SummaryThe Difficult Airway Society recommends that all patients should be pre‐oxygenated before the induction of general anaesthesia, but this may not always be easy or comfortable and anaesthesia may often be induced without full pre‐oxygenation. We tested the hypothesis that high‐flow nasal oxygen cannulae would be easier and more comfortable than facemasks for pre‐oxygenation. We randomly allocated 199 patients undergoing elective surgery aged ≥ 10 years to pre‐oxygenation using either high‐flow nasal oxygen or facemask. Ease and comfort were assessed by anaesthetists and patients on 10‐cm visual analogue scale and six‐point smiley face scale, respectively. Secondary endpoints included end‐tidal oxygen fraction after securing a definitive airway and time to secure an airway. A mean difference (95%CI) between groups in ratings of ‐0.76 (‐1.25 to ‐0.27) cm for ease of use (p = 0.003) and ‐0.45 (‐0.75 to ‐0.13) points for comfort (p = 0.006), both favoured high‐flow nasal oxygen. A mean difference (95%CI) between groups in end‐tidal oxygen fraction of 3.89% (2.41–5.37%) after securing a definitive airway also favoured high‐flow nasal oxygen (p < 0.001). There was no significant difference between groups in the number of patients with hypoxaemia (SpO2 < 90%) or severe hypoxaemia (SpO2 < 85%) lasting ≥ 1 min or ≥ 2 min; in the proportion of patients with an end‐tidal oxygen fraction < 87% in the first 5 min after tracheal intubation (52.2% vs. 58.9% in facemask and high‐flow nasal oxygen groups, respectively; p = 0.31); or in time taken to secure an airway (11.6 vs. 12.2 min in facemask and high‐flow nasal oxygen groups, respectively; p = 0.65). In conclusion, we found pre‐oxygenation with high‐flow nasal oxygen to be easier for anaesthetists and more comfortable for patients than pre‐oxygenation with a facemask, with no clinically relevant differences in end‐tidal oxygen fraction after securing a definitive airway or time to secure an airway. The differences in ease and comfort were modest.

We implemented the World Health Organization surgical safety checklist at Auckland City Hospital from November 2007. We hypothesised that the checklist would reduce postoperative mortality and increase days alive and out of hospital, both measured to 90 postoperative days. We compared outcomes for cohorts who had surgery during 18-month periods before vs. after checklist implementation. We also analysed outcomes during 9 years that included these periods (July 2004-December 2013). We analysed 9475 patients in the 18-month period before the checklist and 10,589 afterwards. We analysed 57,577 patients who had surgery from 2004 to 2013. Mean number of days alive and out of hospital (95%CI) in the cohort after checklist implementation was 1.0 (0.4-1.6) days longer than in the cohort preceding implementation, p < 0.001. Ninety-day mortality was 395/9475 (4%) and 362/10,589 (3%) in the cohorts before and after checklist implementation, multivariable odds ratio (95%CI) 0.93 (0.80-1.09), p = 0.4. The cohort changes in these outcomes were indistinguishable from longer-term trends in mortality and days alive and out of hospital observed during 9 years, as determined by Bayesian changepoint analysis. Postoperative mortality to 90 days was 228/5686 (4.0%) for Māori and 2047/51,921 (3.9%) for non-Māori, multivariable odds ratio (95%CI) 0.85 (0.73-0.99), p = 0.04. Māori spent on average (95%CI) 1.1 (0.5-1.7) fewer days alive and out of hospital than non-Māori, p < 0.001. In conclusion, our patients experienced improving postoperative outcomes from 2004 to 2013, including the periods before and after implementation of the surgical checklist. Māori patients had worse outcomes than non-Māori.

Background: Etomidate is frequently selected over propofol for induction of anaesthesia because of a putatively favourable haemodynamic profile, but data confirming this perception are limited. Methods: Patients undergoing cardiac surgery were randomised to induction of anaesthesia with propofol or etomidate. Phase I (n = 75) was conducted as open-label, whereas Phase II (n = 75) was double blind. Mean arterial blood pressure (MAP) and boluses of vasopressor administered after induction were recorded. The primary endpoint was the area under the curve below baseline MAP (MAP-time integral) during the 10 min after induction. Secondary endpoints were the use of vasopressors over the same period, and the effect of blinding on the aforementioned endpoints. Groups were compared using regression models with phase and anaesthetist as factors. Results: The mean difference between etomidate and propofol in the MAP-time integral below baseline was 2244 mm Hg s (95% confidence interval, 581-3906; P = 0.009), representing a 34% greater reduction with propofol. Overall, vasopressors were used in 10/75 patients in the etomidate group vs 21/75 in the propofol group (P = 0.38), and in 20/74 patients during the blinded phase vs 11/76 during the open-label phase (P = 0.31). The interaction between randomisation and phase (open-labelled or blinded) was not significant for either primary (P = 0.73) or secondary endpoints (P = 0.90). Conclusions: Propofol caused a 34% greater reduction in MAP-time integral from baseline after induction of anaesthesia than etomidate, despite more frequent use of vasopressors with propofol, confirming the superior haemodynamic profile of etomidate in this context. The proportion of patients receiving vasopressors increased slightly, albeit not significantly, in both groups in the blinded phase.

There is evidence that even mild hyperthermia may exacerbate brain injury. There seem reasonable grounds for considering patients undergoing craniotomy as at risk for brain injury. A retrospective observational study was undertaken to measure the incidence of mild hyperthermia in craniotomy cases in which the patient was initially normothermic. Auckland City Hospital's database of electronic anaesthetic records was searched for adult patients who were normothermic (≤37°C) prior to undergoing craniotomy procedures. For each case, demographic data, intraoperative naso- or oropharyngeal temperature measurements, and paracetamol use were extracted. We identified the proportion of patients whose temperature rose to exceed normal (>37°C) and subdivided that group into the proportion in whom the temperature rose to ≥38°C. Two thousand, nine hundred and thirty-five craniotomy cases began their operations while normothermic and had adequate temperature data collected. There were 984 (33.5%) cases that had at least one temperature reading >37°C, for a mean (standard deviation [SD]) time of 66.0 (64.6) minutes, and 49 (1.7%) cases that had at least one reading ≥38°C for a mean (SD) time of 40.4 (38.1) minutes. The majority (77.8%) who became mildly hyperthermic remained so at the end of the procedure. New mild hyperthermia occurs commonly during craniotomy. In view of the compelling evidence of potential harm arising from mild hyperthermia in brain injury, these findings suggest an opportunity for practice improvement in the anaesthetic management of craniotomy patients. Reasonable steps should be taken by anaesthetists to avoid intraoperative hyperthermia of any degree.

AIMS To develop a one day simulation-based course and simulators for training full operating room multidisciplinary teams (OR-MDT). BACKGROUND Few centres worldwide have reported on simulation-based team training for operating room staff1. Cited barriers to success include logistics (particularly recruitment of surgical participants), simulation realism, and cost. We describe how these obstacles have been overcome to create a simulation-based education day for OR-MDT training. METHODS Focus groups with surgeons, anaesthetists, anaesthetic technicians, and nurses established learning objectives2. Scenarios were based on real general surgical cases with critical events designed to engage all members of the team. The research group included senior members of each discipline, facilitating successful recruitment. We used a realistic operating room environment and a METI HPS manikin. We engaged a local special-effects company to create custom-built abdominal and lower limb models in consultation with surgical experts. These models were manufactured to fit the anaesthetic simulator in an anatomically-realistic manner. Financial barriers were reduced through a major innovation grant from Health Workforce New Zealand and top-up grants from other funding bodies. A number of companies also provided sponsorship in the form of consumable surgical items. Video recordings of the simulations were reviewed to describe surgeons’ engagement with the models, and an end-of course questionnaire asked participants to rate the realism of the simulation. RESULTS We have conducted ten course days engaging 60 participants. Surgeons attempted procedures beyond model limitations in 23.3% of cases. There were technical failures with the surgical models in 5 cases (16.7%). Despite these, participants rated the manikin, surgical model, environment, and simulation realism as 4.19, 4.27, 4.52, and 4.61 out of 5 respectively on average and 80% of surgical teams were reluctant to stop the case when it was ended. CONCLUSIONS Our results suggest it is possible to overcome logistic, realism, and cost barriers to create a full-day OR-MDT simulation course. Given a lack of available surgical models for our needs, continual improvement of the custom solutions is necessary. Recruitment is a challenge and until simulation is more ingrained in continuing medical training, recruitment of participants will continue to be a threat to success. REFERENCES 1. Cumin D, Boyd MJ, Webster CS, Weller JM. A systematic review of simulation for multidisciplinary team training in operating rooms. Simulation in Healthcare 2013;In Press. 2. Boyd M, Cumin D, Weller J. Whole team OR simulations: what are the educational needs? SimHealth. Sydney, 2012. DISCLOSURE STATEMENT All authors disclose no relevant financial relationships or conflicts of interest. SimHealth 2013 Research Award for Best Research Abstract

Summary A safety‐orientated system of delivering parenteral anaesthetic drugs was assessed in a prospective incident monitoring study at two hospitals. Anaesthetists completed an incident form for every anaesthetic, indicating if an incident occurred. Case mix data were collected and the number of drug administrations made during procedures estimated. From February 1998 at Hospital A and from June 1999 at Hospital B, until November 2003, 74 478 anaesthetics were included, for which 59 273 incident forms were returned (a 79.6% response rate). Fewer parenteral drug errors occurred with the new system than with conventional methods (58 errors in an estimated 183 852 drug administrations (0.032%, 95% CI 0.024–0.041%) vs 268 in 550 105 (0.049%, 95% CI 0.043–0.055%) respectively, p = 0.002), a relative reduction of 35% (difference 0.017%, 95% CI 0.006–0.028%). No major adverse outcomes from these errors were reported with the new system while 11 (0.002%) were reported with conventional methods (p = 0.055). We conclude that targeted system re‐design can reduce medical error.

Simulation is an accepted part of training, assessment, and research in aviation, nuclear power, and the military. Confidence in results in these industries is underpinned by relatively comprehensive and widely accepted standards. In contrast, although there have been major advances in the technology and tools used for simulation in the healthcare industry over the last few decades, little work has been done in setting standards for simulation in healthcare. Standards are essential for achieving the full potential of simulation-based education, assessment, and research at all levels and specialities in healthcare. The absence of standards undermines confidence in the results of any simulation-based endeavour and increases the risk of negative learning. We propose a practical framework for setting standards for simulators for anaesthesia.

In many airlines a pilot qualified to fly a Boeing 737 can be trained and licensed to fly paying passengers in an Airbus A300 and be fully accredited for landing this aeroplane at airports around the world without ever leaving the ground [1-3]. One caveat is a requirement for twice yearly training and assessment sessions; failure implies immediate suspension from flying. This suspension is less draconian than it may seem because intensive retraining is provided promptly, with the opportunity for assessment. The reassessment is almost always passed, and it is hard to argue with the principle of ensuring that pilots are competent in the key skills of their trade. All of this is achieved through simulation. Consider, by contrast, the situation in anaesthesia. The oversight of continued professional development tends to be light-handed, with little emphasis on ensuring that core competencies are in place, and it seldom involves high-stakes assessment of the kind described above. It is only when something goes wrong that the competence of a doctor is likely to be brought into question – and at that stage not only is the response too late but the processes are typically punitive and destructive. Society's continuing appetite for blame is illustrated by the extraordinary increase in manslaughter charges arising from simple errors in medical practice in the UK over the last decade [4, 5]. Little of this is surprising when one considers the traditional apprenticeship method of training in medicine (anaesthesia being no exception). Junior doctors were expected to 'see one and then do one' hoping not to 'harm one' before, all too soon, becoming the person to 'teach one'. The clinical 'curriculum' was determined by the random presentation of patients to the unit on any particular day. More recently it has been recognised that something better is needed than simply throwing trainees into the whirlpool of acute medicine and hoping for the best. This has certainly led to more structured curricula and more explicit separation of training from service. (Imagine the response if the announcement on take-off was that the pilot was a 'trainee', and that supervision would be 'distant' or 'remote'). The emphasis on supervision and on the provision of consultant-led patient care has increased dramatically. Nevertheless, the unpredictability of medical practice may challenge even an experienced consultant. It is difficult to gain and then to maintain competence in all aspects of practice. The problem lies not just in retaining in infrequently needed knowledge and skills; it lies also in the rapid pace of medical progress. Imagine now what the application of simulation could potentially mean in anaesthesia, applied at the level expected in aviation. No one method of training fits all needs, but imagine the gains in the quality and safety of our patient care that could be achieved through enhancing the established theoretical and clinical strands of anaesthesia training by introducing a planned curriculum of properly constructed simulation-based educational modules. Because simulation allows one to set the 'clinical' agenda, the educational objectives of each session could be pre-defined and the measures used in assessment could be chosen to drive learning towards these objectives. It would be possible to ensure that anaesthetists were competent to handle most relevant conditions, from common to rare but life-threatening. To some extent this is already happening. In healthcare, anaesthetists have been early to adopt simulation for training. From early beginnings with resuscitation manikins of the 1960s, anaesthetists have gone on to develop a range of more sophisticated simulators [6, 7]. The benefits of simulation in the education of anaesthetists is now fairly widely accepted [8-10], with enthusiasts even referring to simulation-based medical education as an 'ethical imperative' [11]. The United States Food and Drug Administration, the American College of Surgeons, the American Council for Graduate Medical Education, and the American Board of Anesthesiologists now all require some aspect of simulation-based training for a number of their qualifications [12]. Many simulators are now available and several societies have been established to nurture the expanding body of knowledge and professional activity related to simulation in anaesthesia [13]. Nevertheless, the use of simulation in healthcare lags far behind other high-risk industries, particularly aviation and the nuclear industry [14-18]. Uptake of simulation-based training is still patchy, especially in the context of the continuous professional development of specialist anaesthetists. However, the validity of simulation for training and, in particular, for assessment remains controversial [12, 19-23]. Few anaesthetists in a survey of 60 centres agreed with the use of simulation for maintenance of certification [24] and the majority of anaesthetists surveyed in Australia and the USA were opposed to making simulation-based testing compulsory [25]. Even the well-established Effective Management of Anaesthetic Crises (EMAC) [26] courses run under licence from the Australian and New Zealand College of Anaesthetists (ANZCA) include no summative assessment. If instructors observe participants whose performance in this course is worrying, they have little option but to allow them to return to practice with no remedial action. There are several good practical and theoretical justifications for excluding assessment from this course but this approach is nevertheless in stark contrast to the situation in aviation, as outlined above. Why this difference, given many obvious parallels [26, 27]? Several reasons come to mind. The number of simulation manufacturers in anaesthesia is limited, and the market is relatively small (notably in contrast to the market for advanced life support training). Anaesthesia shares only some similarities with aviation; the differences are substantial, not the least being the extraordinary variability between patients – even apparently similar patients, and even the same patient at different times. The weather may be unpredictable, but aeroplanes follow the principles of physics, while patients (it often seems) tend to be laws unto themselves [9, 28, 29]. The difficulty of capturing this variability in simulation is one of several reasons for the pervading uncertainty about the adequacy of available simulators in representing patients. Furthermore, evidence to demonstrate the effectiveness (particularly cost-effectiveness) of simulation in the training of health professionals is relatively sparse [11, 30, 31], and even more so in relation to their assessment. A more worrying basis for scepticism is expressed in the following question: does performance in 'anaesthetising' the simulators we have today reliably reflect performance in the clinical situation? Perhaps, perhaps not; or perhaps the answer depends on the context and the skills in question. This uncertainty is one of several reasons for the hesitancy mentioned above in relation to assessment in simulation courses. However an even more fundamental uncertainty in respect of simulation arises from the almost complete absence of agreed standards for any aspect of simulation-based education in healthcare. This, we think, is a major and very much under-appreciated barrier to realising the full potential of simulation in anaesthesia. Perhaps the most striking single difference between simulation in anaesthesia and simulation in aviation is the fact that in the latter it is underpinned by a clear understanding that all simulators have met well-defined and widely accepted standards (and the same can be said of simulation in the nuclear industry) [32, 33]. These standards, which are regularly updated [34], promote reproducibility and define benchmarks. They make it possible for a purchaser or user of a simulator to know what to expect and what not to expect and give the user confidence in the results they obtain when using that simulator. In 2006, the Society for Simulation in Healthcare held a Simulation Summit in Chicago, IL. Fifty-five individuals participated, representing 33 organisations. They identified the need for standards and guidelines as one of the most important requirements for reaching the full potential of medical simulation [35], yet there has still not been a concerted effort to establish such standards. Some organisations have made a start in this process. For example, ANZCA have defined guidelines for the simulator, the instructors and the environment to be used in their EMAC course (see their website: http://www.anzca.edu.au). Those who wish to provide the EMAC course must have their centres accredited in accordance with these guidelines and re-examined at least every 5 years. This is an important step toward the establishment of standards, but the guidelines give few, if any, quantitative criteria by which to evaluate a particular centre or simulator. But is there a problem? Surely we can simply depend on manufacturers to ensure that the simulators perform to specification? We thought so. Our department recently purchased a new high-end simulator. We were surprised to discover that it appeared to suffer from coarctation of the aorta (that is to say, the pulse at the right wrist was full and bounding while that at the left wrist was weak and thready). We were even more surprised (and initially seized by clinical self-doubt) when we found that the simulator routinely died when we gave it what we believed to be appropriate doses of isoflurane. To be clear, these were specific problems in a very sophisticated, complex and valuable educational tool, but they were not the only ones. Could we say, then, that our simulator failed to meet specifications? There indeed lay the rub – there weren't any performance specifications. The company has been very helpful in addressing these problems, and we commend them for that, but surely there should be documentation defining the parameters for acceptable responses to particular inhaled concentrations of isoflurane, the volume and pressure of the pulses at the wrist, and many other aspects of how a simulator should look and function? We believe that standards for simulators, and for simulation centres, courses and instructors, described in quantitative terms and requiring documentation of compliance, are overdue. The specification, implementation, maintenance, and enforcing of standards will not be a trivial task. It will require the cooperation of members of academic institutions and leaders of industry. Organisations such as the Society in Europe for Simulation Applied to Medicine (SESAM) [36] and the Society for Simulation in Healthcare (SSH), as well as ANZCA, the Royal College of Anaesthetists and the Association of Anaesthetists of Great Britain and Ireland, have roles to play in this regard. It will take time, but it is within the grasp of these groups, working collaboratively, to establish a set of standards for anaesthesia simulators. This will be a very important step towards realising the full potential of simulation in anaesthesia – and this potential is very far-reaching. Anaesthetists and their patients need to be confident that they can correctly manage the full range of critical events they may face in practice. A major step towards assuring this confidence would be regular training in which core skills are both effectively taught and reliably tested in simulation centres in which all concerned can be confident that the simulators, the trainers and the assessments conform to the standards required for this purpose. The authors acknowledge constructive comments from Dr Jane Torrie, Dr Lara Hopley, and Kaylene Henderson.

In this article, we have generalised the Kuramoto model to allow one to model neuronal synchronisation more appropriately. The generalised version allows for different connective arrangements, time-varying natural frequencies and time-varying coupling strengths to be realised within the framework of the original Kuramoto model. By incorporating the above mentioned features into the original Kuramoto model one can allow for the adaptive nature of neurons in the brain to be accommodated. Extensive tests using the generalised Kuramoto model were performed on a N=4 coupled oscillator network. Examination of how different connective arrangements, time-varying natural frequencies and time-varying coupling strengths affected synchronisation separately and in combination are reported. The effects on synchronisation for large N are also reported.

There are many simulators available for use in anaesthetic-related education and research. Those who wish to purchase a simulator or to establish a simulation facility face a daunting task in understanding the differences between simulators. Recent reviews have focused on narrower areas of simulation, such as airway management or basic life support, or on the application of simulators. It would be difficult to deal in detail with every simulator ever made for anaesthesia, but in the present review we cover the spectrum of currently available anaesthetic simulators, provide an overview of different types of simulator, and discuss a selection of simulators of particular interest, including some of historical significance and some examples of 'home made' simulators. We have found no common terminology amongst authors for describing or classifying simulators, and propose a framework for describing (or classifying) them that is simple, clear and applicable to any simulator.