Advances in pediatric perioperative care using artificial intelligence.

PURPOSE OF THIS REVIEW: This article explores how artificial intelligence (AI) can be used to evaluate risks in pediatric perioperative care. It will also describe potential future applications of AI, such as models for airway device selection, controlling anesthetic depth and nociception during surgery, and contributing to the training of pediatric anesthesia providers. RECENT FINDINGS: The use of AI in healthcare has increased in recent years, largely due to the accessibility of large datasets, such as those gathered from electronic health records. Although there has been less focus on pediatric anesthesia compared to adult anesthesia, research is on- going, especially for applications focused on risk factor identification for adverse perioperative events. Despite these advances, the lack of formal external validation or feasibility testing results in uncertainty surrounding the clinical applicability of these tools. SUMMARY: The goal of using AI in pediatric anesthesia is to assist clinicians in providing safe and efficient care. Given that children are a vulnerable population, it is crucial to ensure that both clinicians and families have confidence in the clinical tools used to inform medical decision- making. While not yet a reality, the eventual incorporation of AI-based tools holds great potential to contribute to the safe and efficient care of our patients.

A survey of operating theatre staff on the impact of automated medication dispensing systems in operating theatres in an Australian hospital.

There is a lack of published literature investigating the impact of anaesthesia-specific automated medication dispensing systems on theatre staff. This study aimed to investigate the perspectives of theatre staff from multiple disciplines on their experience using anaesthesia stations three years after implementation at our Western Australian quaternary hospital institution. A web-based survey was distributed to 440 theatre staff, which included consultant anaesthetists, anaesthetic trainees, nurses, anaesthetic technicians and pharmacists, and 118 responses were received (response rate 26.8%). Eighty-one percent of the anaesthetic medical staff responders reported that the anaesthesia stations were fit for purpose and 66.67% of the anaesthetic medical staff reported that they were user friendly. Sixty-seven percent of anaesthetic medical staff agreed that controlled medication (e.g. schedule 8 and schedule 4 recordable) transactions were more efficient with the anaesthesia stations, and 66.67% agreed that the anaesthesia stations improved accountability for these transactions. Sixty-seven percent of anaesthetic medical staff preferred to use anaesthesia stations and 21.2% of all the responders preferred a manual medication trolley (P ≤ 0.001). This survey of user experience with anaesthesia stations was found to be predominantly positive with the majority of theatre staff and anaesthetic medical staff preferring anaesthesia stations.

The World Federation of Societies of Anaesthesiologists Minimum Capnometer Specifications 2021-A Guide for Health Care Decision Makers.

Capnometry, the measurement of respiratory carbon dioxide, is regarded as a highly recommended safety technology in intubated and nonintubated sedated and/or anesthetized patients. Its utility includes confirmation of initial and ongoing placement of an airway device as well as in detecting gas exchange, bronchospasm, airway obstruction, reduced cardiac output, and metabolic changes. The utility applies prehospital and throughout all phases of inhospital care. Unfortunately, capnometry devices are not readily available in many countries, especially those that are resource-limited. Constraining factors include cost, durability of devices, availability of consumables, lack of dependable power supply, difficulty with cleaning, and maintenance. There is, thus, an urgent need for all stakeholders to come together to develop, market, and distribute appropriate devices that address costs and other requirements. To foster this process, the World Federation of Societies of Anaesthesiologists (WFSA) has developed the "WFSA-Minimum Capnometer Specifications 2021." The intent of the specifications is to set the minimum that would be acceptable from industry in their attempts to reduce costs while meeting other needs in resource-constrained regions. The document also includes very desirable and preferred options. The intent is to stimulate interest and engagement among industry, clinical providers, professional associations, and ministries of health to address this important patient safety need. The WFSA-Minimum Capnometer Specifications 2021 is based on the International Organization for Standardization (ISO) capnometer specifications. While industry is familiar with such specifications and their presentation format, most clinicians are not; therefore, this article serves to more clearly explain the requirements. In addition, the specifications as described can be used as a purchasing guide by clinicians.

Comparing Ventilation Parameters for COVID-19 Patients Using Both Long-Term ICU and Anesthetic Ventilators in Times of Shortage.

In the first months of the COVID-19 pandemic in Europe, many patients were treated in hospitals using mechanical ventilation. However, due to a shortage of ICU ventilators, hospitals worldwide needed to deploy anesthesia machines for ICU ventilation (which is off-label use). A joint guidance was written to apply anesthesia machines for long-term ventilation. The goal of this research is to retrospectively evaluate the differences in measurable ventilation parameters between the ICU ventilator and the anesthesia machine as used for COVID-19 patients. In this study, we included 32 patients treated in March and April 2020, who had more than 3 days of mechanical ventilation, either in the regular ICU with ICU ventilators (Hamilton S1), or in the temporary emergency ICU with anesthetic ventilators (Aisys, GE). The data acquired during regular clinical treatment was collected from the Patient Data Management Systems. Available ventilation parameters (pressures and volumes: PEEP, Ppeak, Pinsp, Vtidal), monitored parameters EtCO2, SpO2, derived compliance C, and resistance R were processed and analyzed. A sub-analysis was performed to compare closed-loop ventilation (INTELLiVENT-ASV) to other ventilation modes. The results showed no major differences in the compared parameters, except for Pinsp. PEEP was reduced over time in the with Hamilton treated patients. This is most likely attributed to changing clinical protocol as more clinical experience and literature became available. A comparison of compliance between the 2 ventilators could not be made due to variances in the measurement of compliance. Closed loop ventilation could be used in 79% of the time, resulting in more stable EtCO2. From the analysis it can be concluded that the off-label usage of the anesthetic ventilator in our hospital did not result in differences in ventilation parameters compared to the ICU treatment in the first 4 days of ventilation.

The repurposed use of anesthesia machines to ventilate critically ill patients with coronavirus disease 2019 (COVID-19).

BACKGROUND: The surge of critically ill patients due to the coronavirus disease-2019 (COVID-19) overwhelmed critical care capacity in areas of northern Italy. Anesthesia machines have been used as alternatives to traditional ICU mechanical ventilators. However, the outcomes for patients with COVID-19 respiratory failure cared for with Anesthesia Machines is currently unknow. We hypothesized that COVID-19 patients receiving care with Anesthesia Machines would have worse outcomes compared to standard practice. METHODS: We designed a retrospective study of patients admitted with a confirmed COVID-19 diagnosis at a large tertiary urban hospital in northern Italy. Two care units were included: a 27-bed standard ICU and a 15-bed temporary unit emergently opened in an operating room setting. Intubated patients assigned to Anesthesia Machines (AM group) were compared to a control cohort treated with standard mechanical ventilators (ICU-VENT group). Outcomes were assessed at 60-day follow-up. A multivariable Cox regression analysis of risk factors between survivors and non-survivors was conducted to determine the adjusted risk of death for patients assigned to AM group. RESULTS: Complete daily data from 89 mechanically ventilated patients consecutively admitted to the two units were analyzed. Seventeen patients were included in the AM group, whereas 72 were in the ICU-VENT group. Disease severity and intensity of treatment were comparable between the two groups. The 60-day mortality was significantly higher in the AM group compared to the ICU-vent group (12/17 vs. 27/72, 70.6% vs. 37.5%, respectively, p = 0.016). Allocation to AM group was associated with a significantly increased risk of death after adjusting for covariates (HR 4.05, 95% CI: 1.75-9.33, p = 0.001). Several incidents and complications were reported with Anesthesia Machine care, raising safety concerns. CONCLUSIONS: Our results support the hypothesis that care associated with the use of Anesthesia Machines is inadequate to provide long-term critical care to patients with COVID-19. Added safety risks must be considered if no other option is available to treat severely ill patients during the ongoing pandemic. CLINICAL TRIAL NUMBER: Not applicable.

Anesthesia screen use may impact operating room communication practices in otolaryngology.

OBJECTIVES: Failures in communication are a leading contributor to medical error. There is increasing attention on cultivating robust communication practices in the Operating Room (OR) to mitigate against patient injury and optimize efficient patient care. Few studies have evaluated how surgical equipment may introduce barriers to team dynamics. DESIGN: We conducted a pilot observational study to examine the relationship between anesthesia screen drapes (which are used inconsistently) and the frequency of verbal exchanges between surgical and anesthesia members. 25 procedures spanning various procedures in Otolaryngology were covertly observed, 12 of which employed a screen. Verbal exchanges were recorded across three stages of the surgery: pre-procedure (before the draping), procedure (drapes placed throughout) and post-procedure (after the removal of the draping). Speaker and content of the exchange was noted as well as various features about the procedure. RESULTS: Decreases in rates of exchanges were most pronounced during the procedure stage, although they did not reach significance on T-testing (p = 0.0719). After controlling for attending, table orientation and number of professionals, regression analysis did reveal a statistically significant decrease in rates of verbal exchanges during the procedure in the presence of the anesthesia screen (7.17 (± 6.33) versus 2.23 (± 1.00), p = 0.0318). Differences were also significant among surgeon-initiated and patient-care-related exchanges (p = 0.0168 and p = 0.0432, respectively). Decreases in anesthesiologist-initiated and non-clinical exchanges did not reach significance (p = 0.1530 and p = 0.5120, respectively). CONCLUSION: This pilot study suggests that anesthesia screens may negatively impact communication practices in the OR.

Smart Portable Pen for Continuous Monitoring of Anaesthetics in Human Serum With Machine Learning.

Continuous monitoring of anaesthetics infusion is demanded by anaesthesiologists to help in defining personalized dose, hence reducing risks and side effects. We propose the first piece of technology tailored explicitly to close the loop between anaesthesiologist and patient with continuous drug monitoring. Direct detection of drugs is achieved with electrochemical techniques, and several options are present in literature to measure propofol (widely used anaesthetics). Still, the sensors proposed do not enable in-situ detection, they do not provide this information continuously, and they are based on bulky and costly lab equipment. In this paper, we present a novel smart pen-shaped electronic system for continuous monitoring of propofol in human serum. The system consists of a needle-shaped sensor, a quasi digital front-end, a smart machine learning data processing, in a single wireless battery-operated embedded device featuring Bluetooth Low Energy (BLE) communication. The system has been tested and characterized in real, undiluted human serum, at 37  °C. The device features a limit of detection of 3.8  µM, meeting the requirement of the target application, with an electronics system 59% smaller and 81% less power consuming w.r.t. the state-of-the-art, using a smart machine learning classification for data processing, which guarantees up to twenty continuous measure.

Coronavirus Disease 2019: Anesthesia Machine Circuit Pressure During Use as an Improvised Intensive Care Unit Ventilator.

BACKGROUND: Use of anesthesia machines as improvised intensive care unit (ICU) ventilators may occur in locations where waste anesthesia gas suction (WAGS) is unavailable. Anecdotal reports suggest as much as 18 cm H2O positive end-expiratory pressure (PEEP) being inadvertently applied under these circumstances, accompanied by inaccurate pressure readings by the anesthesia machine. We hypothesized that resistance within closed anesthesia gas scavenging systems (AGSS) disconnected from WAGS may inadvertently increase circuit pressures. METHODS: An anesthesia machine was connected to an anesthesia breathing circuit, a reference manometer, and a standard bag reservoir to simulate a lung. Ventilation was initiated as follows: volume control, tidal volume (TV) 500 mL, respiratory rate 12, ratio of inspiration to expiration times (I:E) 1:1.9, fraction of inspired oxygen (Fio2) 1.0, fresh gas flow (FGF) rate 2.0 liters per minute (LPM), and PEEP 0 cm H2O. After engaging the ventilator, PEEP and peak inspiratory pressure (PIP) were measured by the reference manometer and the anesthesia machine display simultaneously. The process was repeated using prescribed PEEP levels of 5, 10, 15, and 20 cm H2O. Measurements were repeated with the WAGS disconnected and then were performed again at FGF of 4, 6, 8, 10, and 15 LPM. This process was completed on 3 anesthesia machines: Dräger Perseus A500, Dräger Apollo, and the GE Avance CS2. Simple linear regression was used to assess differences. RESULTS: Utilizing nonparametric Bland-Altman analysis, the reference and machine manometer measurements of PIP demonstrated median differences of -0.40 cm H2O (95% limits of agreement [LOA], -1.00 to 0.55) for the Dräger Apollo, -0.40 cm H2O (95% LOA, -1.10 to 0.41) for the Dräger Perseus, and 1.70 cm H2O (95% LOA, 0.80-3.00) for the GE Avance CS2. At FGF 2 LPM and PEEP 0 cm H2O with the WAGS disconnected, the Dräger Apollo had a difference in PEEP of 0.02 cm H2O (95% confidence interval [CI], -0.04 to 0.08; P = .53); the Dräger Perseus A500, <0.0001 cm H2O (95% CI, -0.11 to 0.11; P = 1.00); and the GE Avance CS2, 8.62 cm H2O (95% CI, 8.55-8.69; P < .0001). After removing the hose connected to the AGSS and the visual indicator bag on the GE Avance CS2, the PEEP difference was 0.12 cm H2O (95% CI, 0.059-0.181; P = .0002). CONCLUSIONS: Displayed airway pressure measurements are clinically accurate in the setting of disconnected WAGS. The Dräger Perseus A500 and Apollo with open scavenging systems do not deliver inadvertent continuous positive airway pressure (CPAP) with WAGS disconnected, but the GE Avance CS2 with a closed AGSS does. This increase in airway pressure can be mitigated by the manufacturer's recommended alterations. Anesthesiologists should be aware of the potential clinically important increases in pressure that may be inadvertently delivered on some anesthesia machines, should the WAGS not be properly connected.

Controlling Anesthesia Hardware With Simple Hand Gestures: Thumbs Up or Thumbs Down?

BACKGROUND: Modern consumer electronic devices and automobiles are often controlled by interfaces that sense physical gestures and spoken commands. In contrast, patient monitors and anesthesia devices are typically equipped with panel-mounted buttons, dials, and keyboards. The increased use of noncontact gesture-based interfaces in anesthesia may improve patient safety through more intuitive and prompter control of equipment and also through reduced rates of surface contamination. A novel gesture-based controller was designed and retrofitted to a standard GE Solar 8000M patient monitor. This type of technical innovation is rare, due to closely held proprietary input control systems on commercially produced clinical equipment. Nevertheless, we hypothesized that anesthesiologists would find a contactless gesture interface straightforward to use. METHODS: A gesture-based interface system was developed to control a Solar 8000M patient monitor using a millimeter-wave radar sensor. The system was programmed to detect noncontact "rotate" and "press" gestures to control the patient monitor by implementing a virtual trim knob for interface control. Fifty anesthesiologists tested a prototype interface and evaluated usability by completing a short questionnaire incorporating modified Likert scales. These evaluations were performed in a nonpatient care environment so that respondents were not adversely task loaded during assessment, also allaying any ethical or safety concerns regarding use of this novel interface for patient management. RESULTS: Anesthesia hardware was controlled reliably with 2 distinct gestures above the gesture sensor. The gesture-based interface generally was well received by anesthesiologists (8.09; confidence interval, 8.06-8.12 on a 10-point scale), who preferred the simpler "press" gesture to the "rotate" gesture (8.45; 8.39-8.51 vs 7.73; 7.67-7.79 on a 10-point scale; P = .005). The correlation between the preference scores for the 2 gestures from each anesthesiologist was strong (Pearson r = 0.49; 0.25-0.68; P < .001). Advancing level of training (resident, fellow, attending 1-10 years, attending >10 years) was not correlated with preference scores for either gesture (Spearman ρ = -0.02; -0.30 to 0.26; P = .87 for "press" and Spearman ρ = 0.08; -0.20 to 0.35; P = .58 for "rotate"). CONCLUSIONS: The use of gesture sensing for controlling anesthesia equipment was well received by a cohort of anesthesiologists. Even though the simpler "press" gesture was preferred over the "rotate" gesture, the intrarespondent correlation indicates that the preference for gestures as a whole is the stronger effect. No adverse relationship was found between acceptability and anesthesia experience level. Gesture sensing is a promising new area to simplify and improve the interaction between the anesthesiologist and the anesthesia workstation.

Patient-maintained propofol sedation for adult patients undergoing surgical or medical procedures: a scoping review of current evidence and technology.

Patient-maintained propofol sedation (PMPS) is the delivery of procedural propofol sedation by target-controlled infusion with the patient exerting an element of control over their target-site propofol concentration. This scoping review aims to establish the extent and nature of current knowledge regarding PMPS from both a clinical and technological perspective, thereby identifying knowledge gaps to guide future research. We searched MEDLINE, EMBASE, and OpenGrey databases, identifying 17 clinical studies for analysis. PMPS is described in the context of healthy volunteers and in orthopaedic, general surgical, dental, and endoscopic clinical settings. All studies used modifications to existing commercially-available infusion devices to achieve prototype systems capable of PMPS. The current literature precludes rigorous generalisable conclusions regarding the safety or comparative clinical effectiveness of PMPS, however cautious acknowledgement of efficacy in specific clinical settings is appropriate. Based on the existing literature, together with new standardised outcome reporting recommendations for sedation research and frameworks designed to assess novel health technologies research, we have made recommendations for future pharmacological, clinical, behavioural, and health economic research on PMPS. We conclude that high-quality experimental clinical trials with relevant comparator groups assessing the impact of PMPS on standardised patient-orientated outcome measures are urgently required.

Assessment of Anesthesia Capacity in Public Surgical Hospitals in Guatemala.

BACKGROUND: International standards for safe anesthetic care have been developed by the World Federation of Societies of Anaesthesiologists (WFSA) and the World Health Organization (WHO). Whether these standards are met is unknown in many nations, including Guatemala, a country with universal health coverage. We aimed to establish an overview of anesthesia care capacity in public surgical hospitals in Guatemala to help guide public sector health care development. METHODS: In partnership with the Guatemalan Ministry of Public Health and Social Assistance (MSPAS), a national survey of all public hospitals providing surgical care was conducted using the WFSA anesthesia facility assessment tool (AFAT) in 2018. Each facility was assessed for infrastructure, service delivery, workforce, medications, equipment, and monitoring practices. Descriptive statistics were calculated and presented. RESULTS: Of the 46 public hospitals in Guatemala in 2018, 36 (78%) were found to provide surgical care, including 20 district, 14 regional, and 2 national referral hospitals. We identified 573 full-time physician surgeons, anesthesiologists, and obstetricians (SAO) in the public sector, with an estimated SAO density of 3.3/100,000 population. There were 300 full-time anesthesia providers working at public hospitals. Physician anesthesiologists made up 47% of these providers, with an estimated physician anesthesiologist density of 0.8/100,000 population. Only 10% of district hospitals reported having an anesthesia provider continuously present intraoperatively during general or neuraxial anesthesia cases. No hospitals reported assessing pain in the immediate postoperative period. While the availability of some medications such as benzodiazepines and local anesthetics was robust (100% availability across all hospitals), not all hospitals had essential medications such as ketamine, epinephrine, or atropine. There were deficiencies in the availability of essential equipment and basic intraoperative monitors, such as end-tidal carbon dioxide detectors (17% availability across all hospitals). Postoperative care and access to resuscitative equipment, such as defibrillators, were also lacking. CONCLUSIONS: This first countrywide, MSPAS-led assessment of anesthesia capacity at public facilities in Guatemala revealed a lack of essential materials and personnel to provide safe anesthesia and surgery. Hospitals surveyed often did not have resources regardless of hospital size or level, which may suggest multiple factors preventing availability and use. Local and national policy initiatives are needed to address these deficiencies.

A Forensic Disassembly of the BIS Monitor.

BACKGROUND: The bispectral index (BIS) monitor has been available for clinical use for >20 years and has had an immense impact on academic activity in Anesthesiology, with >3000 articles referencing the bispectral index. Despite attempts to infer its algorithms by external observation, its operation has nevertheless remained undescribed, in contrast to the algorithms of other less commercially successful monitors of electroencephalogram (EEG) activity under anesthesia. With the expiration of certain key patents, the time is therefore ripe to examine the operation of the monitor on its own terms through careful dismantling, followed by extraction and examination of its internal software. METHODS: An A-2000 BIS Monitor (gunmetal blue case, amber monochrome display) was purchased on the secondary market. After identifying the major data processing and storage components, a set of free or inexpensive tools was used to retrieve and disassemble the monitor's onboard software. The software executes primarily on an ARMv7 microprocessor (Sharp/NXP LH77790B) and a digital signal processor (Texas Instruments TMS320C32). The device software can be retrieved directly from the monitor's hardware by using debugging interfaces that have remained in place from its original development. RESULTS: Critical numerical parameters such as the spectral edge frequency (SEF), total power, and BIS values were retraced from external delivery at the device's serial port back to the point of their calculation in the extracted software. In doing so, the locations of the critical algorithms were determined. To demonstrate the validity of the technique, the algorithms for SEF and total power were disassembled, comprehensively annotated and compared to their theoretically ideal behaviors. A bug was identified in the device's implementation of the SEF algorithm, which can be provoked by a perfectly isoelectric EEG. CONCLUSIONS: This article demonstrates that the electronic design of the A-2000 BIS Monitor does not pose any insuperable obstacles to retrieving its device software in hexadecimal machine code form directly from the motherboard. This software can be reverse engineered through disassembly and decompilation to reveal the methods by which the BIS monitor implements its algorithms, which ultimately must form the definitive statement of its function. Without further revealing any algorithms that might be considered trade secrets, the manufacturer of the BIS monitor should be encouraged to release the device software in its original format to place BIS-related academic literature on a firm theoretical foundation and to promote further academic development of EEG monitoring algorithms.

The history of "modern" anesthesia technology - A critical reappraisal: Part I: Key criteria of "modern" anesthesia: Technology and professionalism definitions, backgrounds and a short introduction to a changing evidence-base.

This paper is the first in a series of publications. These investigate, whether important elements of the historiography of anesthesia require a critical reappraisal. A systematic, combined presentation, contextualization and assessment of recent European research is provided. This includes the author's own findings. These emanate from two extensive projects. They combine very recent findings with results of earlier research, conducted by the author and numerous collaborators over the last 18 years. The findings represent an ever increasing and ever more robust body of evidence. They add an important new element to our international historiography. As an introduction, several definitions will be given for criteria, which designate "modern" anesthesia and its technology. On one of these criteria, the history of professionalization and specialization, a short overview will be given. This will be followed by an overview of general contexts, key features and early achievements of anesthesia-related technology. All results will be compared with a currently dominating narrative: This alleges "dominance" of US-American and British pioneers and developments. Apparent biases and inconsistencies are identified. These suggest that our current, international historiography of anesthesia may require a critical reassessment. Three subsequent articles will focus on specific aspects of anesthesia technique and technology. Their results likewise suggest a history of internationalism and trans-disciplinary reciprocity, rather than of national dominances. Further investigations will aim to ascertain the nature and extent of potential interactions, which may nowadays be underrecognized.

The history of modern anesthesia technology - A critical reappraisal (Part II) An international comparison of contemporary devices and of nitrous-oxide-based anesthesia (c. 1900-1930s)- recognizing another changing evidence-base.

This paper is the continuation (Part 2) of an extensive, critical reappraisal of the international historiography on modern anesthesia and its technology. The first paper of this series provided general definitions, backgrounds and an update on recent research on one aspect of this topic: the history of professionalization / specialization (Part 1).1This paper goes on to provide a first, international comparison of entire anesthesia devices and on the history of nitrous-oxide-based anesthesia (c. 1900-1930s). Results: A comparative chronology of internationally recognized milestones of entire anesthesia machines does not suggest significant differences between the nations of continental Europe on one side, or the USA and Britain on the other. The international historiography on one of the key techniques for which these devices were designed (nitrous-oxide-based anesthesia), is likewise demonstrably biased. These findings are further evidence that a frequently held hypothesis, which suggests national dominances in these fields, is incorrect. Contributing factors and wider contexts of this phenomenon can be further confirmed: These are an under-recognition of non-Anglo-American (particularly continental-European) and of primarily surgical contributions; contemporary international conflicts and inter-professional demarcation disputes. In addition, it can be shown that these phenomena had already started around the same time (c. 1900s-1930s). There also is evidence to suggest that they were at times reciprocal and quite deliberate. The author illustrates and argues that the currently prevalent historiography on modern anesthesia requires a thorough reassessment. This should be based on a perspective of internationalism and transdisciplinary reciprocity and should recognize much broader historical contexts.

Time to adapt in the pandemic era: a prospective randomized non -inferiority study comparing time to intubate with and without the barrier box.

BACKGROUND: The challenges posed by the spread of COVID-19 disease through aerosols have compelled anesthesiologists to modify their airway management practices. Devices such as barrier boxes are being considered as potential adjuncts to full PPE's to limit the aerosol spread. Usage of the barrier box raises concerns of delay in time to intubate (TTI). We designed our study to determine if using a barrier box with glidescope delays TTI within acceptable parameters to make relevant clinical conclusions. METHODS: Seventy-eight patients were enrolled in this prospective non-inferiority controlled trial and were randomly allocated to either group C (without the barrier box) or the study group BB (using barrier box). The primary measured endpoint is time to intubate (TTI), which is defined as time taken from loss of twitches confirmed with a peripheral nerve stimulator to confirmation of end-tidal CO 2. 15 s was used as non-inferiority margin for the purpose of the study. We used an unpaired two-sample single-sided t-test to test our non- inferiority hypothesis (H 0: Mean TTI diff ≥15 s, H A: Mean TTI diff < 15 s). Secondary endpoints include the number of attempts at intubation, lowest oxygen saturation during induction, and the need for bag-mask ventilation. RESULTS: Mean TTI in group C was 42 s (CI 19.2 to 64.8) vs. 52.1 s (CI 26.1 to 78) in group BB. The difference in mean TTI was 10.1 s (CI -∞ to 14.9). We rejected the null hypothesis and concluded with 95% confidence that the difference of the mean TTI between the groups is less than < 15 s (95% CI -∞ to 14.9,p = 0.0461). Our induction times were comparable (67.7 vs. 65.9 s).100% of our patients were intubated on the first attempt in both groups. None of our patients needed rescue breaths. CONCLUSIONS: We conclude that in patients with normal airway exam, scheduled for elective surgeries, our barrier box did not cause any clinically significant delay in TTI when airway manipulation is performed by well-trained providers. The study was retrospectively registered at clinicaltrials.gov (NCT04411056) on May 27, 2020.

Environmental sustainability in anaesthesia and critical care.

The detrimental health effects of climate change continue to increase. Although health systems respond to this disease burden, healthcare itself pollutes the atmosphere, land, and waterways. We surveyed the 'state of the art' environmental sustainability research in anaesthesia and critical care, addressing why it matters, what is known, and ideas for future work. Focus is placed upon the atmospheric chemistry of the anaesthetic gases, recent work clarifying their relative global warming potentials, and progress in waste anaesthetic gas treatment. Life cycle assessment (LCA; i.e. 'cradle to grave' analysis) is introduced as the definitive method used to compare and contrast ecological footprints of products, processes, and systems. The number of LCAs within medicine has gone from rare to an established body of knowledge in the past decade that can inform doctors of the relative ecological merits of different techniques. LCAs with practical outcomes are explored, such as the carbon footprint of reusable vs single-use anaesthetic devices (e.g. drug trays, laryngoscope blades, and handles), and the carbon footprint of treating an ICU patient with septic shock. Avoid, reduce, reuse, recycle, and reprocess are then explored. Moving beyond routine clinical care, the vital influences that the source of energy (renewables vs fossil fuels) and energy efficiency have in healthcare's ecological footprint are highlighted. Discussion of the integral roles of research translation, education, and advocacy in driving the perioperative and critical care environmental sustainability agenda completes this review.