Peri-operative management of the obese surgical patient 2015: Association of Anaesthetists of Great Britain and Ireland Society for Obesity and Bariatric Anaesthesia

Evaluation of Response to Weight-based Dosing Strategies of Continuous, Fixed-Rate Atracurium Infusions in Critically Ill, Obese Adults With Acute Respiratory Distress Syndrome

BACKGROUND

Fixed-rate infusions of weight-based neuromuscular blocking agents (NMBAs) were adopted during the COVID pandemic to limit caregiver exposure during titrations. Although fixed-rate infusions are supported in studies of acute respiratory distress syndrome (ARDS), the optimal scalar for weight-based NMBAs in patients with obesity remains controversial.

OBJECTIVE

This study sought to compare change in oxygenation using two weight-based dosing strategies for atracurium in obese patients with ARDS. Secondary outcomes included total atracurium dose, mortality, and intensive care unit (ICU) and ventilator-free days.

METHODS

Following an institutional practice update to use ideal body weight (IBW) for patients with obesity, we retrospectively compared adults (≥18 years) with ARDS and a body mass index (BMI) ≥ 30 kg/m2 who received atracurium (15 µg/kg/min) based on actual body weight (ABW) with those using IBW. The primary outcome was change in PaO2/FiO2 ratio (P/F) 48 hours after atracurium initiation. Analysis-of-covariance compared change in P/F between groups after adjustment for confounders.

RESULTS

The IBW group (n = 123), compared with the ABW group (n = 133), had lower baseline P/F (85.0 [71.0, 118.3] vs 93.3 [76.0, 128.3], P = 0.025) and sequential organ failure assessment (SOFA) score (9.7 ± 2.6 vs 10.5 ± 2.6, P = 0.015), with greater use of steroids (96% vs 89%, P = 0.032) and prone positioning (72% vs 58%, P = 0.015). No difference was detected in change in P/F at 48 hours (adjusted least squares mean [95% confidence interval, CI]: 55.8 [37.0, 74.5] vs 56.9 [39.6, 74.1], P = 0.90). Atracurium doses were higher in the ABW group (97.4 mg/h [84.4, 110.3] vs 55.4 [47.2, 65.7], P < 0.001). There was no difference in hospital mortality, ICU mortality, and ICU-free days or ventilator-free days.

CONCLUSION AND RELEVANCE

In patients with obesity with ARDS receiving fixed-rate atracurium infusions, the change in P/F at 48 hours did not differ based on weight. Atracurium dosed on IBW may use less total drug without compromising ability to improve oxygenation. This is the first study comparing the dosing weight used for continuous infusion atracurium in hospitalized, critically ill ARDS patients with obesity. Additional studies are warranted to optimize dosing in obese patients.

Comparison of pre-treatment with different diluted sufentanil in reducing propofol injection pain in gastrointestinal endoscopy: A randomized controlled study

BACKGROUND

This study aimed to investigate the efficacy of pre-treatment with different concentrations of sufentanil in mitigating propofol injection-induced pain.

METHODS

This study included 421 patients who were scheduled for gastrointestinal endoscopy between June 2023 and December 2024. Participants were randomly assigned to one of the four groups with different concentrations sufentanil: 0 µg/mL group(0.9% normal saline), 0.5 µg/mL group, 1 µg/mL group and 5 µg/mL group.

RESULTS

Among the four groups, the rates of pain relief were 82 (77.4%), 93 (89.4%), 96 (89.7%), and 91 (87.5%), respectively. Compared to the 0 µg/mL group, the other groups demonstrated significantly reduced pain following propofol injection (p < 0.05). The recovery times were 14.59 ± 3.92 min, 15.13 ± 3.20 min, 14.27 ± 3.06 min, and 15.57 ± 3.24 min, respectively. Notably, the 1 µg/mL group did not exhibit a prolonged recovery time compared to the 0 µg/mL group. The total propofol consumption was recorded as 218.5 ± 36.8 mg, 196.7 ± 31.0 mg, 183.8 ± 25.0 mg, and 189.6 ± 31.4 mg, respectively, with the 1 µg/mL group showing the lowest total propofol consumption among the groups. The incidences of adverse events (AEs) were 61.3%, 70.2%, 58.9%, and 76.9%, respectively. In comparison to the 1 µg/mL group, the 5 µg/mL group exhibited a higher incidence of AEs. Furthermore, multivariate analysis indicated that a 5 µg/mL dilution of sufentanil increases the risk of AEs (p < 0.05).

CONCLUSIONS

The 1 µg/mL group demonstrated greater safety and efficacy when combined with propofol.

TRIAL REGISTRATION

The study has been registered in the Chinese Clinical Trial Registry (ChiCTR). Link of the registry: http://www.chictr.org.cn. Date of registration: 2023/06/12. Trial registration number: ChiCTR2300072402.

Dosing optimisation of intravenous lidocaine in patients with class 1-3 obesity by population pharmacokinetic analysis

INTRODUCTION

Evidence to support intra-operative lidocaine infusion regimens in patients with obesity is lacking, risking underdosing or toxicity. We aimed to measure the plasma concentrations of lidocaine and its active metabolites to develop a pharmacokinetic model and optimised dosing regimen in patients with obesity.

METHODS

A standardised weight-based intravenous lidocaine regimen was administered to patients with a BMI ≥ 30 kg.m-2 undergoing elective laparoscopic abdominal surgery. Using lean body weight, a 1.5 mg.kg-1 loading dose over 10 min and infusion of 1.5 mg.kg-1.h-1 was administered intra-operatively. Arterial blood was sampled during and after the infusion. The total and unbound plasma concentrations of lidocaine, monoethylglycinexylidide and glycinexylidide were measured using liquid chromatography-mass spectrometry. Monolix was used for population pharmacokinetic analysis. Dosing simulations were performed using Simulx to develop a regimen that best targeted a therapeutic plasma concentration between 2.5 and 5 μg.ml-1.

RESULTS

Thirty patients provided 221 plasma samples (median (IQR [range]) age 51 (44-61 [32-76]) y and 21 female). Median (IQR [range]) total body weight was 107.0 (91.8-132.5 [80.0-189.0]) kg and BMI was 37.7 (33.6-46.5 [30.2-58.4]) kg.m-2. Using total and unbound plasma concentrations of lidocaine, monoethylglycinexylidide and glycinexylidide, a four-compartment model was developed. Unbound lidocaine volume of distribution was 2.1 l.kg-1 and clearance 1.7 l.kg-1.h-1. Simulations showed that doses used currently had a low probability of target attainment of 0%. A loading dose of 2 mg.kg-1 over 20 min followed by an infusion of 3 mg.kg-1.h-1 based on lean body weight improved probability of target attainment to 18.6%. The infusion should be reduced to 2 mg.kg-1.h-1 after 80 min.

DISCUSSION

Our simulated dosing regimen achieved therapeutic concentrations more successfully in patients with obesity. Further studies should evaluate the clinical safety and efficacy of this dosing regimen.

Utilising a modified accelerated Delphi process to develop a national multidisciplinary consensus on peri-operative optimisation of patients with obesity undergoing non-bariatric surgery

BACKGROUND

In the last three decades, the worldwide prevalence of obesity has increased by threefold. Using a modified Delphi consensus technique, the Irish Surgical Research Collaborative (ISRC) aimed to formulate consensus guidelines on the peri-operative optimisation of patients with obesity undergoing non-bariatric surgery.

METHODS

Subgroups within the ISRC were established to formulate consensus statements using a nominal group technique (NGT) to address the three domains of pre-operative, intra-operative and post-operative care. Three Delphi rounds were circulated nationally to multidisciplinary members of the peri-operative team via electronic survey. Consensus was considered achieved for any statement with >80 % agreement. Data was analysed using Microsoft Excel (Microsoft Corp, Redmond, WA).

RESULTS

Following three Delphi rounds, a total of 94 statements centred around optimising peri-operative care for patients with obesity undergoing non-bariatric surgery reached consensus. Pre-operatively, access to prehabilitation, use of pre-operative risk stratification tools and strategies to reduce obesity-related co-morbidities were all deemed important along with nomination of a hospital obesity lead. Intra-operatively, the prioritised domains were involvement of consultant anaesthetist and surgeon for safe and considered patient positioning, utilisation of minimally invasive surgical techniques, adherence to venous thromboembolism prophylaxis and surgical site infection prevention strategies as well as adoption of multimodal analgesia. Appropriate analgesia prescription, nutritional support, enhanced recovery after surgery and the role of physiotherapy were all deemed essential elements of post-operative care.

CONCLUSION

As a multidisciplinary peri-operative group, through Delphi consensus, we report agreed perioperative standards to optimise the perioperative care of patients with obesity undergoing non-bariatric surgery. This consensus can be utilised to standardise clinical practice and identify areas for quality improvement.

Ultrasound-guided transversus abdominis plane block in obese cats: a preliminary cadaveric study

ObjectivesThe aim of the present study was to investigate the distribution of adipose tissue in the abdominal wall of obese cats and compare the injectate spread and spinal nerve staining after ultrasound-guided transversus abdominis plane (TAP) block using lean (LBW) vs actual body weight (ABW).MethodsFour cat cadavers with a body condition score ⩾8/9 were included. Cat 1 was dissected to identify the TAP and describe abdominal fat distribution. Cats 2 and 3 received a two-point ultrasound-guided TAP injection of 0.25 ml/kg/point based on LBW and ABW, respectively. In cat 4, both hemiabdomens were randomly injected with the two volumes. Subsequent anatomic dissection assessed injectate distribution and the number of thoracic (T) and lumbar (L) spinal nerves stained ⩾1 cm circumferentially.ResultsThe mean weight of the cats was 7.5 ± 0.3 kg and they had a body condition score of 9/9. A thick layer of hypoechoic adipose tissue was observed ventral to the costal arch, between the rectus and transversus abdominis muscles, and a second thinner layer between the obliquus internus and transversus abdominis muscles. After crossing the adipose tissue, the ventral branches of spinal nerves lie in the fascial plane, superficial to the transversus abdominis muscle. LBW- and ABW-based injectate volumes stained the ventral branches from T12 to L1 and T11 to L1, respectively.Conclusions and relevanceTwo separate layers of adipose tissues are localized superficially to the transversus abdominis muscle in obese cats. Identifying the transversus abdominis muscle and adipose layers is crucial for the success of the TAP block. Injectate volumes based on ABW may provide wider staining of thoracolumbar spinal nerves than LBW. Further randomized clinical trials are needed in obese cats using locoregional anesthesia.

Regional anesthesia in obese patients: Challenges, considerations, and solutions

The increasing global prevalence of obesity has significant implications for anesthesiologists, particularly in the context of regional anesthesia. Anesthesiologists face numerous challenges during anesthesia in obese patients, including compromised respiratory function, altered pharmacokinetics of local anesthetics, and difficulties in identifying anatomical landmarks. Obesity often leads to reduced respiratory reserve, increased risk of hypoventilation, and conditions such as obstructive sleep apnea syndrome and obesity hypoventilation syndrome, which increase the likelihood of postoperative complications. Additionally, altered body composition in obese patients affects the distribution of local anesthetics, requiring adjustments in dosing based on lean body weight rather than total body weight. Furthermore, excess adipose tissue complicates the identification of anatomical landmarks and the use of ultrasound for regional block procedures, as the increased tissue depth and reduced image resolution hinder needle placement. Proper positioning, the use of low-frequency transducers, and harmonic imaging techniques are essential for optimizing ultrasound guidance. Additionally, the use of longer needles and the application of trigonometric calculations based on ultrasound scans can help determine the appropriate needle length. To overcome these challenges, anesthesiologists should adopt strategies that involve adjusting drug dosages, utilizing specialized equipment, and continuously monitoring patients for potential complications. A holistic approach involving knowledge of these technical and pathological challenges, as well as adapting techniques and equipment, is crucial for ensuring the safety and effectiveness of regional anesthesia in obese patients.

Anesthetic Considerations in Athletes: A Review

Athletes present a unique challenge for anesthesiologists because of their specific physiology and the demands of their sport. Anesthesia for athletes requires careful consideration of factors such as muscle mass, hydration status, and the potential for drug interactions with performance-enhancing substances. Additionally, the use of specific anesthetic agents, such as inhalational and intravenous anesthetics, requires adjustments to the dosing regimen to ensure adequate anesthesia. Sports anesthesia is a subspecialty that encompasses not only expert knowledge regarding regional and general anesthesia and pain management but also the pathophysiology unique to athletes and psychological concerns associated with professional sports and complete knowledge about World Anti-Doping Agency guidelines as well as substance abuse. Moreover, the pressure of being scrutinized by a broad circle of concerned persons, including family members, team members, coaches, club owners, media, and fans, makes this an area of excellence and expertise. This review highlights how an athlete's physiological changes can alter anesthetic drug effects. Considering the importance of vigilant preoperative assessment, selecting the proper anesthesia plan, and perioperative strategies for better recovery and performance outcomes.

Airway management and ventilation strategy among obese adult patients: a comprehensive review and analysis

Background

Difficulties with mask ventilation and intubation are more prevalent in obese patients. Hence, health care practitioners engaged in airway management of obese individuals must exercise particular vigilance and care. Ventilation strategies can potentially have a detrimental impact on postoperative pulmonary function, prolong hospital stays, and increase costs. As a result, the aim of this review was to investigate airway management technique and ventilation strategies in obese adult patients.

Methods

The PubMed, HINARI, Google Scholar, and Cochrane Review databases were searched using appropriate keywords and search engines for adequate evidence from studies meeting the inclusion criteria to reveal the endpoint, which was ventilation strategy and airway management in adult obese patients. Duplicate entries were eliminated through EndNote software. Screening of literature was conducted with proper appraisal checklist. This review was reported in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analyses 2020 statement.

Results

The included literature covers a wide range of topics, including preoxygenation, making the patient in a 25° head-up position, use of 10-12cmH2O of positive end-expiratory pressure (PEEP) and continuous positive airway pressure (CPAP) during induction, placing the patient in a ramping posture during intubation, high-flow oxygenation (15 L/min) through the nasopharyngeal airway or nasal cannula during laryngoscopy, using low tidal volume during surgery, a 1:1/1.5:1 I:E ratio, PEEP of 10-20 cmH2O, Fio2 reduced to make SpO2 > 90, pressure-controlled (PC)/volume-controlled (VC) ventilation mode, and recruitment maneuver (RM). Following surgery, it was essential to provide oxygen therapy to maintain preoperative levels, provide CPAP/non-invasive positive pressure ventilation, place patients in semi-sitting positions, and provide thorough postanesthesia care unit monitoring in order to enhance patient outcomes with regard to morbidity and mortality among obese patients. To safely manage and overcome airway challenges in severely obese patients with a suspected difficult airway, awake fiberoptic intubation is recommended.

Conclusions

Positioning the patient in a head-up position (semi-sitting), utilizing CPAP during preoxygenation, and administering oxygen via nasal cannula during intubation to prolong apnoea time and awake fibrotic for suspected difficult airway. Additionally, selecting appropriate ventilation modes (PC/VC), PEEP + RM, and positions during the intraoperative phase is crucial to improving outcomes in obese surgical patients.

Perioperative Medicine for Ambulatory Surgery

Ambulatory anesthesia for same-day surgery is a fast-growing and ever-improving branch of modern anesthesia. This is primarily driven by the involvement of anesthesiologists as perioperative physicians working in multidisciplinary groups. These groups work together to improve patient safety, patient outcomes, and overall efficiency of both in-patient and out-patient surgery. Appropriate patient selection and optimization are critical to maintain and improve the foundational entities of best ambulatory anesthesia practice. In this review article, a selection of considerations in the field of ambulatory anesthesia are featured, such as the aging population, sleep apnea, obesity, diabetes, cardiac disease, substance abuse, preoperative medication management, multimodal analgesia, social determinants of health, and surgical facility resources.

Efficacy of nonopioid analgesics and adjuvants in multimodal analgesia for reducing postoperative opioid consumption and complications in obesity: a systematic review and network meta-analysis

BACKGROUND

Managing postoperative pain in patients with obesity is challenging. Although multimodal analgesia has proved effective for pain relief, the specific impacts of different nonopioid i.v. analgesics and adjuvants on these patients are not well-defined. This study aims to assess the effectiveness of nonsteroidal antiinflammatory drugs, paracetamol, ketamine, α-2 adrenergic receptor agonists, lidocaine, magnesium, and oral gabapentinoids in reducing perioperative opioid consumption and, secondarily, in mitigating the occurrence of general and postoperative pulmonary complications (POPCs), nausea, vomiting, PACU length of stay (LOS), and hospital LOS among surgical patients with obesity.

METHODS

A systematic review and network meta-analysis was performed. PubMed, Scopus, Web of Science, CINAHL, and EMBASE were searched. Only English-language RCTs investigating the use of nonopioid analgesics and adjuvants in adult surgical patients with obesity were included. The quality of evidence and certainty were assessed using the RoB 2 tool and GRADE framework, respectively.

RESULTS

In total, 37 RCTs involving 3602 patients were included in the quantitative analysis. Compared with placebo/no intervention or a comparator, dexmedetomidine, ketamine, lidocaine, magnesium, and gabapentin significantly reduced postoperative opioid consumption after surgery. Ketamine/esketamine also significantly reduced POPCs. Ibuprofen, dexmedetomidine, and lidocaine significantly reduced postoperative nausea, whereas dexmedetomidine, either alone or combined with pregabalin, and lidocaine reduced postoperative vomiting. Dexmedetomidine significantly reduced PACU LOS, whereas both paracetamol and lidocaine reduced hospital LOS.

CONCLUSIONS

Intravenous nonopioid analgesics and adjuvants are crucial in multimodal anaesthesia, reducing opioid consumption and enhancing postoperative care in adult surgical patients with obesity.

SYSTEMATIC REVIEW PROTOCOL

CRD42023399373 (PROSPERO).

Spinal anesthesia in ambulatory patients

PURPOSE OF REVIEW

To assess current practice in the use of spinal anesthesia in major ambulatory surgery, highlighting its advantages over general anesthesia and identifying potential areas for improvement to facilitate a transition to a sustainable healthcare system.

RECENT FINDINGS

Spinal anesthesia might be preferred in selected populations when compared to general anesthesia providing the highest standards of healthcare quality.The use of local anesthetics with short half-life has proven to be efficient in achieving high anesthesia success rates. Spinal anesthesia does not increase perioperative complications; instead, it has shown a reduction in postoperative nausea and vomiting, an improvement in patient comfort, and a favorable economic impact when compared to general anesthesia.

SUMMARY

Spinal anesthesia is an appropriate method for anesthesia in ambulatory patients, offering advantages over general anesthesia in selected populations.The use of spinal anesthesia is expanding to meet surgical needs. Therefore, it is crucial to plan ahead and anticipate organizational failures in the ambulatory setting to maintain safety and efficiency during outpatient procedures and surgeries.

Challenges of laparoscopic radical nephrectomy at the upper limits of obesity

As worldwide obesity rates increase the number of patients with an elevated BMI requiring urological surgery will increase. Although obesity has previously been considered a relative contra-indication to laparoscopic surgery, here we present a case of successful laparoscopic nephrectomy performed due to renal cancer in a patient with a BMI >60 kg/m2 together with a review of the associated challenges.

Health optimisation for patients with obesity before elective orthopaedic surgery: a qualitative study of professionals' views on restrictive approaches and future practice

BACKGROUND

Preoperative health optimisation for elective surgery entails supporting patients to improve their health in preparation for their treatment and recovery. While there is consensus that this process should address obesity, approaches vary across England. Despite guidance from the National Institute for Health and Care Excellence to the contrary, restrictive approaches with body mass index thresholds for referral to arthroplasty are in use. This qualitative study aimed to investigate the views of professionals on the current use and future implications of these policies.

METHODS

Semi-structured interviews were conducted with 20 professionals including clinicians, commissioners, policymakers, and health service managers, with experience of developing and/or implementing health optimisation policies for elective arthroplasty. Participants were sampled from areas in England with and without restrictive policies. We undertook thematic analysis of the interview data.

RESULTS

Participants described pre-surgical health optimisation as an important trigger for health improvement but identified current resourcing and inadequacies in provision of weight management support as significant barriers to success. Participants expressed concerns about the appropriateness and fairness of including obesity as a determinant to restrict access to surgery. They described short-term financial pressures underlying the use of restrictive body mass index thresholds and a lack of an evidence base, such that policies amounted to rationing and risked exacerbations of health inequalities. The study identified four priorities for improvements to future health optimisation practices: developing and implementing national guidance with flexibility for local variation, initiating patient engagement in primary care with onward integration across all services, improving resourcing to support effective equitable impact, and addressing wider determinants of obesity through societal change.

CONCLUSIONS

Overall, participants had limited expectations of the impact of health optimisation policies on obesity without additional support, investment, and national guideline implementation. They raised strong concerns over current restrictive approaches. We conclude that addressing concerns around weight management support service availability and impacts on health inequalities is essential for shaping effective health optimisation policies. Future policy direction should support health optimisation to be offered early (ideally in primary care). Health optimisation interventions should be non-restrictive, inclusive, and well-monitored, particularly around equality impact.

Adapting general anaesthesia for a patient with class III obesity and obstructive sleep apnoea undergoing day case laparoscopic cholecystectomy: A case report

This report describes the anaesthesia provided for a class III obese patient with obstructive sleep apnoea, undergoing an elective laparoscopic cholecystectomy. Several adaptations were required to provide safe anaesthesia. A McGrath video laryngoscopy was utilised for intubation. The patient was positioned in the ramped position, thereby increasing time to desaturation on induction of anaesthesia. Pressure controlled ventilation - volume guaranteed mode was selected for ventilation to provide consistent tidal volumes. An increased level of positive end-expiratory pressure was utilised to minimise atelectasis. Drug doses were carefully considered and calculated with the aid of The Society for Obesity and Bariatric Anaesthesia dose calculator. The airway management adaptations provided an unobstructed view for intubation. Peak airway pressures during surgery remained within safe limits and no atelectasis was evident postoperatively. Pain was kept under control and desaturation was avoided during postanaesthetic care. The patient was discharged home later that evening.

Perioperative Care for Bariatric Surgery

This review will start with a brief pathophysiology of obesity and the requirement for bariatric surgery, and it continues with a preoperative assessment, which includes a surgical mortality risk assessment, respiratory and cardiovascular assessments, and a psychological assessment. In-hospital postoperative care will be discussed, including which patients need a surgical intensive care unit and the monitoring tools required. The need for postoperative medications, postoperative complications, strategies for management, and a follow-up plan are also reviewed. This manuscript is written in a narrative review form with a chance of bias as a possible limitation.

Ultrasonographic Evaluation of Difficult Airway in Obese Patients: A Prospective Study

Background

The management of the airway is difficult in obese patients owing to their anatomical and physiological attributes. This study aims to assess the ultrasonographic measurements of anterior neck soft tissue thickness in diagnosing difficult mask ventilation (DMV) and difficult laryngoscopy (DL) among obese patients.

Methods

Patients of age 18-65 years and body-mass index (BMI) >30 scheduled to undergo general anesthesia for elective surgery were included in the study. Ultrasonography-guided measurements of soft tissue distances were performed in the preoperative evaluation room. The distance between the hyoid bone and skin, distance between vocal chord anterior commissure and skin, distance between the trachea and the skin at the level of the suprasternal notch, distance between the thyroid isthmus and skin, and distance between epiglottis and skin were measured. The degree of DMV and DL was quantified.

Results

A total of 128 patients (30 men and 98 women) were enrolled. The average patient age, BMI, and neck circumference were recorded as 50.4 ± 12.2 years, 38.0 ± 5.19 kg/m2, and 41.3 ± 4.05 cm, respectively. The incidence of DMV and DL was 11.7% and 10.9%, respectively. DMV exhibited a significant correlation with neck circumference (p = 0.02), whereas difficult airways did not demonstrate any association with anterior neck soft tissue ultrasonography measurements.

Conclusion

Anterior neck soft tissue measurements may not be predictive of DL and DMV in obese patients. Further studies might be helpful in developing new predictors for difficult airway in obese patients.

A Comparison of the Effectiveness of the McCoy Laryngoscope and the C-MAC D-Blade Video Laryngoscope in Obese Patients

Background and Objective: Obesity is associated with difficult or failed intubation attempts, making general anesthesia challenging for anesthesiologists to perform. The purpose of this study was to evaluate and compare the efficacy of a McCoy laryngoscope and a C-MAC D-blade video laryngoscope for intubation in obese patients with a body mass index (BMI) ≥ 35 kg/m2. Methods: In total, 104 patients were randomly assigned to be intubated with a McCoy (McCoy group) or C-MAC D-blade video laryngoscope (C-MAC group). The primary outcome was intubation time. The secondary outcomes were vocal cord exposure time, vocal cord passage time, proportion of successful intubation, mask ventilation scale, intubation difficulty scale (IDS), percentage of glottis opening (POGO) score, and hemodynamic variables. Results: Although the intubation time did not significantly differ, the C-MAC group showed shorter vocal cord exposure times and a higher rate of successful vocal cord exposure within 5 s. The IDS value was significantly lower in the C-MAC group than in the McCoy group. The proportion of patients who required an increase in lifting force during laryngoscopy was higher in the McCoy group than in the C-MAC group, which may explain the difference in MAP between the groups. Conclusions: Both the McCoy laryngoscope and the C-MAC D-blade video laryngoscope were useful during the intubation of obese patients. The C-MAC D-blade video laryngoscope might be more useful for obese patients in terms of hemodynamic stability.

Cesarean Section in a Morbidly Obese Patient With Severe Preeclampsia and Pulmonary Edema: A Case Report

Severe preeclampsia and pulmonary edema pose significant challenges for an anesthesiologist. Pregnancy is associated with major physiologic changes to meet the increased demands of the mother and fetus. Preeclampsia complicates this balance by adding additional stress to the mother and baby. Pulmonary edema is a rare complication of preeclampsia, and it is a potentially life-threatening condition. Meticulous care is needed in the anesthetic management of this condition, especially when the patient is morbidly obese and presents for an emergency cesarean section.

Pharmacokinetics of propofol in severely obese surgical patients

BACKGROUND

Existing PK models of propofol include sparse data from very obese patients. The aim of this study was to develop a PK model based on standardised surgical conditions and spanning from normal-weight up to, and including, a high number of very obese patients.

METHODS

Adult patients scheduled for laparoscopic cholecystectomy or bariatric surgery were studied. Anaesthesia was induced with propofol 2 mg/kg adjusted body weight over 2 min followed by 6 mg/kg/h adjusted body weight over 30 min. For the remainder of the operation anaesthesia was maintained with sevoflurane. Remifentanil was dosed according to clinical need. Eight arterial samples were drawn in a randomised block sampling regimen over a span of 24 h. Time-concentration data were analysed by population PK modelling using non-linear mixed-effects modelling.

RESULTS

Four hundred and seventy four serum propofol concentrations were collected from 69 patients aged 19-60 years with a BMI 21.6-67.3 kg/m2. Twenty one patients had a BMI above 50 kg/m2. A 3-compartment PK model was produced wherein three different body weight descriptors and sex were included as covariates in the final model. Total body weight was found to be a covariate for clearance and Q3; lean body weight for V1, V2 and Q2; predicted normal weight for V3 and sex for V1. The fixed allometric exponent of 0.75 applied to all clearance parameters improved the performance of the model. Accuracy and precision were 1.4% and 21.7% respectively in post-hoc performance evaluation.

CONCLUSION

We have developed a new PK model of propofol that is suitable for all adult weight classes. Specifically, it is based on data from an unprecedented number of individuals with very high BMI.

Pre-oxygenation with high-flow oxygen through the nasopharyngeal airway compared to facemask on carbon dioxide clearance in emergency adults: a prospective randomized non-blinded clinical trial

INTRODUCTION

Before tracheal intubation, it is essential to provide sufficient oxygen reserve for emergency patients with full stomachs. Recent studies have demonstrated that high-flow nasal oxygen (HFNO) effectively pre-oxygenates and prolongs apneic oxygenation during tracheal intubation. Despite its effectiveness, the use of HFNO remains controversial due to concerns regarding carbon dioxide clearance. The air leakage and unknown upper airway obstruction during HFNO therapy cause reduced oxygen flow above the vocal cords, possibly weaken the carbon dioxide clearance.

METHODS

Patients requiring emergency surgery who had fasted < 8 h and not drunk < 2 h were randomly assigned to the high-flow group, who received 100% oxygen at 30-60 L/min through nasopharyngeal airway (NPA), or the mask group, who received 100% oxygen at 8 L/min. PaO2 and PaCO2 were measured immediately before pre-oxygenation (T0), anesthesia induction (T1), tracheal intubation (T2), and mechanical ventilation (T3). The gastric antrum's cross-sectional area (CSA) was measured using ultrasound technology at T0, T1, and T3. Details of complications, including hypoxemia, reflux, nasopharyngeal bleeding, postoperative pulmonary infection, postoperative nausea and vomiting (PONV), and postoperative nasopharyngeal pain, were recorded. The primary outcomes were PaCO2 measured at T1, T2, and T3. The secondary outcomes included PaO2 at T1, T2, and T3, CSA at T1 and T3, and complications happened during this trial.

RESULTS

Pre-oxygenation was administered by high-flow oxygen through NPA (n = 58) or facemask (n = 57) to 115 patients. The mean (SD) PaCO2 was 32.3 (6.7) mmHg in the high-flow group and 34.6 (5.2) mmHg in the mask group (P = 0.045) at T1, 45.0 (5.5) mmHg and 49.4 (4.6) mmHg (P < 0.001) at T2, and 47.9 (5.1) mmHg and 52.9 (4.6) mmHg (P < 0.001) at T3, respectively. The median ([IQR] [range]) PaO2 in the high-flow and mask groups was 404.5 (329.1-458.1 [159.8-552.9]) mmHg and 358.9 (274.0-413.3 [129.0-539.1]) mmHg (P = 0.007) at T1, 343.0 (251.6-428.7 [73.9-522.1]) mmHg and 258.3 (162.5-347.5 [56.0-481.0]) mmHg (P < 0.001) at T2, and 333.5 (229.9-411.4 [60.5-492.4]) mmHg and 149.8 (87.0-246.6 [51.2-447.5]) mmHg (P < 0.001) at T3, respectively. The CSA in the high-flow and mask groups was 371.9 (287.4-557.9 [129.0-991.2]) mm2 and 386.8 (292.0-537.3 [88.3-1651.7]) mm2 at T1 (P = 0.920) and 452.6 (343.7-618.4 [161.6-988.1]) mm2 and 385.6 (306.3-562.0 [105.5-922.9]) mm2 at T3 (P = 0.173), respectively. The number (proportion) of complications in the high-flow and mask groups is shown below: hypoxemia: 1 (1.7%) vs. 9 (15.8%, P = 0.019); reflux: 0 (0%) vs. 0 (0%); nasopharyngeal bleeding: 1 (1.7%) vs. 0 (0%, P = 1.000); pulmonary infection: 4 (6.9%) vs. 3 (5.3%, P = 1.000); PONV: 4 (6.9%) vs. 4 (7.0%, P = 1.000), and nasopharyngeal pain: 0 (0%) vs. 0 (0%).

CONCLUSIONS

Compared to facemasks, pre-oxygenation with high-flow oxygen through NPA offers improved carbon dioxide clearance and enhanced oxygenation prior to tracheal intubation in patients undergoing emergency surgery, while the risk of gastric inflation had not been ruled out.

TRIAL REGISTRATION

This trial was registered prospectively at the Chinese Clinical Research Registry on 26/4/2022 (Registration number: ChiCTR2200059192).

2023 Cardiac Society of Australia and New Zealand Expert Position Statement on Catheter and Surgical Ablation for Atrial Fibrillation

Catheter ablation for atrial fibrillation (AF) has increased exponentially in many developed countries, including Australia and New Zealand. This Expert Position Statement on Catheter and Surgical Ablation for Atrial Fibrillation from the Cardiac Society of Australia and New Zealand (CSANZ) recognises healthcare factors, expertise and expenditure relevant to the Australian and New Zealand healthcare environments including considerations of potential implications for First Nations Peoples. The statement is cognisant of international advice but tailored to local conditions and populations, and is intended to be used by electrophysiologists, cardiologists and general physicians across all disciplines caring for patients with AF. They are also intended to provide guidance to healthcare facilities seeking to establish or maintain catheter ablation for AF.

Pharmacokinetics and exposure-safety relationship of ciprofol for sedation in mechanically ventilated patients in the intensive care unit

Ciprofol (HSK3486) is a newly developed, highly selective γ-aminobutyric acid-A (GABAA) receptor potentiator that is recently approved for a new indication of sedation for patients in the intensive care unit (ICU) in China. This analysis aimed to characterize the population pharmacokinetics (PopPKs) of ciprofol and evaluate the relationship of exposure with hypotension in mechanically ventilated patients in the ICU. A total of 462 subjects with 3918 concentration measurements from two clinical trials of mechanically ventilated patients in the ICU, four clinical trials of elective surgical patients, and six clinical trials of healthy subjects were used in the PopPK analysis. Exposure-safety relationship for hypotension was evaluated based on the data gathered from 112 subjects in two clinical trials of mechanically ventilated patients in the ICU. Ciprofol pharmacokinetics (PKs) was adequately described by a three-compartment linear disposition model with first-order elimination. Body weight, age, sex, blood sampling site (vein vs. arterial), study design (long-term infusion vs. short-term infusion), and patient population (ICU vs. non-ICU) were identified as statistically significant covariates on the PKs of ciprofol. Within the exposure range of the mechanically ventilated ICU patient population, no meaningful association was observed between ciprofol exposure and the incidence of hypotension. These results support the dosing regimen currently used in mechanically ventilated patients in the ICU.

Obesity at term: What to consider? How to deliver?

Obesity presents significant challenges during pregnancy, increasing the risk of complications and adverse outcomes for both mother and baby. With the rising prevalence of obesity among pregnant women, questions arise regarding optimal management, including timing of delivery and choice of delivery mode. Labour induction in obese women may require a combination of mechanical and pharmacological methods due to increased risk of failed induction. Caesarean section in obese women presents unique challenges, requiring comprehensive perioperative planning and specialized care to optimize outcomes. However, specific guidelines tailored to obese patients undergoing caesarean sections are lacking. Postpartum care should include vigilant monitoring for complications. Addressing obesity in pregnancy necessitates a multidisciplinary approach and specialized care to ensure the best outcomes.

Airway and respiratory complications during anaesthesia and associated with peri-operative cardiac arrest as reported to the 7th National Audit Project of the Royal College of Anaesthetists

The 7th National Audit Project (NAP7) of the Royal College of Anaesthetists studied complications of the airway and respiratory system during anaesthesia care including peri-operative cardiac arrest. Among 24,721 surveyed cases, airway and respiratory complications occurred commonly (n = 421 and n = 264, respectively). The most common airway complications were: laryngospasm (157, 37%); airway failure (125, 30%); and aspiration (27, 6%). Emergency front of neck airway was rare (1 in 8370, 95%CI 1 in 2296-30,519). The most common respiratory complications were: severe ventilation difficulty (97, 37%); hyper/hypocapnia (63, 24%); and hypoxaemia (62, 23%). Among 881 reports to NAP7 and 358 deaths, airway and respiratory complications accounted for 113 (13%) peri-operative cardiac arrests and 32 (9%) deaths, with hypoxaemia as the most common primary cause. Airway and respiratory cases had higher and lower survival rates than other causes of cardiac arrest, respectively. Patients with obesity, young children (particularly infants) and out-of-hours care were overrepresented in reports. There were six cases of unrecognised oesophageal intubation with three resulting in cardiac arrest. Of these cases, failure to correctly interpret capnography was a recurrent theme. Cases of emergency front of neck airway (6, approximately 1 in 450,000) and pulmonary aspiration (11, approximately 1 in 25,000) leading to cardiac arrest were rare. Overall, these data, while distinct from the 4th National Audit Project, suggest that airway management is likely to have become safer in the last decade, despite the surgical population having become more challenging for anaesthetists.

Waist-to-height ratio is a better predictor of hypertension in women during recovery from anesthesia compared to BMI, waist-to-hip ratio, and waist circumference

This was an observational study of patients with benign breast tumors intended to investigate and compare the predictive value of body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR) for hypertension in the recovery room. Logistic regression analysis was used to determine the association between these body fat anthropometric indices and hypertension. Receiver operating characteristic curve (ROC) analysis was performed to assess the comparative predictive ability. A total of 689 women were evaluated. Patients with BMI ≥28 (kg/m2), WC > 85 cm, WHR ≥0.82, and WHtR ≥0.5 had a significantly higher probability of increased systolic blood pressure (SBP) and diastolic blood pressure (DBP) than patients with less than threshold values (all P < 0.05). The areas under the ROC curve (AUC) of BMI, WC, and WHtR where all modestly significant (all AUC ≥0.65) and nearly identical at 0.6592, 0.65, and 0.6724, respectively. Conclusion: body fat anthropometric indices are useful predicting hypertension during recovery from general anesthesia in patients with benign breast tumors undergoing day surgery; WHtR outperformed the other indices and nearly identical.

The effect of age on clinical dose equivalency of fentanyl and morphine analgosedation in mechanically ventilated patients: Findings from the ANALGESIC trial

BACKGROUND

The dose equivalency of fentanyl vs. morphine is widely considered to be approximately 1:100. However, little is known about the effect of age on this ratio when these agents are used as infusions for analgosedation.

OBJECTIVES

To assess the impact of age on the clinical dose equivalency of fentanyl and morphine when used as infusions for analgosedation in mechanically ventilated intensive care unit patients.

METHODS

We performed a post hoc analysis of the Assessment of Opioid Administration to Lead to Analgesic Effects and Sedation in Intensive Care (ANALGESIC) cluster randomised crossover trial of fentanyl and morphine infusions for analgosedation. Dose and analgosedative clinical equivalency of fentanyl and morphine were assessed by age and by using different body-size descriptors.

RESULTS

We studied 663 patients (338 fentanyl, 325 morphine). Median (interquartile range) hourly dose of fentanyl and morphine were 58.1 (40.0-89.2) mcg and 3400 (2200-5000) mcg, respectively. The ratio of total dose of fentanyl:morphine was 1:93 in the 18- to 29-year-old group and 1:25 in the ≥80-year-old group (p = 0.015), respectively, with fentanyl becoming relatively less clinically effective as age increased. This effect was also seen when comparing dosing by different body-size descriptors with the strongest age-related change when using body surface area as body-size descriptor (p = 0.009).

CONCLUSION

The analgosedative clinical dose equivalency of fentanyl vs. morphine is heterogeneous when used as infusions for analgosedation, with fentanyl becoming relatively less clinically effective as age increases. This information can help guide prescription of these agents during transition from one agent to the other in critically ill patients.

Feasibility of same-day discharge after laparoscopic sleeve gastrectomy in the Netherlands

BACKGROUND

There is a trend towards laparoscopic sleeve gastrectomy (SG) with same-day discharge (SDD), as an efficient healthcare pathway to alleviate the burden on clinical capacity. This approach seems to be safe, if patients are carefully selected. In our bariatric center, a protocol for Roux-en-Y gastric bypass with SDD has already been successfully implemented. The aim of this study was to evaluate feasibility of applying the same SDD protocol for SG.

METHODS

A single-center prospective feasibility study was conducted at a high-volume bariatric center. Low-risk patients who were scheduled for primary SG were included. Strict criteria were used for approval upon SDD. The primary outcome was the rate of successful SDD without readmission within 48 h. Secondary outcomes included short-term complications, emergency department visits, readmissions, and mortality.

RESULTS

Fifty patients were included in the study, of whom 45 were successfully discharged on the same day of the surgery. Nausea and vomiting were the most common reasons for overnight hospitalization (three patients). One patient was readmitted within the first 48 h due to a mild complication related to bleeding, resulting in a success rate of 88% for SDD without readmission within 48 h. No severe complications or mortality were reported in the cohort.

CONCLUSION

Our SDD protocol for SG has demonstrated feasibility, with a high success rate of SDD and no severe complications. Strict conditions should be met for the safe implementation of a SDD protocol, including careful patient selection and the establishment of a safety net to detect early complications.

Surgical transversus abdominis plane block with liposomal bupivacaine at cesarean: a pilot randomized trial

BACKGROUND

Postcesarean pain control is challenging. In addition to intrathecal morphine, recent studies have shown that liposomal bupivacaine administered via conventional transversus abdominis plane block reduces postcesarean opioid use. However, whether the administration of liposomal bupivacaine via a surgical approach also reduces opioid use is unknown.

OBJECTIVE

This study aimed to investigate whether the administration of liposomal bupivacaine via surgical transversus abdominis plane block (TAP block) reduces the cumulative dose of opioids administered in the first 48 hours after cesarean delivery among participants who also receive intrathecal morphine.

STUDY DESIGN

This was a pilot single-blind randomized controlled trial of 60 parturients undergoing cesarean delivery at a community tertiary referral hospital staffed by academic physicians. Immediately before fascial closure during cesarean delivery, a total of 80 mL of dilute bupivacaine plus liposomal bupivacaine or dilute bupivacaine alone was administered via surgical transversus abdominis plane block (40 mL on each side). The primary outcome was a median cumulative opioid dose received within the first 48 hours after cesarean delivery measured in morphine milligram equivalents. In addition, opioid use at other time points, pain scores, and participant satisfaction were assessed. A sample size of 60 was determined to be adequate to inform a potential future adequately powered randomized trial. The primary outcome of morphine milligram equivalents and pain scores were compared using a Wilcoxon rank-sum test.

RESULTS

Between October 11, 2021, and August 29, 2022, 60 participants were randomized and analyzed: 31 were allocated to liposomal bupivacaine plus regular bupivacaine (intervention group), and 29 were allocated to regular bupivacaine alone (control group). Participants allocated to the intervention group used a median cumulative dose of 2 morphine milligram equivalents of opioids (interquartile range, 0-24) in the first 48 hours compared with 8 morphine milligram equivalents (interquartile range, 0-40) among participants allocated to the control group (P=.236). The percentage of participants who used ≤15 morphine milligram equivalents of opioids was 61% in the intervention arm and 41% in the control arm (P=.123), and the percentage who used zero opioids was 45% in the intervention arm and 34% in the control arm (P=.399). The total number of opioid pills prescribed at discharge was fewer in the intervention arm than in the control arm (P=.029). Patient satisfaction with the intervention group and control group was similar.

CONCLUSION

Our pilot study suggests that liposomal bupivacaine administered via surgical transversus abdominis plane block is worth critical evaluation as an adjunctive analgesic modality in an adequately powered randomized trial.

Airway management of lingual tonsillar hypertrophy: A narrative review

Lingual tonsillar hypertrophy is rarely identified on routine airway assessment but may cause difficulties in airway management. We conducted a narrative review of case reports of lingual tonsillar hypertrophy to examine associated patient factors, success rates of airway management techniques and complications. We searched the literature for anaesthetic management of cases with lingual tonsillar hypertrophy. We found 89 patients in various case reports, from which we derived 92 cases to analyse. 64% of cases were assessed as having a normal airway. Difficult and impossible face mask ventilation occurred in 29.6% and 1.4% of cases, respectively. Difficult intubation and failed intubation occurred in 89.1% and 21.7% of cases, respectively. Multiple attempts (up to six) at intubation were performed, with no successful intubation after the third attempt with direct laryngoscopy. Some 16.5% of patients were woken up and 4.3% required emergency front of neck access. Complications included oesophageal intubation (10.9%), bleeding (9.8%) and severe hypoxia (3.2%). Our findings show that severe cases of lingual hypertrophy may cause an unanticipated difficult airway and serious complications, including hypoxic brain damage and death. A robust airway strategy is required which includes limiting the number of attempts at laryngoscopy, and early priming and performance of emergency front of neck access if required. In patients with known severe lingual tonsillar hypertrophy, awake intubation should be considered.

Bed tilt and ramp positions are associated with increased first-pass success of adult endotracheal intubation in the emergency department: A registry study

OBJECTIVE

Successful endotracheal intubation in the ED requires optimum body positioning. In patients with obesity, the ramp position was suggested to achieve better intubating conditions. However, limited data are available on the airway management practices for patients with obesity in Australasian EDs. The aim of this study was to identify current patient positioning practices during endotracheal intubation and its association with first-pass success (FPS) at intubation and adverse event (AE) rates in obese and non-obese populations.

METHODS

Prospectively collected data from the Australia and New Zealand ED Airway Registry (ANZEDAR) between 2012 and 2019 were analysed. Patients were categorised into two groups according to their weight: <100 kg (non-obese) or ≥100 kg (obese). Four position categories were investigated; supine, pillow or occipital pad, bed tilt and ramp or head-up with relation to FPS and complication rate using logistic regression modelling.

RESULTS

A total of 3708 intubations from 43 EDs were included. Overall, the non-obese cohort had a greater FPS rate (85.9%) compared to the obese group (77.0%). The bed tilt position had the highest FPS rate (87.2%), whereas the supine position had the lowest (83.0%). AE rates were highest in the ramp position (31.2%) compared to all other positions (23.8%). Regression analysis showed ramp, or bed tilt positions and a consultant-level intubator were associated with higher FPS. Obesity, in addition to other factors, was independently associated with lower FPS.

CONCLUSION

Obesity was associated with lower FPS, which could be improved through performing a bed tilt or ramp positioning.

Anesthesia for Morbidly Obese Patients

BACKGROUND

The prevalence of morbid obesity (BMI >35 kg/m2) has risen steadily in recent decades. With the corresponding rise in the number of bariatric operations, anesthesiologists deal with this patient group more commonly than before, particularly in specialized centers.

METHODS

This review is based on publications retrieved by a selective search in PubMed, including current guidelines and recommendations issued by specialist societies, as well as expert opinion.

RESULTS

In the anesthesiological care of morbidly obese patients, a preoperative assessment and risk stratification are just as important as the thoughtful selection of the anesthesia technique, the drugs used and their dosage, and perioperative management. A thorough understanding of the pathophysiological changes and comorbidities of morbid obesity and the associated risks is essential. The risk of pulmonary complications such as respiratory failure, hypoxia, and apnea is markedly higher in morbidly obese patients, especially those with obstructive sleep apnea. Short-acting, less lipophilic anesthetic drugs are particularly useful, as is multimodal pain therapy for the avoidance of high opiate doses. The indication for intensified postoperative monitoring depends on the patient's preexisting illnesses, the type of anesthesia, and the type of surgical procedure. Regional anesthetic techniques should be used if possible.

CONCLUSION

The perioperative care of morbidly obese patients presents special challenges. The anesthesiologist must be aware of potential comorbidities, specific risks, and pathophysiological changes in order to provide adequate care to this patient group.

Perioperative management of Obstructive Sleep Apnoea: Present themes and future directions

PURPOSE OF REVIEW

Obstructive sleep apnoea (OSA) is an increasingly common pathology that all those involved in perioperative care will come across. Patients with the condition present a challenge at many stages along the perioperative journey, not least because many patients living with OSA are unaware of their diagnosis.Key interventions can be made pre, intra-, and postoperatively to improve outcomes. Knowledge of screening tools, diagnostic tests, and the raft of treatment options are important for anyone caring for these patients.

RECENT FINDINGS

Recent literature has highlighted the increasing complexity of surgical patients and significant underdiagnosis of OSA in this patient population. Work has demonstrated how and why patients with OSA are at a higher perioperative risk and that effective positive airways pressure (PAP) therapy can reduce these risks, alongside evidencing how best to optimise adherence to therapy, a key issue in OSA.

SUMMARY

OSA, and particularly undiagnosed OSA, presents a huge problem in the perioperative period. Perioperative PAP reduces the risk of postoperative complications but adherence remains an issue. Bespoke perioperative pathways should be developed to identify and optimise high risk patients, although at present evidence on how best to achieve this is lacking.

Propofol-remifentanil patient-controlled sedation for endoscopic procedures: a prospective service audit

PURPOSE

Following demand, we established a patient-controlled propofol-remifentanil sedation service for endoscopy overseen by an anesthesiologist. To assess the effectiveness of the intervention of this service and any complications, we prospectively audited the service. Our primary outcomes of interest were adequacy of sedation and patient satisfaction. Secondary outcomes included any adverse events associated with the sedation.

METHODS

Patients were referred for failure of procedure under endoscopist-administered sedation, refusal of procedure without general anesthesia (GA), or planned complex procedure. We included all 670 procedures performed between 2017 and 2021. We used a mixture of 8.9 mg·mL-1 propofol and 5.4 µg·mL-1 remifentanil with a 1-mL bolus and 20-sec lockout. We assessed the adequacy of sedation using the Modified Gloucester Scale and categorized adverse events according to the Tracking and Reporting Outcomes of Procedural Sedation.

RESULTS

All 670 procedures were accomplished with adequate sedation without the need for ventilation or GA, and all patients were satisfied with the sedation. The complication rate was low, with no sentinel airway or respiratory events. Nineteen out of 670 patients (2.8%) had an incidence of airway obstruction (requiring a simple airway maneuver). The body mass index (BMI) was documented in 18/19 of these patients and the average BMI in this group was 35 kg·m-2. Seven of the 670 patients (1%) had self-terminating apnea, 3/670 patients (0.4%) vomited, no patients aspirated, and 17/665 patients (2.6%) required a vasopressor to maintain blood pressure within 20% of preprocedure values.

CONCLUSION

The results from our prospective service audit indicate that propofol-remifentanil patient-controlled sedation is a safe and reliable technique in patients undergoing endoscopic procedures.

Effect of Sevoflurane on the Deep Neuromuscular Blockade in Obese Patients Undergoing Laparoscopic Sleeve Gastrectomy: A Single Center Prospective Randomized Controlled Study

Objective

Our study aimed to demonstrate that the combination of sevoflurane inhalation with continuous intravenous anesthesia can effectively reduce the dosage of muscle relaxants, shorten extubation time under anesthesia while meeting the requirements of laparoscopic deep neuromuscular block (dNMB) in obese patients. Additionally, we sought to assess the potential reduction in postoperative residual muscle relaxants.

Methods

Fifty-nine patients were randomly assigned. Anesthesia-related variables, such as anesthetics dosages, muscle relaxant effective time, clinical muscle relaxant time, muscle relaxant in vivo action time, muscle relaxant recovery time, body movement times, and extubation duration were recorded. Surgery-related variables (the Leiden-Surgical Rating Scale (L-SRS), duration of the procedure) were recorded. Pain was measured using the visual analog scale (VAS) score before leaving the PACU. The duration of the PACU stay and patients' satisfaction levels in the PACU were also recorded.

Results

Patients who inhaled sevoflurane during the operation required a lower dosage of muscle relaxant to achieve the same deep neuromuscular block (dNMB) effect. The time from stopping the rocuronium pump to T1 recovery of 90% was shorter, and the time for T1 to recover from 25% to 75% was faster among patients who inhaled sevoflurane during the operation. Furthermore, the sevoflurane combined with continuous intravenous anesthesia group exhibited a shorter extubation time for obese patients undergoing laparoscopic bariatric surgery, along with a reduced risk of experiencing hypoxemia and a shorter observation time in the PACU.

Conclusion

Inhaling sevoflurane combined with continuous intravenous anesthesia during the operation effectively reduces the dosage of muscle relaxant required to achieve the same deep neuromuscular block (dNMB) effect. Additionally, this approach significantly shortens the extubation time for obese patients undergoing laparoscopic bariatric surgery and reduces the risk of experiencing hypoxemia, along with reducing the observation time in the PACU.

Individualized Positive End-expiratory Pressure Titration Strategies in Superobese Patients Undergoing Laparoscopic Surgery: Prospective and Nonrandomized Crossover Study

BACKGROUND

Superobesity and laparoscopic surgery promote negative end-expiratory transpulmonary pressure that causes atelectasis formation and impaired respiratory mechanics. The authors hypothesized that end-expiratory transpulmonary pressure differs between fixed and individualized positive end-expiratory pressure (PEEP) strategies and mediates their effects on respiratory mechanics, end-expiratory lung volume, gas exchange, and hemodynamic parameters in superobese patients.

METHODS

In this prospective, nonrandomized crossover study including 40 superobese patients (body mass index 57.3 ± 6.4 kg/m2) undergoing laparoscopic bariatric surgery, PEEP was set according to (1) a fixed level of 8 cm H2O (PEEPEmpirical), (2) the highest respiratory system compliance (PEEPCompliance), or (3) an end-expiratory transpulmonary pressure targeting 0 cm H2O (PEEPTranspul) at different surgical positioning. The primary endpoint was end-expiratory transpulmonary pressure at different surgical positioning; secondary endpoints were respiratory mechanics, end-expiratory lung volume, gas exchange, and hemodynamic parameters.

RESULTS

Individualized PEEPCompliance compared to fixed PEEPEmpirical resulted in higher PEEP (supine, 17.2 ± 2.4 vs. 8.0 ± 0.0 cm H2O; supine with pneumoperitoneum, 21.5 ± 2.5 vs. 8.0 ± 0.0 cm H2O; and beach chair with pneumoperitoneum; 15.8 ± 2.5 vs. 8.0 ± 0.0 cm H2O; P < 0.001 each) and less negative end-expiratory transpulmonary pressure (supine, -2.9 ± 2.0 vs. -10.6 ± 2.6 cm H2O; supine with pneumoperitoneum, -2.9 ± 2.0 vs. -14.1 ± 3.7 cm H2O; and beach chair with pneumoperitoneum, -2.8 ± 2.2 vs. -9.2 ± 3.7 cm H2O; P < 0.001 each). Titrated PEEP, end-expiratory transpulmonary pressure, and lung volume were lower with PEEPCompliance compared to PEEPTranspul (P < 0.001 each). Respiratory system and transpulmonary driving pressure and mechanical power normalized to respiratory system compliance were reduced using PEEPCompliance compared to PEEPTranspul.

CONCLUSIONS

In superobese patients undergoing laparoscopic surgery, individualized PEEPCompliance may provide a feasible compromise regarding end-expiratory transpulmonary pressures compared to PEEPEmpirical and PEEPTranspul, because PEEPCompliance with slightly negative end-expiratory transpulmonary pressures improved respiratory mechanics, lung volumes, and oxygenation while preserving cardiac output.

EDITOR’S PERSPECTIVE

Intravenous Lidocaine Decreased the Median Effective Concentration of Sufentanil for Tracheal Intubation in Obese Patients

Purpose

Sufentanil has been widely used to inhibit the hemodynamic responses caused by tracheal intubation. Using intravenous lidocaine may reduce the dose of sufentanil and better maintain the hemodynamics. This study aimed to determine the effects of intravenous lidocaine on the median effective concentration (EC50) of sufentanil for endotracheal intubation in obese patients.

Patients and Methods

This is a randomized, double-blind, up-and-down sequential allocation study. Fifty obese patients undergoing bariatric surgery were randomly allocated in a 1:1 ratio into the lidocaine group and the saline group. Anesthesia was induced using a target-controlled infusion of propofol and sufentanil. The effect-site concentration (Ce) of propofol was 3.5 μg/mL. The Ce of sufentanil for the first patient was 0.4 ng/mL, and the sufentanil dose for the next patient was determined according to the responses of the previous patient, using Dixon's up-and-down sequential method with an interval of 0.05 ng/mL. When the target concentration of propofol and sufentanil was reached, lidocaine 1.5 mg/kg or the same volume of normal saline was infused over 3 min. Tracheal intubation was performed 3 min after the end of the lidocaine or normal saline infusion. Probit regression was used to calculate the EC50 and 95% confidence interval (CI) of sufentanil.

Results

Thirty-eight patients completed this study. The EC50 of sufentanil was 0.36 ng/mL (95% CI: 0.31-0.41 ng/mL) in the lidocaine group, which was significantly lower than 0.50 ng/mL (95% CI: 0.43-0.62 ng/mL) in the saline group. In addition, compared with saline group, the dosage of sufentanil in lidocaine group decreased significantly during the test. The hemodynamics of the two groups were stable during the study period.

Conclusion

Intravenous lidocaine 1.5 mg/kg decreased the EC50 of sufentanil required for tracheal intubation in obese patients undergoing bariatric surgery.

Anaesthetic nurse specialist role in perioperative anaesthetic management of patients who are morbidly obese

This integrative literature review examined the role of an anaesthetic nurse specialist (ANS) in the perioperative anaesthetic nursing management of morbidly obese patients associated with elective orthopaedic surgery. The responsibility of the ANS is to provide high-quality perioperative anaesthetic care to ensure patient safety. Morbid obesity is increasing globally, with significant implications for healthcare delivery, care and treatment, including perioperative care. The Association of Anaesthetists of Great Britain and Ireland emphasises that the perioperative management of these patients presents significant organisational and practical issues. However, there are limited data or guidelines on whether surgeons, anaesthetists and nurses routinely take special precautions in managing morbidly obesity patients undergoing elective orthopaedic operative procedures. The authors carried out a search of databases, followed by an integrated literature review and synthesis of 11 studies. The main findings revealed significant clinical challenges and resource requirements for perioperative anaesthetic management of this patient group. Recommendations are made to prepare for and manage these surgical patients, from preoperative assessment to postoperative care.

Feasibility of Same-Day Discharge After Laparoscopic Roux-en-Y Gastric Bypass in Patients with Well-Regulated Obstructive Sleep Apnea

INTRODUCTION

Same-day discharge after bariatric surgery is increasingly being performed. In current practice, patients with only minor comorbidities are considered eligible for same-day discharge after laparoscopic Roux-en-Y gastric bypass (RYGB). Obstructive sleep apnea (OSA) is a common comorbidity in patients with morbid obesity, with a prevalence of around 70-80% among patients undergoing bariatric surgery. Continuous positive airway pressure (CPAP) is the current gold standard treatment for OSA. We aimed to investigate whether same-day discharge after RYGB is feasible for patients with compliant use of CPAP.

METHODS

In this single-center prospective feasibility study, patients were selected who were scheduled for RYGB and were adequately treated for OSA. Compliance on the use of CPAP had to be proved (> 4 h per night for 14 consecutive nights). There were strict criteria on approval upon same-day discharge. The primary outcome was the rate of successful same-day discharge. Secondary outcomes included short-term complications, emergency department presentations, readmissions, and mortality.

RESULTS

Forty-nine patients underwent RYGB with intended same-day discharge, of whom 45 (92%) were successfully discharged. Three patients had an overnight stay because of divergent vital signs and one patient due to a delayed start of the surgery. Two patients (4%) were readmitted in the first 48 h postoperatively, both due to intraluminal bleeding which was managed conservatively (Clavien-Dindo 2). There were no severe complications in the first 48 h after surgery.

CONCLUSION

Same-day discharge after RYGB can be considered feasible for selected patients with well-regulated OSA.

Same-Day Discharge After Laparoscopic Roux-en-Y Gastric Bypass: a Cohort of 500 Consecutive Patients

INTRODUCTION

There is an increasing demand on hospital capacity worldwide due to the COVID-19 pandemic and local staff shortages. Novel care pathways have to be developed in order to keep bariatric and metabolic surgery maintainable. Same-day discharge (SDD) after laparoscopic Roux-en-Y gastric bypass (RYGB) is proved to be feasible and could potentially solve this challenge. The aim of this study was to investigate whether SDD after RYGB is safe for a selected group of patients.

METHODS

In this single-center cohort study, low-risk patients were selected for primary RYGB with intended same-day discharge with remote monitoring. All patients were operated according to ERAS protocol. There were strict criteria on approval upon same-day discharge. It was demanded that patients should contact the hospital in case of any signs of complications. Primary outcome was the rate of successful same-day discharge without readmission within 48 h. Secondary outcomes included short-term complications, emergency department visits, readmissions, and mortality.

RESULTS

Five hundred patients underwent RYGB with intended SDD, of whom 465 (93.0%) were successfully discharged. Twenty-one patients (4.5%) were readmitted in the first 48 h postoperatively. None of these patients had a severe bleeding. This results in a success rate of 88.8% of SDD without readmission within 48 h.

CONCLUSIONS

Same-day discharge after RYGB is safe, provided that patients are carefully selected and strict discharge criteria are used. It is an effective care pathway to reduce the burden on hospital capacity.

Five-year follow-up after pancreatoduodenectomy performed for malignancy: A single-centre study

Backgrounds/Aims

The aim of this study was to describe short- and long-term outcomes of patients who underwent pancreatoduodenectomy (PD) at a typical United Kingdom hepatopancreatobiliary unit.

Methods

A retrospective analysis of all PD patients with histologically-confirmed pancreatic ductal adenocarcinoma (PDAC), ampullary adenocarcinoma (AA), or distal cholangiocarcinoma (CC) from September 1st, 2006 to May 31st, 2015 was carried out. The following information was obtained: demographics, comorbidities, preoperative investigations, neoadjuvant treatment, operative details, postoperative management, complications, adjuvant treatment, five-year recurrence, and five-year survival. Effects of selected preoperative variables on short- and long-term outcomes were investigated.

Results

Of 271 included patients, 57.9% had PDAC, 25.8% had AA, and 16.2% had CC. In total, 67.9% experienced morbidity and 17.3% developed a Clavien-Dindo grade ≥ III complication. The 90-day mortality was 3.3%. Clinically-relevant postoperative pancreatic fistula, bile leak, gastrojejunal leak, postpancreatectomy haemorrhage and delayed gastric emptying affected 8.1%, 4.1%, 0.0%, 9.2%, and 19.9% of patients, respectively. American Society of Anesthesiologists grade III-VI correlated with overall morbidity (p = 0.002) and major morbidity (p = 0.009), but not 90-day mortality or five-year survival. The same pattern was observed in patients with a preoperative serum bilirubin > 29 μmol/L and/or a neutrophil/lymphocyte ratio > 3.1. Five-year cancer recurrence and five-year survival were 68.3% and 22.5%, respectively. PDAC patients had higher five-year recurrence but lower five-year survival rates (both p = 0.001).

Conclusions

In our series, the majority of patients experienced a complication. However, few patients experienced major morbidity. Surgical risk factors did not affect five-year survival.

[Anesthesia in obesity surgery : Recommendations from the practice for the practice]

BACKGROUND

Due to unsuccessful conservative treatment concepts and the steady increase in the prevalence of obesity, obesity surgery has gained importance worldwide. In Germany alone, around 20,000 surgical operations for obesity are performed each year. In addition to patient history and physical examination a close interdisciplinary cooperation taking into account the currently applicable standards and guidelines of the professional societies are prerequisites for best patient care and to evaluate and mitigate patient risks.

AIM

The aim of this work was to compile and consent experiences of experts in the implementation of applicable standards and guidelines for anesthesia in obesity surgery for daily clinical practice.

METHOD

Anesthesiologists from five bariatric centers, comprising about 10% of the obesity surgery caseload of Germany per year, have collated their clinical experiences to agree on a consensus for procedures. The procedures for preoperative patient evaluation, drug premedication and PONV prophylaxis, induction of anesthesia and drug dosage recommendations for anesthetics were consented based on the authors' practice.

RESULTS AND CONCLUSION

The procedures described herein were developed as part of a joint work process. The authors describe a practically applicable approach to the anesthesiological care of obesity surgery patients and recommend using a pragmatic formula for dosing the medication calculated on the basis of total body weight (TBW).

Ramped versus sniffing position in the videolaryngoscopy-guided tracheal intubation of morbidly obese patients: a prospective randomized study

BACKGROUND

Ramped positioning is recommended for intubating obese patients undergoing direct laryngoscopy. However, whether the use of the ramped position can provide any benefit in videolaryngoscopy-guided intubation remains unclear. This study assessed intubation time using videolaryngoscopy in morbidly obese patients in the ramped versus sniffing positions.

METHODS

This is a prospective randomized study in patients with morbid obesity (n = 82; body mass index [BMI] ≥ 35 kg/m2). Patients were randomly allocated to either the ramped or the standard sniffing position groups. During the induction of general anesthesia, difficulty in mask ventilation was assessed using the Warters scale. Tracheal intubation was performed using a C-MAC® D-Blade videolaryngoscope, and intubation difficulty was assessed using the intubation difficulty scale (IDS). The primary endpoint was the total intubation time calculated as the sum of the laryngoscopy and tube insertion times.

RESULTS

The percentage of difficult mask ventilation (Warters scale ≥ 4) was significantly lower in the ramped (n = 40) than in the sniffing group (n = 41) (2.5% vs. 34.1%, P < 0.001). The percentage of easy intubation (IDS = 0) was significantly higher in the ramped than in the sniffing group (70.0% vs. 7.3%, P < 0.001). The total intubation time was significantly shorter in the ramped than in the sniffing group (22.5 ± 6.2 vs. 40.9 ± 9.0, P < 0.001).

CONCLUSIONS

Compared with the sniffing position, the ramped position reduced intubation time in morbidly obese patients and effectively facilitated both mask ventilation and tracheal intubation using videolaryngoscopy.

Thromboembolic Complications After Bariatric Surgery: Is the High Risk Real?

INTRODUCTION

Nowadays, a large number of bariatric surgery (BS) procedures are undertaken worldwide as surgery has become an efficient strategy to treat the obesity epidemic. The risk of venous thromboembolism (VTE) is increased in patients undergoing BS not only due to the intrinsic surgical risk but also because patients with obesity have a 2-3-fold higher risk of VTE. The optimal strategy for VTE prevention in BS setting, including optimal dose and thromboprophylaxis regimen, is still not fully clarified. The aim of this study was to report a bariatric high-volume center experience and to propose a practical thromboprophylaxis protocol for this population.

METHODS

A single-center, observational, retrospective, and longitudinal study was conducted from January 2018 to December 2020, a total of 901 patients who underwent primary and revisional bariatric surgery were included.

RESULTS

The overall frequency of VTE events was 0.44% (n=4), one patient had pulmonary embolism (PE) during index hospital admission; another patient had simultaneous deep venous thrombosis (DVT) and PE, two months after surgery; and two other patients had DVT, nine and 16 months after surgery. The median time for VTE was four months. The incidence of females was 75% (n=3) and the median age was 57 years. Only one female patient was using oral contraception. None had a previous history of thromboembolic events, chronic venous insufficiency, or other known diseases that could increase the VTE risk.

CONCLUSION

Considering the outcomes reported by this experienced center with low rates of thromboembolic events, we suggest a thromboprophylaxis protocol that can be easily applied to the majority of bariatric patients.

Apnoeic oxygenation in morbid obesity: a randomised controlled trial comparing facemask and high-flow nasal oxygen delivery

BACKGROUND

Obesity is a risk factor for airway-related incidents during anaesthesia. High-flow nasal oxygen has been advocated to improve safety in high-risk groups, but its effectiveness in the obese population is uncertain. This study compared the effect of high-flow nasal oxygen and low-flow facemask oxygen delivery on duration of apnoea in morbidly obese patients.

METHODS

Morbidly obese patients undergoing bariatric surgery were randomly allocated to receive either high-flow nasal (70 L min^-1) or facemask (15 L min^-1) oxygen. After induction of anaesthesia, the patients were apnoeic for 18 min or until peripheral oxygen saturation decreased to 92%.

RESULTS

Eighty patients were studied (41 High-Flow Nasal Oxygen, 39 Facemask). The median apnoea time was 18 min in both the High-Flow Nasal Oxygen (IQR 18-18 min) and the Facemask (inter-quartile range [IQR], 4.1-18 min) groups. Five patients in the High-Flow Nasal Oxygen group and 14 patients in the Facemask group desaturated to 92% within 18 min. The risk of desaturation was significantly lower in the High-Flow Nasal Oxygen group (hazard ratio=0.27; 95% confidence interval [CI], 0.11-0.65; P=0.007).

CONCLUSIONS

In experienced hands, apnoeic oxygenation is possible in morbidly obese patients, and oxygen desaturation did not occur for 18 min in the majority of patients, whether oxygen delivery was high-flow nasal or low-flow facemask. High-flow nasal oxygen may reduce desaturation risk compared with facemask oxygen. Desaturation risk is a more clinically relevant outcome than duration of apnoea. Individual physiological factors are likely to be the primary determinant of risk rather than method of oxygen delivery.

CLINICAL TRIAL REGISTRATION

NCT03428256.

Oxford guidelines for adult day-case tonsillectomy

Oxford guidelines were developed after critically reviewing the existing literature and aim to assist anaesthetists, surgeons and allied healthcare staff in providing optimal care for patients undergoing tonsillectomy as a day-case procedure. Appropriate patient selection, provision of robust analgesia, antiemesis, perioperative warming and hydration are key factors to ensure patient comfort and allow same-day discharge. Patients can be discharged home after a minimum observation of 6h as this is the period with the greatest risk of primary haemorrhage. All patients must have a clear and safe understanding of which complications may occur and know how to seek help. A team effort and close collaboration between the anaesthetic, surgical, theatre and ward teams are essential to achieve optimum outcomes and reduce the rate of failed discharges.

The Role of Thromboprophylaxis in Patients with Portal Vein Thrombosis: A Life-Threatening Complication after Laparoscopic Sleeve Gastrectomy Following 8 Years of Experience in a Bariatric Center of Excellence

Porto-mesenteric vein thrombosis (PVMT) is a rare but life-threatening complication after laparoscopic sleeve gastrectomy (LSG). Laparoscopic sleeve gastrectomy (LSG) is considered the most common procedure for efficiently realizing weight loss and treating obesity-related co-morbidities. This study aimed to shed light on this relatively rare complication by presenting a series of patients who developed PMVT after LSG in light of the need to change the specific protocol of thromboprophylaxis in bariatric patients. We proposed to answer two questions: whether we should perform a thrombophilia workup as a standard practice and whether we should extend chemoprophylaxis to more than 3 weeks among all bariatric patients. This study also aimed to investigate the possible risk factors and eventually present our updated protocol for PMVT management and prophylaxis.