Andrew D. McRae

Background: Foreign body airway obstruction (FBAO) is a life-threatening emergency; however, bystander treatment recommendations rely on retrospective data. We evaluated the feasibility of a population-based prospective cohort study of FBAO interventions. Methods: We conducted a prospective observational pilot study in Alberta, Canada, between November 2025 and April 2026. We identified individuals with out-of-hospital FBAO who called emergency medical services or attended an emergency department using a validated health-record case definition. Participants were stratified into adults and children (aged>2 years) and younger children (aged≤ 2 years) cohorts. The primary outcome was included cases per month, with several secondary feasibility (proportion of eligible cases included, data completeness) and clinical outcomes (FBAO relief, survival to acute care discharge, favourable neurological outcome, intervention-associated injuries). Results: Among 5,208 screened encounters, 147 FBAO cases were identified. Of these, 91 adults and children (89.2%) and 39 young children (86.7%) were enrolled. Mean recruitment was 15.2 participants/month (SD=1.1) in the adult and child cohort, exceeding the predefined feasibility threshold (≥13/month), and 6.5 participants/month (SD=1.3) in the young child cohort, meeting the amber-zone criterion (6-8/month). Data completeness exceeded 90% across all participants. In adults and children, bystander intervention relieved the obstruction in 59 cases (66.3%), and 80(87.9%) survived to acute care discharge. In young children, bystander intervention relieved the obstruction in 33 cases (84.6%); all survived with favourable neurological outcomes. Conclusions: Prospectively identifying and recruiting individuals with FBAO is feasible using population-based prehospital and emergency department records. These findings support a larger adequately powered prospective cohort study comparing the effectiveness and safety of FBAO interventions.

Objectives To systematically identify and describe optimal methodology used to improve the diagnostic accuracy of high-sensitivity cardiac troponin for diagnosis of myocardial infarction in patients with kidney dysfunction. Methods Cochrane, MEDLINE, EMBASE, and Google Scholar were systematically searched for studies describing strategies to increase the diagnostic accuracy of high-sensitivity cardiac troponin testing in emergency department patients with kidney dysfunction and suspected myocardial infarction. Study eligibility ascertainment and data extraction was performed by two independent reviewers. Findings of included studies were summarized and categorized according to methodological approach for improving diagnostic accuracy. Results Data extraction was organized using Covidence online software. A total of 946 papers were identified in the electronic search. Of these, 878 were excluded based on review of titles and abstracts, 59 were removed after full-text review, and 9 studies were included in the final synthesis. Most studies identified alternative diagnostic troponin concentrations while one adjusted for kidney function using a multivariable model. Optimal cutoff concentrations for single and serial troponin samples varied by glomerular filtration rate and across published studies. Multivariable adjustment did not improve diagnostic accuracy of troponin testing, and glomerular filtration rate was not a significant covariate suggesting that kidney function acts as an effect measure modifier rather than as a confounder. Conclusion Diagnosing myocardial infarction is particularly challenging in individuals with kidney dysfunction. High initial concentrations and serial changes seem specific for ruling in myocardial infarction, while low initial concentrations and minimal serial changes appear to safely rule out myocardial infarction. However, no strategy has been externally validated for widespread adoption. Further work should focus on identifying diagnostic strategies that use kidney function as an effect measure modifier, and that can be externally validated.

Background: People with kidney failure have complex care needs and frequently access care using the emergency department (ED). Little is known about how continuity of care (CoC) relates to ED care seeking for people with kidney failure. To understand the experiences of CoC among adults with kidney failure in relation to their recent ED encounter. Methods: Using a qualitative descriptive methodology, we purposively sampled adults with kidney failure (defined as eGFR <15 mL/min/1.73m2 and/or receipt of maintenance dialysis) from Alberta who accessed the ED for a non-life-threatening indication within the preceding six weeks between May 2024 and January 2025. We conducted individual semi-structured interviews and analyzed transcripts in duplicate using a framework analysis approach with reference to an established framework defining CoC according to 3 types (i.e., relational, management, and informational). Thematic development involved both inductive and deductive techniques. Results: 29 patients were included (12 in-center hemodialysis, 1 in-center nocturnal hemodialysis, 7 peritoneal dialysis, 5 home hemodialysis, and 4 without kidney replacement therapy). Themes were identified within CoC types and across settings of before, during, and after the acute care encounter. Key relational continuity themes included: stability and trust in care teams, disrupted therapeutic relationships, and re-establishing engagement in circles of care. Management continuity themes included: safeguarding kidney supports and kidney care fragmentation in the ED. Informational continuity themes included: patients as continuity self-advocates, bridging care through information sharing, and extending continuity beyond the ED. Conclusions: Patients with kidney failure expressed varied experiences of CoC and identified important gaps relevant to the emergency care context. Strategies that bridge these perceived gaps across outpatient and acute care settings may help to mitigate the burden of ED use in this population.

Background Patients with symptoms of acute coronary syndrome make up a significant proportion of emergency department (EDs) presentations. High-sensitivity troponin testing is a standard component of evaluating patients with suspected symptomatic coronary disease. We sought to synthesize the evidence of the accuracy of 0/2-h and 0/3-h algorithms using the Beckman Access high-sensitivity cardiac troponin I (hs-cTnI) assay. Methods We developed an electronic search strategy retrieving research from three electronic databases (Medline, Embase, and Wiley Cochrane Library). Relevant research studies were screened and data extracted by a team of reviewers. Study quality and risk assessment were appraised using the QUADAS-2 tool. Findings were reported according to PRISMA guidelines. Results Five studies met inclusion criteria. No studies directly compared the 0 h/2 h and 0 h/3 h algorithms using the Beckman Coulter Access hs-cTnI assay, and heterogeneity in study design precluded meta-analysis. Included studies variably used 2-h, 3-h, or intermediate timepoints for serial troponin measurement. All studies reported consistently high sensitivity (> 97.7%) and NPV (> 98.9%) for ruling out acute myocardial infarction, supporting the reliability of both 0/2 h and 0/3 h hs-cTnI algorithms in the ED. Conclusions Of the five studies included, two studies suggest that a two-hour hs-TnI algorithm can effectively rule out myocardial infarction with similar accuracy to a longer three-hour protocol. Use of a 2-h hs-cTnI algorithm may lead to operational gains compared to a 3-h serial testing algorithm.

Objective: To conduct a randomised, open label comparison of the effectiveness and safety of intravenous vernakalant and intravenous procainamide for the management of acute atrial fibrillation in the emergency department. Design: Randomised clinical trial (RAFF4 trial). Setting: 12 tertiary care emergency departments in Canada. Participants: Patients with acute atrial fibrillation for whom acute rhythm control was a safe option. Interventions: Patients were randomised (1:1) to an intravenous infusion of vernakalant or procainamide; when rapid conversion did not occur, patients were offered electrical cardioversion. Main outcomes and measures: The primary outcome was conversion to sinus rhythm within 30 minutes of drug infusion completion. Secondary outcomes included time to conversion to sinus rhythm and whether the patient required electrical cardioversion. Results: Of the 350 enrolled eligible patients, baseline characteristics were similar in the procainamide (n=172) and vernakalant (n=178) groups. For the primary outcome of conversion success, vernakalant was more effective (62.4% v 48.3%; adjusted absolute difference 15.0%, 95% confidence interval 4.6% to 25.0%, P=0.005; adjusted odds ratio 1.87, 95% confidence interval 1.2 to 2.9, P=0.006). With vernakalant, time to conversion was faster (21.8 v 44.7 minutes; mean difference −22.9, 95% confidence interval −29.9 to −16.0, Pv 44.2%; odds ratio 0.62, 95% confidence interval 0.39 to 0.96, P=0.033). Adverse events were similar in both groups, were generally mild and brief, and most patients were discharged home. Subgroup analysis strongly favoured vernakalant for conversion in patients younger than 70 years (73.3% v 47.2%; adjusted odds ratio 3.1, 95% confidence interval 1.7 to 5.5, P=0.001, interaction P=0.005). Conclusions: In this head-to-head comparison, vernakalant was superior to procainamide for patients with higher conversion rates and faster times to conversion. Therefore, vernakalant is a safe and highly effective intravenous alternative for the rapid cardioversion and discharge home of patients with acute atrial fibrillation. Trial registration: ClinicalTrials.gov NCT04485195

Background: In the emergency setting, many diagnostic pathways incorporate change in high-sensitivity cardiac troponin (hs-cTn) concentrations (i.e., the delta) to classify patients as low-risk (rule-out) or high-risk (rule-in) for possible myocardial infarction (MI). However, the impact of analytical variation on the delta for correct classification is unknown, especially at concentrations below and around the 99th percentile. Our objective was to assess the impact of delta variation for correct risk classification across the European Society of Cardiology (ESC 0/1 h and 0/2 h), the High-STEACS, and the common change criteria (3C) pathways. Methods: A yearlong accuracy study for hs-cTnT was performed where laboratories across Canada tested three patient-based samples (level 1 target value = 6 ng/L, level 2 target value = 9 ng/L, level 3 target value = 12 ng/L) monthly across 41 different analyzers. The assigned low-delta between levels 1 and 2 was 3 ng/L (i.e., 9 − 6 = 3 ng/L) and the assigned high-delta between levels 1 and 3 was 6 ng/L (i.e., 12 − 6 = 6 ng/L). The low- and high-deltas for each analyzer were determined monthly from the measured values, with the difference calculated from the assigned deltas. The obtained deltas were then assessed via the different pathways on correct classification (i.e., percent correct with 95% confidence intervals, CI) and using non-parametric analyses. Results: The median (interquartile range) difference between the measured versus assigned low-delta (n = 436) and high-delta (n = 439) was −1 ng/L (−1 to 0). The correct classification differed among the pathways. The ESC 0/1 h pathway yielded the lowest percentage of correct classification at 35.3% (95% CI: 30.8 to 40.0) for the low-delta and 90.0% (95% CI: 86.8 to 92.6) for the high-delta. The 3C and ESC 0/2 h pathways yielded higher and equivalent estimates on correct classification: 95.2% (95% CI: 92.7 to 97.0) for the low-delta and 98.2% (95% CI: 96.4 to 99.2) for the high-delta. The High-STEACS pathway yielded 99.5% (95% CI: 98.4 to 99.9) of correct classifications for the high-delta but only 36.2% (95% CI: 31.7 to 40.9) for the low-delta. Conclusions: Analytical variation will impact risk classification for MI when using hs-cTn deltas alone per the pathways. The 3C and ESC 0/2 h pathways have <5% misclassification when using deltas for hs-cTnT in this dataset. Additional studies with different hs-cTnI assays at concentrations below and near the 99th percentile are warranted to confirm these findings.

Objective The Canadian Association of Emergency Physicians 2024 Academic Symposium Panel on adaptive platform trials explored whether adaptive platform trials could be implemented in Canadian emergency departments (EDs). This panel aimed to propose and refine recommendations formulated by the results of a rapid review and responses from a panel of experts about conducting adaptive platform trials in EDs. Methods From November 2023 to May 2024, a rapid review was conducted on the existing logistical and ethical barriers and facilitators to structuring adaptive platform trials in emergency medicine. The emerging themes and ideas were collected and used to conduct individual semi-structured interviews with key stakeholders, including leaders in emergency medicine research, methodologists and biostatisticians specializing in these designs, patient partners, research personnel, and investigators involved in platform trials across Canada and abroad. Results From 23 articles and 17 expert interviews, we identified facilitators and barriers to adaptive platform trials in Canadian emergency medicine spread across five domains: evidence strength and quality, relative advantage, adaptability, complexity, and implementation climate and readiness. The most salient needs according to investigators were purposeful and clinically relevant trial design, methodological expertise, and harmonious collaboration with ethics authorities. We provide 14 recommendations across 4 levels: policy, trialist, site, and patient to address barriers to adaptive platform trials in emergency medicine. For each recommendation, we provided corresponding implementation strategies from the Expert Recommendations for Implementing Change (ERIC). Conclusions Adaptive trial designs are well suited for emergency settings provided the interventions are both easy for clinicians to administer and relevant enough to ameliorate the practice of emergency medicine. These designs are particularly tailored to tackle confirmatory trials, emerging diseases, and trauma care, but barriers like a chaotic ED, complex statistical and methodological requirements, and regulatory considerations persist and require thoughtful implementation strategies.