy was administered in a minority of the cohort experiencing postoperative nausea and vomiting.

CONCLUSION

There is substantial opportunity for provider education and adherence to best prescribing practices. Enhanced adherence to evidence-based rescue therapy prescribing may improve patient outcomes and satisfaction.

The Effects of Bispectral Index-Guided Anesthesia on Postoperative Delirium in Elderly Patients: A Systematic Review and Meta-Analysis

OBJECTIVE

Postoperative delirium (POD) is a form of delirium that affects patients who have undergone surgical procedures and anesthesia, usually peaking between 1 and 3 days after their operation. The aim of this meta-analysis was to determine whether monitoring of depth of anesthesia may influence the incidence of POD.

METHODS

A systematic literature search was conducted on studies that reported POD in elderly patients (>60 years old) who underwent surgery. This meta-analysis was carried out using random-effects model.

RESULTS

Compared with control group, intraoperative bispectral index (BIS) monitoring reduced POD (odds ratio 1.32, 95% confidence interval 1.11-1.57, P = 0.001, I² = 51%). In the mixed-surgery group, compared with the control group, BIS monitoring decreased the incidence of POD (odds ratio 1.24, 95% confidence interval 1.07-1.44, P = 0.004, I² = 61%). There was also no significant difference in the incidence of POD among patients who underwent cardiac, colon, and orthopedic surgeries.

CONCLUSIONS

BIS monitoring during surgery can reduce the incidence of POD in elderly patients. Whether BIS monitoring may reduce the incidence of POD in a single type of surgery needs further study.

Is there a place for genetics in the management of PONV?

Antiemetic prophylaxis for postoperative nausea and vomiting (PONV) - a frequent complication in the postoperative period - is routinely given to high-risk patients. However, standard PONV risk models do not account for genetic factors, which have been shown to have a significant influence on PONV incidence and drug response. In this review, we describe the polymorphisms of various genes (serotonin, dopamine, cholinergic, etc.) and how pharmacogenomics is involved in the pathophysiology of PONV. This review also addresses how genetics is involved in today's clinical practice related to PONV and how it will change in the upcoming years as personalized medicine advances.

Propofol-based total intravenous anesthesia decreases the incidence of postoperative nausea and vomiting without affecting flap survival in free flap breast reconstruction

Background

Postoperative nausea and vomiting (PONV) may cause undesirable effects after microsurgical breast reconstruction. Although total intravenous anesthesia (TIVA) with propofol has been demonstrated to be effective in reducing PONV, it has not been assessed in autologous free flap breast reconstruction. The purpose of this study was to investigate the antiemetic prophylaxis effect and safety of TIVA in microvascular breast reconstruction.

Methods

Eighty-three patients undergoing microsurgical breast reconstruction with propofol (31 patients) or sevoflurane (52 patients) were retrospectively reviewed. The incidence of PONV was assessed at 2, 6, and 24 hours after surgery. Mean arterial blood pressure (MAP) was compared at T₁ (after flap elevation but before transfer), T₂ (15 minutes after revascularization), and T₃ (at the end of surgery).

Results

The incidence of nausea was significantly reduced in the TIVA group over 0 to 2 hours period (P=0.017), and over 2 to 6 hours period (P=0.033). The incidence of vomiting was significantly reduced in the TIVA group over 0 to 2 hours period (P=0.006), and over 2 to 6 hours period (P=0.005). MAP was higher in the TIVA group at T₁ (P=0.018), T₂ (P=0.005), and T₃ (P=0.007). The incidence of flap failure was similar between the two groups (P=0.373).

Conclusions

Compared with sevoflurane maintaining anesthesia, propofol-based TIVA improves PONV with less fluctuation of MAP, and did not affect flap survival.

Guidelines for Perioperative Care in Cytoreductive Surgery (CRS) with or without hyperthermic IntraPEritoneal chemotherapy (HIPEC): Enhanced recovery after surgery (ERAS®) Society Recommendations - Part I: Preoperative and intraoperative management

BACKGROUND

Enhanced recovery after surgery (ERAS) pathways have been shown to considerably reduce complications, length of stay and costs after most of surgical procedures by standardised application of best evidence-based perioperative care. The aim was to elaborate dedicated recommendations for cytoreductive surgery (CRS) ± hyperthermic intraperitoneal chemotherapy (HIPEC) in a two-part series of guidelines based on expert consensus. The present part I of the guidelines highlights preoperative and intraoperative management.

METHODS

The core group assembled a multidisciplinary panel of 24 experts involved in peritoneal surface malignancy surgery representing the fields of general surgery (n = 12), gynaecological surgery (n = 6), and anaesthesia (n = 6). Experts systematically reviewed and summarized the available evidence on 72 identified perioperative care items, following the GRADE (grading of recommendations, assessment, development, evaluation) system. Final consensus (defined as ≥50%, or ≥70% of weak/strong recommendations combined) was reached by a standardised 2-round Delphi process, regarding the strength of recommendations.

RESULTS

Response rates were 100% for both Delphi rounds. Quality of evidence was evaluated high, moderate low and very low, for 15 (21%), 26 (36%), 29 (40%) and 2 items, respectively. Consensus was reached for 71/72(98.6%) items. Strong recommendations were defined for 37 items, No consensus could be reached regarding the preemptive use of fresh frozen plasma.

CONCLUSION

The present ERAS recommendations for CRS±HIPEC are based on a standardised expert consensus process providing clinicians with valuable guidance. There is an urgent need to produce high quality studies for CRS±HIPEC and to prospectively evaluate recommendations in clinical practice.

The combination of transversus abdominis plane block and rectus sheath block reduced postoperative pain after splenectomy: a randomized trial

Background

Splenectomy performed with a curved incision results in severe postoperative pain. The aim of this study was to evaluate the effect of transversus abdominis plane block and rectus sheath block on postoperative pain relief and recovery.

Methods

A total of 150 patients were randomized into the control (C), levobupivacaine (L) and levobupivacaine/morphine (LM) groups. The patients in the C group received only patient-controlled analgesia. The patients in the L and LM groups received transversus abdominis plane block and rectus sheath block with levobupivacaine or levobupivacaine plus morphine. The intraoperative opioid consumption; postoperative pain score; time to first analgesic use; postoperative recovery data, including the times of first exhaust, defecation, oral intake and off-bed activity; the incidence of postoperative nausea and vomiting and antiemetics use; and the satisfaction score were recorded.

Results

Transversus abdominis plane block and rectus sheath block reduced intraoperative opioid consumption. The patients in the LM group showed lower postoperative pain scores, opioid consumption, postoperative nausea and vomiting incidence and antiemetic use and presented shorter recovery times and higher satisfaction scores.

Conclusions

The combination of transversus abdominis plane block and rectus sheath block with levobupivacaine and morphine can improve postoperative pain relief, reduce the consumption of analgesics, and partly accelerate postoperative recovery.

Trial registration

Chinese Clinical Trial Registry, ChiCTR 1,800,015,141, 10 March 2018.

The effect of bispectral index monitoring on cognitive performance following sedation for outpatient colonoscopy: a randomized controlled trial

BACKGROUND

Bispectral index (BIS) monitoring can positively affect cognitive performance through decreasing the use of sedative agents. We aimed to evaluate the effect of BIS monitoring on early cognitive performance among patients undergoing sedation for colonoscopy.

DESIGN AND SETTING

Randomized, controlled trial in a university hospital.

METHODS

100 patients were randomized into two groups. In the monitored group (n = 50), the depth of anesthesia was monitored using the BIS, and BIS scores were maintained between 60 and 80. In the usual care group (n = 50), BIS monitoring was not performed. To determine the patients' baseline cognitive performance levels, the mini-mental state examination (MMSE), Trieger dot test (TDT) and clock drawing test (CDT) were used. The patients' post-procedure cognitive performance levels were determined when they were classified as ready for discharge.

RESULTS

The total volume (mg) of propofol used [median (range) IQR] in the sedation procedure was lower in the monitored group [100 (50-200) 100-140] than in the usual care group [150 (75-200) 100-200] (P < 0.001). The discharge scores [mean (SD)] using MMSE and CDT were higher in the monitored group [26 (3) and 3 (1), respectively] than in the usual care group [23 (3) and 2 (1), respectively] (P = 0.002 and P = 0.002, respectively). The discharge scores using TDT [mean (SD)] were lower in the monitored group [11 (7)] than in the usual care group [15 (11)] (P = 0.033).

CONCLUSION

BIS monitoring among sedated patients was associated with lower propofol use and smaller decline in cognitive performance.

CLINICAL TRIAL REGISTRATION

This trial was registered in the Australian New Zealand Clinical Trial Registry (ACTRN12617000134325).

Enhanced Recovery After Surgery: Are the Principles Applicable to Adult and Geriatric Acute Care and Trauma Surgery?

The incorporation of enhanced recovery after surgery (ERAS) fundamentals into perioperative medicine has improved the patient care experience and hastened recovery time while reducing hospital costs. Research studies have shown that incorporating ERAS principles in the adult or geriatric acute care surgery populations minimizes time to resumption of preoperative activity and reduces hospital length of stay. ERAS principles are widely applicable to these patient cohorts and may be applicable in trauma patients. Increased physician and nursing education to promote widespread utilization of enhanced recovery protocols will further improve quality of health care administered in the twenty-first century.

The Role of Endoscopic Sphenopalatine Ganglion Block on Nausea and Vomiting After Sinus Surgery

Background Postoperative nausea and vomiting (PONV) are among the most common unpleasant and distressing adverse events following surgery under general anesthesia. Functional endoscopic sinus surgery (FESS) is a common otolaryngology procedure. Prevention of PONV and early recovery are cost-effective. Objective The aim of this study was to evaluate the prophylactic effect of bilateral endoscopic injection of lidocaine with epinephrine in the sphenopalatine ganglion (SPG) on PONV in patients undergoing FESS. Methods One hundred patients with chronic rhinosinusitis undergoing general anesthesia for FESS were enrolled in this double-blind, placebo-controlled study. Patients were randomized to receive injection of 2 mL of 2% lidocaine with epinephrine or 2 mL of saline at the end of surgery. Postoperatively, patients were observed for 24 h. PONV was evaluated immediately, 6 h, and 24 h after surgery. Results The 2 groups were comparable in characteristic and intraoperative features. In general, the incidence of PONV after FESS was 36%. The average time that patients can tolerate oral feeding was 3.4 h after surgery. Endoscopic SPG injection with lidocaine significantly reduced the incidence of vomiting and PONV. In addition, SPG injection with lidocaine reduced the incidence of severe vomiting and decreased the number of vomiting episodes. No complications were encountered in either group. Conclusion SPG injection with lidocaine at the end of surgery is a safe, noninvasive, and an effective technique in reducing early PONV in endoscopic sinus surgery patients.

The effect of a multifaceted postoperative nausea and vomiting reduction strategy on prophylaxis administration amongst higher-risk adult surgical patients

Postoperative nausea and vomiting (PONV) is a common and distressing problem for patients and increases the burden of care in post-anaesthesia care units (PACU). As such it has been a recent focus for quality improvement. Evidence-based guidelines have demonstrated the benefit of PONV risk stratification and prophylaxis, but may be underutilised in clinical practice. This prospective pre-/post-intervention study was conducted at an adult tertiary hospital in non-cardiac adult surgical patients at higher-risk of PONV. The intervention included promotion of an evidence-based PONV guideline, and provision of individualised prescribing and patient outcome data to anaesthetists. Six hundred and twenty-eight patients with ≥2 risk factors for PONV following general anaesthesia for non-cardiac surgery were included (333 pre-intervention and 295 post-intervention). Prior to the intervention, 9.0% (30/333) of moderate- and high-risk patients received antiemetic prophylaxis consistent with our guideline. Post-intervention, the rate of guideline adherence was 19.3% (57/295). In the high-risk PONV group, the time in PACU was significantly reduced post-intervention, 66 minutes versus 83 minutes (<i>P</i>=0.032). This institution-specific PONV reduction strategy had a modest but significant effect on improving prophylaxis administration. However, our findings indicate that further efforts would be required to ensure fuller compliance with the current extensive evidence base for PONV management in higher-risk patients.

BIS Monitoring on Intraoperative Awareness: A Meta-analysis

Intraoperative awareness is a very serious complication of general anesthesia. Several studies have evaluated the potential association between bispectral index (BIS) and intraoperative awareness, however, the results obtained were controversial. Therefore, we performed a meta-analysis to further assess the association between the BIS monitoring and the incidence of intraoperative awareness. A comprehensive search was conducted to identify all eligible studies from the online literature databases published prior to Feb. 2017. A total of five studies with 17 432 cases and 16 749 controls were included. An odds ratio (OR) and a 95% confidence interval (CI) were calculated to examine the strength of the association. The results showed that in the overall analysis, the association between the BIS monitoring and the incidence of intraoperative awareness was not significant (OR=0.58, 95% CI= 0.22-1.58, P=0.29). A stratified analysis by comparing different anesthesia methods revealed that BIS monitoring group showed a lower incidence of intraoperative awareness in patients with intravenous anesthesia when compared with non-BIS monitoring group (OR=0.20, 95% CI=0.08-0.49, P=0.0004), whereas there was no statistically significant difference in the incidence of intraoperative awareness between BIS and non-BIS monitoring groups in patients with inhalation anesthesia (OR=1.13, 95% CI=0.56-2.26, P=0.73). In conclusion, our meta-analysis showed that BIS monitoring had no appreciable advantage in the reduction of the intraoperative awareness incidence in inhalation anesthesia, while showed a remarkable superiority in intravenous anesthesia.

Comparison of Palonosetron with Granisetron for Prevention of Postoperative Nausea and Vomiting in Patients Undergoing Laparoscopic Abdominal Surgery

Background:

In patients undergoing laparoscopic surgeries, postoperative nausea and vomiting (PONV) is a serious concern. With an incidence of 46%–72%, PONV hampers the postoperative recovery in spite of the availability of many antiemetic drugs. The purpose of this study was to prospectively evaluate the efficacy of palonosetron and granisetron for the prevention of PONV in patients undergoing laparoscopic abdominal surgery.

Aims:

The aim of this study was to evaluate and compare the efficacy of palonosetron and granisetron in preventing PONV and to compare the duration of action and side effects in patients undergoing laparoscopic abdominal surgery under general anesthesia.

Settings and Design:

Eighty patients who were comparable in all aspects were considered for this study. After their consent, they participated in this prospective, randomized, double-blinded, comparative study.

Materials and Methods:

In this observational study, 80 patients of either gender who were undergoing laparoscopic abdominal surgery under general anesthesia were enrolled in the study. Based on computer randomization, these patients were divided equally into two groups of 40 patients each in double-blinded manner. The treatments were given intravenously 5 min before induction of anesthesia. The episodes of PONV, severity of nausea/vomiting, and side effects were observed during the first 48 h after surgery.

Statistical Tests:

At the end of study, results were compiled and SPSS^® statistical package version 18.0 (SPSS Inc., Chicago, IL, USA). Two independent samples t-test was used for quantitative data, and Chi-square or Fisher's exact test was used for qualitative data. P < 0.05 was considered significant.

Results:

The incidence of PONV during 0–2 h in the postoperative period was 15% with palonosetron and 27.5% with granisetron; the incidence during 2–24 h postoperatively was 20% with palonosetron and 30% with granisetron. Both palonosetron and granisetron had comparable effectiveness as antiemetic during the early postoperative periods (0–24 h). During 24–48 h, the incidence was 17.5% and 37.5%, respectively (P = 0.04). Safety profile was similar in both the groups (P = 0.6).

Conclusion:

There were no significant differences in the overall incidence of PONV and complete responders for palonosetron and granisetron group in the early recovery period. However, due to its prolonged duration of action, palonosetron was more effective than granisetron for long-term prevention of PONV after laparoscopic abdominal surgery.

Effects of remifentanil versus nitrous oxide on postoperative nausea, vomiting, and pain in patients receiving thyroidectomy: Propensity score matching analysis

Remifentanil and nitrous oxide (N2O) are 2 commonly used anesthetic agents. Both these agents are known risk factors for postoperative nausea and vomiting (PONV). However, remifentanil and N2O have not been directly compared in a published study. Remifentanil can induce acute tolerance or hyperalgesia, thus affecting postoperative pain. The objective of this retrospective study is to compare the effects of remifentanil and N2O on PONV and pain in patients receiving intravenous patient-controlled analgesia (IV-PCA) after thyroidectomy.We analyzed the electronic medical records of 992 patients receiving fentanyl-based IV-PCA after thyroidectomy at Chung-Ang University Hospital from January 1, 2010 to April 30, 2016. We categorized the patients according to anesthetic agents used: group N2O (n = 745) and group remifentanil (n = 247). The propensity score matching method was used to match patients in the 2 groups based on their covariates. Finally, 128 matched subjects were selected from each group.There were no differences between groups for all covariates after propensity score matching. The numeric rating scale for nausea (0.55 ± 0.88 vs 0.27 ± 0.76, P = 0.01) was higher and complete response (88 [68.8%] vs 106 [82.8%], P = 0.001) was lower in group N2O compared with group remifentanil on postoperative day 0. However, the visual analog scale score for pain (3.47 ± 2.02 vs 3.97 ± 1.48, P = 0.025) was higher in group remifentanil than group N2O on postoperative day 0.In patients receiving IV-PCA after thyroidectomy, postoperative nausea was lower but postoperative pain was higher in group remifentanil.

Remifentanil in Combination With Propofol Is Suitable for Use in the Dental Outpatient Setting

Although several adjuncts to the general anesthetic propofol have been proposed, there is insufficient research identifying the ideal agent, and in what dosage, to combine with propofol in dental outpatient anesthesia. Here we examined the combination of remifentanil or nitrous oxide and propofol in patients with severe dental avoidance undergoing dental treatment in the outpatient setting. Eighty patients were randomized to 4 groups and administered propofol/saline solution (PS; n = 20), propofol/remifentanil 0.25 μg/kg/min (PRe-0.25; n = 20), propofol/remifentanil 0.125 μg/kg/min (PRe-0.125; n = 20), or propofol/66% nitrous oxide (PN; n = 20). During anesthesia, the bispectral index value was kept between 40 and 60. Body movements and hemodynamic changes during anesthesia, emergence, and recovery as well as anesthetic cost were compared between the combinations. Body movements were observed in all patients administered PS but in no patients administered PRe-0.25, PRe-0.125, or PN. Postoperative nausea was observed in 5 patients (25%) administered PRe-0.25 and in 1 patient (5%) administered PN. Although both PRe-0.125 and PN were useful clinically, PRe-0.125 was the least expensive combination.

Palonosetron and granisetron in postoperative nausea vomiting: A randomized double-blind prospective study

BACKGROUND

Postoperative nausea and vomiting (PONV) is a common occurrence after laparoscopic surgeries. A number of pharmacological agents (antihistamines, butyrophenones, dopamine receptor antagonists) have been tried of which the 5-hydroxytryptamine type 3 receptor antagonists are devoid of most side effects and highly effective in prevention and treatment of PONV. Thus, we evaluated the effectiveness of granisetron and palonosetron in prevention of PONV after laparoscopic surgeries under general anesthesia.

AIMS

We conducted a study to evaluate the effectiveness of granisetron and palonosetron, to compare the duration of action and side effects if any, in patients undergoing elective laparoscopic surgery under general anesthesia.

SETTINGS AND DESIGN

This was a prospective, randomized, double-blinded, comparative study. Sixty patients (18-65 years of age) of the American Society of Anesthesiologists Grade I and II undergoing elective laparoscopic surgeries were considered.

MATERIALS AND METHODS

They were randomly allocated into one of the two groups (Group G and Group P) of thirty patients each. Group G received injection granisetron 0.05 mg/kg; Group P received injection palonosetron 1.5 mcg/kg intravenous bolus 30 min before the induction of anesthesia.

STATISTICAL TESTS

All statistical analyses were performed using the SPSS® statistical package version 18.0 (Chicago: SPSS Inc). Two independent sample t-test was used for quantitative data, and the χ2 or Fisher's exact test was used for qualitative data. A difference was regarded as statistically significant at a P < 0.05.

RESULTS

The need for rescue antiemetic was significantly lower in Group P in the 24-72 h postoperative period (ρ - 0.007). The PONV score was significantly less in Group P in the same period (ρ - 0.008). The incidence of side effects was statistically insignificant in both the groups (ρ - 0.999).

CONCLUSION

Prophylactic therapy with palonosetron is more effective than granisetron in the prevention of PONV after laparoscopic surgeries under general anesthesia.

Nitrous oxide-based versus nitrous oxide-free general anaesthesia and accidental awareness during general anaesthesia in surgical patients

BACKGROUND

Accidental awareness during general anaesthesia (AAGA) is when a patient unintentionally becomes conscious during a procedure performed with general anaesthesia and subsequently has explicit recall of this event. Incidence estimates for AAGA vary, with the most common estimate being one to two cases per 1000 general anaesthetics. Evidence linking nitrous oxide use and an increased risk of AAGA has come from observational studies data but the literature is contradictory, with some studies finding a protective effect of nitrous oxide.

OBJECTIVES

To assess the effect of general anaesthesia including nitrous oxide on the risk of AAGA in patients aged five years and over.

SEARCH METHODS

We searched the following databases: Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and trial registers ((www.clinicaltrials.gov), the WHO International Clinical Trials Registry Platform (www.who.int/ictrp/network/en/) and Current Controlled Trials (www.isrctn.com/)) for eligible studies on December 9 2015. In addition, we conducted forward and backward citation searching using key identified papers.

SELECTION CRITERIA

We considered all randomized controlled trials (RCTs), including quasi-randomized studies and cluster-randomized studies, of participants aged five years or older receiving general anaesthesia for any type of surgery.We included trials in which participants receiving general anaesthesia that included nitrous oxide for maintenance at a concentration of at least 30% were compared with participants receiving no nitrous oxide during general anaesthesia. The intervention group must have received nitrous oxide in conjunction with an additional anaesthetic. We excluded studies where the depth of anaesthesia differed between the study arms. For inclusion in the review, studies needed to state in their methods that they planned to assess AAGA. We defined this as when a patient becomes conscious during a procedure performed with general anaesthesia and subsequently has explicit recall of this event.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane to identify studies. We extracted data and conducted 'Risk of bias' assessment using the Covidence database.

MAIN RESULTS

We included 15 studies. The total number of participants included in the analyses was 3520. Most studies were small with fewer than 120 participants, although two larger studies with 2012 and 671 participants were included. There was considerable variation in many of the study characteristics, including the anaesthetics used. The concentrations of nitrous oxide varied between 50% and 70%, and half of the studies used clinical signs and haemodynamic changes to monitor depth of anaesthesia.As it was not possible to blind the anaesthetist to the anaesthetic used, we rated all studies at high risk of performance bias and we therefore downgraded the quality of evidence by one level for risk of bias using the GRADE approach. Other types of bias were generally low, or were rated unclear due to missing information.No studies were designed to measure AAGA as the primary outcome, and were therefore statistically underpowered to answer this review question. Despite the inclusion of 3520 participants, only three awareness events were reported by two studies. In one study the event was due to technical failure. Due to the rarity of the events, we did not consider it appropriate to pool the data, and we therefore downgraded the quality of evidence by a further level for imprecision using GRADE.

AUTHORS' CONCLUSIONS

It is not possible to draw any conclusions from this review. The included studies were mainly small (fewer than 120 participants) and there were limited estimates of effect, with only two studies reporting any events. We cannot therefore determine whether the use of nitrous oxide in general anaesthesia increases, decreases or has no effect on the risk of accidental awareness.

Severe Nausea and Vomiting in the Evaluation of Nitrous Oxide in the Gas Mixture for Anesthesia II Trial

Background

The Evaluation of Nitrous oxide in the Gas Mixture for Anesthesia II trial randomly assigned 7,112 noncardiac surgery patients to a nitrous oxide or nitrous oxide–free anesthetic; severe postoperative nausea and vomiting (PONV) was a prespecified secondary end point. Thus, the authors evaluated the association between nitrous oxide, severe PONV, and effectiveness of PONV prophylaxis in this setting.

Methods

Univariate and multivariate analyses of patient, surgical, and other perioperative characteristics were used to identify the risk factors for severe PONV and to measure the impact of severe PONV on patient outcomes.

Results

Avoiding nitrous oxide reduced the risk of severe PONV (11 vs. 15%; risk ratio [RR], 0.74 [95% CI, 0.63 to 0.84]; P &lt; 0.001), with a stronger effect in Asian patients (RR, 0.55 [95% CI, 0.43 to 0.69]; interaction P = 0.004) but lower effect in those who received PONV prophylaxis (RR, 0.89 [95% CI, 0.76 to 1.05]; P = 0.18). Gastrointestinal surgery was associated with an increased risk of severe PONV when compared with most other types of surgery (P &lt; 0.001). Patients with severe PONV had lower quality of recovery scores (10.4 [95% CI, 10.2 to 10.7] vs. 13.1 [95% CI, 13.0 to 13.2], P &lt; 0.0005); severe PONV was associated with postoperative fever (15 vs. 20%, P = 0.001). Patients with severe PONV had a longer hospital stay (adjusted hazard ratio, 1.14 [95% CI, 1.05 to 1.23], P = 0.002).

Conclusions

The increased risk of PONV with nitrous oxide is near eliminated by antiemetic prophylaxis. Severe PONV, which is seen in more than 10% of patients, is associated with postoperative fever, poor quality of recovery, and prolonged hospitalization.

Applicability of Risk Scores for Postoperative Nausea and Vomiting in a Taiwanese Population Undergoing General Anaesthesia

Five popular scoring systems for postoperative nausea and vomiting (PONV) were validated and compared with two new predictive models in a Taiwanese population. Nine hundred and ninety-two patients receiving general anaesthesia in a tertiary hospital were investigated in a prospective observational cohort study. Patient demographic data and the incidence of nausea or vomiting in the first 24 hours after surgery were recorded. The overall incidence of PONV was 42%. The area under the curve (AUC) of the five published PONV risk scoring systems was 0.62 to 0.67. Logistic regression analysis in this study cohort showed that female sex and a history of PONV/car sickness were the only statistically significant independent risk factors for PONV (likelihood ratio test P <0.001). The AUCs of our two-predictor and gender-only models were 0.668 and 0.643, respectively (Nagelkerke R2=0.122 and 0.109). Goodness-of-fit showed that a two-predictor model predicted an outcome that was in agreement with the observed outcome ( P=0.973). Both the two-predictor model and the Apfel score had a similar AUC that was significantly different from the AUCs of the other models. The AUC for the gender-only model in our population was similar to that of the simplified Koivuranta and the Palazzo and Evans scores (AUC=0.659 and 0.632; P=0.137 and 0.513 respectively). All AUCs had only moderate discrimination power but our female gender-only model was much simpler. Using female gender as the only predictor of PONV had predictive power with 75% sensitivity and 54% specificity.

Prediction of Nociceptive Responses during Sedation by Linear and Non-Linear Measures of EEG Signals in High Frequencies

The level of sedation in patients undergoing medical procedures evolves continuously, affected by the interaction between the effect of the anesthetic and analgesic agents and the pain stimuli. The monitors of depth of anesthesia, based on the analysis of the electroencephalogram (EEG), have been progressively introduced into the daily practice to provide additional information about the state of the patient. However, the quantification of analgesia still remains an open problem. The purpose of this work is to improve the prediction of nociceptive responses with linear and non-linear measures calculated from EEG signal filtered in frequency bands higher than the traditional bands. Power spectral density and auto-mutual information function was applied in order to predict the presence or absence of the nociceptive responses to different stimuli during sedation in endoscopy procedure. The proposed measures exhibit better performances than the bispectral index (BIS). Values of prediction probability of Pk above 0.75 and percentages of sensitivity and specificity above 70% were achieved combining EEG measures from the traditional frequency bands and higher frequency bands.

Palonosetron, Ondansetron, and Granisetron for antiemetic prophylaxis of postoperative nausea and vomiting - A comparative evaluation

Background:

Postoperative nausea and vomiting is commonly associated with adverse consequences and hamper the postoperative recovery in spite of the availability of many antiemetic drugs and regimens for its prevention. The study was aimed to compare the prophylactic effects of intravenously administered palonosetron, ondansetron, and granisetron on prevention of postoperative nausea and vomiting after general anesthesia.

Materials and Methods:

This prospective, double-blind study, comprised 120 adult consented patients of ASA grade I and II of either gender, was carried out after approval of Institutional Ethical Committee. Patients were randomized into three equal groups of 40 patients each in double-blind manner. Group P received inj. palonosetron (0.075 mg), group O received inj. ondansetron (4 mg), and group G received inj. granisetron (2 mg) intravenously five minutes before induction of anesthesia. The need for rescue antiemetic, episode of postoperative nausea and vomiting, and side effects were observed for 12 hours in the post-anesthesia care unit. At the end of study, results were compiled and statistical analysis was done by using ANOVA, Chi-square test, and Kruskal Wallis Test. Value of P < 0.05 was considered significant.

Results:

The incidence of nausea and vomiting was maximal during the first four hours postoperatively. The complete control of postoperative nausea and vomiting for first 12 hours was achieved in 30% patients of ondansetron group, 55% patients of granisetron group, and 90% patients of palonosetron group. Safety profile was more with palonosetron.

Conclusion:

Palonosetron was comparatively highly effective to prevent the PONV after anesthesia due to its prolonged duration of action than ondansetron and granisetron.

Pure oxygen ventilation during general anaesthesia does not result in increased postoperative respiratory morbidity but decreases surgical site infection. An observational clinical study

Background. Pure oxygen ventilation during anaesthesia is debatable, as it may lead to development of atelectasis. Rationale of the study was to demonstrate the harmlessness of ventilation with pure oxygen.

Methods. This is a single-centre, one-department observational trial. Prospectively collected routine-data of 76,784 patients undergoing general, gynaecological, orthopaedic, and vascular surgery during 1995–2009 were retrospectively analysed. Postoperative hypoxia, unplanned ICU-admission, surgical site infection (SSI), postoperative nausea and vomiting (PONV), and hospital mortality were continuously recorded. During 1996 the anaesthetic ventilation for all patients was changed from 30% oxygen plus 70% nitrous oxide to 100% oxygen in low-flow mode. Therefore, in order to minimize the potential of confounding due to a variety of treatments being used, we directly compared years 1995 (30% oxygen) and 1997 (100%), whereas the period 1998 to 2009 is simply described.

Results. Comparing 1995 to 1997 pure oxygen ventilation led to a decreased incidence of postoperative hypoxic events (4.3 to 3.0%; p < 0.0001) and hospital mortality (2.1 to 1.6%; p = 0.088) as well as SSI (8.0 to 5.0%; p < 0.0001) and PONV (21.6 to 17.5%; p < 0.0001). There was no effect on unplanned ICU-admission (1.1 to 0.9; p = 0.18).

Conclusions. The observed effects may be partly due to pure oxygen ventilation, abandonment of nitrous oxide, and application of low-flow anesthesia. Pure oxygen ventilation during general anaesthesia is harmless, as long as certain standards are adhered to. It makes anaesthesia simpler and safer and may reduce clinical morbidity, such as postoperative hypoxia and surgical site infection.

Nitrous oxide-related postoperative nausea and vomiting depends on duration of exposure

BACKGROUND

Inclusion of nitrous oxide in the gas mixture has been implicated in postoperative nausea and vomiting (PONV) in numerous studies. However, these studies have not examined whether duration of exposure was a significant covariate. This distinction might affect the future place of nitrous oxide in clinical practice.

METHODS

PubMed listed journals reporting trials in which patients randomized to a nitrous oxide or nitrous oxide-free anesthetic for surgery were included, where the incidence of PONV within the first 24 postoperative hours and mean duration of anesthesia was reported. Meta-regression of the log risk ratio for PONV with nitrous oxide (lnRR PONVN2O) versus duration was performed.

RESULTS

Twenty-nine studies in 27 articles met the inclusion criteria, randomizing 10,317 patients. There was a significant relationship between lnRR PONVN2O and duration (r = 0.51, P = 0.002). Risk ratio PONV increased 20% per hour of nitrous oxide after 45 min. The number needed to treat to prevent PONV by avoiding nitrous oxide was 128, 23, and 9 where duration was less than 1, 1 to 2, and over 2 h, respectively. The risk ratio for the overall effect of nitrous oxide on PONV was 1.21 (CIs, 1.04-1.40); P = 0.014.

CONCLUSIONS

This duration-related effect may be via disturbance of methionine and folate metabolism. No clinically significant effect of nitrous oxide on the risk of PONV exists under an hour of exposure. Nitrous oxide-related PONV should not be seen as an impediment to its use in minor or ambulatory surgery.

Gastric Decompression Decreases Postoperative Nausea and Vomiting in ENT Surgery

There is a passive blood flow to the stomach during oral and nasal surgery. It may cause postoperative nausea and vomiting (PONV). We researched the relationship between gastric decompression (GD) and severity of PONV in ear, nose, and throat (ENT) surgery. 137 patients who have been into ENT surgery were included in the study. In Group I (n = 70), patients received GD after surgery before extubation; patients in Group II (n = 67) did not receive GD. In postoperative 2nd, 4th, 8th, and 12th hours, the number and ratio of patients demonstrating PONV were detected to be significantly more in Group II as compared to Group I. PONV was also significantly more severe in Group II as compared to Group I. In Group I, the PONV ratio in the 2nd hour was significantly more for those whose amounts of stomach content aspired were more than 10 mL as compared to those whose stomach content aspired was less than 10 mL. In the 4th, 8th, and 24th hours, there is no statistically significant difference between the stomach content aspired and PONV ratio. GD reduces the incidence and severity of PONV in ENT surgery.

Does anaesthesia with nitrous oxide affect mortality or cardiovascular morbidity? A systematic review with meta-analysis and trial sequential analysis

BACKGROUND

The role of nitrous oxide in modern anaesthetic practice is contentious. One concern is that exposure to nitrous oxide may increase the risk of cardiovascular complications. ENIGMA II is a large randomized clinical trial currently underway which is investigating nitrous oxide and cardiovascular complications. Before the completion of this trial, we performed a systematic review and meta-analysis, using Cochrane methodology, on the outcomes that make up the composite primary outcome.

METHODS

We used conventional meta-analysis and trial sequential analysis (TSA). We reviewed 8282 abstracts and selected 138 that fulfilled our criteria for study type, population, and intervention. We attempted to contact the authors of all the selected publications to check for unpublished outcome data.

RESULTS

Thirteen trials had outcome data eligible for our outcomes. We assessed three of these trials as having a low risk of bias. Using conventional meta-analysis, the relative risk of short-term mortality in the nitrous oxide group was 1.38 [95% confidence interval (CI) 0.22-8.71] and the relative risk of long-term mortality in the nitrous oxide group was 0.94 (95% CI 0.80-1.10). In both cases, TSA demonstrated that the data were far too sparse to make any conclusions. There were insufficient data to perform meta-analysis for stroke, myocardial infarct, pulmonary embolus, or cardiac arrest.

CONCLUSION

This systematic review demonstrated that we currently do not have robust evidence for how nitrous oxide used as part of general anaesthesia affects mortality and cardiovascular complications.

The perioperative use of nitrous oxide: renaissance of an old gas or funeral of an ancient relict?

PURPOSE OF REVIEW

Conflicting reports about adverse events following nitrous oxide (N(2)O) application have spurred a discussion whether N(2)O should be abandoned from clinical practice. Concurrently, N(2)O is increasingly used as a single anesthetic agent in medical procedures. This article reviews and discusses reports about the present use of N(2)O.

RECENT FINDINGS

Multiple publications demonstrate an increasing use of N(2)O as a procedural analgesic and sedative. Results from the Evaluation of Nitrous Oxide in the Gas Mixture for Anesthesia trial have been contrasted by recent studies reporting no increased risk for perioperative complications, particularly related to the cardiovascular and cerebrovascular system. Recent studies show that electroencephalogram-based anesthesia depth monitoring is not compatible with the use of N(2)O because of its distinct influence on electroencephalogram wave patterns. The clinical relevance of the proposed neurotoxicity, immunosuppression and influence on methionine metabolism remains unclear. Recently, its acute and long-term analgesic potency has been proven. Occupational exposure might pose a relevant health hazard.

SUMMARY

Based on the present literature, abolishment of N(2)O is controversial. When avoided in patients at risk for adverse events, N(2)O is still a valuable supplement to general anesthesia and a potent procedural analgesic drug. In the latter, its use by nonanesthesiologists should be discouraged.

Pathophysiological and neurochemical mechanisms of postoperative nausea and vomiting

Clinical research shows that postoperative nausea and vomiting (PONV) is caused primarily by the use of inhalational anesthesia and opioid analgesics. PONV is also increased by several risk predictors, including a young age, female sex, lack of smoking, and a history of motion sickness. Genetic studies are beginning to shed light on the variability in patient experiences of PONV by assessing polymorphisms of gene targets known to play roles in emesis (serotonin type 3, 5-HT3; opioid; muscarinic; and dopamine type 2, D2, receptors) and the metabolism of antiemetic drugs (e.g., ondansetron). Significant numbers of clinical trials have produced valuable information on pharmacological targets important for controlling PONV (e.g., 5-HT3 and D2), leading to the current multi-modal approach to inhibit multiple sites in this complex neural system. Despite these significant advances, there is still a lack of fundamental knowledge of the mechanisms that drive the hindbrain central pattern generator (emesis) and forebrain pathways (nausea) that produce PONV, particularly the responses to inhalational anesthesia. This gap in knowledge has limited the development of novel effective therapies of PONV. The current review presents the state of knowledge on the biological mechanisms responsible for PONV, summarizing both preclinical and clinical evidence. Finally, potential ways to advance the research of PONV and more recent developments on the study of postdischarge nausea and vomiting (PDNV) are discussed.

Prognostic factors for chemotherapy induced nausea and vomiting

PURPOSE

to review the topic of prognostic factors for chemotherapy-induced nausea and vomiting. Multiple patient factors such as age, gender and alcohol intake have been found that affect the likelihood of emesis with a given chemotherapy. Pharmacogenomics has also been explored as a cause for variation in emetic response. In theory these risk factors could be used to optimize antiemetic therapy for individual patients but guidelines for prophylactic antiemetics are based solely upon the type of chemotherapy administered. Attempts to identify subgroups of patients for whom guidelines recommendations are suboptimal have thus far been unsuccessful except for those with a poor experience in a previous cycle of the same chemotherapy. At present, there is no basis for deviating from evidence-based guidelines when prescribing antiemetics prior to the first cycle of chemotherapy.