Introduction: Most ambulance communication officers receive minimal education on agonal breathing, often leading to unrecognized out-of-hospital cardiac arrest (OHCA). We sought to evaluate the impact of an educational program on cardiac arrest recognition, and on bystander CPR and survival rates. Methods: Ambulance communication officers in Ottawa, Canada received additional training on agonal breathing, while the control site (Windsor, Canada) did not. Sites were compared to their pre-study performance (before-after design), and to each other (concurrent control). Trained investigators used a piloted-standardized data collection tool when reviewing the recordings for all potential OHCA cases submitted. OHCA was confirmed using our local OHCA registry, and we requested 9-1-1 recordings for OHCA cases not initially suspected. Two independent investigators reviewed medical records for non-OHCA cases receiving telephone-assisted CPR in Ottawa. We present descriptive and chi-square statistics. Results: There were 988 confirmed and suspected OHCA in the “before” (540 Ottawa; 448 Windsor), and 1,076 in the “after” group (689 Ottawa; 387 Windsor). Characteristics of “after” group OHCA patients were: mean age (68.1 Ottawa, 68.2 Windsor); Male (68.5% Ottawa, 64.8% Windsor); witnessed (45.0% Ottawa, 41.9% Windsor); and initial rhythm VF/VT (Ottawa 28.9, Windsor 22.5%). Before-after comparisons were: for cardiac arrest recognition (from 65.4% to 71.9% in Ottawa p=0.03; from 70.9% to 74.1% in Windsor p=0.37); for bystander CPR rates (from 23.0% to 35.9% in Ottawa p=0.0001; from 28.2% to 39.4% in Windsor p=0.001); and for survival to hospital discharge (from 4.1% to 12.5% in Ottawa p=0.001; from 3.9% to 6.9% in Windsor p=0.03). “After” group comparisons between Ottawa and Windsor (control) were not statistically different, except survival (p=0.02). Agonal breathing was common (25.6% Ottawa, 22.4% Windsor) and present in 18.5% of missed cases (15.8% Ottawa, 22.2% Windsor p=0.27). In Ottawa, 31 patients not in OHCA received chest compressions resulting from telephone-assisted CPR instructions. None suffered injury or adverse effects. Conclusion: While all OHCA outcomes improved over time, the educational intervention significantly improved OHCA recognition in Ottawa, and appeared to mitigate the impact of agonal breathing.

Introduction: This study aims to describe the long-term functional outcome and health-related quality of life of elderly (≥65 years old) out-of-hospital cardiac arrest (OHCA) survivors in Victoria, Australia. Methods: Elderly OHCA patients who arrested between January 1st, 2010 and December 31st, 2014 were identified from the Victorian Ambulance Cardiac Arrest Registry (VACAR). Living status, Glasgow Outcome Scale-Extended (GOS-E), Euro-QoL (EQ-5D) and Twelve-item Short Form (SF-12) Health Survey were collected by telephone 12 months following the OHCA. Results: Emergency medical services attended on 14,678 elderly OHCA during the study period, 6,851 (46.7%) of which received a resuscitation attempt. Of these, 668 patients (9.8%) survived to hospital discharge. The mean age of the survivors was 75 (standard deviation (SD) 7.4) years and 504 (75.4%) were male. Eighty-five patients subsequently died within 12 months of their OHCA. A total of 483 patients were interviewed (response rate 82.9%). At 12 months, 313 responders (64.9%) were living at home without care. Most responders (n=324 (67.2%)) had a good long-term functional recovery with a GOS-E ≥7. The proportion of patients with a GOS-E≥7 progressively decreased with increasing age (65-74 years: 66.1%, 75-84 years: 53.0%,≥85 years: 27.3%). On the EQ-5D, the majority of survivors reported no problem with mobility (n=266 (55.1%)), self-care (n=403 (83.4%)), activity (n=293 (60.6%)), pain (n=335 (69.3%)) and anxiety (n=358 (74.1%)). On the SF-12, the mean mental component summary was 56.3 (SD 6.6) while the mean physical component summary was 44.7 (SD 11.4) (both measures range from 0-100). Among the 1,951 patients who arrested in a supported accommodation, 849 (43.5%) had a resuscitation attempt, and of these, 21 survived to hospital discharge (2.5%). Only eight (1.0%) of these patients were still alive 12 months after the OHCA and one survivor (0.12%) had a good functional outcome (GOS-E≥7). Conclusion: Most elderly OHCA survivors have an adequate long-term functional status and health-related quality of life. However, the likelihood of having a good functional recovery decreases with increasing age, and is rare for patients arresting in a supported accommodation.

Introduction: Sodium bicarbonate (SB) is still widely used for resuscitation in out-of- hospital cardiac arrest (OHCA) despite limited clinical indications but the effect on neurological recovery is unclear. Methods: From 2006 to 2016, we prospectively conducted a province-wide population-based observational study of adult non-traumatic OHCA patients managed by EMS. According to provincial guidelines, paramedics administered SB to OHCA patients based on their clinical assessment. Outcome of interest was favorable neurological outcome at hospital discharge, defined as CPC of 1 and 2 or modified Rankin scale of 3 or less. We performed multivariable logistic regression, comparing the proportion of outcome between SB and non-SB groups, further stratified by the median of the length of resuscitation. We also applied propensity score matching technique adjusting for baseline characters to the same model to reduce potential selection bias. Results: Of 13,008 OHCA patients, 4,699 (36.1%) were managed with SB. In the SB treated group, 64 / 4,699 (1.3%) patients had favorable neurological outcomes, compared to 823 / 8,309 (9.9%) in the non-SB treated group (crude odds ratio [OR] 0.12, 95% CI 0.09 to 0.16). In logistic regression model, SB was associated with decreased probability of favorable outcomes (adjusted OR 0.63, 95% CI 0.45 to 0.89). Similarly, with stratification by length of resuscitation, the SB group had a lower probability of favorable outcomes (≦24 min: adjusted OR 0.68, 95% CI 0.46 to 1.02, >24 min: adjusted OR 0.47, 95% CI 0.23 to 0.97). In 1:1 propensity matched cohort including 5,126 OHCA patients, the adjusted association also persisted (adjusted OR 0.59, 95% CI 0.39 to 0.89). Conclusion: Prehospital administration of SB to OHCA patients was associated with worse neurological outcomes and the trend persisted even after stratification by resuscitation length.

Introduction: The Canadian Triage and Acuity Scale (CTAS) is the standard used in all Canadian (and many international) emergency departments (EDs) for establishing the priority by which patients should be assessed. In addition to its clinical utility, CTAS has become an important administrative metric used by governments to estimate patient care requirements, ED funding and workload models. Despite its importance, the process by which CTAS scores are derived is highly variable. Emphasis on ED wait times has also drawn attention to the length of time the triage process takes. The primary objective of this study was to determine the interrater agreement of CTAS in current clinical practice. The secondary objective was to determine the time it takes to triage in a variety of ED settings. Methods: This was a prospective, observational study conducted in 7 hospital EDs, selected to represent a mix of triage processes (electronic vs. manual), documentation practices (electronic vs. paper), hospital types (rural, community and teaching) and patient volumes (annual ED census ranged from 38,000 to 136,000). An expert CTAS auditor observed on-duty triage nurses in the ED and assigned independent CTAS in real time. Research assistants not involved in the triage process independently recorded the triage time. Interrater agreement was estimated using unweighted and quadratic-weighted kappa statistics with 95% confidence intervals (CIs). Results: 738 consecutive patient CTAS assessments were audited over 21 seven-hour triage shifts. Exact modal agreement was achieved for 554 (75.0%) patients. Using the auditor’s CTAS score as the reference standard, on-duty triage nurses over-triaged 89 (12.1%) and under-triaged 95 (12.9%) patients. Interrater agreement was “good” with an unweighted kappa of 0.63 (95% CI: 0.58, 0.67) and quadratic-weighted kappa of 0.79 (95% CI: 0.67, 0.90). Research assistants captured triage time for 3808 patients over 69 shifts at 7 different EDs. Median (IQR) triage time was 5.2 (3.8, 7.3) minutes and ranged from 3.9 (3.1, 4.8) minutes to 7.5 (5.8, 10.8) minutes. Conclusion: Variability in the accuracy, and length of time taken to perform CTAS assessments suggest that a standardized approach to performing CTAS assessments would improve both clinical decision making, and administrative data accuracy.

Introduction: The use of procedural sedation and analgesia (PSA) for the performance of Emergency Department (ED) procedures has been reported to be safe and effective. However, few studies have evaluated the safety of PSA in the elderly, with conflicting results. Our primary objective was to determine if elderly patients undergoing PSA for the management of an orthopedic injury had an increased risk of adverse events (AEs) during the procedure. Methods: This retrospective review of prospectively recorded data between 2006 and 2016 included patients aged ≥16 years undergoing PSA at a single institution to facilitate treatment of a fracture or dislocation. Patients were separated into 3 age groups for analysis: young (18-40), middle-aged (41-64) and elderly (≥65). Elderly patients were divided into 3 subgroups. The primary AEs studied include hypoxia (SpO2<90 %) and hypotension (systolic blood pressure <100 mmHg, or >15% reduction from baseline if initial <100 mmHg). Logistic regression (LR) models tested for associations between age and outcome measurements. Effect sizes were described as odds ratios (OR) and 95% confidence intervals. Results: 4171 patients were studied, including 1125 patients ≥65 years of age. More than 90% of the time, propofol was used as a single agent sedative. Fentanyl was given as an analgesic adjunct in 88% of patients. Medication dosing declined as patients aged. In the young group, the average total propofol dose was 2.34 mg/kg compared to 1.42 mg/kg in the elderly (≥85 years subgroup: 1.07 mg/kg). Despite this, hypoxia was more likely to occur in elderly patients (2.3%) compared to younger patients (0.4%). LR models demonstrated that hypoxia was more likely to occur in: the elderly [OR 4.29 (1.58,11.70)], patients with an ASA classification score of 3 or higher [OR 4.71 (1.89,11.70)], and higher dosing of fentanyl in the elderly [OR 2.35 (1.21,4.57)]. Oral or nasal airway, assisted ventilation, and suctioning were required in less than 1% of all patients. Endotracheal intubation was never required. Hypotension was more likely in elderly patients (11.6%) than younger patients (8.3%). Conclusion: When performing PSA, clinicians should be aware of the increased risk of AEs in the elderly, particularly hypoxia, and modify selection, dosing, and administration of the PSA medication(s) appropriately. Future study should examine the intermediate and long-term outcomes of elderly patients following ED PSA.

Introduction: The Geriatric Emergency Management (GEM) model has been developed to facilitate identification of older patients that are at higher risk of functional decline, repeat Emergency Department (ED) visits and future hospitalization. Those identified at risk, are referred for more in-depth evaluation and management in community-based specialized geriatric services. Our objective was to: 1) determine the compliance rate to outpatient evaluation following ED recommendation; and 2) identify barriers and facilitators to attendance. Methods: We conducted a prospective cohort study at two sites of an academic, tertiary level hospital ED between July and December 2016. We enrolled a convenience sample of ED patients, 65 years and older who were seen by a GEM nurse, referred to outpatient specialized geriatric services and consented to study participation. The GEM nurses conducted targeted geriatric assessments, identifying those who would benefit from further community management. We conducted a chart review and a structured telephone follow-up at 6 weeks. Descriptive statistics were used. Results: A total of 101 patients were prospectively enrolled, with 30.4% of eligible participants declining outpatient referral. Enrolled subjects had a mean age of 83.3 years, 58.4% female and 62.0% cognitively impaired. Reasons for referral to specialized geriatric services included: mobility (86.1%), cognition (57.4%), pain (38.6%), mood (34.7%), medication management (33.6%) and nutrition (30.7%). Outpatient referrals were to: geriatric day hospital (51.5%), geriatric outreach (22.7%), falls clinic (11.8%) and geriatric psychiatry (9.9%). Compliance with follow-up within 6 weeks was 64.4%. Barriers to attendance included: patient did not feel specialized geriatric services was needed (52.6%); admitted to hospital (10.5%); reported not called for appointment (15.8%); forgot appointment (5.3%) and transportation (5.3%). Family support with scheduling and transportation to appointments, reported by 68.6%, was the most common enabler to compliance. Conclusion: Over one third of older ED patients referred by GEM for further specialized geriatric services are non-compliant with their community-based evaluation, while one in four older ED patients decline referral to these evaluations while in the ED. Future work should focus on interventions that promote increased referral acceptance and address barriers to attendance.

Introduction: The Clinical Frailty Scale (CFS) has been validated internationally to predict adverse outcomes and mortality. Frailty assessments in the Emergency Departments (ED) are challenging to due to a lack of training and time. We studied the use of a tablet-based CFS that used graphics and short descriptors to assist choice of the 9 frailty categories. Methods: We conducted a prospective observational cohort study of people >65 years seen in the ED of 3 Canadian academic centers. We excluded critically ill patients, and those with significant visual impairment or inability to communicate in English or French. We compared agreement on the tablet-based CFS between 4 categories of assessors: Patients, ED Physicians, trained Research Assistance and Caregivers using the kappa statistic. Results: We enrolled 274/380 eligible patients who provided complete data (72.1%). Their average age was 75.8 years, and 48.9% were female. Their median MOCA score was 23/30 (IQR=17-26) and their median OARS was 26/28 (IQR 22-28). Agreement between physicians and research assistants was good (κ=0.60, 95% CI 0.50-0.70), as was physician-caregiver agreement and patient-caregiver agreement (κ=0.66, 95% CI 0.40-0.93). Agreement between physicians and patients was only moderate (κ=0.47, 95% CI 0.36-0.58). Conclusion: There was less agreement between physicians and patient self-assessments for the CFS compared to physicians-research assistant agreement and care-giver patient assessments of frailty. Future research should validate whether MD, patient, or caregiver rated CFS have higher predictive validity.

Introduction: It remains unclear whether widespread use of computed tomography angiography (CTA) in acute strokes and transient ischemic attacks (TIAs) has tangible benefits for patient outcomes or management. We conducted a systematic review and meta-analysis of observational studies and randomized controlled trials (RCTs) investigating the use of CTA and patient-important outcomes (recurrent stroke, mortality, disability, and emergency department (ED) revisits) or changes in management in patients presenting with acute stroke or TIA. PROSPERO: 349590 Methods: MEDLINE, EMBASE, and the Cochrane Registry were searched through May 24, 2016 for eligible trials. We included observational cohort studies and RCTs evaluating use of CTA against a control group for outcomes of interest in patients presenting acutely with suspected stroke or TIA. Two independent reviewers extracted data and assessed study quality using the Newcastle Ottawa Scale. Data for mortality and stroke rate were pooled by the generic inverse variance method and expressed as risk ratios (RRs) with 95% confidence intervals (95% CI). Data for disability were reported as the mean difference (MD) and 95% CI. Heterogeneity was assessed using the Cochran’s Q statistic and quantified by the I2 statistic. Overall strength of the evidence was assessed by the GRADE approach. Results: Three observational cohort studies involving 979 patients over an average of 1 year follow up met inclusion criteria; there were no eligible RCTs. CTA use in acute stroke or TIA patients was associated with a decreased mortality rate (RR=0.55, 95% CI 0.33 to 0.91, P=0.02; Phet=0.88, I2=0%). No changes were detected in stroke rate (RR=0.84, 95% CI 0.40 to 1.73, P=0.63; Phet=0.79, I2=0%). One study with data for disability showed no changes in mRS (MD=0.01, 95% CI -0.70 to 0.73, P=0.97). There were no eligible studies with data for ED revisits or changes in management. The strength of the evidence was assessed as very low quality due to imprecision for mortality, stroke rate, and disability. Conclusion: CTA use was associated with significantly reduced mortality in acute stroke and TIA patients, possibly due to confounding from poor baseline status of patients not receiving CTA. No significant changes were found for stroke rate or disability. There is a need for RCTs to confirm the effects of CTA use on patient outcomes and management.

Introduction: Most acute asthma presentations to the emergency department (ED) are uncomplicated and do not require chest radiographs (CXR). Evidence suggests that the proportion of acute asthma patients receiving CXRs in the ED is high and varies substantially within and across sites and studies. This study explored CXR ordering and variation in acute asthma presentations to Alberta’s EDs. Methods: Administrative health data for Alberta was obtained from the National Ambulatory Care Reporting System (NACRS) for all adult (>17 years) acute asthma (ICD-10-CA: J45) ED visits from 2011-2015. Patients with a primary or secondary diagnosis of asthma were included, provided they had a Canadian Triage and Acuity Scale score of 2-5. NACRS data were linked with Alberta Health Services’ (AHS) diagnostic imaging database. Preliminary analysis on variation in imaging at the zone, ED site, and physician level was completed using SAS (v.9.4). Physicians who saw less than an average of 10 asthma patients per year were excluded. Results: Overall, 51,511 acute asthma ED presentations occurred (~10,000/year). The average proportion of CXRs among presentations was 39.5% (2011-2015) with an average annual increase of 6.7%. From 2011-2015, CXR ordering varied across the five AHS zones (variation [V]: 25%; range: 26.0%-51.0%). Substantial variation was observed across ED sites V: 60%; range: 5.9-66.4%) and physicians (V: 89%; range: 1.4-90.6%). The mean CXR ordering among physicians was 44%. Conclusion: From 2011-2015, CXR use among acute asthma ED presentations has increased. Substantial variation in CXR use suggests that evidence-based interventions are needed to improve imaging appropriateness.

Introduction: Diagnosing pulmonary embolism (PE) can be challenging because the signs and symptoms are often non-specific. Studies have shown that evidence-based diagnostic algorithms are not always adhered to in the Emergency Department (ED), which leads to unnecessary CT scanning. In 2013, the American College of Chest Physicians identified CT pulmonary angiography as one of the top five avoidable tests. One solution is to use a clinical prediction rule combined with the D-dimer, which safely reduces the use of CT scanning. The objective of this study was to compare the proportion of patients tested for PE in two emergency departments, who 1) had a CT-PE and 2) whose diagnosis of PE was missed. We compared these rates to those if the Wells rule and D-dimer had been applied as standard. Methods: This was a retrospective chart review of ED patients investigated for PE at two hospitals from April 2013 to March 2015 (24 months). Inclusion criteria were the ED physician ordered CT-PE, Ventilation-Perfusion (VQ) scan or D-dimer for investigation of PE. Patients under the age of 18 were excluded. PE was defined as CT/VQ diagnosis of acute PE or acute PE/DVT in 30-day follow-up. Trained researchers extracted anonymized data. The rate of CT/VQ imaging and the false-negative rates were calculated. The false-negative rate was calculated as the number of patients diagnosed with PE within 30 days as a proportion of those patients who did not have a CT/VQ scan at initial presentation. Results: There were 1,189 patients included in this study. 55/1,189 patients (4.6%; 95%CI 3.6-6.0%) were ultimately diagnosed with PE within 30 days. 397/1,189 patients (33.4%; 95%CI 30.8-36.1%) had CT/VQ scans for PE. 3 out of 792 who were not scanned had a missed PE resulting in a false-negative rate of 0.4% (95% CI 0.1-1.1%). 80 patients had an elevated D-dimer or high Wells score but were not imaged. Furthermore, 75 patients who did not have an elevated D-dimer nor a high Wells score were imaged. Had Wells rule/D-dimer been adhered to, 402/1,189 patients (33.8%; 95%CI 31.9-36.6%) would have undergone imaging and the false negative rate would be 0/727, 0% (95%CI 0.0-0.5%). Conclusion: If the Wells rule and D-dimer was used in all patients tested for PE, a similar proportion would have a CT scan but fewer PEs would be missed.

Introduction: Point-of-care ultrasound (POCUS) has been suggested as an initial investigation in the management of renal colic. Our objectives were: 1) to determine the accuracy of POCUS for the diagnosis of nephrolithiasis, and 2) to assess its prognostic value in the management of renal colic (PROSPERO: 42016035331). Methods: An electronic database search of MEDLINE, EMBASE, and PubMed was conducted utilizing subject headings, keywords, and synonyms that address our research question. Bibliographies of included studies and narrative reviews were manually examined. Studies of adult emergency department patients with renal colic symptoms were included. Any degree of hydronephrosis was considered a positive POCUS finding. Accepted criterion standards were CT evidence of renal stone or hydronephrosis, direct stone visualization, or surgical findings. Screening of abstracts, quality assessment with the QUADAS-2 instrument, and data extraction were performed by two reviewers, with discrepancies resolved by conference with a third reviewer.Test performance was assessed by pooled sensitivity and specificity, calculated likelihood ratios, and a summary receiver operator curve (SROC). The secondary outcome of prognostic value was reported as a narrative summary. Results: The electronic search yielded 627 unique titles. After relevance screening, 25 papers underwent full-text review, and 8 articles met all inclusion criteria. Of these, 5 high-quality studies (N=1773) were included in the meta-analysis for diagnostic accuracy, and three yielded data on prognostic value. The pooled results for sensitivity and specificity were 70.2% (95% CI=67.1% to 73.2%) and 75.4% (95% CI=72.5% to 78.2%), respectively. The calculated positive and negative likelihood ratios were 2.85 and 0.39. The SROC generated did not show evidence of a threshold effect.Three studies examining prognostic value noted a higher likelihood of a large stone or surgical intervention with positive POCUS findings. The largest randomized trial showed lower cumulative radiation exposure and no increase in adverse events in those who received POCUS investigation as the initial renal colic investigation. Conclusion: Point-of-care ultrasound is of modest accuracy for the diagnosis of nephrolithiasis. While positive POCUS findings are associated with larger stones and greater likelihood for intervention, the clinical importance of this is unclear.

Introduction: Unnecessary imaging of adult cervical spine (C-spine) injury patients in the Emergency Department (ED) is a concern. Guidance for C-spine image ordering exists; however, the effectiveness and safety of their implementation in the ED is not well studied. This review examines their implementation and effectiveness at reducing C-spine imaging in adults presenting to the ED with stable neck trauma. Methods: Six electronic databases and the grey literature were searched. Comparative studies examining interventions to reduce C-spine imaging were eligible for inclusion. Two independent reviewers screened for study eligibility, assessed study quality, and extracted data. Data were analyzed using RevMan (Version 5.3) to explore the effectiveness of these interventions in safely reducing C-Spine radiography. Results: A total of 848 unique citations were screened of which six before-after studies and one randomized controlled trial were included. The study population varied with respect to injury severity (i.e., stability status). None of the studies were assessed as high quality. The interventions employed included locally developed guidelines and clinical decision rules, specifically the National X-radiography Utilization Study (NEXUS) criteria and the Canadian C-Spine Rule (CCR). Various implementation strategies, such as teaching sessions, pocket reminder cards, posters and computerized decision support were used. Several studies used multi-faceted interventions. Overall, of the five study groups that examined change in x-ray ordering, three groups reported a significant reduction in c-spine radiography. The remaining two showed no change in imaging. A pooled estimate of the effectiveness of the interventions was prohibited by significant heterogeneity. Conclusion: The evidence regarding the effectiveness of interventions to reduce C-spine imaging in adult ED patients with stable neck trauma is inconclusive. Given the national and international focus on improving appropriateness and reducing unnecessary imaging through campaigns such as Choosing Wisely®, additional interventional research in this field is warranted.

Introduction: Headaches are a common emergency department (ED) presentation. Evidence demonstrates that computed tomography (CT) imaging varies significantly within and across sites. This study explored CT ordering and variation among headache presentations across Alberta EDs. Methods: Administrative health data for Alberta were obtained from the National Ambulatory Care Reporting System (NACRS) for all adult (>17 years) headache (ICD-10-CA: G44, G43, R51) ED visits from 2011-2015. Patients with a primary or secondary diagnosis code of headache were included. Exclusions were: sites without CT scanners, Canadian Triage and Acuity Scale score of 1, patients with trauma or external mechanism of injury (e.g., ICD-10-CA S,T,V,W,X,Y), or enhanced/contrast CTs. NACRS data were linked with Alberta Health Services’ (AHS) diagnostic imaging data. Preliminary analysis on imaging variation at the zone, ED site, and physician level was completed using SAS (v.9.4). Physicians who saw less than an average of 10 headache patients per year were excluded. Results: Overall, 98,804 headache presentations were recorded (~20,000/year; 8.5% average annual increase) in 30 EDs. The average proportion of visits receiving CT was 25.1% with an average 6.2% increase per year. CT ordering varied across AHS zones (Variation [V]:23%; range:9.6-32.7%). Site ordering variation was more dramatic (V:45%; range:1.4-46.5%). The greatest variation was observed among physicians (V:84 %; range: 0.0-83.7%) with mean ordering proportion of 28.7%. Conclusion: From 2011-2015, headache presentations and CT imaging for these patients in the ED increased. Substantial variation in CT ordering exists at multiple levels in Alberta. Further exploration of CT appropriateness is urgently needed.

Introduction: Computerized tomography for pulmonary embolism (CTPE) has come under increased scrutiny with recommendations for evidence-based use found on Choosing Wisely lists in both Canada and the US. However practice variation in ordering patterns and diagnostic yield have not been well-reported for the Canadian context. Our objective was to investigate practice variation in CTPE ordering and rule-in rates within a large group of specialty-trained emergency physicians. Methods: We undertook an analysis of a computerized physician order entry database from four tertiary care EDs covering a 12-month period from August 1, 2016 to July 30, 2016 with 31 419 visits for potential pulmonary embolism (PE) as determined by a previously validated algorithm based on presenting complaints. CTPE utilization and diagnostic yield were determined for 149 physicians who ordered at least 10 studies over that time period. Outcomes of interest included CT utilization as determined by electronic order entry and a confirmed diagnosis of PE based on ICD-10 coding of the emergency visit. Descriptive statistics using medians, IQR and 95% confidence intervals are reported. This study is approved through REB14-0650 and is a component of a larger cluster RCT to improve CTPE utilization. Results: During the study period 2670 CTPE studies were ordered for potential PE patients representing 8.5% of the total with relevant complaints. We observed a 10-fold variation in CTPE ordering among physicians with rates as low as 2.7% and as high as 25%. The median rate of CTPE ordering for potential PE was 8.8% with an IQR of 6.0% to 11.7%. A total of 4146 CTPE studies were ordered during the study period with physicians ordering an average of 28 CTPE studies each; range 10-90. In terms of diagnostic yield, 591/4146 studies, or 14.3% (95% CI 13.2-15.3%) were associated with a diagnosis of PE. Diagnostic yield per physician ranged from 0 to 50%, with a median of 13.5% and an IQR of 7.6% to 21.4%. Conclusion: In this large, robust administrative dataset from four Canadian urban EDs, threshold for CTPE ordering varies widely among physicians as does diagnostic yield. Efforts to improve appropriate utilization are justified with an eye to reducing unnecessary radiation, costs and incidental findings.

Introduction: Computed tomography (CT) has increasingly been used as a standard initial investigation for patients presenting to the Emergency Department (ED) with suspected nephrolithiasis. Compared to ultrasound, CT has increased system-level costs, ionizing radiation exposure and frequently does not alter management. For these reasons, Choosing Wisely (CW) recommends avoiding CT imaging of otherwise healthy patients younger than age 50 years presenting with symptoms of uncomplicated renal colic that have a known history of nephrolithiasis or ureterolithiasis. We aimed to evaluate the degree of utilization of CT imaging for this subgroup of patients in a tertiary care centre ED. Methods: A retrospective chart review was performed for all patients younger than 50 years who visited Sunnybrook Health Sciences Centre ED for six months between December 2015 and May 2016 with renal colic symptoms and a history of nephrolithiasis. Demographic data, relevant past medical history, clinical presentation, lab values, urology consultation, ED treatments administered, diagnostic imaging orders and dispositions were recorded for each eligible patient. Results: Out of 130 reviewed patient charts, 73 patients were identified with a previous history of nephrolithiasis and a presentation consistent with uncomplicated renal colic. 54 patients received ultrasound, KUB x-ray, or no imaging. The other 19 (26.0%) of these patients received an abdominal/pelvic CT with an indication of looking for renal or ureteral stones. Of the patients that received CT, none demonstrated significant findings warranting hospital admission or leading to identifiable changes in ED management. Five (26.3%) of these 19 patients had received a total of three to four CTs for renal colic during past Sunnybrook ED visits, while one had previously received 13 CTs. Conclusion: CT scans are often used as an initial diagnostic modality for suspected renal colic despite a Choosing Wisely recommendation to restrict the use of CT scans in a target population and infrequent changes in management after obtaining a CT. These findings highlight the need for quality improvement strategies to decrease CT utilization in this patient population with suspected renal colic.

Introduction: Canadian stroke best practice guidelines recommend patients suspected of Acute Cerebrovascular Syndrome (ACVS) receive urgent brain imaging, preferably CTA. Yet, high requisition rates for non-ACVS patients overburdens limited radiological resources. We hypothesize that our clinical prediction rule (CPR) previously developed for diagnosis of ACVS in the emergency department (ED), and which incorporates Canadian guidelines, could improve CTA utilization. Methods: Our data consists of records for 1978 ED-referred patients to our TIA clinic in Victoria, BC from 2015-2016. Clinic referral forms captured all data needed for the CPR. For patients who received CTA, orders were placed in the ED or at the TIA clinic upon arrival. We use McNemar’s test to compare the sensitivity (sens) and specificity (spec) of our CPR vs. the baseline CTA orders for identifying ACVS. Results: Our sample (49.5% male, 60.6% ACVS) has a mean age of 70.9±13.6 yrs. Clinicians ordered 1190 CTAs (baseline) for these patients (60%). Where CTA was ordered, 65% of patients (n=768) were diagnosed as ACVS. To evaluate our CPR, predicted probabilities of ACVS were computed using the ED referral data. Those patients with probabilities greater than the decision threshold and presenting with at least one focal neurological deficit clinically symptomatic of ACVS were flagged as would have received a CTA. Our CPR would have ordered 1208 CTAs (vs. 1190 baseline). Where CTA would have been ordered, 74% of patients (n=893) had an ACVS diagnosis. This is a significantly improved performance over baseline (sens 74.5% vs. 64.1%, p<0.001; spec 59.6% vs. 45.9%, p<0.001). Specifically, the CPR would have ordered an additional 18 CTAs over the 2-yr period, while simultaneously increasing the number of imaged-ACVS patients by 125 with imaging 107 fewer non-ACVS patients. Conclusion: Using ED physician referral data, our CPR demonstrates significantly higher sensitivity and specificity for CTA imaging of ACVS patients than baseline CTA utilization. Moreover, our CPR would assist ED physicians to apply and practice the Canadian stroke best practice guidelines. ED physician use of our CPR would increase the number of ACVS patients receiving CTA imaging before ED discharge (rather than later at TIA clinics), and ultimately reduce the burden of false-positives on radiological departments.

Introduction: Previous studies have suggested that emergency physicians (EP) highly experienced in point-of-care ultrasound (POCUS) have similar performance to formal ultrasound to identify appendicitis in children. The aim of this study was to evaluate the ability of EP with various levels of POCUS experience to detect appendicitis with POCUS among children visiting a pediatric ED. Methods: A prospective cohort study was conducted in an urban, tertiary care pediatric ED. Children aged 2 to 18 years old who presented to the ED with acute abdominal pain suggesting appendicitis were included. Patients were excluded if they had a history of appendectomy, hemodynamic instability requiring resuscitation, or were transferred with proven diagnosis of appendicitis. Participating EP had various levels of POCUS experience. Four of the 22 physicians were experienced in bowel sonography (EDU 2 level and higher) while the others were inexperienced in bowel sonography (EDU 1). All the participants received a 1-hour didactical and practical training session on appendix ultrasound. The treating physician performed all POCUS following initial physical exam, before further radiological evaluation. Final outcomes were determined by pathology and/or operative reports for surgical cases, and telephone follow-up at 3 weeks for those who did not have surgery. The primary analysis was a simple proportion for sensitivity and specificity for POCUS. Expecting a sensitivity of 80% based on previous studies, we calculated that a sample size of 50 cases would provide a 95%CI ranging from 66 to 90%. Results: We approached 140 patients, of which 121 accepted to participate and were recruited. After excluding 4 patients for missing POCUS data, 117 patients were included in the primary analysis, of which 51 (44%) had appendicitis. Twenty-two EP performed between 1 and 20 POCUS. The POCUS identified 27 out of 51 appendicitis for a sensitivity of 0.53 (95%CI 0.40-0.66). A negative POCUS was reported for 54 out of 66 patients without appendicitis (specificity of 0.82; 95%CI 0.71-0.89). Conclusion: This study shows limited sensitivity and specificity of POCUS when performed by EP with various level of experience for appendicitis in children. While showing lower sensitivity and specificity than previous studies, the inclusion of a large number of physicians solidifies the external validity of our conclusion.

Introduction: Trauma code activation is initiated by emergency physicians using physiologic and anatomic criteria, mechanism of injury and patient demographic factors in conjunction with data obtained from emergency medical service personnel. This enables rapid definitive treatment of trauma patients. Our objective was to identify factors associated with delayed trauma team activation. Methods: We conducted a health records review to supplement data from a regional trauma center database. We assessed consecutive cases from the trauma database from January 2008 to March 2014 including all cases in which a trauma code was activated by an emergency physician. We defined a delay in trauma code activation as a time greater than 30 minutes from time to arrival to trauma team activation. Data were collected in Microsoft Excel and analyzed in Statistical Analysis System (SAS). We conducted univariate analysis for factors potentially influencing trauma team activation and we subsequently used multiple logistic regression analysis models for delayed activation in relation to mortality, length of stay and time to operative management. Results: 1020 patients were screened from which 174 patients were excluded, as they were seen directly by the trauma team. 846 patients were included for our analysis. 4.1% (35/846) of trauma codes were activated after 30 minutes. Mean age was 40.8 years in the early group versus 49.2 in the delayed group p=0.01. There was no significant difference in type of injury, injury severity or time from injury between the two groups. Patients were over 70 years in 7.6% in the early activation group vs 17.1% in the delayed group (p=0.04). 77.7% of the early group were male vs 71.4% in the delayed group (p=0.39). There was no significant difference in mortality (15.2% vs 11.4% p=0.10), median length of stay (10 days in both groups p=0.94) or median time to operative management (331 minutes vs 277 minutes p=0.52). Conclusion: Delayed activation is linked with increasing age with no clear link with increased mortality. Given the severe injuries in the delayed cohort which required activation of the trauma team further emphasis on the older trauma patient and interventions to recognize this vulnerable population should be made. When assessing elderly trauma patients emergency physicians should have a low threshold to activate trauma teams.

Introduction: Trauma teams have been shown to improve outcomes in severely injured patients. The criteria used to mobilize trauma teams is highly variable and debated. This study was undertaken to define the triage accuracy at our level 1 trauma centre and identify the criteria predictive of appropriate activations. Methods: A 3-month prospective observational study was performed and all patients presenting to the ER who received a trauma flag were identified. Patient demographics, vital signs, trauma team activation and criteria for activation were documented. Trauma activations were deemed appropriate if the patient met any of the following; airway intervention, needle/tube thoracostomy, resuscitative thoracotomy, ED blood product transfusion, invasive hemodynamic monitoring, central line insertion, emergent OR (<8 hours), admission to ICU, and death within 72 hours. Over and undertriage rates were calculated and a multivariate logistic regression was performed to identify activation criteria predictive of appropraite activations. The activation criteria were then modified and the prospective study was repeated to assess the impact on triage accuracy. Results: Between September to December 2015, 188 patients received a trauma flag. 137 patients met the activation criteria, however only 78 received a trauma team activation. 57% of patients who had TTA met the definition of appropriate activation, while 45% who met criteria for activation met the definition of appropriate. The rates of under and overtriage were 30.4% and 30.3%, respectively. Logistic regression revealed the following criteria to be predictive of appropriate activation; hypotension (OR 10.2 95% CI 2.3,45.5), arrival by HEMS (OR 3.2, 95% CI 1.4,7.6), pedestrian struck (OR 3.5, 95% CI 1.4,8.5) and fall (OR 5.1, 95% CI 1.7, 15.1). Tachycardia (OR 1.1, 95% 0.3,4.6) and high energy MVC (OR 1.4, 95% CI 0.7,3.1) were not found to be predictive. The post-modification study occured between September to December 2016. Data analysis to assess the impact of criteria alteration are currently underway and will be presented at CAEP 2017. Conclusion: Triage accuracy for the mobilization of a multi-disciplinary trauma team is important, both to ensure optimal patient care as well as to reduce unnecessary resource strain. Our previous criteria lead to high rates of undertriage and subsequent modifications have been made. The impact of these changes will be ascertained and presented at CAEP 2017.

Introduction: Adverse drug events (ADEs), unintended and harmful events associated with medications, cause or contribute to 2 million annual emergency department (ED) visits in Canada. Australian data indicate that 27% of ADEs requiring admission are events caused by re-exposure to drugs that previously caused harm. Our objective was to estimate the frequency of repeat ADEs. Methods: We reviewed the charts of ADE patients who had been enrolled in 1 of 3 prospective studies conducted in 2 tertiary care and 1 urban community ED. In the parent studies, researchers enrolled patients by applying a systematic selection algorithm to minimize selection bias, and physicians and pharmacists evaluated patients prospectively to evaluate the causal association between the drug regimens and patient presentations. After completion of the parent studies, a research pharmacist and a physician independently reviewed the charts of ADE patients, abstracted data using electronic forms, and searched that hospital’s records for previously recorded ADEs. The main outcome was a repeat ADE, defined as a same or same-class drug re-exposure, or repeat inappropriate drug withdrawal, causing a same or similar presentation as a prior ADE. Sample size was based on enrolment into the parent studies. Results: We reviewed the charts of 614 ED patients diagnosed with 655 ADEs. Of these, 20% (133/665, 95%CI 17.0-23.0%) were repeat events. Most repeat ADEs were moderate (61%) or severe (32%) in nature, and 33% (95%CI 25.1-41.1%) required hospital admission. The most commonly implicated drugs were warfarin (10%), hydrochlorothiazide (4%) and insulin (4%), and the most commonly implicated drug classes were antithrombotics (17%), psychotropics (12%) and analgesics (9%). Repeat ADEs commonly required clinical monitoring (59%), additional medications to treat the ADE (50%) and follow-up lab testing (35%). Overall, 61% (95%CI 51.3-70.7%) of culprit drug re-exposures were deemed potentially or definitely inappropriate. Conclusion: Inappropriate re-exposures to previously harmful medications cause a substantial number of recurrent ADEs, and may represent an ideal target for prevention. We were unable to search for repeat ADEs in the records of other hospitals that our patients may have visited, and could not detect ADEs that were not documented in the medical record. As a result, we likely underestimated the frequency of repeat ADEs.