IMPORTANCEThe management of patients with syncope in the emergency department (ED) is challenging because no robust risk tool available has been recommended for clinical use.OBJECTIVE To validate the Canadian Syncope Risk Score (CSRS) in a new cohort of patients with syncope to determine its ability to predict 30-day serious outcomes not evident during index ED evaluation. DESIGN, SETTING, AND PARTICIPANTSThis prospective multicenter cohort study conducted at 9 EDs across Canada included patients 16 years and older who presented to EDs within 24 hours of syncope. Patients were enrolled from March 2014 to April 2018. MAIN OUTCOMES AND MEASURES Baseline characteristics, CSRS predictors, and 30-day adjudicated serious outcomes, including arrhythmic (arrhythmias, interventions for arrhythmia, or unknown cause of death) and nonarrhythmic (myocardial infarction, structural heart disease, pulmonary embolism, or hemorrhage) serious outcomes, were collected. Calibration and discrimination characteristics for CSRS validation were calculated. RESULTS A total of 3819 patients were included (mean [SD] age 53.9 [22.8] years; 2088 [54.7%] female), of whom 139 (3.6%) experienced 30-day serious outcomes, including 13 patients (0.3%) who died. In the validation cohort, there were no differences between the predicted and observed risk, the calibration slope was 1.0, and the area under the receiver operating characteristic curve was 0.91 (95% CI, 0.88-0.93). The empirical probability of a 30-day serious outcome during validation was 3.64% (95% CI, 3.09%-4.28%) compared with the model-predicted probability of 3.17% (95% CI, 2.66%-3.77%; P = .26). The proportion of patients with 30-day serious outcomes increased from 3 of 1631 (0.3%) in the very-low-risk group to 40 of 78 (51.3%) in the very-high-risk group (Cochran-Armitage trend test P < .001). There was a similar significant increase in the serious outcome subtypes with increasing CSRS risk category. None of the very-low-risk and low-risk patients died or experienced ventricular arrhythmia. At a threshold score of −1 (2145 of 3819 patients), the CSRS sensitivity and specificity were 97.8% (95% CI, 93.8%-99.6%) and 44.3% (95% CI, 42.7%-45.9%), respectively. CONCLUSIONS AND RELEVANCEThe CSRS was successfully validated and its use is recommended to guide ED management of patients when serious causes are not identified during index ED evaluation. Very-low-risk and low-risk patients can generally be discharged, while brief hospitalization can be considered for high-risk patients. We believe CSRS implementation has the potential to improve patient safety and health care efficiency.

Objectives: Propofol is an agent commonly used for procedural sedation and analgesia (PSA) in the emergency department (ED), but it can cause respiratory depression and hypotension. The combination of ketamine-propofol (K-P) is an alternative that theoretically provides a reduction in adverse events compared to propofol. The primary objective of this review was to determine if K-P has a lower frequency of adverse respiratory events in patients undergoing PSA in the ED than propofol alone. Secondary objectives were to compare the proportion of overall adverse events, sedation time, procedure time, and recovery time between K-P and propofol.Methods: Electronic searches of Medline, EMBASE, Cochrane Central Register of Controlled Trials, and CINAHL were conducted and reference lists were hand-searched. Randomized controlled trials (RCTs) published in English comparing the use of K-P to propofol alone for PSA in the ED were included.Results: Six RCTs were included with a combined total of 932 patients (K-P = 520, propofol = 412). Five RCTs reported the proportion of adverse respiratory events; the pooled estimate revealed fewer adverse respiratory events with K-P compared to propofol (29.0% vs. 35.4%; risk ratio [RR] = 0.82; 95% confidence interval [CI] = 0.68 to 0.99). There was no significant difference with respect to the proportion of overall adverse events (38.8% vs. 42.5%; RR = 0.88; 95% CI = 0.75 to 1.04). Procedure time was similar when the groups were compared. Conclusions:The premise of combining ketamine with propofol is based on the many synergies that theoretically exist between these two agents. In this study, K-P had a lower frequency of adverse respiratory events in patients undergoing PSA in the ED compared to propofol alone.

T he coronavirus disease 2019 (COVID-19) pandemic is the largest public health crisis in over a century. 1 As of Jan. 15, 2021, COVID-19 has resulted in over 113 million infections and almost 2.5 million deaths globally. 2 The global crude mortality rate among patients diagnosed with COVID-19 is about 3%, but some countries have reported rates that are up to 3 times higher. 2,3 Factors explaining these variations include population differences in demographics, health status and socioeconomics, as well as system factors such as the availability of testing, pandemic preparedness and response, with others yet to be uncovered. 4,5 There is an urgent need for high-quality, populationlevel data to understand modifiable risks for disease severity

Objective: Computed tomography (CT) is an imaging modality used to detect renal stones. However, there is concern about the lifetime cumulative radiation exposure attributed to CT. Ultrasonography (US) has been used to diagnose urolithiasis, thereby avoiding radiation exposure. The objective of this study was to determine the ability of US to identify renal colic patients with a low risk of requiring urologic intervention within 90 days of their initial emergency department (ED) visit. Methods: We completed a retrospective medical record review for all adult patients who underwent ED-ordered renal US for suspected urolithiasis over a 1-year period. Independent, double data extraction was performed for all imaging reports and US results were categorized as "normal," "suggestive of ureterolithiasis," "ureteric stone seen" or "disease unrelated to urolithiasis." Charts were reviewed to determine how many patients underwent subsequent CT and urologic intervention. Results: Of the 817 renal US procedures ordered for suspected urolithiasis during the study period, the results of 352 (43.2%) were classified as normal, and only 2 (0.6%) of these patients required urologic intervention. The results of 177 (21.7%) renal US procedures were suggestive of ureterolithiasis. Of these, 12 (6.8%) patients required urologic intervention. Of the 241 (29.5%) patients who had a ureteric stone seen on US, 15 (6.2%) required urologic intervention. The rate of urologic intervention was significantly lower in those with normal results on US (p < 0.001) than in those with abnormal results on US. Conclusion: A normal result on renal US predicts a low likelihood for urologic intervention within 90 days for adult ED patients with suspected urolithiasis.Keywords: renal colic, urolithiasis, urologic intervention, ultrasonography, emergency department RÉSUMÉObjectif : Le tomodensitogramme est une technique d'imagerie utilisée pour détecter les calculs rénaux. Cependant, on se préoccupe de l'exposition cumulative aux rayonnements associés aux appareils de tomodensitométrie. On utilise les échographies pour diagnostiquer l'urolithiase, évi-tant ainsi l'exposition aux rayonnements. L'objectif de cette étude était de déterminer la capacité des échographies à repérer les patients atteints de colique néphrétique et pré -sentant un faible risque de devoir subir une intervention urologique dans les 90 jours suivant leur visite à l'urgence. Méthodes : Nous avons réalisé une étude rétrospective des dossiers médicaux pour tous les patients adultes qui avaient subi, sur une période d'un an, une échographie rénale prescrite à l'urgence pour suspicion d'urolithiase. Nous avons procédé à l'extraction de données en double pour tous les rapports d'imagerie, et les résultats des échographies ont été classés ainsi : normaux, évocateurs d'une urolithiase, calcul rénal détecté, ou maladie non associée à une l'urolithiase. Nous avons examiné les dossiers médicaux pour déterminer combien de patients avaient subi ultérieurement une tomodensitométrie et une interventi...