The association of extreme environmental heat with incidence and outcomes of out-of-hospital cardiac arrest in British Columbia: A time series analysis

Background

The impact of extreme heat on out-of-hospital cardiac arrest (OHCA) incidence and outcomes is under-studied. We investigated OHCA incidence and outcomes over increasing temperatures.

Methods

We included non-traumatic EMS (Emergency Medical Services)-assessed OHCAs in British Columbia during the warm seasons of 2020-2021. We fit a time-series quasi-Poisson generalized linear model to estimate the association between temperature and incidence of both EMS-assessed, EMS-treated, and EMS-untreated OHCAs. Second, we employed a logistic regression model to estimate the association between "heatwave" periods (defined as a daily mean temperature > 99th percentile for ≥ 2 consecutive days, plus 3 lag days) with survival and favourable neurological outcomes (cerebral performance category ≤ 2) at hospital discharge.

Results

Of 5478 EMS-assessed OHCAs, 2833 were EMS-treated. OHCA incidence increased with increasing temperatures, especially exceeding a daily mean temperature of 25 °C Compared to the median daily mean temperature (16.9 °C), the risk of EMS-assessed (relative risk [RR] 3.7; 95%CI 3.0-4.6), EMS-treated (RR 2.9; 95%CI 2.2-3.9), and EMS-untreated (RR 4.3; 95%CI 3.2-5.7) OHCA incidence were higher during days with a temperature over the 99th percentile. Of EMS-treated OHCAs, during the heatwave (n = 179) and non-heatwave (n = 2654) periods, 4 (2.2%) and 270 (10%) survived and 4 (2.2%) and 241 (9.2%) had favourable neurological outcomes, respectively. Heatwave period OHCAs had decreased odds of survival (adjusted OR 0.28; 95%CI 0.10-0.79) and favourable neurological outcome (adjusted OR 0.31; 95%CI 0.11-0.89) at hospital discharge, compared to other periods.

Conclusion

Extreme heat was associated with a higher incidence of OHCA, and lower odds of survival and favourable neurological status at hospital discharge.

External Validation of the Post-Concussion Symptoms Rule for Predicting Mild Traumatic Brain Injury Outcome

Persistent symptoms are common after a mild traumatic brain injury (mTBI). The Post-Concussion Symptoms (PoCS) Rule is a newly developed clinical decision rule for the prediction of persistent post-concussion symptoms (PPCS) 3 months after an mTBI. The PoCS Rule includes assessment of demographic and clinical characteristics and headache presence in the emergency department (ED), and follow-up assessment of symptoms at 7 days post-injury using two thresholds (lower/higher) for symptom scoring. We examined the PoCS Rule in an independent sample. We analyzed a clinical trial that recruited participants with mTBI from EDs in Greater Vancouver, Canada. The primary analysis used data from 236 participants, who were randomized to a usual care control group, and completed the Rivermead Postconcussion Symptoms Questionnaire at 3 months. The primary outcome was PPCS, as defined by the PoCS authors. We assessed the overall performance of the PoCS rule (area under the receiver operating characteristic curve [AUC]), sensitivity, and specificity. More than 40% of participants (median age 38 years, 59% female) reported PPCS at 3 months. Most participants (88%) were categorized as being at medium risk based on the ED assessment, and a majority were considered as being at high risk according to the final PoCS Rule (81% using a lower threshold and 72% using a higher threshold). The PoCS Rule showed a sensitivity of 93% (95% confidence interval [CI], 88-98; lower threshold) and 85% (95% CI, 78-92; higher threshold), and a specificity of 28% (95% CI, 21-36) and 37% (95% CI, 29-46), respectively. The overall performance was modest (AUC 0.61, 95% CI 0.59, 0.65). In conclusion, the PoCS Rule was sensitive for PPCS, but had a low specificity in our sample. Follow-up assessment of symptoms can improve risk stratification after mTBI.

Concordance between 8-1-1 HealthLink BC Emergency iDoctor-in-assistance (HEiDi) virtual physician advice and subsequent health service utilization for callers to a nurse-managed provincial health information telephone service

BACKGROUND

British Columbia 8-1-1 callers who are advised by a nurse to seek urgent medical care can be referred to virtual physicians (VPs) for supplemental assessment and advice. Prior research indicates callers' subsequent health service use may diverge from VP advice. We sought to 1) estimate concordance between VP advice and subsequent health service use, and 2) identify factors associated with concordance to understand potential drivers of discordant cases.

METHODS

We linked relevant provincial administrative databases to obtain inpatient, outpatient, and emergency service use by callers. We developed operational definitions of concordance collaboratively with researcher, patient, VP, and management perspectives. We used Kaplan-Meier curves to describe health service use post-VP consultation and Cox regression to estimate the association of caller factors (rurality, demography, attachment to primary care) and call factors (reason, triage level, time of day) with concordance as hazard ratios.

RESULTS

We analyzed 17,188 calls from November 16, 2020 to April 30, 2021. Callers advised to attend an emergency department (ED) immediately were the most concordant (73%) while concordance was lowest for those advised to seek Family Physician (FP) care either immediately (41%) or within 7 days (47%). Callers unattached to FPs were less likely to schedule an FP visit (hazard ratio = 0.76 [95%CI: 0.68-0.85]). Rural callers were less likely to attend an ED within 48 h when advised to go immediately (0.53 [95%CI:0.46-0.61]) compared to urban callers. Rural callers advised to see an FP, either immediately (1.28 [95%CI:1.01-1.62]) or within 7 days (1.23 [95%CI: 1.11-1.37]), were more likely to do so than urban callers.

INTERPRETATION

Concordance between VP advice and subsequent caller health service use varies substantially by category of advice and caller rurality. Concordance with advice to "Go to ED" is high overall but to access primary care is below 50%, suggesting potential issues with timely access to FP care. Future research from a patient/caller centered perspective may reveal additional barriers and facilitators to concordance.

Association between toxic drug events and encephalopathy in British Columbia, Canada: a cross-sectional analysis

BACKGROUND

Encephalopathy can occur from a non-fatal toxic drug event (overdose) which results in a partial or complete loss of oxygen to the brain, or due to long-term substance use issues. It can be categorized as a non-traumatic acquired brain injury or toxic encephalopathy. In the context of the drug toxicity crisis in British Columbia (BC), Canada, measuring the co-occurrence of encephalopathy and drug toxicity is challenging due to lack of standardized screening. We aimed to estimate the prevalence of encephalopathy among people who experienced a toxic drug event and examine the association between toxic drug events and encephalopathy.

METHODS

Using a 20% random sample of BC residents from administrative health data, we conducted a cross-sectional analysis. Toxic drug events were identified using the BC Provincial Overdose Cohort definition and encephalopathy was identified using ICD codes from hospitalization, emergency department, and primary care records between January 1st 2015 and December 31st 2019. Unadjusted and adjusted log-binomial regression models were employed to estimate the risk of encephalopathy among people who had a toxic drug event compared to people who did not experience a toxic drug event.

RESULTS

Among people with encephalopathy, 14.6% (n = 54) had one or more drug toxicity events between 2015 and 2019. After adjusting for sex, age, and mental illness, people who experienced drug toxicity were 15.3 times (95% CI = 11.3, 20.7) more likely to have encephalopathy compared to people who did not experience a drug toxicity event. People who were 40 years and older, male, and had a mental illness were at increased risk of encephalopathy.

CONCLUSIONS

There is a need for collaboration between community members, health care providers, and key stakeholders to develop a standardized approach to define, screen, and detect neurocognitive injury related to drug toxicity.

Qualitative Exploration of Emergency Department Care Experiences Among People With Opioid Use Disorder

STUDY OBJECTIVE

We described the experiences and preferences of people with opioid use disorder who access emergency department (ED) services regarding ED care and ED-based interventions.

METHODS

Between June and September 2020, we conducted phone or in-person semistructured qualitative interviews with patients recently discharged from 2 urban EDs in Vancouver, BC, Canada, to explore experiences and preferences of ED care and ED-based opioid use disorder interventions. We recruited participants from a cohort of adults with opioid use disorder who were participating in an ED-initiated outreach program. We transcribed audio recordings verbatim. We iteratively developed a thematic coding structure, with interim analyses to assess for thematic saturation. Two team members with lived experience of opioid use provided feedback on content, wording, and analysis throughout the study.

RESULTS

We interviewed 19 participants. Participants felt discriminated against for their drug use, which led to poorer perceived health care and downstream ED avoidance. Participants desired to be treated like ED patients who do not use drugs and to be more involved in their ED care. Participants nevertheless felt comfortable discussing their substance use with ED staff and valued continuous ED operating hours. Regarding opioid use disorder treatment, participants supported ED-based buprenorphine/naloxone programs but also suggested additional options (eg, different initiation regimens and settings and other opioid agonist therapies) to facilitate further treatment uptake.

CONCLUSION

Based on participant experiences, we recommend addressing potentially stigmatizing practices, increasing patient involvement in their care during ED visits, and increasing access to various opioid use disorder-related treatments and community support.

Health system use and outcomes of urgently triaged callers to a nurse-managed telephone service for provincial health information after initiation of supplemental virtual physician assessment: a descriptive study

BACKGROUND

British Columbia's 8-1-1 telephone service connects callers with nurses for health care advice. As of Nov. 16, 2020, callers advised by a registered nurse to obtain in-person medical care can be subsequently referred to virtual physicians. We sought to determine health system use and outcomes of 8-1-1 callers urgently triaged by a nurse and subsequently assessed by a virtual physician.

METHODS

We identified callers referred to a virtual physician between Nov. 16, 2020, and Apr. 30, 2021. After assessment, virtual physicians assigned callers to 1 of 5 triage dispositions (i.e., go to emergency department [ED] now, see primary care provider within 24 hours, schedule an appointment with a health care provider, try home treatment, other). We linked relevant administrative databases to ascertain subsequent health care use and outcomes.

RESULTS

We identified 5937 encounters with virtual physicians involving 5886 8-1-1 callers. Virtual physicians advised 1546 callers (26.0%) to go to the ED immediately, of whom 971 (62.8%) had 1 or more ED visits within 24 hours. Virtual physicians advised 556 (9.4%) callers to seek primary care within 24 hours, of whom 132 (23.7%) had primary care billings within 24 hours. Virtual physicians advised 1773 (29.9%) callers to schedule an appointment with a health care provider, of whom 812 (45.8%) had primary care billings within 7 days. Virtual physicians advised 1834 (30.9%) callers to try a home treatment, of whom 892 (48.6%) had no health system encounters over the next 7 days. Eight (0.1%) callers died within 7 days of assessment with a virtual physician, 5 of whom were advised to go to the ED immediately. Fifty-four (2.9%) callers with a "try home treatment" disposition were admitted to hospital within 7 days of a virtual physician assessment, and no callers who were advised home treatment died.

INTERPRETATION

This Canadian study evaluated health service use and outcomes arising from the addition of virtual physicians to a provincial health information telephone service. Our findings suggest that supplementation of this service with an assessment from a virtual physician safely reduces the overall proportion of callers advised to seek urgent in-person visits.

Drug overdose and the risk of cardiovascular diseases: a nested case-control study

BACKGROUND

North America has been experiencing an unprecedented epidemic of drug overdose. This study investigated the associations of drug overdose with the risk of cardiovascular disease (CVD) and 11 major CVD subtypes.

METHODS

This nested case-control study was based on a cohort of 20% random sample of residents in British Columbia, Canada, who were aged 18-80 years and did not have known CVD at baseline (n = 617,863). During a 4-year follow-up period, persons who developed incident CVD were identified as case subjects, and the onset date of CVD was defined as the index date. For each case subject, we used incidence density sampling to randomly select up to five control subjects from the cohort members who were alive and did not have known CVD by the index date, were admitted to an emergency department or hospital on the index date for non-CVD causes, and were matched on age, sex, and region of residence. Overdose exposure on the index date and each of the previous 5 days was examined for each subject.

RESULTS

This study included 16,113 CVD case subjects (mean age 53 years, 59% male) and 66,875 control subjects. After adjusting for covariates, overdose that occurred on the index date was strongly associated with CVD [odds ratio (OR), 2.9; 95% confidence interval (CI), 2.4-3.5], especially for arrhythmia (OR, 8.6; 95% CI, 6.2-12.0), ischemic stroke (OR, 5.3; 95% CI, 2.0-14.1), hemorrhagic stroke (OR, 3.1; 95% CI, 1.2-8.3), and myocardial infarction (OR, 3.0; 95% CI, 1.5-5.8). The CVD risk was decreased but remained significantly elevated for overdose that occurred on the previous day, and was not observed for overdose that occurred on each of the previous 2-5 days.

CONCLUSIONS

Drug overdose appears to be associated with increased risk of cardiovascular diseases.

Risk factors associated with 1-week revisit among emergency department patients with alcohol withdrawal

BACKGROUND

Approximately one-quarter of emergency department (ED) visits for alcohol withdrawal result in unscheduled 1-week ED return visits, but it is unclear what patient and clinical factors may impact this outcome METHODS: From January 1, 2015, to December 31, 2018, at three urban EDs in Vancouver, Canada, we studied patients who were discharged with a primary or secondary diagnosis of alcohol withdrawal. We performed a structured chart review to ascertain patient characteristics, ED treatments, and the outcome of an ED return within 1 week of discharge. We used univariable and multivariable Bayesian binomial regression to identify characteristics associated with being in the upper quartile of 1-week ED revisits.

RESULTS

We collected 935 ED visits among 593 unique patients. Median age was 45 years (interquartile range 34 to 55 years) and 71% were male. The risk of a 1-week ED revisit was 15.0% (IQR 12.3; 19.5%). After adjustment, factors independently associated with a high risk for return included any prior ED visit within 30 days, no fixed address, initial blood alcohol level > 45 mmol/L, and initial Clinical Institute Withdrawal Assessment-alcohol revised score > 23. These factors explained 41% of the overall variance in revisits.

CONCLUSION

Among discharged ED patients with alcohol withdrawal, we describe high-risk patient characteristics associated with 1-week ED revisits, and these findings may assist clinicians to facilitate appropriate discharge planning with access to integrated follow-up support.

Effect of specialist consultation on emergency department revisits among patients with uncomplicated recent-onset atrial fibrillation or flutter

OBJECTIVES

To examine the association between specialist consultation and risk of 30-day ED revisit in emergency department (ED) patients with recent-onset uncomplicated atrial fibrillation or flutter (AF/AFL).

METHODS

As a secondary analysis of a previously published trial, clinical experts identified predictors of consultation including age and sex, ED sinus conversion, thromboembolic risk, heart rate, rate control medication use, coronary artery disease and anti-platelet use, and chronic obstructive pulmonary disease. These were included in a propensity-matched hierarchical Bayesian model accounting for hospital site as a random effect, with 30-day ED revisit as the primary outcome. We also measured ED length of stay for consulted and non-consulted patients.

RESULTS

We analyzed data from 11 sites for 829 ED patients with AF/AFL, of whom 364 (44%) had specialist consultation. A total of 128 patients (15.4%) had an ED revisit, 78 (16.8%) from the no consult group and 50 (13.7%) from the consult group. Consultation rates ranged from 8.8 to 71% between sites. Median length of stay was 591 min (interquartile range [IQR] 359-1024) for consulted patients and 300 min (IQR 212-409) for patients without consultation. After propensity-matching, consulted patients had a 0.6% (IQR - 4 to 3%) lower risk of 30-day revisits than non-consulted patients (probability of lower risk 55%).

CONCLUSIONS

In ED patients with uncomplicated AF/AFL, there was substantial between-site variation in specialist consultations; such consultation was unlikely to influence revisits within 30 days while ED length of stay was nearly double. ED specialist consultations may not be necessary for uncomplicated patients.

Are higher antibody levels against seasonal human coronaviruses associated with a more robust humoral immune response after SARS-CoV-2 vaccination?

The SARS-CoV-2 belongs to the coronavirus family, which also includes common endemic coronaviruses (HCoVs). We hypothesized that immunity to HCoVs would be associated with stronger immunogenicity from SARS-CoV-2 vaccines. The study included samples from the COSRIP observational cohort study of adult paramedics in Canada. Participants provided blood samples, questionnaire data, and results of COVID-19 testing. Samples were tested for anti-spike IgG against SARS-CoV-2, HCoV-229E, HCoV-HKU1, HCoV-NL63, and HCoV-OC43 antigens. We first compared samples from vaccinated and unvaccinated participants, to determine which HCoV antibodies were affected by vaccination. We created scatter plots and performed correlation analysis to estimate the extent of the linear relationship between HCoVs and SARS-CoV-2 anti-spike antibodies. Further, using adjusted log-log multiple regression, we modeled the association between each strain of HCoV and SARS-CoV-2 antibodies. Of 1510 participants (mean age of 39 years), 94 (6.2%) had a history of COVID-19. There were significant differences between vaccinated and unvaccinated participant in anti-spike antibodies to HCoV-HKU1, and HCoV-OC43; however, levels for HCoV-229E and HCoV-NL63 were similar (suggesting that vaccination did not affect these baseline values). Among vaccinated individuals without prior COVID-19 infection, SARS-COV-2 anti-spike IgG demonstrated a weak positive relationship between both HCoV-229E (r = 0.11) and HCoV-NL63 (r = 0.12). From the adjusted log-log multiple regression model, higher HCoV-229E and HCoV-NL63 anti-spike IgG antibodies were associated with increased SARS-COV-2 anti-spike IgG antibodies. Vaccination appears to result in measurable increases in HCoV-HKU1, and HCoV-OC43 IgG levels. Anti-HCoV-229E and HCoV-NL63 antibodies were unaffected by vaccination, and higher levels were associated with significantly higher COVID-19 vaccine-induced SARS-COV-2 antibodies.

Effectiveness of a guideline implementation tool for supporting management of mental health complications after mild traumatic brain injury in primary care: protocol for a randomised controlled trial

INTRODUCTION

Mental health problems frequently interfere with recovery from mild traumatic brain injury (mTBI) but are under-recognised and undertreated. Consistent implementation of clinical practice guidelines for proactive detection and treatment of mental health complications after mTBI will require evidence-based knowledge translation strategies. This study aims to determine if a guideline implementation tool can reduce the risk of mental health complications following mTBI. If effective, our guideline implementation tool could be readily scaled up and/or adapted to other healthcare settings.

METHODS AND ANALYSIS

We will conduct a triple-blind cluster randomised trial to evaluate a clinical practice guideline implementation tool designed to support proactive management of mental health complications after mTBI in primary care. We will recruit 535 adults (aged 18-69 years) with mTBI from six emergency departments and two urgent care centres in the Greater Vancouver Area, Canada. Upon enrolment at 2 weeks post-injury, they will complete mental health symptom screening tools and designate a general practitioner (GP) or primary care clinic where they plan to seek follow-up care. Primary care clinics will be randomised into one of two arms. In the guideline implementation tool arm, GPs will receive actionable mental health screening test results tailored to their patient and their patients will receive written education about mental health problems after mTBI and treatment options. In the usual care control arm, GPs and their patients will receive generic information about mTBI. Patient participants will complete outcome measures remotely at 2, 12 and 26 weeks post-injury. The primary outcome is rate of new or worsened mood, anxiety or trauma-related disorder on the Mini International Neuropsychiatric Interview at 26 weeks.

ETHICS AND DISSEMINATION

Study procedures were approved by the University of British Columbia's research ethics board (H20-00562). The primary report for the trial results will be published in a peer-reviewed journal. Our knowledge user team members (patients, GPs, policymakers) will co-create a plan for public dissemination.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT04704037).

Temporal trends of suicide-related non-traumatic out-of-hospital cardiac arrest characteristics and outcomes with the COVID-19 pandemic

Background

Jurisdictions have reported COVID-19-related increases in the incidence and mortality of non-traumatic out-of-hospital cardiac arrest (OHCA). We hypothesized that changes in suicide incidence during the COVID-19 pandemic may have contributed to these changes. We investigated whether the COVID-19 pandemic was associated with changes in the: (1) incidence of suicide-related OHCA, and (2) characteristics and outcomes of such cases.

Methods

We used the provincial British Columbia Cardiac Arrest Registry, including non-traumatic emergency medical system (EMS)-assessed OHCA, to compare suicide-related OHCA (defined as clear self-harm or a priori communication of intent) one-year prior to, and one year after, the start of the COVID-19 pandemic (March 15, 2020). We calculated differences in incidence (with 95% CI), overall and within subgroups of mechanism (hanging, suffocation, poisoning, or unclear mechanism), and in case characteristics and hospital-discharge favourable neurological outcomes (CPC 1–2).

Results

Of 13,785 EMS-assessed OHCA, we included 274/6430 (4.3%) pre-pandemic and 221/7355 (3.0%) pandemic-period suicide-related cases. The median age was 43 years (IQR 30–57), 157 (32%) were female, and 7 (1.4%) survived with favourable neurological status. Suicide-related OHCA incidence decreased from 5.4 pre-pandemic to 4.3 per 100 000 person-years (-1.1, 95% CI −2.0 to −0.28). Hanging-related OHCA incidence also decreased. Patient characteristics and hospital discharge outcomes between periods were similar.

Conclusion

Suicide-related OHCA incidence decreased with the COVID-19 pandemic and we did not detect changes in patient characteristics or outcomes, suggesting that suicide is not a contributor to increases in COVID-related OHCA incidence or mortality. Overall suicide-related OHCA outcomes in both time periods were poor.

The Journal Club 3.0: A qualitative, multisite study examining a new educational paradigm in the era of open educational resources

BACKGROUND

The journal club is a ubiquitous and time-honored tradition within medical education. However, in recent years, open educational resources (OERs) have become increasingly influential in how physicians interact with the medical literature across multiple specialties. The authors sought to explore how emergency medicine (EM) resident physicians reconcile different perspectives across OERs into their educational experience at the journal club.

METHODS

From January 2018 to September 2019, the authors enrolled 25 EM residents from four teaching sites associated with the University of British Columbia, Canada, to participate in either a focus group (seven residents) or individual interviews (18 residents). The authors used a snowball sampling technique. Using a constructivist grounded theory analysis, two investigators independently reviewed transcripts, meeting regularly to discuss themes until sufficiency was achieved.

RESULTS

The study data expand the theoretical understanding of the resident journal club experience. Residents used multiple sources including OERs to learn about new evidence in the specialty. The rise of OERs helped residents to focus on developing critical appraisal skills and social bonds during the journal club. The local journal club gained a new relevancy in acting as a quality control mechanism against the premature adoption of research findings discussed in OERs.

DISCUSSION

To date, most educators assume that residents prepare for a journal club by reading the selected articles and applying knowledge from their previous education. Instead, our findings suggest a more dynamic experience that integrates OERs. OERs enhance the journal club experience by allowing junior residents to more easily participate in discussions and to broaden the discussion to multiple clinical settings. Understanding these processes could inform future educational strategies around the journal club.

Out-of-Hospital Cardiac Arrests Terminated without full Resuscitation Attempts: Characteristics and Regional Variability

BACKGROUND

Out-of-hospital cardiac arrest (OHCA) investigations may elect to exclude cases with resuscitation terminated for reasons other than a full resuscitative attempt. We sought to examine characteristics of these cases and regional variability in classification.

METHODS

Using the North American Resuscitation Outcomes Consortium Epistry, we included adult emergency medical services (EMS)-treated cases, examining the rationale ("futility", do-not resuscitate (DNR) order, "verbal directive", or "obvious death") and timing of resuscitation termination, and the timing of ROSC among hospital-discharge survivors. We tested regional variability in EMS patient arrival-to-termination intervals with one-way ANOVA.

RESULTS

Of 63,554 included cases, 27,232 were declared dead in the prehospital setting: (1) 23,009 (36%) for futility (after a median of 24 minutes (IQR 19-31) of professional resuscitation); (2) 1622 (2.6%) for a DNR order (at 6.3 minutes [IQR 3.0-11]); (3) 1018 (1.6%) for a verbal directive (at 12 minutes [IQR 7.0-17]); and, (4) 1583 (2.5%) for obvious death (at 5.4 minutes [IQR 3.0-9.0]). The EMS patient arrival-to-ROSC interval among hospital-discharge survivors was 7.7 (3.8 - 13) minutes. Among regions, 0.20-12% and 0.20-5.3% were terminated to due to obvious death or verbal directives, respectively. There were significant regional differences in the EMS patient arrival-to-termination interval for futility (p<0.010) and obvious death (p<0.010).

CONCLUSION

There is significant variation in the rationale and interval until termination of resuscitation between regions. Cases terminated due to obvious death or DNR orders/verbal directives often are treated with similar durations of resuscitation as survivors. These data highlight a considerable risk of bias in between-region comparisons or observational analyses.

Risk of cardiovascular diseases in relation to substance use disorders

BACKGROUND

Substance use disorder (SUD) has become increasingly prevalent worldwide, this study investigated the associations of SUD and alcohol, cannabis, opioid, or stimulant use disorder with cardiovascular disease (CVD) and 11 major CVD subtypes.

METHODS

This study was based on a 20% random sample of residents in British Columbia, Canada, who were aged 18 - 80 years at baseline on January 1, 2015. Using linked administrative health data during 2010 - 2014, we identified people with various SUDs and prevalent CVDs at baseline, and examined the cross-sectional associations between SUDs and CVDs. After excluding people with CVDs at baseline, we followed the cohort for 4 years to identify people who developed incident CVDs, and examined the longitudinal associations between SUDs and CVDs.

RESULTS

The cross-sectional analysis at baseline included 778,771 people (mean age 45 years, 50% male), 13,279 (1.7%) had SUD, and 41,573 (5.3%) had prevalent CVD. After adjusting for covariates, people with SUD were 2.7 (95% confidence interval [CI], 2.5 - 2.8) times more likely than people without SUD to have prevalent CVD. The longitudinal analysis included 617,863 people, 17,360 (2.8%) developed incident CVD during the follow-up period. After adjusting for covariates, people with SUD were 1.7 (95% CI, 1.6 - 1.9) times more likely than people without SUD to develop incident CVD. The cross-sectional and longitudinal associations were more pronounced for people with opioid or stimulant use disorder.

CONCLUSIONS

People with SUD are more likely to have prevalent CVD and develop incident CVD compared with people without SUD.

Emergency medical services employing intra-arrest transport less frequently for out-of-hospital cardiac arrest have higher survival and favorable neurological outcomes

BACKGROUND

There is substantial regional variation in out-of-hospital cardiac arrest (OHCA) survival. We investigated whether regional emergency medical services (EMS) intra-arrest transport (IAT) practices are associated with patient outcomes.

METHODS

We performed a secondary analysis of a multi-center North American clinical trial dataset, which enrolled EMS-treated adult OHCA cases from 49 regional population-based clusters. The exposure of interest was regional-level intra-arrest transport (IAT), calculated as the proportion of cases in each cluster transported to hospital prior to return of spontaneous circulation, examined as quartiles and as a continuous variable. Multilevel mixed-effects logistic regression modeling estimated the association between regional IAT with survival to hospital discharge and favorable neurologic status (modified Rankin Scale ≤ 3) at hospital discharge.

RESULTS

Of 26,148 subjects (median age 68 years; 36% female; 23% shockable initial rhythm) 2424 (9.3%), survived to hospital discharge and 1993 (7.6%) had favourable neurological outcomes. Across regional clusters, IAT ranged from 0.84% to 75% (quartiles <6.2%, 6.2-19.6%, 19.6-30.4%, and ≥30.4%). For each quartile, 13.3%, 7.9%, 7.4%, and 4.8% survived, and 10.4%, 7.8%, 7.4%, and 4.8% had favourable neurological status. Regional IAT (per 10% change) was associated with decreased probability of survival (AOR 0.86, 95% CI 0.82-0.91) and favorable neurological outcome (AOR 0.80, 95% CI 0.76-0.85).

CONCLUSION

Treatment within a region that utilizes IAT less frequently was associated with improved clinical outcomes at hospital discharge. These findings may account for some of the known regional variation in OHCA outcomes.

Does early intervention improve outcomes for patients with acute ureteral colic?

OBJECTIVES

Early surgical intervention is increasingly employed for patients with ureteral colic, but guidelines and current practice are variable. We compared 60-day outcomes for matched patients undergoing early intervention vs. spontaneous passage.

METHODS

This multicentre propensity-matched cohort analysis used administrative data and chart review to study all eligible emergency department (ED) patients with confirmed 2.0-9.9 mm ureteral stones. Those having planned stone intervention within 5 days comprised the intervention cohort. Controls attempting spontaneous passage were matched to intervention patients based on age, sex, stone width, stone location, hydronephrosis, ED site, ambulance arrival and acuity level. The primary outcome was treatment failure, defined as rescue intervention or hospitalization within 60 days, using a time to event analysis. Secondary outcome was ED revisit rate.

RESULTS

Among 1154 matched patients, early intervention did not reduce the risk of treatment failure (adjusted hazard ratio 0.94; P = 0.61). By 60 days, 21.8% of patients in both groups experienced the composite primary outcome (difference 0.0%; 95% confidence interval - 4.8 to 4.8%). Intervention patients required more hospitalizations (20.1% vs. 12.8%; difference 7.3%; 95% CI 3.0-11.5%) and ED revisits (36.1% vs. 25.5%; difference 10.6%; 95% CI 5.3-15.9%), but (insignificantly) fewer rescue interventions (18.9% vs. 21.3%; difference - 2.4%; 95% CI - 7.0 to 2.2%).

CONCLUSIONS

In matched patients with 2.0-9.9 mm ureteral stones, early intervention was associated with similar rates of treatment failure but greater patient morbidity, evidenced by hospitalizations and emergency revisits. Physicians should adopt a selective approach to interventional referral and consider that spontaneous passage probably provides better outcomes for many low-risk patients.

Rapid Agitation Control With Ketamine in the Emergency Department: A Blinded, Randomized Controlled Trial

STUDY OBJECTIVE

We hypothesized that the use of intramuscular ketamine would result in a clinically relevant shorter time to target sedation.

METHODS

We conducted a randomized clinical trial comparing the rapidity of onset, level of sedation, and adverse effect profile of ketamine compared to a combination of midazolam and haloperidol for behavioral control of emergency department patients with severe psychomotor agitation. We included patients with severe psychomotor agitation measured by a Richmond Agitation Score (RASS) ≥+3. Patients in the ketamine group were treated with a 5 mg/kg intramuscular injection. Patients in the midazolam and haloperidol group were treated with a single intramuscular injection of 5 mg midazolam and 5 mg haloperidol. The primary outcome was the time, in minutes, from study medication administration to adequate sedation, defined as RASS ≤-1. Secondary outcomes included the need for rescue medications and serious adverse events.

RESULTS

Between June 30, 2018, and March 13, 2020, we screened 308 patients and enrolled 80. The median time to sedation was 14.7 minutes for midazolam and haloperidol versus 5.8 minutes for ketamine (difference 8.8 minutes [95% confidence interval (CI) 3.0 to 14.5]). Adjusted Cox proportional model analysis favored the ketamine arm (hazard ratio 2.43, 95% CI 1.43 to 4.12). Five (12.5%) patients in the ketamine arm and 2 (5.0%) patients in the midazolam and haloperidol arm experienced serious adverse events (difference 7.5% [95% CI -4.8% to 19.8%]).

CONCLUSION

In ED patients with severe agitation, intramuscular ketamine provided significantly shorter time to adequate sedation than a combination of intramuscular midazolam and haloperidol.

Experiences of people with opioid use disorder during the COVID-19 pandemic: A qualitative study

AIM

To capture pandemic experiences of people with opioid use disorder (OUD) to better inform the programs that serve them.

DESIGN

We designed, conducted, and analyzed semi-structured qualitative interviews using grounded theory. We conducted interviews until theme saturation was reached and we iteratively developed a codebook of emerging themes. Individuals with lived experience of substance use provided feedback at all steps of the study.

SETTING

We conducted phone or in-person interviews in compliance with physical distancing and public health regulations in outdoor Vancouver parks or well-ventilated indoor spaces between June to September 2020.

PARTICIPANTS

Using purposive sampling, we recruited participants (n = 19) who were individuals with OUD enrolled in an intensive community outreach program, had visited one of two emergency departments, were over 18, lived within catchment, and were not already receiving opioid agonist therapy.

MEASUREMENTS

We audio-recorded interviews, which were later transcribed verbatim and checked for accuracy while removing all identifiers. Interviews explored participants' knowledge of COVID-19 and related safety measures, changes to drug use and healthcare services, and community impacts of COVID-19.

RESULTS

One third of participants were women, approximately two thirds had stable housing, and ages ranged between 23 and 59 years old. Participants were knowledgeable on COVID-19 public health measures. Some participants noted that fear decreased social connection and reluctance to help reverse overdoses; others expressed pride in community cohesion during crisis. Several participants mentioned decreased access to housing, harm reduction, and medical care services. Several participants reported using drugs alone more frequently, consuming different or fewer drugs because of supply shortages, or using more drugs to replace lost activities.

CONCLUSION

COVID-19 had profound effects on the social lives, access to services, and risk-taking behaviour of people with opioid use disorder. Pandemic public health measures must include risk mitigation strategies to maintain access to critical opioid-related services.

Hydronephrosis severity clarifies prognosis and guides management for emergency department patients with acute ureteral colic

OBJECTIVE

In emergency department patients with ureteral colic, the prognostic value of hydronephrosis is unclear. Our goal was to determine whether hydronephrosis can differentiate low-risk patients appropriate for trial of spontaneous passage from those with clinically important stones likely to experience passage failure.

METHODS

We used administrative data and structured chart review to evaluate a consecutive cohort of patients with ureteral stones who had a CT at nine Canadian hospitals in two cities. We used CT, the gold standard for stone imaging, to assess hydronephrosis and stone size. We described classification accuracy of hydronephrosis severity for detecting large (≥ 5 mm) stones. In patients attempting spontaneous passage we used hierarchical Bayesian regression to determine the association of hydronephrosis with passage failure, defined by the need for rescue intervention within 60 days. To illustrate prognostic utility, we reported pre-test probability of passage failure among all eligible patients (without hydronephrosis guidance) to post-test probability of passage failure in each hydronephrosis group.

RESULTS

Of 3251 patients, 70% male and mean age 51, 38% had a large stone, including 23%, 29%, 53% and 72% with absent, mild, moderate and severe hydronephrosis. Passage failure rates were 15%, 20%, 28% and 43% in the respective hydronephrosis categories, and 23% overall. "Absent or mild" hydronephrosis identified a large subset of patients (64%) with low passage failure rates. Moderate hydronephrosis predicted slightly higher, and severe hydronephrosis substantially higher passage failure risk.

CONCLUSIONS

Absent and mild hydronephrosis identify low-risk patients unlikely to experience passage failure, who may be appropriate for trial of spontaneous passage without CT imaging. Moderate hydronephrosis is weakly associated with larger stones but not with significantly greater passage failure. Severe hydronephrosis is an important finding that warrants definitive imaging and referral. Differentiating "moderate-severe" from "absent-mild" hydronephrosis provides risk stratification value. More granular hydronephrosis grading is not prognostically helpful.

What are Canadian emergency physicians' attitudes and self-perceived competence toward patients who present with suicidal ideation?

INTRODUCTION

Suicide is the 9th leading cause of death in Canada, and a common reason for patients to present to Canadian emergency departments (ED). Little knowledge exists around Canadian emergency physicians (EPs) attitudes toward and understanding of individuals with suicidal ideation.

METHODS

We developed a web-based survey on suicide knowledge, which was pilot tested by two EPs and one psychiatrist for clarity and content. The survey was distributed via email to attending physician members of the Canadian Association of Emergency Physicians. Data were described using counts, means, medians and interquartile ranges. The Understanding of Suicidal Patients (USP) Scale is an 11-point questionnaire to assess healthcare providers' attitudes toward individuals with suicidal ideation. Other questions pertaining to suicidal ideation, self-perceptions on ability to treat suicidal patients, and personal experiences with suicide were asked in Likert format.

RESULTS

One hundred eighty-eight Canadian EPs responded to the survey (15% response rate), with a median age of 49 (IQR 39-55), academic practice reported by 55% of respondents, and 65% of respondents identified as male. The mean USP score was 21.8 (95% CI 21.1-22.5), which indicates a generally positive attitude and willingness to provide care for suicidal patients. Only 17% of respondents had participated in specific training for treatment of suicidal patients in the last five years, while the majority of respondents estimate treating 5-15 patients with suicidal ideation a month. Sixty four percent of respondents indicated they had the skills to screen patients for suicidal ideation, but less than one-third felt they could create a personalized safety plan for patients.

CONCLUSIONS

Respondents have a generally positive attitude toward treating individuals with suicidal ideation. Respondents scored highly on the USP scale that measured willingness to provide care for and empathize with suicidal patients. Respondents felt they had the skills to adequately screen patients for suicidal ideation. Key gaps in knowledge were identified suggesting improved residency and ongoing medical education opportunities are needed to better improve care for this vulnerable population.

Comparing mortality and healthcare utilization in the year following a paramedic-attended non-fatal overdose among people who were and were not transported to hospital: A prospective cohort study using linked administrative health data

BACKGROUND

As the overdose emergency continues in British Columbia (BC), paramedic-attended overdoses are increasing, as is the proportion of people not transported to hospital following an overdose. This study investigated risk of death and subsequent healthcare utilization for people who were and were not transported to hospital after a paramedic-attended non-fatal overdose.

METHODS

Using a linked administrative health data set which includes all overdoses that come into contact with health services in BC, we conducted a prospective cohort study of people who experienced a paramedic-attended non-fatal overdose between 2015 and 2016. People were followed for 365 days after the index event. The primary outcomes assessed were all-cause mortality and overdose-related death. Additionally, we examined healthcare utilization after the index event.

RESULTS

In this study, 8659 (84%) people were transported and 1644 (16%) were not transported to hospital at the index overdose event. There were 279 overdose deaths (2.7% of people, 59.4% of deaths) during follow-up. There was no significant difference in risk of overdose-related death, though people not transported had higher odds of a subsequent non-fatal overdose event captured in emergency department and outpatient records within 90 days. People transported to hospital had higher odds of using hospital and outpatient services for any reason within 365 days.

CONCLUSIONS

Transport to hospital after a non-fatal overdose is an opportunity to provide care for underlying and chronic conditions. There is a need to better understand factors that contribute to non-transport, particularly among people aged 20-59 and people without chronic conditions.

Death after emergency department visits for opioid overdose in British Columbia: a retrospective cohort analysis

BACKGROUND

Visits to the emergency department are critical opportunities to engage individuals after an overdose. We sought to estimate and compare the 12-month mortality between persons with visits to the emergency department related to opioid overdose and those with non-overdose-related visits.

METHODS

We conducted a retrospective cohort study using the Provincial Overdose Cohort, which contains data for patients in British Columbia who had an opioid-related overdose between 2015 and 2017, along with a 20% random sample of BC residents for comparison. We examined all nonfatal visits to the emergency department between Jan. 1, 2015, and Dec. 31, 2016, among persons aged 14 to 74 years and compared the 12-month mortality between those with overdose-related visits and those with non-overdose-related visits. We estimated the hazard ratio for death, with adjustment for age, sex, comorbidity and disposition (discharged or left against medical advice).

RESULTS

We included 3593 persons with overdose-related visits and 216 453 with non-overdose-related visits to the emergency department. Those with overdose-related visits were younger, were predominantly male and had more mental health conditions. The 12-month crude mortality probability was 5.4% (95% confidence interval [CI] 4.7%-6.2%) in this group and 1.7% (95% CI 1.6%-1.8%) among those with non-overdose-related visits. After adjustment, for persons who were discharged, the 12-month mortality hazard was 3.5 (95% CI 3.0-4.2) times higher among those with overdose-related visits than those with non-overdose-related visits. For persons who left against medical advice, the mortality hazard was 7.1 (95% CI 4.0-12.5) times higher among those with opioid overdose.

INTERPRETATION

Among persons with overdose-related visits to the emergency department, 12-month mortality was higher than among those with non-overdose-related visits. Overdose-related visits should prompt urgent evidence-based interventions (e.g., take-home naloxone kits, buprenorphine-naloxone induction) to prevent future deaths.

Impact of cardiology follow-up care on treatment and outcomes of patients with new atrial fibrillation discharged from the emergency department

Aims

The first presentation of atrial fibrillation (AF) is often to an emergency department (ED). We evaluated the association of subsequent specialist care with morbidity and mortality.

Methods and results

Retrospective cohort study of all adults in Alberta, Canada, with a new primary diagnosis of AF treated and released during an index ED visit between 2009 and 2015. Types of physician follow-up within 3 months of ED visit was analysed using Cox proportional hazards models with time-varying covariates. Outcomes were evaluated at 1 year. Of 7986 patients, 476 (6.0%) had no physician follow-up within 3 months, whereas 2730 (34.2%) attended a non-specialist only, 1277 (16.0%) an internal medicine specialist, and 3503 (43.9%) cardiology. An increasing gradient of cardiac investigations occurred across these groups. Cardiology compared with non-cardiologist care was associated with approximately two-fold greater electrophysiology interventions and revascularization, and increased use of beta-blockers (48.9% vs. 43.0%, P &lt; 0.0001), statins (31.4% vs. 26.7%, P &lt; 0.0001), and oral anticoagulation in patients with CHADS2 scores ≥1 (53.7% vs. 43.6%, P &lt; 0.0001). In the subsequent year, cardiology care was associated with fewer deaths [adjusted hazard ratio (aHR) 0.72, 95% confidence interval (CI) 0.55–0.93], strokes (aHR 0.60, 95% CI 0.37–0.96), or major bleeds (aHR 0.69, 95% CI 0.53–0.89). No differences in the risk of hospitalization or ED visits were associated with cardiology care.

Conclusion

Cardiology care after an ED visit for symptomatic new-onset AF is associated with better prognosis. The benefit may be mediated through more intensive investigation, identification, and treatment of cardiovascular risk factors and disease.

Variation in Survival After Out-of-Hospital Cardiac Arrest Between Emergency Medical Services Agencies

Importance

Emergency medical services (EMS) deliver essential initial care for patients with out-of-hospital cardiac arrest (OHCA), but the extent to which patient outcomes vary between different EMS agencies is not fully understood.

Objective

To quantify variation in patient outcomes after OHCA across EMS agencies.

Design, Setting, and Participants

This observational cohort study was conducted in the Resuscitation Outcomes Consortium (ROC) Epistry, a prospective multicenter OHCA registry at 10 sites in North America. Any adult with OHCA treated by an EMS from April 2011 through June 2015 was included. Data analysis occurred from May 2017 to March 2018.

Exposure

Treating EMS agency.

Main Outcomes and Measures

The primary outcome was survival to hospital discharge. Secondary outcomes were return of spontaneous circulation at emergency department arrival and favorable functional outcome at hospital discharge (defined as a modified Rankin scale score ≤3). Multivariable hierarchical logistic regression models were used to adjust confounders and clustering of patients within EMS agencies, and calculated median odds ratios (MORs) were used to quantify the extent of residual variation in outcomes between EMS agencies.

Results

We identified 43 656 patients with OHCA treated by 112 EMS agencies. At EMS agency level, we observed large variations in survival to hospital discharge (range, 0%-28.9%; unadjusted MOR, 1.43 [95% CI, 1.34-1.54]), return of spontaneous circulation on emergency department arrival (range, 9.0%-57.1%; unadjusted MOR, 1.53 [95% CI, 1.43-1.65]), and favorable functional outcome (range, 0%-20.4%; unadjusted MOR, 1.54 [95% CI, 1.40-1.73]). This variation persisted despite adjustment for patient-level and EMS agency-level factors known to be associated with outcomes (adjusted MOR for survival 1.56 [95% CI 1.44-1.73]; adjusted MOR for return of spontaneous circulation at emergency department arrival, 1.50 [95% CI, 1.41-1.62]; adjusted MOR for functionally favorable survival, 1.53 [95% CI, 1.37-1.78]). After restricting analysis to those who survived more than 60 minutes after hospital arrival and including hospital treatment characteristics, the variation persisted (adjusted MOR for survival, 1.49 [95% CI, 1.36-1.69]; adjusted MOR for functionally favorable survival, 1.34 [95% CI, 1.20-1.59]).

Conclusions and Relevance

We found substantial variations in patient outcomes after OHCA between a large group of EMS agencies in North America that were not explained by documented patient-level and EMS agency-level variables.

A Multicenter Randomized Trial to Evaluate a Chemical-first or Electrical-first Cardioversion Strategy for Patients With Uncomplicated Acute Atrial Fibrillation

BACKGROUND

Emergency department (ED) patients with uncomplicated atrial fibrillation (AF) of less than 48 hours may be safely managed with rhythm control. Although both chemical-first and electrical-first strategies have been advocated, there are no comparative effectiveness data to guide clinicians.

METHODS

At six urban Canadian centers, ED patients ages 18 to 75 with uncomplicated symptomatic AF of less than 48 hours and CHADS₂ score of 0 or 1 were randomized using concealed allocation in a 1:1 ratio to one of the following strategies: 1) chemical cardioversion with procainamide infusion, followed by electrical countershock if unsuccessful; or 2) electrical cardioversion, followed by procainamide infusion if unsuccessful. The primary outcome was the proportion of patients discharged within 4 hours of arrival. Secondary outcomes included ED length-of-stay (LOS); prespecified ED-based adverse events; and 30-day ED revisits, hospitalizations, strokes, deaths, and quality of life (QoL).

RESULTS

Eighty-four patients were analyzed: 41 in the chemical-first group and 43 in the electrical-first group. Groups were balanced in terms of age, sex, vital signs, and CHADS₂ scores. All patients were discharged home, with 83 (99%) in sinus rhythm. In the chemical-first group, 13 of 41 patients (32%) were discharged within 4 hours compared to 29 of 43 patients (67%) in the electrical-first group (p = 0.001). In the chemical-first group, the median ED LOS was 5.1 hours (interquartile range [IQR] = 3.5 to 5.9 hours) compared to 3.5 hours (IQR = 2.4 to 4.6 hours) in the electrical-first group, for a median difference of 1.2 hours (95% confidence interval = 0.4 to 2.0 hours, p < 0.001). No patients experienced stroke or death. All other outcomes, including adverse events, ED revisits, and QoL, were similar.

CONCLUSION

In uncomplicated ED AF patients managed with rhythm control, chemical-first and electrical-first strategies both appear to be successful and well tolerated; however, an electrical-first strategy results in a significantly shorter ED LOS.

Racism Is Not a Factor in Door-to-electrocardiogram Times of Patients With Symptoms of Acute Coronary Syndrome: A Prospective, Observational Study

Background

Investigators have identified important racial identity/ethnicity‐based differences in some aspects of acute coronary syndrome (ACS) care and outcomes (time to presentation, symptoms, receipt of coronary angiography/revascularization, repeat revascularization, mortality). Patient‐based differences such as pathophysiology and treatment‐seeking behavior account only partly for these outcome differences. We sought to investigate whether there are racial identity/ethnicity‐based variations in the initial emergency department (ED) triage and care of patients with suspected ACS in Canadian hospitals.

Methods

We prospectively enrolled ED patients with suspected ACS from one university‐affiliated and two community hospitals. Trained research assistants administered a standardized interview to gather data on symptoms, treatment‐seeking patterns, and self‐reported racial/ethnic identity: “white,” South Asian” (SA), “Asian,” or “Other.” Clinical parameters were obtained through chart review. The primary outcome was door‐to‐electrocardiogram (D2ECG) time. ECG times were log‐transformed and two linear regression models, controlling for important demographic, system, and clinical factors, were fit.

Results

Of 448 participants, 214 (48%) reported white identity, 115 (26%) SA, 83 (19%) Asian, and 36 (8%) “Other.” Asian respondents were younger and more likely to report initial discomfort as “low” and be accompanied by family; respondents identifying as “Other” were more likely to report initial discomfort as “high.” There was no difference in D2ECG time between white participants and all other groups, but there were statistically significant differences by sex: women had longer D2ECG times than men. Exploring more specific racial identities revealed similar findings: no significant differences between the white, SA, Asian, and other groups, while sex (women had 13.4% [95% confidence interval, 0.81%–27.57%] longer D2ECG times) remained statistically significantly different in the adjusted models.

Conclusion

Although racial/ethnicity‐based differences in aspects of ACS care have been previously identified, we found no differences in the current study of early ED care in a Canadian urban setting. However, female patients experience longer D2ECG times, and this may be a target for process improvements.

Safety of a Modified Community Trailer to Manage Patients with Presumed Fentanyl Overdose

Opioid overdoses (OD) cause substantial morbidity and mortality globally, and current emergency management is typically limited to supportive care, with variable emphasis on harm reduction and addictions treatment. Our urban setting has a high concentration of patients with presumed fentanyl OD, which places a burden on both pre-hospital and emergency department (ED) resources. From December 13, 2016, to March 1, 2017, we placed a modified trailer away from an ED but near the center of the expected area of high OD and accepted low-risk patients with presumed fentanyl OD. We provided OD treatment as well as on-site harm reduction, addictions care, and community resources. The primary outcome was the proportion of patients requiring transfer to an ED for clinical deterioration, while secondary outcomes were the proportion of patients initiated on opioid agonists and provided take-home naloxone kits. We treated 269 patients with opioid OD, transferred three (1.1%) to a local ED, started 43 (16.0%) on opioid agonists, and provided 220 (81.7%) with THN. Our program appears to be safe and may serve as a model for other settings dealing with a large numbers of opioid OD.

Rapid agitation control with ketamine in the emergency department (RACKED): a randomized controlled trial protocol

Background

The rapid control of patients presenting to the emergency department (ED) with psychomotor agitation and violent behavior is paramount for the safety of patients and ED staff. The use of intramuscular (IM) ketamine in the pre-hospital and ED settings has demonstrated promising preliminary results to provide rapid and safe behavioral control. A prospective, randomized controlled trial is required to measure the potential superiority of IM ketamine compared to current standard care (IM benzodiazepines plus antipsychotics).

Methods

This will be a parallel, prospective, randomized, controlled trial of 5 mg/kg IM ketamine compared to a combination of 5 mg IM midazolam and 5 mg IM haloperidol. The study will enroll approximately 184 patients, randomized equally to two study arms. There will be one study visit during which study medication will be administered and assessments will be completed. A follow-up safety visit will occur on day 3. The primary objective of this study is to compare IM ketamine to a combination of IM midazolam and haloperidol with regards to the time required for adequate behavioral control, in minutes, in patients presenting to the ED with psychomotor agitation and violent behavior, as measured by the Richmond Agitation-Sedation Scale (RASS).

Discussion

We present a novel study to determine whether ketamine is a rapid and safe option, compared to a combination of midazolam and haloperidol for the sedation of patients presenting to the ED with psychomotor agitation and violent behavior. To our knowledge, this study is the first randomized controlled trial to compare ketamine to current standard care for this indication. We have attempted to address numerous logistical issues with the design of this study including a waiver of consent, ensuring adequate blinding of outcome assessors, patient enrolment, and data monitoring.

Trial registration

Clinicaltrials.gov, NCT03375671. Registered on 18 December 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2992-x) contains supplementary material, which is available to authorized users.

A Local Sensitivity Analysis of the Trial of Continuous or Interrupted Chest Compressions during Cardiopulmonary Resuscitation: Is a Local Protocol Change Required?

Objective

The “Trial of Continuous (CCC) or Interrupted Chest Compressions (ICC) during Cardiopulmonary Resuscitation (CPR)” compared two CPR strategies for out-of-hospital cardiac arrest (OHCA). Although results were neutral, there was suggestion of benefit for ICC. However, nearly 50% of study patients had a protocol violation; regional variations may have played a role in protocol adherence and outcomes. We analyzed our British Colombia (BC) cohort to decide whether a protocol change from CCC to ICC was justified.

Methods

This was a post-hoc analysis of BC-enrolled study patients. The primary between-group comparison was favorable neurological outcome (modified Rankin scale ≤ 3) using intention-to-treat. Secondary analyses compared those treated per-protocol (adjusted) and the top compliant clusters (unadjusted). We classified protocol violations using a structured algorithm. We used logistic regression and computed the difference in probabilities using the marginal standardization method with bootstrapping to calculate confidence intervals.

Results

There were 3769 patients included, with a median age of 69 years (IQR: 56–80). There were protocol violations in 3.2% of those in the CCC group and 27% of those in the ICC group. In patients randomized to CCC or ICC, 11.2% and 10.8% (risk difference 0.42%; 95% CI -1.58, 2.41) had favorable neurological outcomes, respectively. In the per-protocol and top compliant clusters comparisons, risk differences were 0.25% (95% CI -1.70, 2.25) and 2.95% (95% CI -0.68, 6.58).

Conclusion

Our comparisons suggest that CCC may be the preferred strategy in our region and is likely not resulting in worse outcomes. Based on the original study and our local analysis, we found no compelling reasons to change our local strategy from CCC to ICC.

Sex Differences in Cardiac Troponin Testing in Patients Presenting to the Emergency Department with Chest Pain

BACKGROUND

Elevated cardiac troponin (cTn), with signs/symptoms of ischemia, is a key element in a diagnosis of myocardial infarction (MI). Underdiagnosis of MI in women has been attributed to atypical symptoms, inconsistent ECG findings, and less diagnostic testing. We sought to determine if there are sex differences in cTn testing following presentation to the emergency department (ED) with a chief complaint of ischemic chest pain (CP) and if presentation affects diagnostic assessment.

METHODS

All adults presenting to six hospital EDs in the Vancouver, Canada with a chief complaint of ischemic CP from 2009 to 2013 were included. The highest cTn level within 24 hours of ED presentation was used. CP was classified into cardiac- or respiratory dominant based on standard Canadian Emergency Department Triage and Acuity Scale coding. Chi-square testing was used to test for sex differences in CP categories and cTn testing within 24 hours. Logistic regression models were used to examine the association between sex, cTn testing, and CP categories.

RESULTS

Of 27,063 patients with ischemic CP, cardiac presentation was more common in men than women, irrespective of age. Among cardiac CP, 24.7% of men were <50 years compared to 18.2% of women; however, more women (19.9%) than men (11.6%) were >80 years. Overall, women were 1.8% less likely to have cTn testing; in patients <50 years, testing was markedly lower in women compared to men [odds ratio, OR (95% confidence intervals, CI) 0.78 (0.70-0.87)]. The odds of cardiac catheterization within 90 days of ED presentation were lower in women [OR, (95% CI) 0.52 (0.44-0.63)]. Even with cardiac CP, 17.7% of women versus 32.7% of men had cardiac catheterization.

CONCLUSIONS

In men and women presenting to the ED with ischemic CP, cTn testing overall is similar except among young women under 50 years old, where it is markedly lower. Women undergo less cardiac catheterization, irrespective of CP type.

Sex Differences in Diagnoses, Treatment, and Outcomes for Emergency Department Patients With Chest Pain and Elevated Cardiac Troponin

OBJECTIVE

While sex differences in the treatment and outcomes of subjects with acute coronary syndromes are well documented, little is known about the impact of cardiac troponin (cTn) levels obtained in the emergency department (ED) on the observed sex differences. We sought to determine whether cTn levels by chest pain features modify sex differences in diagnosis, treatment, and outcomes in patients presenting with chest pain suggestive of ischemia.

METHODS

All adults presenting to two hospitals in Vancouver, Canada, between May 2008 and March 2013 with ischemic chest pain and with cTn testing were included in the study. Outcomes were obtained through data linkage with population-based administrative data sets, including Vital Statistics (death), Discharge Abstract Database (hospitalizations), and PharmaNet (medications). Cumulative event rates for the composite major adverse cardiac event (MACE) endpoint (death, myocardial infarction [MI], incident admission for heart failure or for angina requiring diagnostic catheterization or revascularization) were estimated for each sex and cTn level using the Kaplan-Meier method; Cox models were used to estimate hazard ratios and 95% confidence interval (CIs) for 1-year MACE and 7-day catheterization. Logistic models were used to estimate odds ratios (ORs) and 95% CI for 90-day medication use.

RESULTS

Over the 5-year study period, 25,539 patients presented to the ED with chest pain of which 7,272 (2,933 females and 4,339 males) met the inclusion criteria. Among patients with chest pain with cardiac features/history and cTn > 99th percentile, females were less likely to be diagnosed with MI (46.4% vs. 57.5%). Females in the cTnI > 99th percentile group had the worst outcomes with a 1-year MACE rate of 22.7% (95% CI = 18.5-27.7) versus 18.8% (95% CI = 16.2-21.6), although this difference was attenuated and not statistically significant after adjustment for baseline differences. Overall, females underwent fewer diagnostic catheterizations than males within 7 days of admission to the ED. Even when cTn was above the 99th percentile and the chest pain was cardiac in nature, 48.4% of females underwent a diagnostic catheterization compared to 64.3% of males (p < 0.001). Within 90 days of discharge, females were less likely to use the evidence-based cardiac medications. The most striking sex differences were noted when cTnI levels were > 99th percentile and when the chest pain was cardiac in nature; males filled 25% more prescriptions for statins than their female counterparts. Adjustment for baseline differences did not attenuate this difference.

CONCLUSIONS

Sex differences in diagnosis and treatment after presentation to the ED with chest pain are not explained by differences in chest pain features or levels of cTn. Even when females have cardiac chest pain and cTn levels > 99th percentile, they are less likely to be diagnosed with MI, less likely to undergo diagnostic cardiac catheterization within 7 days, and less likely to use evidence-based cardiac medications, but they have the highest 1-year MACE rate. The higher MACE rate appears to be driven by the higher burden of comorbid conditions.

Gains of Continuing Resuscitation in Refractory Out-of-hospital Cardiac Arrest: A Model-based Analysis to Identify Deaths Due to Intra-arrest Prognostication

OBJECTIVE

Prognostication bias, in which a clinician predicts a negative outcome and terminates resuscitation (TR) thereby ensuring a poor outcome, is a rarely identified limitation of out-of-hospital cardiac arrest (OHCA) research. We sought to estimate the number of deaths due to intra-arrest prognostication in a cohort of OHCA's, and use this data to estimate the incremental benefit of continuing resuscitation.

METHODS

This study examined a cohort of consecutive non-traumatic EMS-treated OHCAs from a provincial ambulance service, between 2007 and 2011 inclusive. We used Cox and logistic regression modeling, adjusting for Utstein covariates, to estimate the probability of ROSC, survival, and favorable neurological outcomes as a function of resuscitation time, and applied these models to estimate the number of missed survivors in those who had TR (prior to 20, 30, or 40 minutes). We determined the time juncture at which (1) the likelihood of survival fell below 1%, and (2) the proportion of survivors who had achieved ROSC exceeded 99%.

RESULTS

Of 5674 adult EMS-treated cases, 46% achieved ROSC, and 12% survived. The median time of TR was 27.0 minutes (IQR 19.0-35.0). Continuing resuscitation until 40 minutes yielded an estimated 17 additional survivors (95% CI 13-21), 10 (95% CI 7-13) with favorable neurological outcomes. The probability of survival of those in refractory arrest decreased below 1% at 28 minutes (95% CI 24-30 minutes). At 36 minutes (95% CI 34-38 minutes) >99% of survivors had achieved ROSC.

CONCLUSION

We identified possible deaths due to intra-arrest prognostication. Resuscitation should be continued for a minimum of 30 minutes in all patients, however for those with initial shockable rhythms 40 minutes appears to be warranted. Interventional trials and observational studies should standardize or adjust for duration of resuscitation prior to TR.

H1-antihistamines Reduce Progression to Anaphylaxis Among Emergency Department Patients With Allergic Reactions

OBJECTIVES

H1-antihistamines (H1a) can be used to treat emergency department (ED) patients with allergic reactions; however, this is inconsistently done, likely because there is no evidence that this therapy has an impact on serious outcomes. Among ED patients initially presenting with allergic reactions, we investigated whether H1a were associated with lower rates of progression to anaphylaxis.

METHODS

This was a retrospective cohort study conducted at two urban Canadian EDs from April 1, 2007, to March 31, 2012. We included consecutive adult patients with allergic reactions while excluding those presenting with anaphylaxis, according to prespecified criteria. The primary outcome was the proportion of patients who subsequently developed anaphylaxis during medical care, either by emergency medical services (EMS) or in the ED. A prespecified subgroup analysis excluded patients who received H1a prior to EMS or ED contact. We compared those who received H1a and those who did not and used multivariable regression and propensity score adjustment techniques to compare outcomes.

RESULTS

Of 2,376 overall patients included, 1,880 (79.1%) were managed with H1a. Of the latter group, 36 of 1,880 (1.9%) developed anaphylaxis, compared to 17 of 496 (3.4%) in the non-H1a-treated group (adjusted odds ratio [AOR] = 0.34, 95% confidence interval [CI] = 0.17-0.70; number needed to treat [NNT] to benefit = 44.74, 95% CI = 35.36-99.67). In the subgroup analysis of 1,717 patients who did not receive H1a prior to EMS or ED contact, a similar association was observed (AOR = 0.26, 95% CI = 0.10-0.50; NNT to benefit 38.20, 95% CI = 32.58-55.24).

CONCLUSIONS

Among ED patient with allergic reactions, H1a administration was associated with a lower likelihood of progression to anaphylaxis. These data indicate that early H1a treatment in the ED or prehospital setting may decrease progression to anaphylaxis.

External Validation of the Universal Termination of Resuscitation Rule for Out-of-Hospital Cardiac Arrest in British Columbia

STUDY OBJECTIVE

The Universal Termination of Resuscitation Rule (TOR Rule) was developed to identify out-of-hospital cardiac arrests eligible for field termination of resuscitation, avoiding futile transportation to the hospital. The validity of the rule in emergency medical services (EMS) systems that do not routinely transport out-of-hospital cardiac arrest patients to the hospital is unknown. We seek to validate the TOR Rule in British Columbia.

METHODS

This study included consecutive, nontraumatic, adult, out-of-hospital cardiac arrests treated by EMS in British Columbia from April 2011 to September 2015. We excluded patients with active do-not-resuscitate orders and those with missing data. Following consensus guidelines, we examined the validity of the TOR Rule after 6 minutes of resuscitation (to approximate three 2-minute cycles of resuscitation). To ascertain rule performance at the different time junctures, we recalculated TOR Rule classification accuracy at subsequent 1-minute resuscitation increments.

RESULTS

Of 6,994 consecutive, adult, EMS-treated, out-of-hospital cardiac arrests, overall survival was 15%. At 6 minutes of resuscitation, rule performance was sensitivity 0.72, specificity 0.91, positive predictive value 0.98, and negative predictive value 0.36. The TOR Rule recommended care termination for 4,367 patients (62%); of these, 92 survived to hospital discharge (false-positive rate 2.1%; 95% confidence interval 1.7% to 2.5%); however, this proportion steadily decreased with later application. The TOR Rule recommended continuation of resuscitation in 2,627 patients (38%); of these, 1,674 died (false-negative rate 64%; 95% confidence interval 62% to 66%). Compared with 6-minute application, test characteristics at 30 minutes demonstrated nearly perfect positive predictive value (1.0) and specificity (1.0) but a lower sensitivity (0.46) and negative predictive value (0.25).

CONCLUSION

In this cohort of adult out-of-hospital cardiac arrest patients, the TOR Rule applied at 6 minutes falsely recommended care termination for 2.1% of patients; however, this decreased with later application. Systems using the TOR Rule to cease resuscitation in the field should consider rule application at points later than 6 minutes.

In patients presenting to the emergency department with skin and soft tissue infections what is the diagnostic accuracy of point-of-care ultrasonography for the diagnosis of abscess compared to the current standard of care? A systematic review and meta-analysis

OBJECTIVES

The primary objective of this systematic review was to determine the accuracy of point-of-care ultrasonography (POCUS) in diagnosing abscess in emergency department (ED) patients with skin and soft tissue infections (SSTI). The secondary objective was the accuracy of POCUS in the paediatric population subgroup.

SETTING

Prospective studies set in emergency departments.

PARTICIPANTS

Emergency department patients (adult and paediatric) presenting with SSTI and suspected abscess.

PRIMARY AND SECONDARY OUTCOME MEASURES

This systematic review was conducted according to Cochrane Handbook guidelines, and the following databases were searched: PubMed, MEDLINE, EMBASE and the Cochrane database of systematic reviews (1946-2015). We included prospective cohort and case-control studies investigating ED patients with SSTI and abscess or cellulitis, a defined POCUS protocol, a clearly defined gold standard for abscess and a contingency table describing sensitivity and specificity. Two reviewers independently ascertained all potentially relevant citations for methodologic quality according to QUADAS-2 criteria. The primary outcome measure was the sensitivity and specificity of POCUS for abscess. A preplanned subgroup (secondary) analysis examined the effects in paediatric populations, and changes in management were explored post hoc.

RESULTS

Of 3028 articles, 8 were identified meeting inclusion criteria; all were rated as good to excellent according to QUADAS-2 criteria. Combined test characteristics of POCUS on the ED diagnosis of abscess for patients with SSTI were as follows: sensitivity 96.2% (95% CI 91.1% to 98.4%), specificity 82.9% (95% CI 60.4% to 93.9%), positive likelihood ratio 5.63 (95% CI 2.2 to 14.6) and negative likelihood ratio 0.05 (95% CI 0.01 to 0.11).

CONCLUSIONS

A total of 8 studies of good-to-excellent quality were included in this review. The use of POCUS helps differentiate abscess from cellulitis in ED patients with SSTI.

TRIAL REGISTRATION NUMBER

CRD42015017115.