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.

Decision-centred design in healthcare: The process of identifying a decision support tool for airway management.

Current decision support interventions for airway management in anaesthesia lack the application of Human Factors Engineering; leading to interventions that can be disruptive, inefficient and error-inducing. This study followed a decision-centred design process to identify decision support that can assist anaesthesia teams with challenging airway management situations. Field observations, Critical Decision Method interviews and focus groups were conducted to identify the most difficult decisions and their requirements. Data triangulation narrowed the focus to key decisions related to preparation and planning, and the transitioning between airway techniques during difficulties. Five decision-support interventions were identified and positively rated by anaesthesia team members in relation to their perceived effectiveness. An organized airway equipment trolley was chosen as the most beneficial decision support intervention. This study reiterated the key importance of both Human Factors Engineering and data triangulation when designing for healthcare.

Human factors enablers and barriers for successful airway management - an in-depth interview study.

Human factors are the individual, team, environmental and organisational aspects of the anaesthetic environment that affect performance and decision-making of anaesthesia teams. This study aimed to identify which human factors were enablers and/or barriers to anaesthesia teams during airway management challenges. Sixteen interviews were conducted with experienced anaesthetists and anaesthetic nurses using an in-depth interview technique (the Critical Decision Method) to identify human factors enablers and/or barriers during successful management of a significant airway challenge. Thematic analysis identified three overarching enablers: equipment location and storage; experience and learning; teamwork and communication. Five overarching barriers were also identified: time and resource limitations; teamwork and communication; equipment location and storage; experience and learning; insufficient back-up planning; and equipment preparation. This study showed that a variety of human factors issues affect the handling of airway challenges, ranging from individual and team to organisational and environmental aspects. Recommendations for the design of airway management decision support tools that relate to equipment standardisation, decision support complexity, inclusive mutual learning and teamwork are discussed.

Combining situated Cognitive Engineering with a novel testing method in a case study comparing two infusion pump interfaces.

We validated the usability of a new infusion pump interface designed with a situated Cognitive Engineering approach by comparing it to a reference interface using a novel testing method employing repeated measurements and process measures, in addition to traditional outcome measures. The sample consisted of 25 nurses who performed eight critical tasks three times. Performance measures consisted of number and type of errors, deviations from a pre-established normative path solution, task completion times, number of keystrokes, mental effort and preferences in use. Results showed that interaction with the new interface resulted in 18% fewer errors, 90% fewer normative path deviations, 42% lower task completion times, 40% fewer keystrokes, 39% lower mental effort and 76% more subjective preferences in use. These outcomes suggest that within the scope of this case study, combining the situated Cognitive Engineering approach with a novel testing method addresses various shortcomings of earlier testing methods.

Molecular analysis of intragenic recombination at the tryptophan synthetase locus in Neurospora crassa.

Fifteen different classically generated and mapped mutations at the tryptophan synthetase locus in Neurospora crassa have been characterized to the level of the primary sequence of the gene. This sequence analysis has demonstrated that intragenic recombination is accurate to order mutations within one open reading frame. While classic genetic analysis correctly ordered the mutations, the position of mutations characterized by gene sequence analysis was more accurate. A leaky mutation was found to have a wild-type primary sequence. The presence of unique polymorphisms in the primary sequence of the trp-3 gene from strain 861 confirms that it has a unique history relative to the other strains studied. Most strains that were previously shown to be immunologically nonreactive with antibody preparations raised against tryptophan synthetase protein were shown to have nonsense mutations. This work defines 14 alleles of the N. crassa trp-3 gene.

Indicators for high physical strain and overload in elite football players.

Laboratory, psychological and performance parameters as possible indicators of physical strain and overload during highly demanding competition phases were evaluated in elite male football players. In two studies with the same objective, periods of high (HE: >270 min during 3 weeks before testing) and low (LE: <270 min) match exposure were compared over the course of an entire season. In study 1 (n=88 players of the first and second German leagues; age: 25.6 ± 4.3 years; body mass index (BMI): 23.2 ± 1.0 kg/m(2) ), blood count, CK, urea, uric acid, CRP and ferritin were determined. In study 2, 19 players of the third German league and the highest under-19 league (age: 19.7 ± 2.8 years; BMI: 22.8 ± 1.7 kg/m(2) ) were screened for individual vertical jump height, maximal velocity and by the Recovery-Stress-Questionnaire for Athletes (REST-Q Sport). The mean differences in exposure times were 180 min (study 1: quartiles: 105, 270 min) and 247 min (study 2: 180, 347 min), respectively. Significant differences were found neither in blood parameters (study 1; P>0.36) nor in physiological testing results or in REST-Q scores (study 2; P>0.20). A 3-week period of high match exposure in elite football players does not affect laboratory, psychometric and performance parameters.

Molecular analysis of mutants of the Neurospora adenylosuccinate synthetase locus.

The ad-8 gene of Neurospora crassa, in addition to being used for the study of purine biology, has been extensively studied as a model for gene structure, mutagenesis and intralocus recombination. Because of this there is an extensive collection of well-characterized N. crassa ad-8 mutants in the Fungal Genetics Stock Center collection. Among these are spontaneous mutants and mutants induced with X-ray, UV or chemical mutagens. The specific lesions in these mutants have been genetically mapped at high resolution. We have sequenced the ad-8 locus from 13 of these mutants and identified the molecular nature of the mutation in each strain. We compare the historical fine-structure map to the DNA and amino acid sequence of each allele. The placement of the individual lesions in the fine-structure map was more accurate at the 5' end of the gene and no mutants were identified in the 3' untranslated region of this gene. We additionally analysed ad-8(+) alleles in 18 N. crassa strains subjected to whole-genome sequence analysis and describe the variability among Neurospora strains and among fungi and other organisms.

Seasonal changes in stress indicators in high level football.

This study aimed at describing changes in stress and performance indicators throughout a competitive season in high level football. 15 players (19.5±3.0 years, 181±5 cm, 75.7±9.0 kg) competing under professional circumstances were tested at baseline and 3 times during the season 2008/09 (in-season 1, 2, 3). Testing consisted of the Recovery-Stress Questionnaire for Athletes (Total Stress and Recovery score), vertical jump tests (counter movement and drop jump (DJ)), and a maximal ramp-like running test. Average match exposure was higher during a 3-weeks period prior to in-season 3 compared to in-season 1 and 2 (1.5 vs. 1 h/week, p=0.05). Total Stress score was elevated at in-season 1 and 2 compared to baseline (p<0.01) with a further increase at in-season 3 (p<0.03; generalized eta squared (η(2)(g))=0.37). Total Recovery score was decreased at in-season 1 and 3 compared to baseline (p<0.05; η(2)(g)=0.21). Maximal running velocity (V(max)) and jumping heights were not significantly affected (η(2)(g)≤0.04). Changes in DJ height and V (max) between baseline and in-season 3 were correlated with the corresponding changes in Total Stress score (r=-0.55 and r=-0.61, p<0.03). Usual match exposure during a professional football season does not induce relevant changes in performance indicators. Accumulated stress and a lack of recovery towards the end of a season might be indicated by psychometric deteriorations.

Readiness potential in different states of physical activation and after ingestion of taurine and/or caffeine containing drinks.

To investigate the influence of taurine and caffeine containing drinks and physical stress on the cortical movement-preparation, the readiness potentials or "Bereitschaftspotentiale" (BPs), preceding voluntary self-placed pedalling movements, were examined after different states of exhaustion on an ergometer. 15 (13 right-handed) healthy men, aged between 22-30, participated in a randomised, cross over, double-blind, placebo controlled study. BPs were averaged out of artefact free EEG-segments from more than 90 triggered events, measured at 17 electrodes of the 10:20 system. With increasing effort the BPs were enlarged differently depending on the drink consumed. In placebo trials after exhaustive exercise premovement negative potential curves could be seen even in frontal areas. With caffeine the BPs increased after lower workload, achieving a level, which was reached in the placebo trials only after submaximal physical activation. Furthermore a significant shortening of premovement-brain-potentials in frontal and parietal regions could be seen in the caffeine trials at rest. Taurine admixture seems to inhibit this effects.