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Background: An analytical benchmark for high-sensitivity cardiac troponin (hs-cTn) assays is to achieve a coefficient of variation (CV) of ≤ 10.0 % at the 99th percentile upper reference limit (URL) used for the diagnosis of myocardial infarction. Few prospective multicenter studies have evaluated assay imprecision and none have determined precision at the female URL which is lower than the male URL for all cardiac troponin assays., Methods: Human serum and plasma matrix samples were constructed to yield hs-cTn concentrations near the female URLs for the Abbott, Beckman, Roche, and Siemens hs-cTn assays. These materials were sent (on dry ice) to 35 Canadian hospital laboratories (n = 64 instruments evaluated) participating in a larger clinical trial, with instructions for storage, handling, and monthly testing over one year. The mean concentration, standard deviation, and CV for each instrument type and an overall pooled CV for each manufacturer were calculated., Results: The CVs for all individual instruments and overall were ≤ 10.0 % for two manufacturers (Abbott CV pooled  = 6.3 % and Beckman CV pooled  = 7.0 %). One of four Siemens Atellica instruments yielded a CV > 10.0 % (CV pooled  = 7.7 %), whereas 15 of 41 Roche instruments yielded CVs > 10.0 % at the female URL of 9 ng/L used worldwide (6 cobas e411, 1 cobas e601, 4 cobas e602, and 4 cobas e801) (CV pooled  = 11.7 %). Four Roche instruments also yielded CVs > 10.0 % near the female URL of 14 ng/L used in the United States (CV pooled  = 8.5 %)., Conclusions: The number of instruments achieving a CV ≤ 10.0 % at the female 99th-percentile URL varies by manufacturer and by instrument. Monitoring assay precision at the female URL is necessary for some assays to ensure optimal use of this threshold in clinical practice., Competing Interests: Declaration of Competing Interest The authors declare that they have no other/known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Objective: To identify individual and site-related factors associated with frequent emergency department (ED) buprenorphine/naloxone (BUP) initiation. BUP initiation, an effective opioid use disorder (OUD) intervention, varies widely across Canadian EDs., Methods: We surveyed emergency physicians in 6 Canadian provinces from 2018 to 2019 using bilingual paper and web-based questionnaires. Survey domains included BUP-related practice, demographics, attitudes toward BUP, and site characteristics. We defined frequent BUP initiation (the primary outcome) as at least once per month, high OUD prevalence as at least one OUD patient per shift, and high OUD resources as at least 3 out of the following 5 resources: BUP initiation pathways, BUP in ED, peer navigators, accessible addiction specialists, and accessible follow-up clinics. We excluded responses from sites with <50% participation (to minimize non-responder bias) and those missing the primary outcome. We used univariate analysis to identify associations between frequent BUP initiation and factors of interest, stratifying by OUD prevalence., Results: We excluded 3 responses for missing BUP initiation frequency and 9 for low response rate at one ED. Of the remaining 649 respondents from 34 EDs, 374 (58%) practiced in metropolitan areas, 384 (59%) reported high OUD prevalence, 312 (48%) had high OUD resources, and 161 (25%) initiated BUP frequently. Age, gender, board certification and years in practice were not associated with frequent BUP initiation. Site-specific factors were associated with frequent BUP initiation (high OUD resources [OR 6.91], high OUD prevalence [OR 4.45], and metropolitan location [OR 2.39],) as were individual attitudinal factors (willingness, confidence, and responsibility to initiate BUP.) Similar associations persisted in the high OUD prevalence subgroup., Conclusions: Individual attitudinal and site-specific factors were associated with frequent BUP initiation. Training to increase physician confidence and increasing OUD resources could increase BUP initiation and benefit ED patients with OUD., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 MacKinnon et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Over the last two decades, hundreds of new psychoactive substances (NPSs), also known as "designer drugs", have emerged on the illicit drug market. The toxic and potentially fatal effects of these compounds oblige laboratories around the world to screen for NPS in seized materials and biological samples, commonly using high-resolution mass spectrometry. However, unambiguous identification of a NPS by mass spectrometry requires comparison to data from analytical reference materials, acquired on the same instrument. The sheer number of NPSs that are available on the illicit market, and the pace at which new compounds are introduced, means that forensic laboratories must make difficult decisions about which reference materials to acquire. Here, we asked whether retrospective suspect screening of population-scale mass spectrometry data could provide a data-driven platform to prioritize emerging NPSs for assay development. We curated a suspect database of precursor and diagnostic fragment ion masses for 83 emerging NPSs and used this database to retrospectively screen mass spectrometry data from 12,727 urine drug screens from one Canadian province. We developed integrative computational strategies to prioritize the most reliable identifications and tracked the frequency of these identifications over a 3 year study period between August 2019 and August 2022. The resulting data were used to guide the acquisition of new reference materials, which were in turn used to validate a subset of the retrospective identifications. Last, we took advantage of matching clinical reports for all 12,727 samples to systematically benchmark the accuracy of our retrospective data analysis approach. Our work opens up new avenues to enable the rapid detection of emerging illicit drugs through large-scale reanalysis of mass spectrometry data.

Study Objective: Post-resuscitation prognostic biomarkers for out-of-hospital cardiac arrest (OHCA) outcomes have not been fully elucidated. We examined the association of acid-base blood values (pH) with patient outcomes and calculated the pH test performance to predict prognosis., Methods: This was a post-hoc analysis of data from the continuous chest compression trial, which enrolled non-traumatic adult emergency medical system-treated OHCA in Canada and the United States. We examined cases who survived a minimum of 24 h post hospital arrival. The independent variables of interest were initial pH, final pH, and the change in pH (δpH). The primary outcome was neurological status at hospital discharge, with favorable status defined as modified Rankin Scale (mRS) ≤ 3. We reported adjusted odds ratios for favorable neurological outcome using multivariable logistic regression models. We calculated the test performance of increasing pH thresholds in 0.1 increments to predict unfavorable neurological status (defined as mRS >3) at hospital discharge., Results: We included 4189 patients. 32% survived to hospital discharge with favorable neurological status. In the adjusted analysis, higher initial pH (OR 6.82; 95% CI 3.71-12.52) and higher final pH (OR 7.99; 95% CI 3.26-19.62) were associated with higher odds of favorable neurological status. pH thresholds with highest positive predictive values were initial pH < 6.8 (92.5%; 95% CI 86.2 %-98.8%) and final pH < 7.0 (100%; 95% CI 95.2 %-100%)., Conclusion: In patients with OHCA, pH values were associated with patients' subsequent neurological status at hospital discharge. Final pH may be clinically useful to predict unfavorable neurological status at hospital discharge., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Background: Certain subgroups of patients with out-of-hospital cardiac arrest (OHCA) may not benefit from treatment. Early identification of this cohort in the prehospital (EMS) setting prior to any resuscitative efforts would prevent futile medical therapy and more appropriately allocate EMS and hospital resources. We sought to validate a clinical criteria from Bokutoh, Japan that identified a subgroup of OHCAs for whom withholding resuscitation may be appropriate., Methods: We performed a secondary analysis of the "Trial of Continuous or Interrupted Chest Compressions during CPR", which enrolled EMS-treated adult non-traumatic OHCA. We classified patients as per the Bokutoh criteria ("Bokutoh Positive": age ≥ 73, unwitnessed arrest, non-shockable initial rhythm) and calculated test performance for the primary outcome of favourable neurologic outcome (mRS ≤ 3) at hospital discharge. We calculated the number of EMS-hours and hospital days per patient with a favourable neurologic outcome., Results: Of 26,148 patients in the parent trial, 5442 (21%) were "Bokutoh Positive", among whom 0.51% (95% CI 0.35- 0.75%) had favourable neurologic outcomes, and 1.2% (95% CI 0.92-1.5%) survived. The positive predictive value was 0.995 (95% CI 0.992-0.997). EMS and hospital-based resource utilization per favourable neurological outcome was 91 h and 199 days for in the "Bokutok Positive" group, respectively, and 5.7 h and 33 hospital days in the "Bokutok Negative" group., Conclusion: In this validation of the Bokutoh criteria in a large North American cohort of OHCA patients, 0.51% meeting criteria had favourable neurological outcomes. This may rapidly and reliably identify the one-fifth of OHCA who are very unlikely to benefit from resuscitation., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: Previous studies have demonstrated that earlier epinephrine administration is associated with improved survival from out-of-hospital cardiac arrest (OHCA) with shockable initial rhythms. However, the effect of epinephrine timing on patients with nonshockable initial rhythms is unclear. The objective of this study was to measure the association between time to epinephrine administration and survival in adults and children with emergency medical services (EMS)-treated OHCA with nonshockable initial rhythms., Methods: We performed a secondary analysis of OHCAs prospectively identified by the Resuscitation Outcomes Consortium network from June 4, 2011, to June 30, 2015. We included patients of all ages with an EMS-treated OHCA and an initial nonshockable rhythm. We excluded those with return of spontaneous circulation in <10 minutes. We conducted a subgroup analysis involving patients <18 years of age. The primary exposure was time (minutes) from arrival of the first EMS agency to the first dose of epinephrine. Secondary exposure was time to epinephrine dichotomized as early (<10 minutes) or late (≥10 minutes). The primary outcome was survival to hospital discharge. We adjusted for Utstein covariates and Resuscitation Outcomes Consortium study site., Results: From 55 568 EMS-treated OHCAs, 32 101 patients with initial nonshockable rhythms were included. There were 12 238 in the early group, 14 517 in the late group, and 5346 not treated with epinephrine. After adjusting for potential confounders, each minute from EMS arrival to epinephrine administration was associated with a 4% decrease in odds of survival for adults, odds ratio=0.96 (95% confidence interval, 0.95-0.98). A subgroup analysis (n=13 290) examining neurological outcomes showed a similar association (adjusted odds ratio, 0.94 per minute; 95% confidence interval, 0.89-0.98). When epinephrine was given late in comparison with early, odds of survival were 18% lower (odds ratio, 0.82; 95% confidence interval, 0.68-0.98). In a pediatric analysis (n=595), odds of survival were 9% lower (odds ratio, 0.91; 95% confidence interval, 0.81-1.01) for each minute delay in epinephrine., Conclusions: Among OHCAs with nonshockable initial rhythms, the majority of patients were administered epinephrine >10 minutes after EMS arrival. Each minute delay in epinephrine administration was associated with decreased survival and unfavorable neurological outcomes. EMS agencies should consider strategies to reduce epinephrine administration times in patients with initial nonshockable rhythms., (© 2018 American Heart Association, Inc.)

Objectives: This retrospective chart audit examined the demographics, investigations, management and outcomes of adult patients with diabetes mellitus presenting to Canadian emergency departments (EDs)., Methods: All sites conducted a search of their electronic medical records using International Classification of Diseases, Tenth Revision, codes to identify ED visits for hypoglycemia between 2008 and 2010. Patient characteristics, demographics, ED management, ED resources and outcome are reported., Results: A total of 1039 patients over the age of 17 years were included in the study; 347 (33.4%) were classified as type 1 diabetes and 692 (66.6%) were classified as type 2 diabetes. Type 2 diabetes patients were significantly older (73 vs. 49 years; p<0.0001) and had more chronic conditions recorded on their chart (all p<0.001). Most subjects arrived by ambulance, and triage scores revealed severe presentations in 39% of cases. Treatments for hypoglycemia were common (75.7%) during prehospital transport; 38.5% received intravenous glucose and 40.1% received glucagon. Hypoglycemia treatments in the ED included oral (76.8%), intravenous (29.6%) and continuous infusion (27.7%) of glucose. Diagnostic testing (81.9%) commonly included electrocardiograms (51.9%), chest radiography (37.5%) and head computed tomography scans (14.5%). Most patients (73.5%) were discharged; however, more subjects with type 2 diabetes required admission (30.3 vs. 8.8%). Discharge instructions were documented in only 55.5% of patients, and referral to diabetes services occurred in fewer than 20% of cases. Considerable variation existed in the management of hypoglycemia across EDs., Conclusions: Patients with diabetes presenting to an ED with hypoglycemia consume considerable healthcare resources, and practice variation exists. Emergency departments should develop protocols for the management of hypoglycemia, with attention to discharge planning to reduce recurrence., (Copyright © 2015 Canadian Diabetes Association. Published by Elsevier Inc. All rights reserved.)