A 27-year-old female is brought to the emergency department (ED) by ambulance following a motor vehicle collision at highway speed. She was the belted driver. She has no significant past medical history and is on no medications. Following a prolonged extrication, she is intubated due to decreased level of consciousness before transport.

A 59-year-old man presents with left shoulder pain after falling while playing with his dog at the park. He drove himself to the emergency department (ED). He reports 5/10 pain and has reduced range of motion of the shoulder. His shoulder looks normal on exam and is not squared off. You wonder if he might have a posterior shoulder dislocation.

A 12-year-old male injured his ankle while playing hockey (Figure 1). His dad reports that he was checked into the boards. His ankle is swollen, but does not appear deformed. His distal neurovascular exam is normal. There is bony tenderness over the lateral malleolus in accordance with the Ottawa Ankle Rules.

A 37-year-old female presents with cough, fever, dyspnea, and myalgias for five days after recent contact with a family member with confirmed 2019 coronavirus disease (COVID-19). Her vital signs include T 38.3° C, HR 108, BP 118/70 mm Hg, RR 26 breaths per minute, and oxygen saturation 67% on room air. She is not in respiratory distress currently and is protecting her airway. Her chest X-ray reveals bilateral airspace opacities. You plan to immediately intervene and address her hypoxia.

Introduction: Rapid diagnostic algorithms using high-sensitivity cardiac troponin can rapidly diagnose or exclude acute myocardial infarction (MI). However, multiple algorithms have been proposed and it is unclear if some outperform others. The objective of this study was to prospectively compare the diagnostic performance of 1- and 2-hour algorithms in clinical practice in a Canadian population. Methods: Emergency department patients with chest pain had high-sensitivity cardiac troponin-T (hs-cTnT) collected on presentation and 1- and 2-hours later at a single academic tertiary hospital and regional percutaneous coronary intervention site over a 2-year period. The primary outcome was index MI, the secondary outcome was 30-day major adverse cardiac events (MACE). All outcomes were 2 physician adjudicated. Results: We enrolled 1,167 patients with hs-cTnT collected on ED presentation. Of these, 350 had a valid 1-hour and 550 had a 2-hour hs-cTnT sample. Index MI prevalence was ~11%. Sensitivity of the 1- and 2-hour algorithms for index MI was 97.3% (95% CI 85.8-99.9%) and 100% (95% CI 91.6-100%) and for 30-day MACE was 80.9% (95% CI 66.7-90.9%) and 83.3% (95% CI 73.2-90.8%), respectively. The 1-hour algorithm was 96.3% specific for index MI (95% CI 93.8-98.2%) whereas specificity for the 2-hour algorithm was 97.9% (95% CI 96.3-100%). Both algorithms classified about one-quarter of patients in an indeterminate observational zone with an ~11% MI prevalence. Conclusion: Both the 1- and 2-hour algorithms were highly sensitive and specific for MI, but were less sensitive for 30-day MACE. However, the 2-hour algorithm trended toward better performance, likely because its larger delta cutoffs reduce the risk of misclassification owing to analytic variability. These findings suggest algorithms using larger delta cutoffs may provide a greater margin of safety. Further comparative evaluation of rapid diagnostic algorithms using different cutoffs and characterization of patients in the observational zone is warranted.

A 58-year-old man is brought by the ambulance to the emergency department (ED) of a tertiary care centre following an out-of-hospital cardiac arrest. Paramedics were called by the patient's wife after he had collapsed. She immediately initiated cardiopulmonary resuscitation (CPR). Prior to his collapse, he had been complaining of chest pain. His initial rhythm in the field was ventricular fibrillation, and he received defibrillation. An automated CPR device was applied prior to transport. En route, return of spontaneous circulation is achieved. An electrocardiogram shows ST-segment elevation in the anterior leads. Just prior to arrival, the patient suffers recurrent cardiac arrest with two further rounds of unsuccessful defibrillation in the ED. At this point, a decision is made to proceed with extracorporeal cardiopulmonary resuscitation (ECPR), prior to transport for cardiac catheterization.

A 16-year-old female presents to a community emergency room following a suicide attempt by hanging. Prehospital, on arrival of paramedics, the patient was in a pulseless electrical activity rhythm. Paramedics provided advanced cardiac life support for 20 minutes before they obtained return of spontaneous circulation. In the emergency department, she had another 25-minute cardiac arrest with ultimate return of spontaneous circulation. She is now hemodynamically stable on Levophed 0.2 µg/kg/min. Her neurological exam shows pupils to be 3 mm and fixed bilaterally, absent cough and gag, and no response to central or peripheral pain. She occasionally triggers 2–3 spontaneous breaths per minute above the set rate on the ventilator. Her CT head scan shows severe anoxic changes and cerebral edema.

Introduction: CAEP recently developed the acute atrial fibrillation (AF) and flutter (AFL) [AAFF] Best Practices Checklist to promote optimal care and guidance on cardioversion and rapid discharge of patients with AAFF. We sought to assess the impact of implementing the Checklist into large Canadian EDs. Methods: We conducted a pragmatic stepped-wedge cluster randomized trial in 11 large Canadian ED sites in five provinces, over 14 months. All hospitals started in the control period (usual care), and then crossed over to the intervention period in random sequence, one hospital per month. We enrolled consecutive, stable patients presenting with AAFF, where symptoms required ED management. Our intervention was informed by qualitative stakeholder interviews to identify perceived barriers and enablers for rapid discharge of AAFF patients. The many interventions included local champions, presentation of the Checklist to physicians in group sessions, an online training module, a smartphone app, and targeted audit and feedback. The primary outcome was length of stay in ED in minutes from time of arrival to time of disposition, and this was analyzed at the individual patient-level using linear mixed effects regression accounting for the stepped-wedge design. We estimated a sample size of 800 patients. Results: We enrolled 844 patients with none lost to follow-up. Those in the control (N = 316) and intervention periods (N = 528) were similar for all characteristics including mean age (61.2 vs 64.2 yrs), duration of AAFF (8.1 vs 7.7 hrs), AF (88.6% vs 82.9%), AFL (11.4% vs 17.1%), and mean initial heart rate (119.6 vs 119.9 bpm). Median lengths of stay for the control and intervention periods respectively were 413.0 vs. 354.0 minutes (P < 0.001). Comparing control to intervention, there was an increase in: use of antiarrhythmic drugs (37.4% vs 47.4%; P < 0.01), electrical cardioversion (45.1% vs 56.8%; P < 0.01), and discharge in sinus rhythm (75.3% vs. 86.7%; P < 0.001). There was a decrease in ED consultations to cardiology and medicine (49.7% vs 41.1%; P < 0.01), but a small but insignificant increase in anticoagulant prescriptions (39.6% vs 46.5%; P = 0.21). Conclusion: This multicenter implementation of the CAEP Best Practices Checklist led to a significant decrease in ED length of stay along with more ED cardioversions, fewer ED consultations, and more discharges in sinus rhythm. Widespread and rigorous adoption of the CAEP Checklist should lead to improved care of AAFF patients in all Canadian EDs.

A 53-year-old male presents with cough, fever, and myalgias for 7 days. Vitals include temperature, 38.0°C; heart rate, 110; blood pressure, 118/70 mm Hg; respiration rate, 28; and oxygen saturation 83% on room air. His only past medical history is hypertension. Your community is in the midst of the coronavirus disease 2019 (COVID-19) pandemic. The patient is hypoxic but responds to oxygen supplementation with nasal cannula and a face mask. His chest x-ray demonstrates multifocal infiltrates. Are there any therapeutic agents currently available for COVID-19?

A 67-year-old male presents to the emergency department (ED) in respiratory distress secondary to pneumonia. His oxygen saturation is 86% on a nonrebreather, respiratory rate is 32 respirations/minute, blood pressure 147/72 mmHg, heart rate 121 beats/minute, and temperature is 38.7° Celsius. The decision is made to intubate the patient. Fentanyl and propofol are used for analgesia and sedation, and rocuronium is used for paralysis. Using video laryngoscopy, the patient is successfully intubated, and now the ED team is awaiting your orders for the postintubation sedation care of this patient.