Prevalence and commonality of non-technical skills and human factors in airway management guidelines: a narrative review of the last 5 years.

The primary aim of this review was to identify, analyse and codify the prominence and nature of human factors and ergonomics within difficult airway management algorithms. A directed search across OVID Medline and PubMed databases was performed. All articles were screened for relevance to the research aims and according to predetermined exclusion criteria. We identified 26 published airway management algorithms. A coding framework was iteratively developed identifying human factors and ergonomic specific words and phrases based on the Systems Engineering Initiative for Patient Safety model. This framework was applied to the papers to delineate qualitative and quantitative results. Our results show that human factors are well represented within recent airway management guidelines. Human factors associated with work systems and processes featured more prominently than user and patient outcome measurement and adaption. Human factors are an evolving area in airway management and our results highlight that further considerations are necessary in further guideline development.

Preventing unrecognised oesophageal intubation: a consensus guideline from the Project for Universal Management of Airways and international airway societies.

Across multiple disciplines undertaking airway management globally, preventable episodes of unrecognised oesophageal intubation result in profound hypoxaemia, brain injury and death. These events occur in the hands of both inexperienced and experienced practitioners. Current evidence shows that unrecognised oesophageal intubation occurs sufficiently frequently to be a major concern and to merit a co-ordinated approach to address it. Harm from unrecognised oesophageal intubation is avoidable through reducing the rate of oesophageal intubation, combined with prompt detection and immediate action when it occurs. The detection of 'sustained exhaled carbon dioxide' using waveform capnography is the mainstay for excluding oesophageal placement of an intended tracheal tube. Tube removal should be the default response when sustained exhaled carbon dioxide cannot be detected. If default tube removal is considered dangerous, urgent exclusion of oesophageal intubation using valid alternative techniques is indicated, in parallel with evaluation of other causes of inability to detect carbon dioxide. The tube should be removed if timely restoration of sustained exhaled carbon dioxide cannot be achieved. In addition to technical interventions, strategies are required to address cognitive biases and the deterioration of individual and team performance in stressful situations, to which all practitioners are vulnerable. These guidelines provide recommendations for preventing unrecognised oesophageal intubation that are relevant to all airway practitioners independent of geography, clinical location, discipline or patient type.

Human factors and the safety of surgical and anaesthetic care.

Safety of patients in the operating theatre relies on a cordial and efficient working relationship between all members of the theatre team. A team that communicates well, defines the roles of its members and is aware of their limitations will provide safe patient care. In this review, we will examine how human factors engineering - the science of how to design processes, equipment and environments to optimise the human contributions to performance - can be used to improve safety and efficiency of surgery. Although these are often dismissed as 'common sense', we will explain how these solutions emerge not from healthcare but from diverse disciplines such as psychology, design and engineering.

Patient and surgery factors associated with the incidence of failed and difficult intubation.

Estimates of the rate and risk-factors for difficult airway rarely include a denominator for the number of anaesthetics. Approaches such as self-reporting and crowd-sourcing of airway incidents may help identify specific lessons from clinical episodes, but the lack of denominator data, biased reporting and under-reporting does not allow a comprehensive population-based assessment. We used an established state-wide dataset to determine the incidence of failed and difficult intubations between 2015 and 2017 in the state of Victoria in Australia, along with associated patient and surgical risk-factors. A total of 861,533 general anaesthesia episodes were analysed. Of these, 4092 patients with difficult or failed intubation were identified; incidence rates of 0.52% (2015-2016) and 0.43% (2016-2017), respectively. Difficult/failed intubations were most common in patients aged 45-75 and decreased for older age groups, with risk being lower for patients aged >85 than patients aged 35-44. The risk for failed/difficult intubation increased significantly for: patients undergoing emergency surgery (OR 1.80); obese patients (OR 2.48); increased ASA physical status; and increased Charlson Comorbidity Index. Across all age groups, procedures on the nervous system (OR 1.92) and endocrine system (OR 2.03) had the highest risk of failed/difficult intubation. The relative reduced risk for failed/difficult intubations in the elderly population is a novel finding that contrasts with previous research and may suggest a 'compression of morbidity' effect as a moderator. Administrative databases have the potential to improve understanding of peri-operative risk of rare events at a population level.

Management of a surgical patient with a label of penicillin allergy: narrative review and consensus recommendations.

Unsubstantiated penicillin-allergy labels are common in surgical patients, and can lead to significant harm through avoidance of best first-line prophylaxis of surgical site infections and increased infection with resistant bacterial strains. Up to 98% of penicillin-allergy labels are incorrect when tested. Because of the scarcity of trained allergists in all healthcare systems, only a minority of surgical patients have the opportunity to undergo testing and de-labelling before surgery. Testing pathways can be modified and shortened in selected patients. A variety of healthcare professionals can, with appropriate training and in collaboration with allergists, provide testing for selected patients. We review how patients might be assessed, the appropriate testing strategies that can be used, and the minimum standards of safe testing.

Consensus clinical scoring for suspected perioperative immediate hypersensitivity reactions.

BACKGROUND: Grading schemes for severity of suspected allergic reactions have been applied to the perioperative setting, but there is no scoring system that estimates the likelihood that the reaction is an immediate hypersensitivity reaction. Such a score would be useful in evaluating current and proposed tests for the diagnosis of suspected perioperative immediate hypersensitivity reactions and culprit agents. METHODS: We conducted a Delphi consensus process involving a panel of 25 international multidisciplinary experts in suspected perioperative allergy. Items were ranked according to appropriateness (on a scale of 1-9) and consensus, which informed development of a clinical scoring system. The scoring system was assessed by comparing scores generated for a series of clinical scenarios against ratings of panel members. Supplementary scores for mast cell tryptase were generated. RESULTS: Two rounds of the Delphi process achieved stopping criteria for all statements. From an initial 60 statements, 43 were rated appropriate (median score 7 or more) and met agreement criteria (disagreement index <0.5); these were used in the clinical scoring system. The rating of clinical scenarios supported the validity of the scoring system. Although there was variability in the interpretation of changes in mast cell tryptase by the panel, we were able to include supplementary scores for mast cell tryptase. CONCLUSION: We used a robust consensus development process to devise a clinical scoring system for suspected perioperative immediate hypersensitivity reactions. This will enable objectivity and uniformity in the assessment of the sensitivity of diagnostic tests.

Anaphylaxis to intravenous gelatin-based solutions: a case series examining clinical features and severity.

The proportion of patients receiving intravenous gelatin-based colloids has increased in the last decade due to safety concerns about starch-based products. Recent research suggests hypersensitivity reactions to intravenous gelatin-based solutions occur at similar rates per administration as non-depolarising neuromuscular blocking agents such as rocuronium (6.2/100,000 administrations). There are scant published data on clinical features, diagnosis and time course of these reactions. We undertook a review of cases reported and tested at one of the UK's largest drug allergy clinics. All patients seen in the drug allergy clinic at Imperial College Healthcare NHS Trust (London, UK) with a confirmed diagnosis of anaphylaxis to gelatin-based solutions between May 2013 and May 2018 were included. We retrospectively reviewed clinical histories, skin test results and severity of reactions in this cohort of patients. Twelve patients with anaphylaxis to gelatin-based solutions were identified (eight women, mean (SD) age 58 (17) years). Eleven reactions were severe or life-threatening with three progressing to cardiac arrest. Presentation was commonly delayed; only three patients suffered reactions within 5 min of the solution being administered with a further six presenting 10-70 min later. Where measured, tryptase was elevated in all patients (median (IQR [range]) 14.7 (8.2-23.8 [6.5-83.4]) ng.ml-1 ). Reactions to gelatin-based solutions are usually severe and can present with latency uncommon with other intravenous anaesthetic triggers. The use of gelatin-based solutions in the peri-operative setting should be re-assessed given the risk of severe allergy.

Radical evolution: the 2015 Difficult Airway Society guidelines for managing unanticipated difficult or failed tracheal intubation.

There is little doubt that these guidelines incorporate advances made in airway management since 2004. They will change day-to-day practice of anaesthesia, as outlined above, from pre-operative airway assessment, to integrating the WHO team briefing, to the use and provision of equipment and drugs, and the recording of information on the anaesthesia chart. They will inform the later analysis of any critical airway incidents, especially as documentation and postoperative management are addressed, and they will encourage training in a range of techniques. Taken together, not quite a revolution but certainly a very 'radical evolution'.Assessment of the utility of the new guidelines should consider if they can be used as tools to enhance knowledge and training, or in addition as a prosthesis to bridge the gap between the requirements of and our abilities during emergencies. Formal testing may reveal which aspects of their design, complex as it is, may distract from, rather than enhance, airway management during crises.All guidelines represent a standard of care or a normative approach to a clinical problem. As such, they not only help guide clinicians, but they also provide the broader community with the opportunity to improve standards, to ensure equipment is available, and that training for the skills and processes required are in place to ensure successful adoption.

The effect of two cognitive aid designs on team functioning during intra-operative anaphylaxis emergencies: a multi-centre simulation study.

This multi-centre repeated measures study was undertaken to determine how contrasting designs of cognitive aids affect team performance during simulated intra-operative anaphylaxis crises. A total of 24 teams consisting of a consultant anaesthetist, an anaesthetic trainee and anaesthetic assistant managed three simulated intra-operative anaphylaxis emergencies. Each team was assigned at random to a counterbalanced order of: no cognitive aid; a linear cognitive aid; and a branched cognitive aid, and scored for team functioning. Scores were significantly higher with a linear compared with either a branched version of the cognitive aid or no cognitive aid for 'Team Overall Behavioural Performance', difference between study groups (F-value) 5.8, p = 0.01. Aggregate scores were higher with the linear compared with the branched aid design (p = 0.03). Cognitive aids improve co-ordination of the team's activities and support team members to verbalise their actions. A linear design of cognitive aid improves team functioning more than a branched design.

The ontogeny of the chin: an analysis of allometric and biomechanical scaling.

The presence of a prominent chin in modern humans has been viewed by some researchers as an architectural adaptation to buttress the anterior corpus from bending stresses during mastication. In contrast, ontogenetic studies of mandibular symphyseal form suggest that a prominent chin results from the complex spatial interaction between the symphysis and surrounding soft tissue and skeletal anatomy during development. While variation in chin prominence is clearly influenced by differential growth and spatial constraints, it is unclear to what degree these developmental dynamics influence the mechanical properties of the symphysis. That is, do ontogenetic changes in symphyseal shape result in increased symphyseal bending resistance? We examined ontogenetic changes in the mechanical properties and shape of the symphysis using subjects from a longitudinal cephalometric growth study with ages ranging from 3 to 20+ years. We first examined whether ontogenetic changes in symphyseal shape were correlated with symphyseal vertical bending and wishboning resistance using multivariate regression. Secondly, we examined ontogenetic scaling of bending resistance relative to bending moment arm lengths. An ontogenetic increase in chin prominence was associated with decreased vertical bending resistance, while wishboning resistance was uncorrelated with ontogenetic development of the chin. Relative to bending moment arm lengths, vertical bending resistance scaled with significant negative allometry whereas wishboning resistance scaled isometrically. These results suggest a complex interaction between symphyseal ontogeny and bending resistance, and indicate that ontogenetic increases in chin projection do not provide greater bending resistance to the mandibular symphysis.

The effects of a displayed cognitive aid on non-technical skills in a simulated 'can't intubate, can't oxygenate' crisis.

Guidelines outlining recommended actions are difficult to implement in the stressful, time-pressured situation of an airway emergency. Cognitive aids such as posters and algorithms improve performance during some anaesthetic emergencies; however, their effects on team behaviours have not been determined. In this study, 64 participants were randomly assigned into control (no cognitive aid) and intervention (cognitive aid provided) groups before a simulated 'can't intubate, can't oxygenate' scenario. Video analysis was undertaken of the non-technical skills and technical performance during the scenarios. All categories had higher Anaesthetists' Non-Technical Skills (ANTS) scores when a cognitive aid was supplied (mean (SD) total ANTS score 10.4 (3.1) vs. 13.2 (2.4), p < 0.001). The number of times the cognitive aid was used was associated with higher ANTS scores (ρ = 0.383, p = 0.002). A trend towards the establishment of an infraglottic airway within 3 min was also noted (control group 55.3% vs. intervention 76.9%, p = 0.076). Non-technical skills are improved when a cognitive aid is present during airway emergencies.

Multilocus sequence analysis (MLSA) of 'Rickettsiella costelytrae' and 'Rickettsiella pyronotae', intracellular bacterial entomopathogens from New Zealand.

AIMS: Larvae of scarab beetles live in the soil and are frequently hosts for microbial pathogens. In New Zealand, larvae of the grass grub, Costelytrae zealandica (Coleoptera: Scarabaeidae), and manuka beetles, Pyronota spp. (Coleoptera: Scarabaeidae), have been collected from field populations showing loss of vigour and a whitened appearance. Diagnosis indicated an intracellular infection of fat body tissues by Rickettsiella-like micro-organisms. Rickettsiella bacteria are under evaluation as a possible new source of insect bio-control agents for important agricultural pests as, e.g. scarabaeid and elaterid larvae. The present study aimed at the unequivocal molecular taxonomic identification and comparison of the bacteria associated with Costelytra and Pyronota. METHODS AND RESULTS: Electron microscopy and phylogenetic reconstruction using a multilocus sequence analysis approach based on the 16S ribosomal RNA gene together with four protein-encoding markers (ftsY, gidA, rpsA, and sucB) demonstrated that both bacteria from New Zealand are phylogenetically closely related, but not identical, and belong to the taxonomic genus Rickettsiella. CONCLUSIONS: The bacteria under study should be referred to as pathotypes 'Rickettsiella costelytrae' and 'Rickettsiella pyronotae', respectively. Moreover, on the basis of the currently accepted systematic organization of the genus Rickettsiella, both pathotypes should be considered synonyms of the nomenclatural type species, Rickettsiella popilliae. SIGNIFICANCE AND IMPACT OF THE STUDY: The study demonstrates that Rickettsiella bacteria are geographically widespread pathogens of scarabaeid larvae. Implications of the phylogenetic findings presented for the stability of host adaptation by Rickettsiella bacteria are critically discussed.