Measured task load in directed observers versus active participants undergoing high-fidelity simulation education in a critical care setting.

Objectives: The use of directed observers in high-fidelity simulation education is increasingly common. While evidence suggests similar educational outcomes for directed observers compared to active participants in technical skills, it remains uncertain if this benefit also exists for senior clinicians, especially in mental workload. We sought to compare the workload between active participants and directed observers using an objective measure. Methods: We performed a prospective, repeated-measures observational study during the New South Wales Ambulance Aeromedical Operations induction training from 2019 to 2020. Participants included senior critical care doctors, paramedics, and nurses undergoing high-fidelity simulation of prehospital and interhospital aeromedical missions. Task load was measured using the National Aeronautics and Space Administration task load index (NASA-TLX) administered following each simulation debrief. Prehospital and interhospital simulations were compared separately by building a multilevel model for complete case and all study data. Post hoc comparisons of NASA-TLX score for each group were performed using estimated marginal means (EMMs). Results: We enrolled 70 participants, comprising 49 physicians (70%), 19 paramedics (27%), and two flight nurses (3%). From the complete case analysis, statistically significant differences were observed for total NASA-TLX scores between active participants and directed observers in both prehospital (participant EMM 78, observer EMM 65, estimated difference -13, 95% confidence interval [CI] -20 to -7) and interhospital simulations (participant EMM 69, observer EMM 59, estimated difference -10, 95% CI -16 to -3). When all available data were included, the pattern of results did not change. Conclusions: In our sample of senior clinicians, the task load experienced by both active participants and directed observers in high-fidelity simulation education was high for both prehospital and interhospital simulation exercises. The statistically significant differences we report are unlikely to be practically significant. Our results support the use of directed observers when resource limitations do not allow all course attendees to participate in every simulation.

Describing the Challenges of Prehospital Rapid Sequence Intubation by Macintosh Blade Video Laryngoscopy Recordings.

STUDY OBJECTIVE: Structured review of video laryngoscopy recordings from physician team prehospital rapid sequence intubations (RSIs) may provide new insights into why prehospital intubations are difficult. The aim was to use laryngoscope video recordings to give information on timings, observed features of the airway, laryngoscopy technique, and laryngoscope performance. This was to both describe prehospital airways and to investigate which factors were associated with increased time taken to intubate. METHODS: Sydney Helicopter Emergency Medical Service (HEMS; the aeromedical wing of New South Wales Ambulance, Australia) has a database recording all intubations. The database comprises free-text case detail, airway dataset, scanned case sheet, and uploaded laryngoscope video. The teams of critical care paramedic and doctor use protocol-led intubations with a C-MAC Macintosh size four laryngoscope and intubation adjunct. First-pass intubation rate is approximately 97%. Available video recordings and their database entries were retrospectively analyzed for pre-specified qualitative and quantitative factors. RESULTS: Prehospital RSI video recordings were available for 385 cases from January 2018 through July 2020. Timings revealed a median of 58 seconds of apnea from laryngoscope entering mouth to ventilations. Median time to intubate (laryngoscope passing lips until tracheal tube inserted) was 35 seconds, interquartile range 28-46 seconds. Suction was required prior to intubation in 29% of prehospital RSIs. Fogging of the camera lens at time of laryngoscopy occurred in 28%. Logistic regression revealed longer time to intubate was associated with airway soiling, Cormack-Lehane Grade 2 or 3, multiple bougie passes, or change of bougie. CONCLUSION: Video recordings averaging 35 seconds for first-pass success prehospital RSI with an adjunct give bed-side "definitions of difficulty" of 30 seconds for no glottic view, 45 seconds for no bougie placement, and 60 seconds for no endotracheal tube placement. Awareness of apnea duration can help guide decision making for oxygenation. All emergency intubators need to be cognizant of the need for suctioning. Improving the management of bloodied airways and bougie usage may reduce laryngoscopy duration and be a focus for training. Video screen fogging and missed recordings from some patients may be something manufacturers can address in the future.

Improving community-based first response to out of hospital cardiac arrest (FirstCPR): protocol for a cluster randomised controlled trial.

INTRODUCTION: Out-of-hospital cardiac arrest (OHCA) is associated with poor survival outcomes, but prompt bystander action can more than double survival rates. Being trained, confident and willing-to-perform cardiopulmonary resuscitation (CPR) are known predictors of bystander action. This study aims to assess the effectiveness of a community organisation targeted multicomponent education and training initiative on being willing to respond to OHCAs. The study employs a novel approach to reaching community members via social and cultural groups, and the intervention aims to address commonly cited barriers to training including lack of availability, time and costs. METHODS AND ANALYSIS: FirstCPR is a cluster randomised trial that will be conducted across 200 community groups in urban and regional Australia. It will target community groups where CPR training is not usual. Community groups (clusters) will be stratified by region, size and organisation type, and then randomly assigned to either immediately receive the intervention programme, comprising digital and in-person education and training opportunities about CPR and OHCA over 12 months, or a delayed programme implementation. The primary outcome is self-reported 'training and willingness-to-perform CPR' at 12 months. It will be assessed through surveys of group members that consent in intervention versus control groups and administered prior to control groups receiving the intervention. The primary analysis will follow intention-to-treat principles, use log binomial regression accounting for baseline covariates and be conducted at the individual level, while accounting for clustering within communities. Focus groups and interviews will be conducted to examine barriers and enablers to implementation and costs will also be examined. ETHICS AND DISSEMINATION: Ethical approval was obtained from The University of Sydney. Findings from this study will be disseminated via presentations at scientific conferences, publications in peer-reviewed journals, scientific and lay reports. TRIAL REGISTRATION NUMBER: ACTRN12621000367842.

Machine learning algorithms to classify self-harm behaviours in New South Wales Ambulance electronic medical records: A retrospective study.

BACKGROUND: There is increasing interest in suicide surveillance solutions to identify non-fatal suicidal and self-harming behaviours in the Australian community not currently captured through national administrative datasets. OBJECTIVE: The aim of the present study was to develop machine learning models to classify self-harm related behaviours using unstructured clinical note text from New South Wales (NSW) Ambulance data and compare their performance via traditional methods. METHODS: Primary data were derived from NSW Ambulance electronic medical records (eMRs) for potential self-harm related NSW Ambulance attendances for the period 2013-2019. Data included paramedic clinical notes detailing the nature of the attendance, clinical outcome, and narrative information. We assessed sensitivity, specificity, positive predictive value, negative predictive value, F-score, and the Matthews correlation coefficient (MCC) for four algorithms (Support Vector Machine, random forest, decision tree, and logistic regression). RESULTS: The performance of these algorithms was compared using the MCC measure. In a test sample of 3157 ambulance attendances (1349 self-harm related behaviours and 1808 unrelated), the MCC for classification of self-harm related behaviour ranged from +0.681 to +0.730. The Support Vector Machine (sensitivity = 82.7%, specificity = 89.6%, MCC = 0.730) and the logistic regression (sensitivity = 83.1%, specificity = 89.3%, MCC = 0.727) models performed best. CONCLUSIONS: This study demonstrates that machine learning models can be applied to paramedic notes within unstructured medical records to classify self-harm related behaviours. The resulting model could be used to compliment current manual abstraction of self-harm behaviours and provide more timely approximations to be used for self-harm surveillance.

Out-of-hospital cardiac arrests and bystander response by socioeconomic disadvantage in communities of New South Wales, Australia.

BACKGROUND & AIM: Bystander response to out-of-hospital cardiac arrest (OHCA) may relate to area-level factors, including socioeconomic status (SES). We aimed to examine whether OHCA among individuals in more disadvantaged areas are less likely to receive bystander cardiopulmonary resuscitation (CPR) compared to those in more advantaged areas. METHODS: We analysed data on OHCAs in New South Wales, Australia collected prospectively through a statewide, population-based register. We excluded non-medical arrests; arrests witnessed by a paramedic; occurring in a medical centre, nursing home, police station; or airport, and among individuals with a Do-Not-Resuscitate order. Area-level SES for each arrest was defined using the Australian Bureau of Statistics' Index of Relative Socioeconomic Disadvantage and its relationship to likelihood of receiving bystander CPR was examined using hierarchical logistic regression models. RESULTS: Overall, 39% (6622/16,914) of arrests received bystander CPR (71% of bystander-witnessed). The OHCA burden in disadvantaged areas was higher (age-standardised incidence 76-87/100,000/year in more disadvantaged quintiles 1-4 versus 52 per 100,000/year in most advantaged quintile 5). Bystander CPR rates were lower (38%) in the most disadvantaged quintile and highest (42%) in the most advantaged SES quintile. In adjusted models, younger age, being bystander-witnessed, arresting in a public location, and urban location were all associated with greater likelihood of receiving bystander CPR; however, the association between area-level SES and bystander CPR rate was not significant. CONCLUSIONS: There are lower rates of bystander CPR in less advantaged areas, however after accounting for patient and location characteristics, area-level SES was not associated with bystander CPR. Concerted efforts to engage with communities to improve bystander CPR in novel ways could improve OHCA outcomes.

The Association of Laryngeal Position on Videolaryngoscopy and Time Taken to Intubate Using Spatial Point Pattern Analysis of Prospectively Collected Quality Assurance Data.

BACKGROUND: During videolaryngoscopy (VL), the larynx appears within the defined area of the video screen, and its location can be measured as a point within this space. Spatial statistics offer methods to explore the relationship between location data and associated variables of interest. The aims of this study were to use spatial point pattern analysis to explore if the position of the larynx on VL is associated with longer times to intubate, increased risk of a needing >1 intubation attempt, or percentage of glottic opening. METHODS: Quality assurance data and clinical notes from all prehospital intubations using C-MAC Pocket Monitor with CMAC-4 blade (Karl Storz) from January 1, 2018, to July 31, 2020, were reviewed. We extracted 6 measurements corresponding to the time taken to obtain the initial and then best laryngeal view, time to manipulate a bougie, and time to place the endotracheal tube, as well a percentage of glottic opening and a number of intubation attempts. Larynx location was the middle of the base of glottis, in cm from the left and bottom on the C-MAC screen. Two plots were produced to summarize the base of glottis location and time to perform each time component of intubation. Next, a cross mark function and a maximum absolute deviation hypothesis test were performed to assess the null hypotheses that the spatial distributions were random. The association between glottis location and >1 intubation attempt was assessed by a spatial relative risk plot. RESULTS: Of 619 eligible intubations, 385 had a video for analysis. The following time variables had a nonrandom spatial distribution with a tendency for longer times when the larynx was off-center to the top or right of the screen: laryngoscope passing from teeth to glottis, glottis first view to best view of the larynx, time from bougie appearing to being placed in the cords, and overall time from teeth to endotracheal tube passing through cords. There was no increased relative risk for >1 intubation attempt. CONCLUSIONS: Spatial point pattern analysis identified a relationship between the position of the larynx during VL and prolonged intubation times. We did not find a relationship between larynx location and >1 attempt. Whether the location of the larynx on the screen is a marker for difficult VL or if optimizing the larynx position to the center of the screen improves intubation times would require further prospective studies.

The reliability of thromboelastography in a simulated rotary wing environment.

BACKGROUND: With the increasing role of point-of-care coagulation testing in trauma, we sought to test the reliability of the thromboelastography (TEG)6s machine in a simulated rotary wing environment. METHOD: A two-arm study was conducted, running TEG6s quality control cartridges in a helicopter flight simulator with realistic vibration and in stable ground conditions. The flight conditions during testing included take-offs, landings and inflight emergencies such as engine failures. TEG values for R time, K time, α-angle and maximum amplitude (MA) were collected and compared with manufacturers' normal ranges. RESULTS: 148 TEG samples were included for analysis (72 simulator arm, 76 ground arm). In the simulator arm, four of our K time values fell below the normal range and four MA values were above the normal range. All other values in both simulator and ground arms were in the normal range. CONCLUSION: The TEG6s is a viable technology in the simulated rotary wing environment, and it is feasible to conduct further studies using human blood in live rotary wing conditions. Extreme flight conditions should be avoided during further testing.

Analysis of Out-of-Hospital Pediatric Intubation by an Australian Helicopter Emergency Medical Service.

STUDY OBJECTIVE: We examine first-look success in emergency pediatric intubation by a physician-staffed helicopter emergency medical service (EMS). METHODS: A database analysis of all pediatric (<16 years) intubations during a 64-month period was undertaken, using data from a prospectively enrolled electronic airway registry form. Recorded findings included patient demographics, operator background, airway intervention including intubation attempts, complications, and critical timings. RESULTS: Eighty-two subjects were identified during the 64-month study. All patients were successfully intubated. The overall first-look success rate was 75 of 82 (91%), registrars achieving a first-look success rate of 26 of 26 (100%), consultants 16 of 17 (94%), and paramedics 33 of 39 (85%). Overall complication rate was 14%; 84% of cases were rapid sequence induction, whereas 16% were "cold intubations." Difficult airway indicators were present in 77% of patients. CONCLUSION: A high first-look success rate for pediatric intubation was achieved by adult helicopter EMS physicians and intensive care paramedics. To our knowledge, this compares favorably with the rate in published literature in pediatric emergency departments and critical care units.

Hemodynamic Response After Rapid Sequence Induction With Ketamine in Out-of-Hospital Patients at Risk of Shock as Defined by the Shock Index.

STUDY OBJECTIVE: Ketamine is considered a stable induction agent for rapid sequence induction; however, hypotension rates up to 24% are reported. The shock index (shock index=pulse rate/systolic blood pressure [SBP]) may identify patients at risk of adverse hemodynamic change. We investigate whether SBP and pulse rate response to ketamine induction differ when patients are classified as being at risk of shock by their shock index. METHODS: We conducted a prospective observational study of electronically collected vital sign data from patients undergoing rapid sequence induction with ketamine. Patients were grouped into low shock index (shock index <0.9) or high shock index (shock index ≥0.9) preinduction. Pulse rate and SBP were compared between 3 minutes preinduction and for 3 measurements postinduction (3-minute intervals) by repeated-measures ANOVA. Proportions of patients developing hypotension or hypertension are also reported. RESULTS: One hundred twelve patients were enrolled (81 low shock index, 31 high shock index). Low shock index patients had increased SBP after induction (16 mm Hg; 95% confidence interval [CI] 11 to 21 mm Hg), whereas high shock index patients did not (2 mm Hg; 95% CI -4 to 7 mm Hg). Pulse rate in low shock index patients increased after induction (20 beats/min; 95% CI 16 to 25 beats/min) and remained elevated, whereas in high shock index patients a difference occurred at the second postinduction measurement only (15 beats/min; 95% CI 11 to 18 beats/min). More high shock index patients became hypotensive (26%; 95% CI 12% to 45%) than low shock index ones (2%; 95% CI 0% to 9%), whereas more low shock index patients became hypertensive (40%; 95% CI 29% to 51%) than high shock index ones (13%; 95% CI 4% to 30%). CONCLUSION: After ketamine induction, high shock index patients exhibited blunted hypertensive responses and more frequent hypotension, whereas low shock index patients had sustained increases in pulse rate and SBP.

Difficult Intubation Factors in Prehospital Rapid Sequence Intubation by an Australian Helicopter Emergency Medical Service.

OBJECTIVE: Prehospital rapid sequence intubation (RSI) of critically ill trauma patients is a high-risk procedure that may be associated with an increased rate of severe complications such as failed intubation, failure of oxygenation, hypoxia, hypotension, or need for surgical airway. The objective of this study was to describe the factors associated with difficult intubation in prehospital RSI as defined by more than a single look at laryngoscopy to achieve tracheal intubation. METHODS: This is an observational study using prospectively collected data. RESULTS: Four hundred forty-three RSIs were performed. Paramedics were the initial laryngoscopist in 290 (65.5%). First-look laryngoscopy resulted in successful tracheal intubation (TI) in 372 (84.0%) (95% confidence interval, 80.3%-87.1%). Intubation was achieved on second look at laryngoscopy in 58 (13.1%). "First-pass" TI was achieved in 394 (88.9%). Overall, successful TI was achieved in 438 (98.9%) (95% confidence interval, 97.4%-99.5%). Complications occurred in 116 (26.2%), with desaturation the commonest in 77 (17.4%). CONCLUSION: Factors associated with more than 1 look at laryngoscopy before TI included paramedic laryngoscopist and the presence of at least 1 of the following indicators: blood/vomitus in the airway, limited mouth opening, and limited neck movement. Trauma to face/neck, obese body habitus, C-spine precautions, cricoid pressure, midline stabilization, and intubation on the ground did not influence the level of difficulty encountered.

Apneic oxygenation was associated with decreased desaturation rates during rapid sequence intubation by an Australian helicopter emergency medicine service.

STUDY OBJECTIVE: The Greater Sydney Area Helicopter Emergency Medical Service undertakes in excess of 2,500 physician/paramedic out-of-hospital and interhospital retrievals each year, of which 8% require intubation. Emergency anesthesia of critically ill patients is associated with complications, including hypoxia. In July 2011, the service introduced apneic oxygenation with nasal cannulae to its emergency anesthesia standard operating procedure to reduce rates of desaturation during rapid sequence intubation. We evaluate the association between the introduction of apneic oxygenation and incidence of desaturation during rapid sequence intubation in both out-of-hospital and interhospital retrievals. METHODS: This was a retrospective study of prospectively collected airway registry data. Consecutive patients who underwent rapid sequence intubation by Greater Sydney Area Helicopter Emergency Medical Service personnel between September 2009 and July 2013, spanning the introduction of apneic oxygenation, were included for analysis (n=728). We compared patients who underwent rapid sequence intubation before the service introduced apneic oxygenation (n=310) with those who underwent it after its introduction (n=418). We evaluated the association between the introduction of apneic oxygenation and the incidence of desaturation. RESULTS: During the study period, 9,901 missions were conducted with 728 rapid sequence intubations (310 pre- and 418 postapneic oxygenation). The introduction of apneic oxygenation was followed by a decrease in desaturation rates from 22.6% to 16.5% (difference=6.1%; 95% confidence interval 0.2% to 11.2%). CONCLUSION: Introduction of apneic oxygenation was associated with decreased incidence of desaturation in patients undergoing rapid sequence intubation.

Improving documentation in prehospital rapid sequence intubation: investigating the use of a dedicated airway registry form.

OBJECTIVE: The quality of medical documentation is integral to audit, clinical governance, education, medico-legal aspects and continuity of patient care. This study aims to investigate the introduction of a dedicated 'Airway Registry Form' (ARF) on the quality of documentation in prehospital rapid sequence intubation. METHODS: A retrospective review and comparison of 96 cases predating the introduction of the ARF and 90 cases immediately following its introduction were performed. RESULTS: The introduction of the ARF yielded significant improvement in the recording of selected data points: difficult airway indicators (p<0.0001), Cormack-Lehane grade of laryngoscopy at first attempt (p<0.0001), documentation of confirmation of tracheal intubation with end-tidal carbon dioxide monitoring (p=0.015) and recording of intubator's details (p<0.0001). CONCLUSIONS: This study validates the use of a dedicated ARF for the improvement of documentation and data collection related to prehospital rapid sequence intubation when compared with post-event extraction of data from a generic case-record.

Helicopter emergency medical service registrars do not comprehensively document primary surveys.

OBJECTIVES: In-hospital primary surveys undertaken on traumatically injured patients can be inaccurate and incomplete. This study examined the documentation of prehospital primary surveys conducted by Greater Sydney Area Helicopter Emergency Medical Service registrars on trauma patients. METHODS: A retrospective case sheet review of prehospital trauma primary surveys documented by Greater Sydney Area Helicopter Emergency Medical Service registrars was carried out using previously published methodologies. A 13-item prehospital primary survey score was created and analysed by registrar specialty. A linear mixed model was used to determine whether differences in prehospital primary survey score existed between specialties. A one-point difference in the mean scores was considered clinically significant. RESULTS: A total of 75 charts were reviewed. An unadjusted mean of 9.5±1.6 (SD) items, out of a possible 13, was documented. Documentation was found to be less complete for anaesthetic trainees (adjusted mean score=9.10) than for emergency medicine trainees (adjusted mean score=10.34). The difference in the mean scores was 1.24 (95% confidence interval, 0.25-2.23, t53d.f.=2.52, P=0.01). A significant clustering effect was identified for individual registrars (χ1d.f.=6.03, P=0.01). A very good level of agreement was obtained between the PPSS raters (κ=0.93, 95% confidence interval, 0.87-0.99). CONCLUSION: Helicopter emergency medical service registrars do not comprehensively document prehospital primary surveys on traumatically injured patients. However, emergency medicine trainees document more completely than anaesthetic trainees. Individual registrar variation contributes significantly towards the completeness of prehospital primary survey documentation.

Incidence trends and gender differences in malignant mesothelioma in New South Wales, Australia.

OBJECTIVES: Features of malignant mesothelioma reportedly differ between men and women, including occupational asbestos exposure, histological subtype, and median survival. In this study, incidence trends and clinical features for malignant mesothelioma were compared between genders in New South Wales (NSW), where notification of malignant mesothelioma to the Central Cancer Registry is a statutory requirement. METHODS: Notifications to the Central Cancer Registry were compared with those to the registry of the NSW Workers' Compensation (Dust Diseases) Board. The latter includes occupational and clinical data. RESULTS: Of the 3090 cases of malignant mesothelioma reported to the Central Cancer Registry between 1972 and 2004, 456 (15%) were female. Altogether 1995 malignant mesotheliomas were compensated between 1969 and 2004, of which 105 (5%) occurred among women. The incidence increased for both genders by approximately 15-fold. Median survival was similar for the men and women for all of the cases (7 versus 6 months), but was better among the women who received compensation (8.5 versus 10.4 months, P<0.0001). The mean disease latency (42.8 years) increased over the study period (P<0.001). CONCLUSIONS: In New South Wales over the last 30 years, the total number of malignant mesotheliomas and the number of compensated cases of malignant mesothelioma have risen for both genders. The mean latency is increasing, and increasing numbers of "nonoccupational" cases are being reported. Survival remains poor.

Projected mesothelioma incidence in men in New South Wales.

OBJECTIVES: Based on observed numbers of incident mesotheliomas since 1972, to predict future numbers in men in New South Wales. METHODS: The incidence of mesothelioma was modelled in two ways. First by using an age/birth cohort model, and second by using a model based on potential exposure to asbestos in terms of age and calendar year. The latter model included a term for clearance of asbestos fibres from the lungs, and a term for diagnostic fraction. The age and calendar year model was based on the model introduced by Hodgson and colleagues but replaced piecewise effects by smooth functions represented by cubic splines. RESULTS: The number of mesotheliomas between 2004 and 2060 was predicted as 6690 with the age-cohort model and as 6779 by the age and calendar year model, with peak annual numbers of 187 in the year 2021 and 196 in the year 2014 with the two models respectively. CONCLUSIONS: The pattern of parameter estimates in the two models was in accord with the known use of amphibole asbestos in Australia. The predicted peak year of 2014-21 is 30-35 years after the phasing out of amphibole use, and this period is in accord with predictions for the UK and the US; in the latter country the peak was 10-15 years earlier corresponding to a marked decline of amphibole use in and following the 1960s.

Effect of budesonide on the perception of induced airway narrowing in subjects with asthma.

The perception of bronchoconstriction may be modulated by airway inflammation. However, the effect of inhaled corticosteroid (ICS) treatment on perception in subjects with asthma has received limited study. The aim of this study was to determine the effect of inhaled budesonide on the perception of breathlessness induced by histamine challenge. Thirty-five subjects with poorly controlled asthma were randomized to receive budesonide (1,600 or 3,200 microg/d) for 8 wk, followed by 8 wk at 1,600 microg/d and subsequent downtitration according to a clinical algorithm. Borg scores were recorded during histamine challenges performed at baseline and at 8, 16, 24, 48, and 72 wk. Perception was estimated as the slope of Borg/% fall FEV(1). The Borg/FEV(1) slope increased significantly after 8 wk of budesonide (0.09 [0.08-0.12] to 0.15 [0.11-0.19], p = 0.002), and remained increased compared with baseline values at all subsequent visits. There were no significant differences in Borg/ FEV(1) slope between subjects who were and were not taking ICS at study entry. The magnitude of change in the Borg/FEV(1) slope did not differ significantly between treatment groups and was not related to changes in baseline FEV(1), airway hyperresponsiveness, blood eosinophils, or serum eosinophil cationic protein (ECP). We conclude that treatment with budesonide enhances the perception of airway narrowing, but the effect is unrelated to budesonide dose, or to changes in circulating eosinophil markers.