Anaesthesia essentials: Articles

Abstract
Volatile anaesthetic agents such as sevoflurane contribute to greenhouse gas emissions, and selecting low fresh gas flows on anaesthetic machines minimises their waste. Facilitating improvements in sevoflurane use requires the education, motivation, and standardised evaluation of anaesthetists. There is currently no standard of practice related to the efficiency of anaesthetic gas delivery per case. We conducted a multi-component study termed 'Low With The Flow' (LWTF) to directly address these requirements by educating and motivating anaesthetists to reduce fresh gas flow and thereby sevoflurane use. We introduced a novel metric, the 'volatile efficiency ratio' (VER), able to be calculated on Draeger Primus™, the Draeger Atlan™ family and Draeger Perseus A500™ machines, to audit sevoflurane use in a case-by-case fashion, and assess whether the intervention could achieve a set VER target. The LWTF intervention significantly improved the efficiency of sevoflurane delivery (VER 0.46 pre-intervention (n = 518) versus VER 0.57 post-intervention (n = 531), 95% confidence interval 0.092 to 0.129, P < 0.0001) resulting in a calculated average of 1.3 kg carbon dioxide equivalent emissions reduction and approximately AUD 3.50 saving per case. Consequently, the financial and environmental outcomes from sevoflurane delivery were considerably reduced. Our LWTF intervention provides a valuable model for other anaesthetic departments to investigate and address the global environmental and financial burdens related to their volatile anaesthetic use. For anaesthetists using anaesthesia machines that do not facilitate calculation of VER, an approach using components of our LWTF intervention may still reduce the environmental and financial impacts associated with administration of volatile anaesthesia.

Abstract
Catheter ablation has become a central part of the non-pharmacological treatment of cardiac arrhythmias. It can be performed under conscious sedation, deep sedation, or general anesthesia, but it is getting clear that the incidence of complications during the procedure and the success rate of treatment (with no recurrence of arrhythmia) may be strongly influenced by sedation or anesthesia method. In particular, in sedated patients, ablation procedure may frequently cause severe pain, and the most common adverse events are related to sedation methods. Therefore, anesthesiologists will increasingly be asked to take care of the patients undergoing catheter ablation. In this article, we describe what anesthesiologists should know about ablation procedure and its associated problems, to provide appropriate anesthesia care to patients undergoing catheter ablation.

Abstract
Psychedelic drugs, known for their perception-altering properties, are gaining popularity in the treatment of mental health and pain disorders. As exploratory studies demonstrate clinical efficacy with few adverse events, it is expected that more patients will ingest psychedelic drugs. For therapeutic reasons, as with any drug, anaesthesiologists must be aware of its physiological effects and contraindications to ensure the safe provision of anaesthesia. Psilocybin is a 5HT1A and 5HT2A serotonin receptor agonist thought to act on excitatory and inhibitory neurons in the brain. Acute ingestion causes sympathetic nervous system activation, which can precipitate haemodynamic instability. Activation of the 5HT serotonin receptors can also place the patient at risk of serotonin syndrome. Chronic use increases plasma concentrations of cortisol, which has implications on prophylactic stress-dosing of glucocorticoids preoperatively. Lysergic acid diethylamide (LSD), a synthetic psychoactive substance, is also a 5HT2A agonist. LSD has been shown to potentiate opioid analgesics, and monoamine oxidase (MAO) inhibition. Historical reports suggest that LSD has anticholinesterase activity and can prolong neuromuscular block with depolarising muscle relaxants. Mescaline is a poorly understood psychedelic with similar autonomic effects. Historical studies have shown decreased neuromuscular transmission and an association with malignant hyperthermia. When managing patients who have consumed psychedelics drugs, it is important to consider delaying surgery whenever possible, to allow acute intoxication to wane. A high degree of suspicion and an understanding of management principles is vital to the safe conduct of anaesthesia. Future research should explore therapeutic doses of psychedelic drugs to understand physiologic effects at various concentrations

Abstract
Background: There are concerns whether (repeated) exposure to general anaesthesia is associated with long-term cognitive decline.

Objective: We investigated the potential, negative relationship between total exposure to surgery under general anaesthesia and its impact on long-term cognitive development.

Design: A prospective longitudinal cohort study.

Setting: The Netherlands.

Participants: 1823 Adults, aged 25-84 with normal cognitive functioning on inclusion with three serial cognitive assessments between 1995 and 2008, with comprehensive documentation on demographic, lifestyle, and health factors.

Main outcome measures: The primary outcomes were test scores in the cognitive domains of learning and memory, executive function, selective attention, mental speed, and information processing speed. Linear mixed models were used to analyse the effects of the estimated total time under general anaesthesia at baseline on cognitive development during a 12-year follow-up period.

Results: When adjusting for demographic and systemic health-related factors, prolonged exposure to surgery under general anaesthesia (measured in total baseline minutes) negatively affected three cognitive domains. These included the CST (executive functioning, P < 0.05), Stroop (selective attention and mental speed, P < 0.001) and LDST (information processing speed, P < 0.005). Age and education were the primary factors impacting lifetime cognitive decline. Hypertension, diabetes, and smoking negatively affected various cognitive domains.

Conclusion: Increased exposure to surgery under general anaesthesia independently contributes to long-term cognitive decline. Demographic variables and health-related factors are key contributors to accelerated cognitive decline over an individual's lifetime.

Abstract
Objectives: The rationale of adoption opioid-sparing anesthesia (OSA) is to achieve perioperative analgesia with a minimal amount of opioids combined with nonopioid adjuvants during and after surgery, namely multimodal anesthesia. The OSA approach was originally developed to overcome the known complications of opioid-based anesthesia (OA), and the present scoping review (ScR) aims at providing clinical evidence of the safety and efficacy of OSA with respect to OA.

Methods: This ScR is mainly focused on studies presenting evidence on the safety and efficacy of OSA versus OA. PubMed and EMBASE databases were utilized to find relevant studies. The search strategy included the following keywords: "opioid sparing anesthesia complications, opioid sparing anesthesia efficacy, opioid sparing anesthesia safety." The findings from the 25 included studies were categorized into the following subsections: article characteristics, goals of the studies, OSA protocols, and surgical settings analyzed.

Results: In the 25 reviewed studies, evidence related to the impact of OSA versus OA was considered. Intraoperative safety and efficacy end points include hemodynamic stability and anesthetic/analgesic requirements. Postoperative end points include early cognitive dysfunction, opioid-induced bowel disorder, the physical status of mothers and newborns after labor and emergency cesarean, systemic immune and inflammation modifications, postoperative recovery, in-hospital and long-term opioid requirement, early postoperative pain, and chronic postsurgical pain. The studies reported lower intraoperative mean arterial pressure and heart rate fluctuations when α 2 agonists were adopted, while no differences were recorded for other complication rates. Analysis of OSA approaches for the postoperative conditions includes α 2 agonists, NMDA receptor blocking agents, gabapentinoids, nefopam hydrochloride, and locoregional anesthesia techniques with a positive impact on most of the end points considered.

Discussion: The clinical implementation of OSA encompasses the perioperative use of nonopioid drugs and locoregional anesthesia techniques. The reviewed studies reported OSA as a feasible approach to reduce opioid-related complications with no impact on patient safety.

Abstract
Anaesthesia is integral to a wide range of clinical procedures; however, there is a global challenge in the anaesthesia workforce due to several contributing factors. This study seeks to assess the knowledge and perceptions of medical students regarding anaesthesia as a specialty. Understanding these perspectives is essential to addressing the global shortage of anaesthesia professionals. PubMed, Scopus, African Journal Online, and ProQuest were searched from the database inception to July 2024 to identify relevant studies. A total of 2,575 articles were identified. After title and abstract screening, 2,137 articles were excluded. After full-text screening, 2,098 articles were excluded. Eight articles were included in this qualitative analysis. We included primary studies published in peer-reviewed journals that reported the perception and choice of anaesthesiology as a future career by medical students in their clinical years (years five and six), with reasons, irrespective of medical institution, age, or gender, were included. In total, 2,135 students from six countries were included in the eight studies: Pakistan, Saudi Arabia, Nigeria, Austria, the United States of America, and South Africa, with Nigeria and Saudi Arabia each contributing two studies. The study designs utilised included cross-sectional surveys, descriptive cross-sectional studies, and questionnaire-based studies. The mean age of the students ranged from 23 to 28 years across the studies, with 748 male students, 530 female students, and 857 students whose gender was not specified. A significant proportion of students were aware of the role of anaesthetists; however, only 178 students expressed an interest in specialising in anaesthesia, with the most common reason being a genuine interest in the specialty. The studies reviewed identified several reasons why students did not consider anaesthesiology as a preferred speciality, including limited patient contact, which affects the doctor-patient relationship, lack of recognition or respect from peers, low income, limited availability of local job opportunities or training positions, and the presence of anaesthetic nurses. A critical factor highlighted across all studies was the length of exposure to anaesthesia during clinical rotations. Medical students recognise the importance of anaesthetists but are often deterred from pursuing the specialty due to various factors, which could be mitigated through enhanced exposure, increased visibility, financial incentives, and mentorship.

Abstract
General anesthesia is a widely used medical practice, affecting more than 300 million patients annually. Despite its ubiquity, the underlying mechanisms through which anesthetic agents induce amnesia remain poorly understood. This review explores the impact of general anesthetics on memory function, with a particular focus on the role of neural oscillations in anesthesia-induced memory suppression. Neural oscillations, such as theta, gamma, delta oscillations, slow oscillations (SO), spindles, and sharp wave ripples (SWR), are critical for memory formation and consolidation. Various anesthetics modulate these oscillations in ways that affect memory, even at subanesthetic concentrations. We highlight recent findings on the molecular and electrophysiological mechanisms by which general anesthetics influence memory-related neural oscillations, including the inhibition of synaptic plasticity, alterations in spike-timing-dependent plasticity (STDP), and disruption of cross-frequency couplings like theta-gamma and SO-spindle-SWR. Additionally, the review addresses the significance of age in anesthesia-related memory loss, with elderly patients being particularly vulnerable to long-term cognitive decline. Electrophysiological techniques, such as Electroencephalography (EEG); and advanced neuromodulation techniques, such as chemogenetics, and optogenetics, have provided insights into the neural dynamics underpinning anesthesia-induced amnesia, yet the causal relationship between EEG rhythms and memory impairment remains to be fully elucidated. This review underscores the importance of further research into the interaction between anesthesia, neural oscillations, and memory. Understanding these mechanisms will not only advance theoretical knowledge of general anesthesia but also aid in the development of safer anesthetic strategies to mitigate postoperative cognitive dysfunction, especially in high-risk populations.

Abstract
Animal studies have shown that exposure of newborns to general anesthesia drugs can lead to neurodegenerative diseases and subsequent decline in learning and memory abilities. The neurotoxicity of general anesthesia drugs can also occur in the fetus. Therefore, in order to investigate the effect of the Long non-coding RNA(LncRNA)-LIN-microRNA(miRNA)-9-Dopamine receptor D2(DRD2) regulatory network on the development of the neuronal system after the inhalation of the anesthetic sevoflurane, RT-qPCR was used to detect the mRNA levels of LncRNA-LIN, miRNA-9, and DRD2. A dual-luciferase reporter system was used to detect the relationship between LncRNA-LIN and miRNA-9, and miRNA-9 and DRD2. Western blotting and immunofluorescence staining was employed to detect the protein levels of DRD2 and cleaved caspase-3. Flow cytometry was carried out to detect the number of apoptotic cells. The escape latency, swimming distance, and platform crossing times were analyzed using the Morris water maze. The results showed that, after treatment with sevoflurane, the mRNA levels of LncRNA-LIN and DRD2, the expression levels of the DRD2 protein, and the number of neuronal levels of DRD2 were significantly decreased, whereas the expression levels of miRNA-9 and the cleaved caspase-3 protein and neuronal apoptosis were significantly increased. miR-9 knockdown revealed that miRNA-9 regulated DRD2 expression and affected the function of mouse neuronal cells. In turn, LncRNA-LIN overexpression indicated that LncRNA-LIN regulated miR-9 and affected the function of mouse neuronal cells. The present results demonstrated that the LncRNA-LIN-miRNA-9-DRD2 regulatory network is involved in the effects of the inhalation anesthetic sevoflurane on neuronal system development.

Abstract in English, French
Purpose: Opioid anesthesia is commonly employed in minimally invasive surgeries but is associated with adverse effects, including postoperative nausea and vomiting (PONV). Opioid-free anesthesia aims to mitigate these issues. We conducted a systematic review, meta-analysis, and trial sequential analysis (TSA) comparing opioid and opioid-free anesthesia in minimally invasive abdominal surgeries.

Methods: We searched the Cochrane Central Register of Controlled Trials, MEDLINE, and Embase for randomized controlled trials (RCTs) comparing these approaches. Our primary outcomes were adverse effects (PONV, bradycardia), while secondary outcomes were pain, opioid consumption, and postanesthesia care unit (PACU) length of stay (LOS). We performed a TSA to investigate the conclusiveness of the results.

Results: We included 26 RCTs encompassing 2,025 patients, with 1,009 (49%) in the opioid-free anesthesia group. Opioid-free anesthesia reduced PONV significantly (risk ratio, 0.55; 95% confidence interval [CI], 0.40 to 0.74; P < 0.001), but we found no significant differences in bradycardia rates. We found nonclinically relevant higher pain scores for opioid anesthesia (mean difference [MD], -0.9; 95% CI, -1.7 to -0.2; P = 0.01) and opioid consumption at 2 hr post surgery (MD, -5.4 mg oral morphine equivalents; 95% CI, -9.1 to -1.8; P = 0.004). We also noted a reduced time to first analgesia (MD, 88 min; 95% CI, 18 to 159; P = 0.01). We found no differences in PACU LOS. The TSA confirmed the sample size's adequacy in showing PONV reduction with opioid-free anesthesia.

Conclusion: Opioid-free anesthesia showed a significant reduction in PONV and a decrease in opioid consumption during the first 2 hr postoperatively, suggesting it can be an alternative to opioid anesthesia in minimally invasive abdominal surgeries.

Study registration: PROSPERO ( CRD42023492385 ); first submitted 18 December 2023.

Abstract
Sevoflurane has been widely used in clinical anesthesia as an inhalation anesthetic. With the development of medicine, there have been several new applications in recent years, such as daytime surgery, labor analgesia, and combined nerve block for some surgeries. Moreover, as research progresses, it has been found that it not only has potential organ protection effects but can also be used to treat severe asthma and relieve the tracheal spasm state. In addition, local administration can effectively treat vascular ulcers. We briefly review the organ protective effect of sevoflurane, its application in dental treatment, asthma treatment, vascular ulcer treatment and some new progress in clinical application.

Abstract
Xenon gas has significant advantages over conventional general anesthetic agents but its use has been limited by the cost associated with its production. Xenon also has significant potential for medical use in the treatment of acquired brain injuries and for mental health disorders. As the demand for xenon gas from other industries increases, the costs associated with its medical use are only likely to increase. One solution to mitigate the significant cost of xenon use in research or medical care is the conservation of xenon gas. During delivery of xenon anesthesia, this can be achieved either by separating xenon from the other gases within the anesthetic circuit, conserving xenon and allowing other gases to be excluded from the circuit, or by selectively recapturing xenon utilized during the anesthetic episode at the conclusion of the case. Several technologies, including the pressurization and cooling of gas mixtures, the utilization of gas selective membranes and the utilization of gas selective adsorbents have been described in the literature for this purpose. These techniques are described in this narrative review along with important clinical context that informs how these technologies might be best applied. Whilst these technologies are discussed in the context of xenon general anesthesia, they could be applied in the delivery of xenon gas inhalation for other therapeutic purposes.

Abstract in English, French
Background: With spinal anesthesia, when cases are taking longer than usual, there may be behavioural tendencies for surgical teams to work more quickly. We conducted a systematic review with meta-analysis to examine standard deviations of surgical times for single-dose spinal anesthetics versus general anesthesia. We compared ratios of mean surgical times as a secondary endpoint.

Methods: We included randomized trials of humans where general or spinal anesthesia was used for one category of surgical procedure (e.g., hip arthroplasty) and the article reported the means and standard deviations of operative durations. We used statistical methods suitable for surgical times following log-normal distributions. We used generalized confidence intervals to calculate point estimates of ratios and standard errors for each study, followed by pooling among studies using DerSimonian and Laird random-effects meta-analysis with Knapp-Hartung adjustment.

Results: Among the 77 included studies, 96% were of high quality for our endpoint (i.e., had a low risk of bias), as no (0%) study focused on comparing variability of surgical times and none had surgical time as the primary endpoint. Spinal anesthesia was associated with 6.6% smaller standard deviations than general anesthesia (95% confidence interval, 15.8% smaller to 1.9% larger, P = 0.13). By meta-regression, there was no significant association of the ratios of standard deviations with study quality (P = 0.39), year of publication (P = 0.76), or categories of procedures (all five P ≥ 0.28). Spinal anesthesia was associated with 1.1% smaller means than general anesthesia (95% confidence interval, 3.7% smaller to 1.5% larger, P = 0.42). There were no significant associations between the ratios of means and study quality (P = 0.47), year of publication (P = 0.95), or categories of procedures (all five, P ≥ 0.63).

Conclusions: The results of this systematic review and meta-analysis show with high confidence that the effect of choosing spinal anesthesia on variability in surgical time, if present, is sufficiently small to have no substantive direct economic effect. The same conclusion applies to mean surgical time. Therefore, although anesthetic choice has a clinical (biological) impact and affects anesthesia times, the direct effects on surgical times and workflow are minimal at most. Anesthetic choice does not influence operating theatre productivity via changes to surgical times. The impact of spinal anesthetic effects is limited to nonoperative times (e.g., reducing anesthesia-controlled times by using a block room before the patient enters the operating room).

Abstract
Objective: The application of sufentanil of anesthesiology has become a popular research area. However, literature-based bibliometric analyses on sufentanil are limited. Therefore, this study aimed to review the application of sufentanil in anesthesiology, and evaluate the research status and trends in this field.

Methods: We searched the SCI-Expanded, SSCI, and CPCI-S databases from the Web of Science core collection as data sources for articles published from 1 January2003, to 31 December2023, and bibliometric and VOSviewer software were used to visualize and analyze the literature in terms of authors, journals, countries, institutions, and their collaborative networks, as well as keyword networks.

Results: Our analysis included 1,473 relevant publications on the application of sufentanil in anesthesiology. The overall number of publications is on the rise; the top three countries of study were China, the US and France; the top three universities that published relevant articles were Anhui Medical University, Capital Medical University and Zhejiang University; the largest number of publications focused on Anesthesia and analgesia; At present, the studies in this field mainly focus on the application scope, mode, and advantages; adverse reactions; and combined effects of sufentanil in combination with other drugs. The adverse factors for the use of sufentanil in anesthesiology and ways to improve its safety and efficacy are hot topics of research. Future research should explore the applicability of population and dose utilization, novel drug combinations, non-opioid adjuncts, and technological innovations.

Conclusion: An increasing number of publications indicates that researchers are showing interest in the field of sufentanil use in anesthesiology, and ongoing research is at a relatively mature level. While the international community has established a strong foundation for cooperation, the cooperation among researchers, institutions, and countries needs to be enhanced. Simultaneously, efforts must be made to explore and strengthen personnel cooperation, expand the coverage of funding support, and improve the quality of the literature.

Abstract
Background: Skilled facilitators are essential to drive effective simulation training in healthcare. Competency-based frameworks support the development of facilitation skills but, to our knowledge, there are no frameworks that specifically address context-sensitive priorities developed with practitioners working in low-resource settings.

Methods: We aimed to develop a core competency framework for healthcare simulation facilitation in low-resource settings using a modified Delphi process. We drew on the domain expertise of members of the Vital Anaesthesia Simulation Training Community of Practice, with the study guided by a four-member steering group experienced in the conduct of simulation in low-resource settings. In survey round 1, participants (n = 54) were presented with an initial competency set derived from a previous qualitative study and co-created a set of 57 competencies for effective simulation facilitation in low-resource settings. In survey round 2, participants (n = 52) ranked competencies by relevance into three performance categories: techniques; artistry; and values. In survey round 3, participants (n = 50) ranked competencies on their importance. The steering group collated results and presented a draft core competency framework. In survey round 4, participants (n = 50) voted with 98% agreement that this framework represented the most relevant and important competencies for effective facilitation of simulation sessions in low-resource settings.

Results: The final 32-item framework encompasses core competencies found in existing standards and includes important new concepts such as demonstration of cultural sensitivity; humility; ability to recognise and respond to potential language barriers; facilitation team collaboration; awareness of logistics; and contingency planning.

Discussion: This competency-based framework highlights specific practices required for effective simulation facilitation in low-resource settings. Further work is required to refine and validate this tool to train simulation facilitators to deliver effective training to improve patient safety.

Abstract
Patient blood management (PBM) is a patient-centered evidence-based strategy designed to preserve a patient's own blood and improve health outcomes. The effectiveness of PBM programs is now well-established globally within tertiary and secondary sectors, with demonstrable outcome benefits and cost savings. However, the role of primary care and the general practitioner in PBM is poorly understood. Yet the essential attributes of primary care, including access, continuity, coordination, and comprehensiveness, align well with PBM principles, enabling general practitioners to provide personalized holistic management of anemia for the community. The skill set of general practitioners in integrating and continuing care through the transition period after hospitalization is especially important. General practitioners are well-suited to the roles of health promotion and prevention, and have the potential to deliver substantial population health benefits. Given the public health imperative of this condition, it is vital that policy-makers appropriately support the role of general practitioners with financing, education, and resources for PBM in primary care.

Abstract
Background: As the primary Ca2+ release channel in skeletal muscle sarcoplasmic reticulum (SR), mutations in type 1 ryanodine receptor (RyR1) or its binding partners underlie a constellation of muscle disorders, including malignant hyperthermia (MH). In patients with MH mutations, triggering agents including halogenated volatile anaesthetics bias RyR1 to an open state resulting in uncontrolled Ca2+ release, increased sarcomere tension, and heat production. Propofol does not trigger MH and is commonly used for patients at risk of MH. The atomic-level interactions of any anaesthetic with RyR1 are unknown.

Methods: RyR1 opening was measured by [3H]ryanodine binding in heavy SR vesicles (wild type) and single-channel recordings of MH mutant R615C RyR1 in planar lipid bilayers, each exposed to propofol or the photoaffinity ligand analogue m-azipropofol (AziPm). Activator-mediated wild-type RyR1 opening as a function of propofol concentration was measured by Fura-2 Ca2+ imaging of human skeletal myotubes. AziPm binding sites, reflecting propofol binding, were identified on RyR1 using photoaffinity labelling. Propofol binding affinity to a photoadducted site was predicted using molecular dynamics (MD) simulation.

Results: Both propofol and AziPm decreased RyR1 opening in planar lipid bilayers (P<0.01) and heavy SR vesicles, and inhibited activator-induced Ca2+ release from human skeletal myotube SR. Several putative propofol binding sites on RyR1 were photoadducted by AziPm. MD simulation predicted propofol KD values of 55.8 μM and 1.4 μM in the V4828 pocket in open and closed RyR1, respectively.

Conclusions: Propofol demonstrated direct binding and inhibition of RyR1 at clinically plausible concentrations, consistent with the hypothesis that propofol partially mitigates MH by inhibition of induced Ca2+ flux through RyR1.

Abstract
In this research methods tutorial of clinical anesthesia, we will explore techniques to estimate the influence of a myriad of factors on patient outcomes. Big data that contain information on patients, treated by individual anesthesiologists and surgical teams, at different hospitals, have an inherent multi-level data structure (Fig. 1). While researchers often attempt to determine the association between patient factors and outcomes, that does not provide clinicians with the whole story. Patient care is clustered together according to clinicians and hospitals where they receive treatment. Therefore, multi-level regression models are needed to validly estimate the influence of each factor at each level. In addition, we will explore how to estimate the influence that variability-for example, one anesthesiologist deciding to do one thing, while another takes a different approach-has on outcomes for patients, using the intra-class correlation coefficient for continuous outcomes and the median odds ratio for binary outcomes. From this tutorial, you should acquire a clearer understanding of how to perform and interpret multi-level regression modeling and estimate the influence of variable clinical practices on patient outcomes in order to answer common but complex clinical questions. Fig. 1 Infographics.

Abstract
This Recommendation was developed by the Japanese Society of Intravenous Anesthesia Recommendation Making Working Group (JSIVA-WG) to promote the safe and effective practice of total intravenous anesthesia (TIVA), tailored to the current situation in Japan. It presents a policy validated by the members of JSIVA-WG and a review committee for practical anesthesia management. Anesthesiologists should acquire and maintain the necessary knowledge and skills to be able to administer TIVA properly. A secure venous access is critically important for TIVA. To visualize and understand the pharmacokinetics of intravenous anesthetics, use of real-time pharmacokinetic simulations is strongly recommended. Syringe pumps are essential for the infusion of intravenous anesthetics, which should be prepared according to the rules of each individual anesthesia department, particularly with regard to dilution. Syringes should be clearly labeled with content and drug concentration. When managing TIVA, particularly with the use of muscle relaxants, monitoring processed electroencephalogram (EEG) is advisable. However, the depth of sedation/anesthesia must be assessed comprehensively using various parameters, rather than simply relying on a single EEG index. TIVA should be swiftly changed to an alternative method that includes inhalation anesthesia if necessary. Use of antagonists at emergence may be associated with re-sedation risk. Casual administration of antagonists and sending patients back to surgical wards without careful observation are not acceptable.

Abstract
In this Pro-Con commentary article, we discuss whether anesthesiologists should be responsible for treating preoperative anemia. This debate was proposed based on the article published in this issue of Anesthesia & Analgesia by Warner et al, which is an advisory on managing preoperative anemia endorsed by both the Society of Cardiovascular Anesthesiologists and the Society for Advancement of Patient Blood Management. All evidence suggests that anemia is not just an innocent "bystander" which can be solved by transfusion. In fact, both anemia and transfusion are independently associated with adverse outcomes, so why not avoid both? It just makes sense that patients show up for surgery with enough red blood cells to avoid needing transfusion with someone else's. Even if we agree that preoperative anemia is worth treating before surgery, the question remains who should be responsible for doing so, and therein lies the reason for this Pro-Con debate. Should it be the responsibility of the anesthesiologist, or not? Let the readers decide.

Abstract
Background: Studies show that the two peak heights of electroencephalographic bicoherence (pBIC-high, pBIC-low) decrease after incision and are restored by fentanyl administration. We investigated whether pBICs are good indicators for adequacy of analgesia during surgery.

Methods: After local ethical committee approval, we enrolled 50 patients (27-65 years, ASA-PS I or II) who were scheduled elective surgery. Besides standard anesthesia monitors, to assess pBICs, we used a BIS monitor and freeware Bispectrum Analyzer for A2000. Fentanyl 5 µg/kg was completely administered before incision, and anesthesia was maintained with sevoflurane. After skin incision, when the peak of pBIC-high or pBIC-low decreased by 10% in absolute value (named LT10-high and LT10-low groups in order) or when either peak decreased to below 20% (BL20-high and BL20-low groups), an additional 1 g/kg of fentanyl was administered to examine its effect on the peak that showed a decrease.

Results: The mean values and standard deviation for pBIC-high 5 min before fentanyl administration, at the time of fentanyl administration, and 5 min after fentanyl administration for LT10-high group were 39.8% (10.9%), 26.9% (10.5%), and 35.7% (12.5%). And those for pBIC-low for LT10-low group were 39.5% (6.0%), 26.8% (6.4%) and 35.0% (7.0%). Those for pBIC-high for BL20-high group were 26.3% (5.6%), 16.5% (2.6%), and 25.7% (7.0%). And those for pBIC-low for BL20-low group were 26.7% (4.8%), 17.4% (1.8%) and 26.9% (5.7%), respectively. Meanwhile, at these trigger points, hemodynamic parameters didn't show significant changes.

Conclusion: Superior to standard anesthesia monitoring, pBICs are better indicators of analgesia during surgery.

Abstract
Purpose: The use of glucagon-like peptide-1 (GLP-1) receptor agonists (RAs) by patients undergoing surgery and procedures requiring anesthesia has become a topic of significant concern for perioperative providers because of the potential increased risk of aspiration resulting from the medication's effect of delaying gastric emptying. There is currently a lack of high-quality data regarding the safety of GLP-1 RAs in patients undergoing surgery, which has led to variations in practice.

Source: We performed an internet search of society-endorsed statements and guidelines related to perioperative management of GLP-1 RAs, focusing on the top 20 countries with the largest anesthesiology societies determined by membership data from the World Federation of Societies of Anesthesiologists. We excluded articles and websites that were not in English.

Principal findings: Our search revealed endorsed statements from fourteen major anesthesiology, endocrinology, and gastroenterology societies. There was considerable variation between societies in the recommendations and guidance for withholding these medications before surgery, the duration of withholding, assessment of the need for avoiding deep sedation or general anesthesia, use of rapid sequence intubation, need for prolonged fasting periods and clear fluid before a nil per os period, recognition of signs and symptoms for aspiration risk, the management of glucose in the perioperative period, and the use of point-of-care ultrasound for risk assessment.

Conclusion: Society-endorsed statements and guidelines provide varying recommendations on the perioperative management of GLP-1 RAs. The insights gained from this comparative analysis may help guide clinical practice, develop institutional practice guidelines, and direct future research efforts.

Abstract
Background: Ketamine and fentanyl are commonly used for sedation and induction of anesthesia in critically ill patients. This study aimed to compare the hemodynamic effects of ketamine versus fentanyl bolus in patients with septic shock.

Methods: This randomized controlled trial included mechanically ventilated adults with septic shock receiving sedation. Patients were randomized to receive either 1 mg/kg ketamine bolus or 1 mcg/kg fentanyl bolus. Cardiac output (CO), stroke volume (SV), heart rate (HR), and mean arterial pressure (MAP) were measured at the baseline, 3, 6, 10, and 15 min after the intervention. Delta CO was calculated as the change in CO at each time point in relation to baseline measurement. The primary outcome was delta CO 6 min after administration of the study drug. Other outcomes included CO, SV, HR, and MAP.

Results: Eighty-six patients were analyzed. The median (quartiles) delta CO 6 min after drug injection was 71(37, 116)% in the ketamine group versus - 31(- 43, - 12)% in the fentanyl group, P value < 0.001. The CO, SV, HR, and MAP increased in the ketamine group and decreased in the fentanyl group in relation to the baseline reading; and all were higher in the ketamine group than the fentanyl group.

Conclusion: In patients with septic shock, ketamine bolus was associated with higher CO and SV compared to fentanyl bolus.

Abstract in English, French
Purpose: Hypotension after induction of general anesthesia is common and is associated with significant adverse events. Identification of patients at high risk can inform the use of preoperative mitigation strategies. We conducted a systematic review and meta-analysis to assess the diagnostic accuracy of the inferior vena cava collapsibility index (IVC-CI) and maximal diameter (dIVCmax) in predicting postinduction hypotension and to identify their predictive performance across different threshold ranges.

Methods: We searched MEDLINE, PubMed®, and Embase from inception to March 2023 for prospective observational studies exploring the performance of IVC-CI and dIVCmax in predicting postinduction hypotension in adults presenting for elective surgery under general anesthesia. We excluded studies reporting on IVC parameters predicting postinduction hypotension in the obstetric patient population or exclusively in patients with obesity. Trials screening and data extraction were conducted independently. We performed meta-analyses to identify the performance of IVC parameters in predicting postinduction hypotension, followed by subgroup analyses that sought the IVC-CI range with the highest hierarchical summary receiver-operating characteristic area under the curve (HSROC-AUC). We used a bivariate random effects model to calculate summary estimates. We evaluated study quality using Newcastle-Ottawa scores and certainty of evidence using the GRADE framework.

Results: We included 14 studies involving 1,166 patients. Pooled sensitivity and specificity of the IVC-CI to predict postinduction hypotension was 0.68 (95% confidence interval [CI], 0.55 to 0.79; coverage probability, 0.91) and 0.78 (95% CI, 0.69 to 0.85; coverage probability, 0.9), respectively, with an HSROC-AUC of 0.80 (95% CI, 0.68 to 0.85, high quality of evidence). An IVC-CI threshold range of 40-45% had an HSROC-AUC of 0.86 (95% CI, 0.69 to 0.93, high quality of evidence).

Conclusions: Preoperative IVC-CI is a strong predictor of postinduction hypotension. We recommend that future studies use an IVC-CI threshold of 40-45% (low certainty of evidence). Future studies are needed to establish whether ultrasound-guided preoperative optimization improves outcomes in high-risk patients.

Study registration: PROSPERO ( CRD42022316140 ); first submitted 10 March 2022.

Abstract
Background: Precise anesthesia delivery helps ensure amnesia, analgesia, and immobility. Conventionally, the end-tidal anesthetic concentration is maintained through manual adjustment of the fresh gas flow and anesthetic vaporizer output. Some anesthesia delivery systems can deliver and maintain clinician-selected end-tidal anesthetic agent (EtAA) concentration using a modified closed-loop system. We evaluated the performance of an End-tidal Control (EtC) system on the Aisys CS2 anesthesia machine (GE HealthCare). We hypothesized EtC anesthetic delivery would be noninferior to manually controlled anesthetic delivery.

Methods: The Multi-site Anesthesia randomized controlled STudy of End-tidal control compared to conventional Results (MASTER) Trial evaluated anesthetic delivery in 210 adult patients receiving inhaled anesthesia. Patients were randomized to either EtC or manual control (MC) anesthetic delivery. The primary objective was to determine whether, compared to conventional anesthesia practice, EtC achieves and maintains clinician-specified EtAA and end-tidal oxygen (Eto2) concentrations within defined noninferiority limits. Noninferiority was concluded if the lower limit of the 95% confidence interval (CI) of the difference between the percent duration within the acceptable range (5% of steady state or a margin of ~10% of each agent's minimum alveolar concentration) for EtC and MC was ≥ -5% for both EtAA and Eto2. Secondary objectives included performance measures: response time: time required to attain 90% of the first desired EtAA, overshoot: amount the controller (or vaporizer delivery) exceeded the desired EtAA, and accuracy: average deviation from the desired EtAA.

Results: EtC achieved and sustained targeted EtAA and Eto2 concentrations within the noninferiority threshold. The EtAA was within 5% of the desired value 98% ± 2.05% of the time with EtC compared to 45.7% ± 31.7% of the time with MC (difference 52.3% [95% CI, 45.9%-58.6%], P < .0001). For Eto2, EtC was within the noninferiority limit 86.3% ± 22.8% of the time compared with MC at 41% ± 33.3% (P < .0001, difference 45.3% [95% CI, 36.1%-54.5%]). The median response time for achieving 90% of the initial EtAA desired value was 75 seconds with EtC and 158 seconds with MC (P = .0013). EtC exhibited a median overshoot of 6.64% of the selected EtAA concentration, whereas MC often failed to reach the clinician's desired value. The difference in median percent deviation from desired EtAA value was 15.7% ([95% CI, 13.5%-19.0%], P < 0001).

Conclusions: EtC achieves and maintains the EtAA and Eto2 concentration in a manner that is noninferior to manually controlled anesthesia delivery.

Keywords: allometry; modeling; pharmacodynamics; pharmacokinetics; pharmacometrics; physiological time.

Abstract
Background: At all Joint Commission-accredited hospitals, the anesthesia department chair must report quantitative assessments of anesthesiologists' and nurse anesthetists' (CRNAs') clinical performance at least annually. Most metrics lack evidence of usefulness, cost-effectiveness, reliability, or validity. Earlier studies showed that anesthesiologists' clinical supervision quality and CRNAs' work habits have content, convergent, discriminant, and construct validity. We evaluated predictive validity by testing for (expected) small but statistically significant associations between higher quality of supervision (work habits) and reduced probabilities of cases taking longer than estimated.

Methods: Supervision quality of each anesthesiologist was evaluated daily by assigned trainees using the 9-item de Oliveira Filho scale. The work habits of each CRNA were evaluated daily by assigned anesthesiologists using a 6-item scale. Both are scored binary, 1 if all items are rated the maximum, 0 otherwise. From 40,718 supervision evaluations and 53,722 work habit evaluations over 8 fiscal years, 16 mixed-effects logistic regression models were estimated, with raters as fixed effects and ratees (anesthesiologists or CRNAs) as random effects. Empirical Bayes means in the logit scale were obtained for 561 anesthesiologist-years and 605 CRNA-years. The binary-dependent variable was whether the case took longer than estimated from the historical mean time for combinations of scheduled procedures and surgeons. From 264,060 cases, 8 mixed-effects logistic regression models were fitted, 1 per fiscal year, using ratees as random effects. Predictive validity was tested by pairing the 8 one-year analyses of clinical supervision, and the 8 one-year analyses of work habits, by ratee, with the 8 one-year analyses of whether OR time was longer than estimated. Bivariate errors in variable linear least squares linear regressions minimized total variances.

Results: Among anesthesiologists, 8.2% (46/561) had below-average supervision quality, and 17.7% (99/561), above-average. Among CRNAs, 6.3% (38/605) had below-average work habits, and 10.9% (66/605) above-average. Increases in the logits of the quality of clinical supervision were associated with decreases in the logits of the probabilities of cases taking longer than estimated, unitless slope = -0.0361 (SE, 0.0053), P < .00001. Increases in the logits of CRNAs' work habits were associated with decreases in the logits of probabilities of cases taking longer than estimated, slope = -0.0238 (SE, 0.0054), P < .00001.

Conclusions: Predictive validity was confirmed, providing further evidence for using supervision and work habits scales for ongoing professional practice evaluations. Specifically, OR times were briefer when anesthesiologists supervised residents more closely, and when CRNAs had better work habits.

Abstract
Human hands have a complex anatomical structure. The thumb, being an integral part of the hand, has an essential function in gripping. In this sense, thumb fractures account for 4% of all hand fractures (it may occur in association with fractures of the trapezium). The majority of hand fractures should be treated non-surgically and surgeons must avoid unnecessary surgery. Historically, hand surgery has used a combination of local/regional/general anaesthesia and a tourniquet. This study aims to carry out a systematic review to determine whether the WALANT technique is an advantageous alternative to conventional anaesthesia for surgical procedures on thumb injuries, in terms of patient function and pain.

Method: We conducted a search in the following databases: Pubmed/Medline, EBSCOhost, Web of Science, Scopus, ScienceDirect and Google Scholar, using the equation "WALANT" OR "Wide Awake Local Anesthesia No Tourniquet" AND "thumb pathology".

Results: In five of the 584 articles included, two studied trapeziometacarpal osteoarthritis, one De Quervain's disease and the remaining two flexor injuries. WALANT showed good results in active movements, but with similar levels of pain between anaesthetics. Patients were more anxious during general anaesthesia, plus the fact that they were fasting and suspending medication.

Conclusion: WALANT is a convenient and favourable option in several studies. It has been demonstrated the benefits in terms of return to function and pain.

Abstract
Background: There is a large global deficit of anesthesia providers. In 2016, the World Federation of Societies of Anaesthesiologists (WFSA) conducted a survey to count the number of anesthesia providers worldwide. Much work has taken place since then to strengthen the anesthesia health workforce. This study updates the global count of anesthesia providers.

Methods: Between 2021 and 2023, an electronic survey was sent to national professional societies of physician anesthesia providers (PAPs), nurse anesthetists, and other nonphysician anesthesia providers (NPAPs). Data included number of providers and trainees, proportion of females, and limited intensive care unit (ICU) capacity data. Descriptive statistics were calculated by country, World Bank income group, and World Health Organization (WHO) region. Provider density is reported as the number of providers per 100,000 population.

Results: Responses were obtained for 172 of 193 United Nations (UN) member countries. The global provider density was 8.8 (PAP 6.6 NPAP 2.3). Seventy-six countries had a PAP density <5, whereas 66 countries had a total provider density <5. PAP density increased everywhere except for high- and low-income countries and the African region.

Conclusions: The overall size of the global anesthesia workforce has increased over time, although some countries have experienced a decrease. Population growth and differences in which provider types that are counted can have an important impact on provider density. More work is needed to define appropriate metrics for measuring changes in density, to describe anesthesia cadres, and to improve workforce data collection processes. Effort to scale up anesthesia provider training must urgently continue.

Abstract in English, French
Background: Online video sharing platforms like YouTube (Google LLC, San Bruno, CA, USA) have become a substantial source of health information. We sought to conduct a systematic review of studies assessing the overall quality of perioperative anesthesia videos on YouTube.

Methods: We searched Embase, MEDLINE, and Ovid for articles published from database inception to 1 May 2023. We included primary studies evaluating YouTube videos as a source of information regarding perioperative anesthesia. We excluded studies not published in English and studies assessing acute or chronic pain. Studies were screened and data were extracted in duplicate by two reviewers. We appraised the quality of studies according to the social media framework published in the literature. We used descriptive statistics to report the results using mean, standard deviation, range, and n/total N (%).

Results: Among 8,908 citations, we identified 14 studies that examined 796 videos with 59.7 hr of content and 47.5 million views. Among the 14 studies that evaluated the video content quality, 17 different quality assessment tools were used, only three of which were externally validated (Global Quality Score, modified DISCERN score, and JAMA score). Per global assessment rating of video quality, 11/13 (85%) studies concluded the overall video quality as poor.

Conclusions: Overall, the educational content quality of YouTube videos evaluated in the literature accessible as an educational resource regarding perioperative anesthesia was poor. While these videos are in demand, their impact on patient and trainee education remains unclear. A standardized methodology for evaluating online videos is merited to improve future reporting. A peer-reviewed approach to online open-access videos is needed to support patient and trainee education in anesthesia.

Abstract
The use of the laryngeal mask airway (LMA), which offers the benefits of ease in insertion and prevention of tracheal damage, is associated with a risk of flow leakage. This study analyzed our extensive database to compare leakage associated with the use of LMA and endotracheal tube (ETT). Adult patients who underwent chest wall, abdominal wall, inguinal region, limb, transurethral, or transvaginal surgery and received either LMA or ETT between January 2007 and March 2020 were included. The leak fraction was calculated as (inspiratory tidal volume-expiratory tidal volume)/(inspiratory tidal volume) × 100% every minute during intraoperative stable positive pressure ventilation. The median leak fraction was calculated for each case. The leak fraction in the LMA group demonstrated a left-skewed distribution with a larger proportion of excessive leak fraction. The leak fraction in the LMA group (median, 7.9%; interquartile range, 4.8-11.4%) was significantly lower than that in the ETT group (median, 9.1%; interquartile range: 5.5-12.4%; P < 0.001). This tendency was consistent across subgroups divided by sex, age, type of surgery, and ventilation mode. We propose that LMA provides leakage comparable to or less than ETT in most cases if stable positive pressure ventilation is achieved.

Abstract
Chronic pain in inflammatory arthritis (IA) reflects a complex interplay between active disease in a peripheral joint and central pronociceptive mechanisms. Because intra-articular lidocaine may be used to abolish joint-specific peripheral input to the central nervous system, we aimed to validate its use as a clinical tool to identify those patients with IA whose pain likely incorporates centrally mediated mechanisms. We began by investigating whether there was a placebo response of intra-articular injection in patients with IA 1:1 randomised to receive intra-articular lidocaine or control (0.9% saline). After, in a larger patient cohort not randomized to placebo vs lidocaine groups, we tested whether patients with IA could be stratified into 2 cohorts based on their response to intra-articular lidocaine according to markers of centrally mediated pain. To this end, we evaluated postlidocaine pain numerical rating scale (NRS) scores alongside baseline painDETECT, fibromyalgia criteria fulfillment, and quantitative sensory testing outcomes. Numerical rating scale scores were collected at baseline and 3-, 5-, and 10-minutes postinjection. Firstly, the placebo effect of intra-articular injection was low: compared to baseline, the mean pain NRS score 5-minutes postinjection was reduced by 3.5 points in the lidocaine group vs 1.2 points in the control group. Secondly, postlidocaine NRS scores were significantly higher in those with a high (>18) baseline painDETECT score, fibromyalgia, and low-pressure pain threshold at the trapezius (P = 0.002, P = 0.001, P = 0.005, respectively). Persistent high pain after intra-articular lidocaine injection could be used as an indicator of pronociceptive mechanisms that are centrally mediated, informing centrally targeted analgesic strategies.

Abstract
Background: Sequential combined spinal epidural anesthesia (CSEA) is probably the greatest advancement in the central neuraxial block in this decade for geriatric patients due to the potential advantages of both spinal and epidural anesthesia. This study was designed to compare the clinical effects of sequential CSEA versus spinal and epidural anesthesia in geriatric patients undergoing transurethral resection of the prostate (TURP).

Methods: Ninety patients aged 65 to 80 years were randomly allocated into three groups of 30 each. Group A (n=30) patients were administered spinal anesthesia with 2.5 ml of 0.5% hyperbaric bupivacaine, group B (n=30) received epidural anesthesia with 15 ml of 0.5% isobaric bupivacaine, and group C (n=30) received sequential CSEA with 1 ml of 0.5% hyperbaric bupivacaine and 6 ml of 0.5% isobaric bupivacaine given through epidural route to extend the block up to T10. Patients were observed for hemodynamic parameters, sensory and motor block, total dose required to establish the desired level, and patient satisfaction score.

Results: None of the patients were excluded in the study. Group A patients reported rapid onset of sensory block (3.08±11.57 minutes) compared to group B (11.57±1.48 minutes), and group C (5.47±1.25 minutes). The onset of motor block was expeditious in group A (8.08±1.0 minutes) compared to group B (20.33±1.86 minutes) and group C (15.53±1.31 minutes). Patients in group B had maximum hemodynamic stability but with delayed onset and were technically more complex than group A. Patients in group C were hemodynamically more stable than group A. They had a faster onset of action with decreased doses of local anesthetic drug required compared to group B.

Conclusion: Sequential CSEA is a safe, effective, and reliable technique that combines the advantages of both spinal and epidural while minimizing their disadvantages. It has the advantage of stable hemodynamic parameters along with the provision of prolongation analgesia for geriatric patients undergoing TURP surgery.

Abstract in English, French
Purpose: Echocardiographic strain analysis by speckle tracking allows assessment of myocardial deformation during the cardiac cycle. Its clinical applications have significantly expanded over the last two decades as a sensitive marker of myocardial dysfunction with important diagnostic and prognostic values. Strain analysis has the potential to become a routine part of the perioperative echocardiographic examination for most anesthesiologist-echocardiographers but its exact role in the perioperative setting is still being defined.

Clinical features: This clinical report reviews the principles underlying strain analysis and describes its main clinical uses pertinent to the field of anesthesiology and perioperative medicine. Strain for assessment of left and right ventricular function as well as atrial strain is described. We also discuss the potential role of strain to aid in perioperative risk stratification, surgical patient selection in cardiac surgery, and guidance of anesthetic monitor choice and clinical decision-making in the perioperative period.

Conclusion: Echocardiographic strain analysis is a powerful tool that allows seeing what conventional 2D imaging sometimes fails to reveal. It often provides pathophysiologic insight into various cardiac diseases at an early stage. Strain analysis is readily feasible and reproducible thanks to the use of highly automated software platforms. This technique shows promising potential to become a valuable tool in the arsenal of the anesthesiologist-echocardiographer and aid in perioperative risk-stratification and clinical decision-making.

Abstract
As the COVID-19 pandemic increased the use of propofol in the intensive care unit for the management of respiratory sequelae and supply had become a major issue. Indeed, most hospitals in Japan were forced to use propofol only for induction of anesthesia with inhalational maintenance. Large amounts of propofol remain in the syringe which exacerbates the problems by increased waste. I propose that use of low dose propofol in combination with a low concentration inhaled anesthetic as an alternative and call this hybrid anesthesia. Several advantages of hybrid anesthesia are evident in the literature. Volatile anesthesia has several disadvantages such as cancer progression, emergence agitation, marked reduction in motor evoked potentials (MEP), laryngospasm with desflurane and postoperative nausea and vomiting (PONV). Volatile anesthesia exerts some beneficial actions such as myocardial protection and fast emergence with desflurane. In contrast, total intravenous anesthesia (TIVA) provides better survival in patients undergoing radical cancer surgery, reduction in emergence agitation, laryngospasm, PONV and better MEP trace Intraoperative awareness occurs more often during TIVA. When intravenous and volatile anesthesia are combined (hybrid anesthesia), the disadvantages of both methods may be offset by clear advantages. Thus, hybrid anesthesia may, therefore, be a viable anesthetic choice.

Abstract
Although anesthesia makes painful or uncomfortable diagnostic and interventional health care procedures tolerable, it may also disrupt key cellular processes in neurons and glia, harm the developing brain, and thereby impair cognition and behavior in children. Many years of studies using in vitro, animal behavioral, retrospective database studies in humans, and several prospective clinical trials in humans have been invaluable in discerning the potential toxicity of anesthetics. The objective of this scoping review was to synthetize the evidence from preclinical studies for various mechanisms of toxicity across diverse experimental designs and relate their findings to those of recent clinical trials in real-world settings.

Abstract
Purpose: Though the finger is generally recommended for pulse oxygen saturation (SpO2) monitoring site, its reliability may be compromised in conditions of poor peripheral perfusion. Therefore, we compared the performance of nasal septum SpO2 monitoring with finger SpO2 monitoring relative to simultaneous arterial oxygen saturation (SaO2) monitoring in generally anesthetized patients.

Methods: In 23 adult patients, comparisons of SpO2 measured at the nasal septum and finger with simultaneous SaO2 were made at four time points during the 90 min study period. A pulse oximetry monitoring failure was defined as a > 10 s continuous failure of in an adequate SpO2 data acquisition. Core temperature as well as finger-tip and nasal septum temperatures were simultaneously measured at 10 min intervals.

Results: A total of 92 sets of SpO2 and SaO2 measurements were obtained in 23 patients. The bias and precision for SpO2 measured at the nasal septum were - 0.8 ± 1.3 (95% confidence interval: - 1.1 to - 0.6), which was similar to those for SpO2 measured at the finger (- 0.6 ± 1.4; 95% confidence interval: - 0.9 to - 0.4) (p = 0.154). Finger-tip temperatures were consistently lower than other two temperatures at all time points (p < 0.05), reaching 33.5 ± 2.3 °C at 90 min after induction of anesthesia. While pulse oximetry monitoring failure did not occur for nasal septum probe, two cases of failure occurred for finger probe.

Conclusions: Considering the higher stability to hypothermia with a similar accuracy, nasal septum pulse oximetry may be an attractive alternative to finger pulse oximetry. Trail registration This study was registered with Clinical Research Information Service (CRIS: https://cris.nih.go.kr/cris/en/ ; ref: KCT0008352).

Abstract
An estimated 1.7 billion children and adolescents do not have access to safe and affordable surgical care, and the vast majority of these are located in low-middle-income countries (LMICs). Pediatric anesthesia, a specialized field that requires a diverse set of knowledge and skills, has seen various advancements over the years and has become well-established in upper-middle and high-income countries. However, in LMICs, due to a multitude of factors including severe workforce shortages, this has not been the case. Collaborations play a vital role in increasing the capacity of pediatric anesthesiology educators and training the pediatric anesthesia workforce. These efforts directly increase access for children who require surgical intervention. Collaboration models can be operationalized through bidirectional knowledge sharing, training, resource allocation, research and innovation, quality improvement, networking, and advocacy. This article aims to highlight a few of these collaborative efforts. Specifically, the role that the World Federation of Societies of Anaesthesiologists, the Safer Anesthesia from Education program, the Asian Society of Pediatric Anaesthesiologists, Pediatric Anesthesia Training in Africa, the Paediatric Anaesthesia Network New Zealand, the Safe Pediatric Anesthesia Network and two WhatsApp™ groups (global ped anesthesia and the Pediatric Difficult Intubation Collaborative) have played in improving anesthesiology care for children.

Abstract
Background: There is a large global deficit of anesthesia providers. In 2016, the World Federation of Societies of Anaesthesiologists (WFSA) conducted a survey to count the number of anesthesia providers worldwide. Much work has taken place since then to strengthen the anesthesia health workforce. This study updates the global count of anesthesia providers.

Methods: Between 2021 and 2023, an electronic survey was sent to national professional societies of physician anesthesia providers (PAPs), nurse anesthetists, and other nonphysician anesthesia providers (NPAPs). Data included number of providers and trainees, proportion of females, and limited intensive care unit (ICU) capacity data. Descriptive statistics were calculated by country, World Bank income group, and World Health Organization (WHO) region. Provider density is reported as the number of providers per 100,000 population.

Results: Responses were obtained for 172 of 193 United Nations (UN) member countries. The global provider density was 8.8 (PAP 6.6 NPAP 2.3). Seventy-six countries had a PAP density <5, whereas 66 countries had a total provider density <5. PAP density increased everywhere except for high- and low-income countries and the African region.

Conclusions: The overall size of the global anesthesia workforce has increased over time, although some countries have experienced a decrease. Population growth and differences in which provider types that are counted can have an important impact on provider density. More work is needed to define appropriate metrics for measuring changes in density, to describe anesthesia cadres, and to improve workforce data collection processes. Effort to scale up anesthesia provider training must urgently continue.

Abstract
How general anesthetics work remains a topic of ongoing study. A parallel field of research has sought to identify methods to reverse general anesthesia. Reversal agents could shorten patients' recovery time and potentially reduce the risk of postoperative complications. An incomplete understanding of the mechanisms of general anesthesia has hampered the pursuit for reversal agents. Nevertheless, the search for reversal agents has furthered understanding of the mechanisms underlying general anesthesia. The study of potential reversal agents has highlighted the importance of rigorous criteria to assess recovery from general anesthesia in animal models, and has helped identify key arousal systems (e.g., cholinergic, dopaminergic, and orexinergic systems) relevant to emergence from general anesthesia. Furthermore, the effects of reversal agents have been found to be inconsistent across different general anesthetics, revealing differences in mechanisms among these drugs. The presynapse and glia probably also contribute to general anesthesia recovery alongside postsynaptic receptors. The next stage in the search for reversal agents will have to consider alternate mechanisms encompassing the tripartite synapse.

Abstract
Recent advances in neural networks have given rise to generative artificial intelligence, systems able to produce fluent responses to natural questions or attractive and even photorealistic images from text prompts. These systems were developed through new network architectures that permit massive computational resources to be applied efficiently to enormous data sets. First, this review examines autoencoder architecture and its derivatives the variational autoencoder and the U-Net in annotating and manipulating images and extracting salience. This architecture will be important for applications like automated x-ray interpretation or real-time highlighting of anatomy in ultrasound images. Second, this article examines the transformer architecture in the interpretation and generation of natural language, as it will be useful in producing automated summarization of medical records or performing initial patient screening. The author also applies the GPT-3.5 algorithm to example questions from the American Board of Anesthesiologists Basic Examination and find that, under surprisingly reasonable conditions, it correctly answers more than half the questions.

Abstract
Background: Adult epiglottitis is a life-threatening airway emergency where airway protection is the immediate priority. Despite its importance, the optimal approach to airway management remains unclear. We performed a systematic review of the airway management for adult epiglottitis, including meta-analysis of trends over time.

Methods: We systematically searched PubMed, Ovid MEDLINE®, and Embase® for adult epiglottitis studies that described the airway management between 1980 and 2020. The primary outcome was the prevalence of airway intervention. Secondary outcomes were prevalence of tracheal intubation, tracheostomy, and failed intubation. A random-effects model meta-analysis was performed with subgroups defined by decade of study publication. Cases that described the specific method of airway intervention and severity of epiglottitis were included in a separate technique summary.

Results: Fifty-six studies with 10 630 patients were included in the meta-analysis. The overall rate of airway intervention was 15.6% (95% confidence interval [CI] 12.9-18.8%) but the rate decreased from 20% to 10% between 1980 and 2020. The overall rate of tracheal intubation was 10.2% (95% CI 7.1-13.6%) and that of failed intubation was 4.2% (95% CI 1.4-8.0%). The airway technique summary included 128 cases, of which 75 (58.6%) were performed awake and 53 (41.4%) involved general anaesthesia. We identified 32 cases of primary technique failure.

Conclusion: The rate of airway intervention for adult epiglottitis has decreased over four decades to a current level of 10%. Tracheal intubation is a high-risk scenario with a 1 in 25 failure rate. Specific technique selection is most likely influenced by contextual factors including the severity of epiglottitis.

Abstract
The optimal consciousness level required for general anesthesia with surgery is unclear, but in existing practice, anesthetic oblivion, may be incomplete. This article discusses the concept of consciousness, how it is altered by anesthetics, the challenges for assessing consciousness, currently used technologies for assessing anesthesia levels, and future research directions. Wakefulness is marked by a subjective experience of existence (consciousness), perception of input from the body or the environment (connectedness), the ability for volitional responsiveness, and a sense of continuity in time. Anesthetic drugs may selectively impair some of these components without complete extinction of the subjective experience of existence. In agreement with Sanders et al. (2012), the authors propose that a state of disconnected consciousness is the optimal level of anesthesia, as it likely avoids both awareness and the possible dangers of oversedation. However, at present, there are no reliably tested indices that can discriminate between connected consciousness, disconnected consciousness, and complete unconsciousness.

Abstract
Purpose: Improvement in delivery of perioperative care depends on the ability to measure outcomes that can direct meaningful changes in practice. We sought to identify and provide an overview of perioperative quality indicators specific to the practice of anesthesia in noncardiac surgery.

Source: We conducted an umbrella review (a systematic review of systematic reviews) according to Joanna Briggs Institute methodology. We included systematic reviews examining perioperative indicators in patients ≥ 18 yr of age undergoing noncardiac surgery. Our primary outcome was any quality indicator specific to anesthesia. Indicators were classified by the Donabedian system and perioperative phase of care. The quality of systematic reviews was assessed using AMSTAR 2 criteria. Level of evidence of quality indicators was stratified by the Oxford Centre for Evidence-Based Medicine Classification.

Principal findings: Our search returned 1,475 studies. After removing duplicates and screening of abstracts and full texts, 23 systematic reviews encompassing 3,164 primary studies met our inclusion criteria. There were 330 unique quality indicators. Process indicators were most common (n = 169), followed by outcome (n = 114) and structure indicators (n = 47). Few identified indicators were supported by high-level evidence (45/330, 14%). Level 1 evidence supported indicators of antibiotic prophylaxis (1a), venous thromboembolism prophylaxis (1a), postoperative nausea/vomiting prophylaxis (1b), maintenance of normothermia (1a), and goal-directed fluid therapy (1b).

Conclusion: This umbrella review highlights the scarcity of perioperative quality indicators that are supported by high quality evidence. Future development of quality indicators and recommendations for outcome measurement should focus on metrics that are supported by level 1 evidence. Potential targets for evidence-based quality-improvement programs in anesthesia are identified herein.

Abstract
Background: Remimazolam is a novel ultra-short-acting benzodiazepine sedative that acts on the gamma-aminobutyric acid type A receptor (GABAAR).

Objective: To compare the efficacies of remimazolam (RMZ), and propofol (PROP) combined with remifentanil and cisatracurium for total intravenous anaesthesia (TIVA) in patients undergoing urological surgery.

Design: A prospective, single-blind, randomised, noninferiority clinical trial.

Setting: Single centre from 1 January 2022 to 30 March 2022.

Patients: A total of 146 adult patients undergoing elective urological surgery.

Intervention: Patients were randomly allocated in a 1 : 1 ratio to the PROP or RMZ groups. In the PROP group, anaesthesia was induced with propofol at 100 mg min-1 to reach a bispectral index score (BIS) of 40 to 60. After loss of consciousness (LOC), intravenous fentanyl 3 μg kg-1 was administered, followed by cisatracurium 0.3 mg kg-1. Patients were intubated 3 min after cisatracurium administration. Anaesthesia was maintained with the combination of propofol (plasma concentration: 2.5 to 4 μg ml-1) and remifentanil (plasma concentration: 2.5 to 4 ng ml-1). In the RMZ group, anaesthesia was induced with remimazolam tosilate starting at 10 mg kg-1 h-1 to reach a BIS of 40 to 60 and maintained between 0.2 and 2 mg kg-1 h-1. After LOC, fentanyl and cisatracurium were administered and intubation was performed as in the PROP group. Anaesthesia was maintained with a combination of remimazolam (0.2 to 2 mg kg-1 h-1) and remifentanil (plasma concentration: 2.5 to 4 ng ml-1).

Main outcome measures: The primary outcome was the TIVA success rate. The predefined noninferiority margin considered an absolute difference of 6% in the primary outcome between the groups. The secondary outcomes were vital signs, anaesthesia and surgery characteristics, and adverse events.

Results: All patients completed the trial. The success rates of TIVA with remimazolam and propofol were 100 and 98.6%, respectively. The incidence of hypotension during anaesthesia was lower in the RMZ group (26%) than in the PROP group (46.6%) (P = 0.016). The median [IQR] total consumption of ephedrine during anaesthesia was higher in the PROP group 10 [0 to 12.5] mg than in the RMZ group 0 [0 to 10] mg (P = 0.0002). The incidence of injection pain was significantly higher in the PROP group (76.7%) than in the RMZ group (0; P < 0.001). No significant differences in the controllability of the anaesthesia depth, anaesthesia and surgery characteristics, or vital signs were observed between the groups.

Conclusion: Remimazolam demonstrated noninferior efficacy to propofol combined with remifentanil and cisatracurium for TIVA in patients undergoing urological surgery.

Abstract
Airway management is required during general anaesthesia and is essential for life-threatening conditions such as cardiopulmonary resuscitation. Evidence from recent trials indicates a high incidence of critical events during airway management, especially in neonates or infants. It is important to define the optimal techniques and strategies for airway management in these groups. In this joint European Society of Anaesthesiology and Intensive Care (ESAIC) and British Journal of Anaesthesia (BJA) guideline on airway management in neonates and infants, we present aggregated and evidence-based recommendations to assist clinicians in providing safe and effective medical care. We identified seven main areas of interest for airway management: i) preoperative assessment and preparation; ii) medications; iii) techniques and algorithms; iv) identification and treatment of difficult airways; v) confirmation of tracheal intubation; vi) tracheal extubation, and vii) human factors. Based on these areas, Population, Intervention, Comparison, Outcomes (PICO) questions were derived that guided a structured literature search. GRADE (Grading of Recommendations, Assessment, Development and Evaluation) methodology was used to formulate the recommendations based on those studies included with consideration of their methodological quality (strong '1' or weak '2' recommendation with high 'A', medium 'B' or low 'C' quality of evidence). In summary, we recommend: 1. Use medical history and physical examination to predict difficult airway management (1С). 2. Ensure adequate level of sedation or general anaesthesia during airway management (1B). 3. Administer neuromuscular blocker before tracheal intubation when spontaneous breathing is not necessary (1С). 4. Use a videolaryngoscope with an age-adapted standard blade as first choice for tracheal intubation (1B). 5. Apply apnoeic oxygenation during tracheal intubation in neonates (1B). 6. Consider a supraglottic airway for rescue oxygenation and ventilation when tracheal intubation fails (1B). 7. Limit the number of tracheal intubation attempts (1C). 8. Use a stylet to reinforce and preshape tracheal tubes when hyperangulated videolaryngoscope blades are used and when the larynx is anatomically anterior (1C). 9. Verify intubation is successful with clinical assessment and end-tidal CO 2 waveform (1C). 10. Apply high-flow nasal oxygenation, continuous positive airway pressure or nasal intermittent positive pressure ventilation for postextubation respiratory support, when appropriate (1B).

Abstract
This narrative review summarizes research about prolonged times to tracheal extubation after general anesthesia with both intubation and extubation occurring in the operating room or other anesthetizing location where the anesthetic was performed. The literature search was current through May 2023 and included prolonged extubations defined either as >15 minutes or at least 15 minutes. The studies showed that prolonged times to extubation can be measured accurately, are associated with reintubations and respiratory treatments, are rated poorly by anesthesiologists, are treated with flumazenil and naloxone, are associated with impaired operating room workflow, are associated with longer operating room times, are associated with tardiness of starts of to-follow cases and surgeons, and are associated with longer duration workdays. When observing prolonged extubations among all patients receiving general anesthesia, covariates accounting for most prolonged extubations are characteristics of the surgery, positioning, and anesthesia provider's familiarity with the surgeon. Anesthetic drugs and delivery systems routinely achieve substantial differences in the incidences of prolonged extubations. Occasional claims made that anesthesia drugs have unimportant differences in recovery times, based on medians and means of extubation times, are misleading, because benefits of different anesthetics are achieved principally by reducing the variability in extubation times, specifically by decreasing the incidence of extubation times sufficiently long to have economic impact (ie, the prolonged extubations). Collectively, the results show that when investigators in anesthesia pharmacology quantify the rate of patient recovery from general anesthesia, the incidence of prolonged times to tracheal extubation should be included as a study end point.

Abstract
There is a potential differential effect of sevoflurane compared with propofol on postoperative delirium and other perioperative neurocognitive disorders. More generally, there are perhaps differences between volatile and intravenous anaesthetic agents in their possible impact on perioperative neurocognitive disorders. Strengths and limitations of a recent study in this journal and its contribution to our understanding of the impact of anaesthetic technique on perioperative neurocognitive disorders are discussed.

Abstract
A recent systematic review and meta-analysis by Wang and colleagues in the British Journal of Anaesthesia calls into question the concept that perioperative benzodiazepine administration is associated with development of postoperative delirium in older individuals after anaesthesia and surgery. This editorial focuses on potential bias within the systematic review and addresses major concerns surrounding benzodiazepine use in the older perioperative population.