Gender Differences in Defibrillator Practices in Out-of-Hospital Cardiac Arrest.

OBJECTIVES: Disparities remain in survival after out-of-hospital cardiac arrest (OHCA) for women compared to men. Our objective was to evaluate differences in automated external defibrillator (AED) use before Emergency Medical Services (EMS) arrival and time from arrival to initial EMS defibrillation by EMS-assessed gender (women or men). METHODS: This was a secondary analysis of adult non-traumatic, EMS-treated OHCA cases in the Portland Cardiac Arrest Epidemiologic Registry from 2018 to 2021. Emergency Medical Services-witnessed cardiac arrests were excluded and the primary outcomes were pre-EMS AED application and the time from EMS arrival to first defibrillation among patients in a shockable rhythm at first rhythm assessment without pre-EMS AED application. We examined pre-EMS AED application rates overall and separately for law enforcement, in cases where they were on-scene before EMS without a lay bystander AED applied, and lay responders, in cases where law enforcement had not applied an AED. We used multivariable logistic and linear regressions to adjust for potential confounders, including age, arrest location, witness status, bystander CPR, year, and time from dispatch to EMS arrival. We accounted for clustering by county of arrest using a mixed-effects approach. RESULTS: Of the 3,135 adult, EMS-treated non-traumatic OHCAs that were not witnessed by EMS, 3,049 had all variables for analysis, of which 1,011 (33.2%) were women. The adjusted odds (adjusted odds ratio [95% CI]) for any pre-EMS placement of an AED was significantly higher for men compared to women (1.40 [1.05-1.86]). These odds favoring men remained when examining law enforcement AED application (1.89 [1.16-3.07]), but not lay bystander AED application (1.19 [0.83-1.71]). Among patients still in arrest on EMS arrival, with a shockable initial EMS rhythm, and without pre-EMS AED application, the time from EMS arrival on-scene to initial defibrillation was significantly longer for women compared to men (+0.81 min [0.22-1.41 min]). CONCLUSIONS: Women with OHCA received lower rates of pre-EMS AED application and delays in initial EMS defibrillation compared to men.

Initial Validity Evidence for the American Board of Emergency Medicine Emergency Medical Services Certification Examination.

OBJECTIVES: The American Board of Emergency Medicine (ABEM) Emergency Medical Services Medicine (EMS) subspecialty was approved by the American Board of Medical Specialties on September 23, 2010. Subspecialty certification in EMS was contingent on two key elements-completing Accreditation Council for Graduate Medical Education (ACGME)-accredited EMS training and passing the subspecialty certification examination developed by ABEM. The first EMS certification examination was offered in October 2013. Meaningful certification requires rigorous assessment. In this instance, the EMS certification examination sought to embrace the tenets of validity, reliability, and fairness. For the purposes of this report, the sources of validity evidence were anchored on the EMS core content, the examination development process, and the association between fellowship training and passing the certification examination. METHODS: We chose to use validity evidence that included: 1) content validity (based on the EMS core content); 2) response processes (test items required intended cognitive processes); 3) internal structure supported by the internal relationships among items; 4) relations to other variables, specifically the association between examination performance and ACGME-accredited fellowship training; and 5) the consequences of testing. RESULTS: There is strong content validity evidence for the EMS examination based on the core content and its detailed development process. The core content and supporting job-task analysis was also used to define the examination blueprint. Internal structure support was evidenced by Cronbach's coefficient alpha, which ranged from 0.82 to 0.92. Physicians who completed ACGME-accredited EMS fellowship training were more likely to pass the EMS certification examination (chi square, p < 0.0001; Cramér's, V = 0.24). Finally, there were two sources of consequential validity evidence-use of test results to determine certification and use of the resulting certificate. CONCLUSIONS: There is substantial and varied validity evidence to support the use of the EMS certifying examination in making summative decisions to award certification in EMS. Of note, there was a statistically significant association between ACGME-accredited fellowship training and passing the examination.

Utility of end-tidal carbon dioxide to guide resuscitation termination in prolonged out-of-hospital cardiac arrest.

STUDY OBJECTIVE: To evaluate if the change in end-tidal carbon dioxide (ETCO2) over time has improved discriminatory value for determining resuscitation futility compared to a single ETCO2 value in prolonged, refractory non-shockable out-of-hospital cardiac arrest (OHCA). METHODS: This is a retrospective analysis of adult refractory non-shockable, non-traumatic OHCA patients in the Portland Cardiac Arrest Epidemiologic Registry (PDX Epistry) from 2018 to 2021. We defined refractory non-shockable OHCA cases as patients with lack of a shockable rhythm at any time or return of spontaneous circulation at any time prior to 30-min of on-scene resuscitation. We abstracted ETCO2 values first recorded after advanced airway placement and nearest to the 30-min mark of on-scene resuscitation (30 min-ETCO2) from EMS charts. The primary outcome was survival to hospital discharge. We compared 30 min-ETCO2 cutoffs of 10 mmHg and 20 mmHg to the trend (increasing or not) from initial to 30 min-ETCO2 (delta-ETCO2) using sensitivity, specificity, and area under the receiver operating curves (AUROC). RESULTS: Of 3837 adult OHCA, 2850 were initially non-shockable, and there were 617 (16.1%) cases of refractory non-shockable OHCA at 30-min. We excluded 320 cases without at least two ETCO2 recordings in the EMS chart, leaving 297 cases that met inclusion criteria. Of these, 176 (59.3%) were transported and 2 (0.7%) survived to discharge. Using absolute 30 min-ETCO2 cutoffs, both survivors were in the >10 mmHg group (sensitivity 100.0%, specificity 12.5%), whereas only one survivor was identified in the >20 mmHg group (sensitivity 50.0%, specificity 32.5%). Using delta-ETCO2, both survivors were in the increasing ETCO2 group (sensitivity 100.0%, specificity 60.7%). In comparing the two tests that did not misclassify survivors, the AUROC [95% CI] was higher when using delta-ETCO2 (0.803 [0.775-0.831]) compared to an absolute cutoff of 10 mmHg (0.563 [0.544-0.582]). CONCLUSIONS: Nearly one-sixth of EMS-treated adult OHCA patients had refractory non-shockable arrests after at least 30 min of ongoing resuscitation. In this group, the ETCO2 trend following advanced airway placement may be more accurate in guiding termination of resuscitation than an absolute ETCO2 cutoff of 10 or 20 mmHg.

Outcomes with Tibial and Humeral Intraosseous Access Compared to Peripheral Intravenous Access in Out-of-Hospital Cardiac Arrest.

BACKGROUND: The optimal initial vascular access strategy for out-of-hospital cardiac arrest (OHCA) remains unknown. Our objective was to evaluate the association between peripheral intravenous (PIV), tibial intraosseous (TIO), or humeral intraosseous (HIO) as first vascular attempt strategies and outcomes for patients suffering OHCA. METHOD: This was a secondary analysis of the Portland Cardiac Arrest Epidemiologic Registry, which included adult patients (≥18 years-old) with EMS-treated, non-traumatic OHCA from 2018-2021. The primary independent variable in our analysis was the initial vascular access strategy, defined as PIV, TIO, or HIO based on the first access attempt. The primary outcome for this study was the return of spontaneous circulation (ROSC) at emergency department (ED) arrival (a palpable pulse on arrival to the hospital). Secondary outcomes included survival to: admission, discharge, and discharge with a favorable outcome (Cerebral Perfusion Category score of ≤2). We conducted multivariable logistic regressions, adjusting for confounding variables and for clustering using a mixed-effects approach, with prespecified subgroup analyses by initial rhythm. RESULTS: We included 2,993 patients with initial vascular access strategies of PIV (822 [27.5%]), TIO (1,171 [39.1%]), and HIO (1,000 [33.4%]). Multivariable analysis showed lower odds of ROSC at ED arrival (adjusted odds ratio [95% CI]) with TIO (0.79 [0.64-0.98]) or HIO (0.75 [0.60-0.93]) compared to a PIV-first strategy. These associations remained in stratified analyses for those with shockable initial rhythms (0.60 [0.41-0.88] and 0.53 [0.36-0.79]) but not in patients with asystole or pulseless electrical activity for TIO and HIO compared to PIV, respectively. There were no statistically significant differences in adjusted odds for survival to admission, discharge, or discharge with a favorable outcome for TIO or HIO compared to the PIV-first group in the overall analysis. Patients with shockable initial rhythms had lower adjusted odds of survival to discharge (0.63 [0.41-0.96] and 0.64 [0.41-0.99]) and to discharge with a favorable outcome (0.60 [0.39-0.93] and 0.64 [0.40-1.00]) for TIO and HIO compared to PIV, respectively. CONCLUSIONS: TIO or HIO as first access strategies in OHCA were associated with lower odds of ROSC at ED arrival compared to PIV.

Utilization and Effect of Direct Medical Oversight during Out-of-Hospital Cardiac Arrest.

STUDY OBJECTIVE: Direct medical oversight (DMO), where emergency medical services (EMS) clinicians contact a physician for real-time medical direction, is used by many EMS systems across the United States. Our objective was to characterize the recommendations made by DMO during out-of-hospital cardiac arrests (OHCA) and to determine their effect on EMS transport decisions and patient outcomes. METHODS: This is a secondary analysis of DMO call recordings from OHCA cases in the Portland, Oregon metropolitan area from January 1, 2018 to February 28, 2021. Data extracted from the audio recordings were linked to OHCA cases in the Portland Cardiac Arrest Epidemiologic Registry (PDX Epistry). The primary outcomes are recommendations made by DMO: transport, continued field resuscitation, or termination of resuscitation (TOR). Secondary outcomes include EMS transport decisions, survival to hospital admission, and survival to hospital discharge. We used descriptive statistics, unpaired t-tests, and chi-square tests as appropriate for data analysis. RESULTS: There were 239 OHCA cases for which DMO was contacted by EMS. The median time from EMS arrival to DMO contact was 25.6 min, and EMS requested TOR for 72.0% of patients. Compared to patients where EMS requested further treatment advice, patients for whom EMS requested TOR had poor prognostic signs including older age, asystole as an initial rhythm, and lower rates of transient return of spontaneous circulation prior to DMO call compared with cases where EMS did not request TOR. DMO recommended transport, continued field resuscitation, or TOR in 21.8%, 18.0%, and 60.2% of patients, respectively. Of the 239 patients, 59 (24.7%) were ultimately transported by EMS to the hospital, 14 (5.9%) survived to admission, and only 1 patient (0.4%) survived to hospital discharge and had an acceptable neurologic outcome (Cerebral Performance Category score of 2). CONCLUSIONS: Patients for whom EMS contacts DMO for further treatment advice or requesting field TOR after prolonged OHCA resuscitation have poor outcomes, even when DMO recommends transport or further resuscitation, and may represent opportunities to reduce unnecessary DMO contact or patient transports. More research is needed to determine which OHCA patients benefit from DMO contact.

Urine culture practices for complicated urinary tract infections in an academic emergency department.

OBJECTIVE: Complicated UTIs (cUTIs) are defined by a heterogenous group of risk factors that place the patient at increased risk of treatment failure in whom urine cultures are recommended. We evaluated the ordering practices for urine cultures for cUTI patients and patient outcomes in an academic hospital setting. METHODS: Retrospective chart review of adults of 18 years and older with cUTIs diagnosed in a single academic emergency department (ED). We reviewed 398 patient encounters based on a range of ICD-10 diagnosis codes consistent with cUTI between 1/1/2019 and 6/30/2019. The definition of cUTI consisted of thirteen subgroups composited from existing literature and guidelines. The primary outcome was ordering a urine culture for cUTI. We also assessed impact of the urine culture results and compared clinical course severity and readmission rates between cultured and not cultured patients. RESULTS: During this period, the ED had 398 potential cUTI visits based on ICD-10 code, of which 330 (82.9%) met the study inclusion criteria for cUTI. Of these cUTI encounters, clinicians failed to obtain urine cultures in 92 (29.8%). Of the 217 cUTI with cultures, 121 (55.8%) demonstrated sensitivity to original treatment, 10 (4.6%) demonstrated the need to change antimicrobial coverage, 49 (22.6%) demonstrated the presence of contamination, and 29 (13.4%) demonstrated insignificant growth. Patients with cUTI who received cultures experienced higher rates of admission to both ED observation (33.2% vs 16.3%, p = 0.003) and the hospital (41.9% vs 23.8%, p = 0.003) compared to those with missed cultures. Admitted cUTI patients experienced greater length of hospital stay when cultures were obtained (3.23 vs 1.53 days, p < 0.001). Readmission rates for patients with cUTI discharged from the ED within 30 days were 4.0% for patients with urine cultures and 7.3% for patients without urine cultures (p = 0.155). CONCLUSION: Over a quarter of cUTI patients in this study did not receive a urine culture. Further studies are needed to assess if improving adherence to urine culturing practices for cUTIs will impact clinical outcomes.

Characterization of non-cardiac arrest PulsePoint activations in public and private settings.

BACKGROUND: Geospatial smartphone application alert systems are used in some communities to crowdsource community response for out-of-hospital cardiac arrest (OHCA). Although the clinical focus of this strategy is OHCA, dispatch identification of OHCA is imperfect so that activation may occur for the non-arrest patient. The frequency and clinical profile of such non-arrest patients has not been well-investigated. METHODS: We undertook a prospective 3-year cohort investigation of patients for whom a smartphone geospatial application was activated for suspected OHCA in four United States communities (total population ~1 million). The current investigation evaluates those patients with an activation for suspected OHCA who did not experience cardiac arrest. The volunteer response cohort included off-duty, volunteer public safety personnel (verified responders) notified regardless of location (public or private) and laypersons notified to public locations. The study linked the smartphone application information with the EMS records to report the frequency, condition type, and EMS treatment for these non-arrest patients. RESULTS: Of 1779 calls where volunteers were activated, 756 had suffered OHCA, resulting in 1023 non-arrest patients for study evaluation. The most common EMS assessments were syncope (15.9%, n=163), altered mental status (15.5%, n=159), seizure (14.3%, n=146), overdose (13.0%, n=133), and choking (10.5%, n=107). The assessment distribution was similar for private and public locations. Overall, the most common EMS interventions included placement of an intravenous line (43.1%, n=441), 12-Lead ECG(27.9%, n=285), naloxone treatment (9.8%, n=100), airway or ventilation assistance (8.7%, n=89), and oxygen administration (6.6%, n=68). CONCLUSIONS: More than half of patients activated for suspected OHCA had conditions other than cardiac arrest. A subset of these conditions may benefit from earlier care that could be provided by both layperson and public safety volunteers if they were appropriately trained and equipped.

Association of Advanced Airway Insertion Timing and Outcomes After Out-of-Hospital Cardiac Arrest.

STUDY OBJECTIVE: While often prioritized in the resuscitation of patients with out-of-hospital cardiac arrest, the optimal timing of advanced airway insertion is unknown. We evaluated the association between the timing of advanced airway (laryngeal tube and endotracheal intubation) insertion attempt and survival to hospital discharge in adult out-of-hospital cardiac arrest. METHODS: We performed a secondary analysis of the Pragmatic Airway Resuscitation Trial (PART), a clinical trial comparing the effects of laryngeal tube and endotracheal intubation on outcomes after adult out-of-hospital cardiac arrest. We stratified the cohort by randomized airway strategy (laryngeal tube or endotracheal intubation). Within each subset, we defined a time-dependent propensity score using patients, arrest, and emergency medical services systems characteristics. Using the propensity score, we matched each patient receiving an initial attempt of laryngeal tube or endotracheal intubation with a patient at risk of receiving laryngeal tube or endotracheal intubation attempt within the same minute. RESULTS: Of 2,146 eligible patients, 1,091 (50.8%) and 1,055 (49.2%) were assigned to initial laryngeal tube and endotracheal intubation strategies, respectively. In the propensity score-matched cohort, timing of laryngeal tube insertion attempt was not associated with survival to hospital discharge: 0 to lesser than 5 minutes (risk ratio [RR]=1.35, 95% confidence interval [CI] 0.53 to 3.44); 5 to lesser than10 minutes (RR=1.07, 95% CI 0.66 to 1.73); 10 to lesser than 15 minutes (RR=1.17, 95% CI 0.60 to 2.31); or 15 to lesser than 20 minutes (RR=2.09, 95% CI 0.35 to 12.47) after advanced life support arrival. Timing of endotracheal intubation attempt was also not associated with survival: 0 to lesser than 5 minutes (RR=0.50, 95% CI 0.05 to 4.87); 5 to lesser than10 minutes (RR=1.20, 95% CI 0.51 to 2.81); 10 to lesser than15 minutes (RR=1.03, 95% CI 0.49 to 2.14); 15 to lesser than 20 minutes (RR=0.85, 95% CI 0.30 to 2.42); or more than/equal to 20 minutes (RR=0.71, 95% CI 0.07 to 7.14). CONCLUSION: In the PART, timing of advanced airway insertion attempt was not associated with survival to hospital discharge.

The Association Between the Number of Prehospital Providers On-Scene and Out-of-Hospital Cardiac Arrest Outcomes.

Objective: The ideal number of emergency medical services (EMS) providers needed on-scene during an out-of-hospital cardiac arrest (OHCA) resuscitation is unknown. Our objective was to evaluate the association between the number of providers on-scene and OHCA outcomes. Methods: This was a secondary analysis of adults (≥18 years old) with non-traumatic OHCA from a 10-site North American prospective cardiac arrest registry (Resuscitation Outcomes Consortium) including a 2005-2011 cohort and a 2011-2015 cohort. The primary outcome was survival to hospital discharge. We calculated the median number of EMS providers on-scene during the first 10 minutes of the resuscitation and used multivariable logistic regression adjusting for age, sex, witness status, bystander CPR, arrest location, initial rhythm, and dispatch to EMS arrival time. Results: There were 30,613 and 41,946 patients with necessary variables in the 2005-2011 and 2011-2015 cohorts, respectively. Survival to hospital discharge (95% CI) was higher with 9 or more providers on-scene (17.2% [15.8-18.5] and 14.0% [12.6-15.4]) compared to 7-8 (14.1% [13.4-14.8] and 10.5% [9.9-11.1]), 5-6 (10.0% [9.5-10.5] and 8.5% [8.1-8.9]), 3-4 (10.5% [9.3-11.6] and 9.3% [8.5-10.1]), and 1-2 (8.6% [7.2-10.0] and 8.0% [7.1-9.0]) providers for the 2005-2011 and 2011-2015 cohorts, respectively. In multivariable logistic regressions, compared to 5-6 providers, there were no significant differences in survival to hospital discharge for 1-2 or 3-4 providers, while having 7-8 (adjusted odds ratios (aORs) 1.53 [1.39-1.67] and 1.31 [1.20-1.44]) and 9 or more (aORs 1.76 [1.56-1.98] and 1.63 [1.41-1.89]) providers were associated with improved survival in both the 2005-2011 and 2011-2015 cohorts, respectively. Conclusions: The presence of seven or more prehospital providers on-scene was associated with significantly greater adjusted odds of survival to hospital discharge after OHCA compared to fewer on-scene providers.

Prehospital Cardiac Arrest Airway Management: An NAEMSP Position Statement and Resource Document.

Airway management is a critical component of out-of-hospital cardiac arrest (OHCA) resuscitation. Multiple cardiac arrest airway management techniques are available to EMS clinicians including bag-valve-mask (BVM) ventilation, supraglottic airways (SGAs), and endotracheal intubation (ETI). Important goals include achieving optimal oxygenation and ventilation while minimizing negative effects on physiology and interference with other resuscitation interventions. NAEMSP recommends:Based on the skill of the clinician and available resources, BVM, SGA, or ETI may be considered as airway management strategies in OHCA.Airway management should not interfere with other key resuscitation interventions such as high-quality chest compressions, rapid defibrillation, and treatment of reversible causes of the cardiac arrest.EMS clinicians should take measures to avoid hyperventilation during cardiac arrest resuscitation.Where available for clinician use, capnography should be used to guide ventilation and chest compressions, confirm and monitor advanced airway placement, identify return of spontaneous circulation (ROSC), and assist in the decision to terminate resuscitation.

Prehospital Airway Management: A Systematic Review.

Objective: To assess comparative benefits and harms across three airway management approaches (bag valve mask [BVM], supraglottic airway [SGA], and endotracheal intubation [ETI]) used by prehospital emergency medical services (EMS) to treat patients with trauma, cardiac arrest, or medical emergencies, and how they differ based on techniques and devices, EMS personnel and patient characteristics. Data sources: We searched electronic citation databases (Ovid® MEDLINE®, CINAHL®, the Cochrane Central Register of Controlled Trials, the Cochrane Database of Systematic Reviews, and Scopus®) from 1990 to September 2020. Review methods: We followed Agency for Healthcare Research and Quality Effective Health Care Program Methods guidance. Outcomes included mortality, neurological function, return of spontaneous circulation (ROSC), and successful advanced airway insertion. Meta-analyses using profile-likelihood random effects models were conducted, with analyses stratified by study design, emergency type, and age. Results: We included 99 studies involving 630,397 patients. We found few differences in primary outcomes across airway management approaches. For survival, there was no difference for BVM versus ETI or SGA in adult and pediatric patients with cardiac arrest or trauma. For neurological function, there was no difference for BVM versus ETI and SGA versus ETI in pediatric patients with cardiac arrest. There was no difference in BVM versus ETI in adults with cardiac arrest, but improved neurological function with BVM or ETI versus SGA. There was no difference in ROSC for patients with cardiac arrest for BVM versus ETI or SGA in adults and pediatrics, or SGA versus ETI in pediatrics. There was higher frequency of ROSC in adults with SGA versus ETI. For successful advanced airway insertion, there was higher first-pass success with SGA versus ETI for all patients except adult medical patients (no difference), and no difference in overall success using SGA versus ETI in adults. Conclusions: The currently available evidence does not indicate benefits of more invasive airway approaches based on survival, neurological function, ROSC, or successful airway insertion. Strength of evidence was low or moderate; most included studies were observational. This supports the need for high-quality randomized controlled trials to advance clinical practice and EMS education and policy, and improve patient-centered outcomes.

There is little association between prehospital delay, persistent symptoms, and post-discharge healthcare utilization in patients evaluated for acute coronary syndrome.

AIMS: Test for an association between prehospital delay for symptoms suggestive of acute coronary syndrome (ACS), persistent symptoms, and healthcare utilization (HCU) 30-days and 6-months post hospital discharge. BACKGROUND: Delayed treatment for ACS increases patient morbidity and mortality. Prehospital delay is the largest factor in delayed treatment for ACS. METHODS: Secondary analysis of data collected from a multi-center prospective study. Included were 722 patients presenting to the Emergency Department (ED) with symptoms that triggered a cardiac evaluation. Symptoms and HCU were measured using the 13-item ACS Symptom Checklist and the Froelicher's Health Services Utilization Questionnaire-Revised instrument. Logistic regression models were used to examine hypothesized associations. RESULTS: For patients with ACS (n = 325), longer prehospital delay was associated with fewer MD/NP visits (OR, 0.986) at 30 days. Longer prehospital delay was associated with higher odds of calling 911 for any reason (OR, 1.015), and calling 911 for chest related symptoms (OR, 1.016) 6 months following discharge. For non-ACS patients (n = 397), longer prehospital delay was associated with higher odds of experiencing chest pressure (OR, 1.009) and chest discomfort (OR, 1.008) at 30 days. At 6 months, longer prehospital delay was associated with higher odds of upper back pain (OR, 1.013), palpitations (OR 1.014), indigestion (OR, 1.010), and calls to the MD/NP for chest symptoms (OR, 1.014). CONCLUSIONS: There were few associations between prehospital delay and HCU for patients evaluated for ACS in the ED. Associations between prolonged delay and persistent symptoms may lead to increased HCU for those without ACS.

Survival After Intravenous Versus Intraosseous Amiodarone, Lidocaine, or Placebo in Out-of-Hospital Shock-Refractory Cardiac Arrest.

BACKGROUND: Antiarrhythmic drugs have not proven to significantly improve overall survival after out-of-hospital cardiac arrest from shock-refractory ventricular fibrillation/pulseless ventricular tachycardia. How this might be influenced by the route of drug administration is not known. METHODS: In this prespecified analysis of a randomized, placebo-controlled clinical trial, we compared the differences in survival to hospital discharge in adults with shock-refractory ventricular fibrillation/pulseless ventricular tachycardia out-of-hospital cardiac arrest who were randomly assigned by emergency medical services personnel to an antiarrhythmic drug versus placebo in the ALPS trial (Resuscitation Outcomes Consortium Amiodarone, Lidocaine or Placebo Study), when stratified by the intravenous versus intraosseous route of administration. RESULTS: Of 3019 randomly assigned patients with a known vascular access site, 2358 received ALPS drugs intravenously and 661 patients by the intraosseous route. Intraosseous and intravenous groups differed in sex, time-to-emergency medical services arrival, and some cardiopulmonary resuscitation characteristics, but were similar in others, including time-to-intravenous/intrasosseous drug receipt. Overall hospital discharge survival was 23%. In comparison with placebo, discharge survival was significantly higher in recipients of intravenous amiodarone (adjusted risk ratio, 1.26 [95% CI, 1.06-1.50]; adjusted absolute survival difference, 5.5% [95% CI, 1.5-9.5]) and intravenous lidocaine (adjusted risk ratio, 1.21 [95% CI, 1.02-1.45]; adjusted absolute survival difference, 4.7% [95% CI, 0.7-8.8]); but not in recipients of intraosseous amiodarone (adjusted risk ratio, 0.94 [95% CI, 0.66-1.32]) or intraosseous lidocaine (adjusted risk ratio, 1.03 [95% CI, 0.74-1.44]). Survival to hospital admission also increased significantly when drugs were given intravenously but not intraosseously, and favored improved neurological outcome at discharge. There were no outcome differences between intravenous and intraosseous placebo, indicating that the access route itself did not demarcate patients with poor prognosis. The study was underpowered to assess intravenous/intraosseous drug interactions, which were not statistically significant. CONCLUSIONS: We found no significant effect modification by drug administration route for amiodarone or lidocaine in comparison with placebo during out-of-hospital cardiac arrest. However, point estimates for the effects of both drugs in comparison with placebo were significantly greater for the intravenous than for the intraosseous route across virtually all outcomes and beneficial only for the intravenous route. Given that the study was underpowered to statistically assess interactions, these findings signal the potential importance of the drug administration route during resuscitation that merits further investigation.

Variation in Bystander Cardiopulmonary Resuscitation Delivery and Subsequent Survival From Out-of-Hospital Cardiac Arrest Based on Neighborhood-Level Ethnic Characteristics.

BACKGROUND: Bystander cardiopulmonary resuscitation (B-CPR) delivery and survival after out-of-hospital cardiac arrest vary at the neighborhood level, with lower survival seen in predominantly black neighborhoods. Although the Hispanic population is the fastest-growing minority population in the United States, few studies have assessed whether the proportion of Hispanic residents in a neighborhood is associated with B-CPR delivery and survival from out-of-hospital cardiac arrest. We assessed whether B-CPR rates and survival vary by neighborhood-level ethnicity. We hypothesized that neighborhoods with a higher proportion of Hispanic residents have lower B-CPR rates and lower survival. METHODS: We conducted a retrospective cohort study using data from the Resuscitation Outcomes Consortium Epistry at US sites. Neighborhoods were classified by census tract based on percentage of Hispanic residents: <25%, 25% to 50%, 51% to 75%, or >75%. We independently modeled the likelihood of receipt of B-CPR and survival by neighborhood-level ethnicity controlling for site and patient-level confounding characteristics. RESULTS: From 2011 to 2015, the Resuscitation Outcomes Consortium collected 27 481 US arrest events; after excluding pediatric arrests, emergency medical services-witnessed arrests, or arrests occurring in a healthcare or institutional facility, 18 927 were included. B-CPR was administered in 37% of events. In neighborhoods with <25% Hispanic residents, B-CPR was administered in 39% of events, whereas it was administered in 27% of events in neighborhoods with >75% Hispanic residents. Compared with <25% Hispanic neighborhoods in a multivariable analysis, out-of-hospital cardiac arrest in predominantly Hispanic neighborhoods had lower B-CPR rates (51% to 75% Hispanic: odds ratio, 0.79 [CI, 0.65-0.95], P=0.014; >75% Hispanic: odds ratio, 0.72 [CI, 0.55-0.96], P=0.025) and lower survival rates (global P value 0.029; >75% Hispanic: odds ratio, 0.56 [CI, 0.34-0.93], P=0.023). CONCLUSIONS: Individuals with out-of-hospital cardiac arrest in predominantly Hispanic neighborhoods were less likely to receive B-CPR and had lower likelihood of survival. These findings suggest a need to understand the underlying disparities in cardiopulmonary resuscitationdelivery and an unmet cardiopulmonary resuscitationtraining need in Hispanic communities.

Fatal Sodium Nitrite Poisoning: Key Considerations for Prehospital Providers.

Sodium nitrite is a powerful oxidizing agent that causes hypotension and limits oxygen transport and delivery in the body through the formation of methemoglobin. Clinical manifestations can include cyanosis, hypoxia, altered consciousness, dysrhythmias, and death. The majority of reports on sodium nitrite poisonings have been the result of unintentional exposures. We report a case of an intentional fatal overdose of sodium nitrite. A 17-year-old female reportedly drank approximately one tablespoon of sodium nitrite in a self-harm attempt. The patient was hypotensive and cyanotic upon EMS arrival. The patient decompensated rapidly into a bradycardic arrest during transport despite intubation, push-dose epinephrine, and intravenous fluid resuscitation. In the Emergency Department (ED), she received methylene blue and packed red cells but could not be resuscitated despite a prolonged effort. EMS professionals should consider sodium nitrite toxicity in patients with a suspected overdose who present with a cyanotic appearance, pulse oximetry that remains around 85% despite oxygen, and dark brown blood seen on venipuncture. Early prehospital contact with the Poison Control Center and ED prenotification in poisoned patients is encouraged.

Relationship Between Duration of Targeted Temperature Management, Ischemic Interval, and Good Functional Outcome From Out-of-Hospital Cardiac Arrest.

OBJECTIVES: Tailoring hypothermia duration to ischemia duration may improve outcome from out-of-hospital cardiac arrest. We investigated the association between the hypothermia/ischemia ratio and functional outcome in a secondary analysis of data from the Resuscitation Outcomes Consortium Amiodarone, Lidocaine, or Placebo Study trial. DESIGN: Cohort study of out-of-hospital cardiac arrest patients screened for Resuscitation Outcomes Consortium-Amiodarone, Lidocaine, or Placebo Study. SETTING: Multicenter study across North America. PATIENTS: Adult, nontraumatic, out-of-hospital cardiac arrest patients screened for Resuscitation Outcomes Consortium-Amiodarone, Lidocaine, or Placebo Study who survived to hospital admission and received targeted temperature management between May 2012 and October 2015. INTERVENTIONS: Targeted temperature management in comatose survivors of out-of-hospital cardiac arrest. We defined hypothermia/ischemia ratio as total targeted temperature management time (initiation through rewarming) divided by calculated total ischemia time (approximate time of arrest [9-1-1 call or emergency medical services-witnessed] to return of spontaneous circulation). MEASUREMENTS AND MAIN RESULTS: The primary outcome was hospital survival with good functional status (modified Rankin Score, 0-3) at hospital discharge. We fitted logistic regression models to estimate the association between hypothermia/ischemia ratio and the primary outcome, adjusting for demographics, arrest characteristics, and Resuscitation Outcomes Consortium enrolling site. A total of 3,429 patients were eligible for inclusion, of whom 36.2% were discharged with good functional outcome. Patients had a mean age of 62.0 years (SD, 15.8), with 69.7% male, and 58.0% receiving lay-rescuer cardiopulmonary resuscitation. Median time to return of spontaneous circulation was 21.1 minutes (interquartile range, 16.1-26.9), and median duration of targeted temperature management was 32.9 hours (interquartile range, 23.7-37.8). A total of 2,579 had complete data and were included in adjusted regression analyses. After adjustment for patient characteristics and Resuscitation Outcomes Consortium site, a greater hypothermia/ischemia ratio was associated with increased survival with good functional outcome (odds ratio, 2.01; 95% CI, 1.82-2.23). This relationship, however, appears to be primarily driven by time to return of spontaneous circulation in this patient cohort. CONCLUSIONS: Although a larger hypothermia/ischemia ratio was associated with good functional outcome after out-of-hospital cardiac arrest in this cohort, this association is primarily driven by duration of time to return of spontaneous circulation. Tailoring duration of targeted temperature management based on duration of time to return of spontaneous circulation or patient characteristics requires prospective study.

Disparity in Receipt and Utilization of Telecommunicator CPR Instruction.

Introduction: Telecommunicator Assisted Cardiopulmonary Resuscitation (T-CPR) is independently associated with improved survival and improved functional outcome after adult Out of Hospital Cardiac Arrest (OHCA). The objective of this study was to evaluate whether there are racial and socioeconomic disparities in the provision of T-CPR instruction and subsequent CPR performance. Methods: We performed a retrospective review of a convenience sample of EMS agencies throughout the United States that utilized the Cardiac Arrest Registry to Enhance Survival (CARES) dispatch registry during the period 1/2014-12/2017. Data were collected by dispatch agencies after review of 9-1-1 OHCA audio recordings. Elements related to dispatcher CPR instruction, barriers to bystander CPR (BCPR) performance, patient race (White, Black, Hispanic-Latino, or other) and Utstein data were captured from the CARES database. These data were merged with census tract data from incident locations. The effects of race and income (Socioeconomic status, SES) on outcome were analyzed using multilevel logistic regression. Results: A total of 3,807 cases were identified from 37 dispatch agencies in 6 states. The sample was predominantly White (57.5%) and male (64.9%) with an average age of 60.3 ± 19.9. In the adjusted analysis, there were no differences in the odds of receiving CPR instruction by race (black vs white), OR = 0.96 (95% CI. 0.70, 1.32) or for increased income, (OR = 1.00, 95% CI 0.99, 1.02). There was a significant difference in receipt of T-CPR instruction by patient age, OR = 0.99 (95% CI, 0.98, 0.99). Subsequent utilization of T-CPR instruction to perform BCPR was less likely for patients that had a lower income, OR = 1.03 (95% CI 1.01, 1.05). There was also a decreased rate of BCPR provision by patient age OR = 0.99 (95% CI, 0.99, 1.00), but there was no difference in rate of BCPR provision by race, OR = 0.86 (95% CI 0.61, 1.23). Conclusion: We identified differences in age but not race or SES in the provision of T-CPR instruction by dispatch centers. We also identified decreased CPR provision by age and income after receipt of T-CPR instructions. In this sample, we found no evidence of racial disparities in the provision of T-CPR instruction or subsequent provision of BCPR.

Characteristics of Anaphylactic Reactions: A Prospective Observational Study in Japan.

BACKGROUND: Anaphylaxis is a systemic, life-threating, allergic reaction in which the clinical features may vary in different populations or due to the allergic triggers. Moreover, the timing and characteristics of biphasic anaphylactic reactions remain unclear. OBJECTIVES: The purpose of this study was to investigate the clinical characteristics of anaphylaxis cases assessed and treated in Japanese hospitals. METHODS: This was a prospective observational study of anaphylactic reactions treated in the Emergency Department (ED) of two medical centers from June 2016 to May 2019. All patients diagnosed with anaphylaxis were enrolled in this study. Data collected included patient demographics, symptoms and signs, treatment, clinical course, and suspected triggers. Descriptive statistics and univariate methods were used in the analyses. RESULTS: We enrolled 302 patients. The median age was 32 years (interquartile range 13-37) and the sample included 182 (60.3%) women. Of the 302 patients, 179 (59.3%) had a history of allergic reactions. The dermatologic, respiratory, gastrointestinal, and cardiac systems were involved in 297 (98.3%), 248 (82.1%), 150 (49.7%), and 55 (18.2%), respectively. Nineteen patients (6.3%) experienced biphasic anaphylactic reactions. Epinephrine use was associated with a lower incidence of biphasic anaphylactic reaction (odds ratio 0.3, 95% confidence interval 0.1-0.9). Time to recurrence of symptoms ranged from 2 to 48 h (median: 10 h). CONCLUSIONS: In this prospective ED study, foods were the most common triggers of anaphylaxis, and epinephrine administration was associated with a decreased occurrence of biphasic anaphylactic reactions. Over half of patients experiencing biphasic anaphylactic reactions developed symptoms more than 10 h after presentation.

Time to Epinephrine Administration and Survival From Nonshockable Out-of-Hospital Cardiac Arrest Among Children and Adults.

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

Amiodarone, Lidocaine, or Placebo in Out-of-Hospital Cardiac Arrest.

BACKGROUND: Antiarrhythmic drugs are used commonly in out-of-hospital cardiac arrest for shock-refractory ventricular fibrillation or pulseless ventricular tachycardia, but without proven survival benefit. METHODS: In this randomized, double-blind trial, we compared parenteral amiodarone, lidocaine, and saline placebo, along with standard care, in adults who had nontraumatic out-of-hospital cardiac arrest, shock-refractory ventricular fibrillation or pulseless ventricular tachycardia after at least one shock, and vascular access. Paramedics enrolled patients at 10 North American sites. The primary outcome was survival to hospital discharge; the secondary outcome was favorable neurologic function at discharge. The per-protocol (primary analysis) population included all randomly assigned participants who met eligibility criteria and received any dose of a trial drug and whose initial cardiac-arrest rhythm of ventricular fibrillation or pulseless ventricular tachycardia was refractory to shock. RESULTS: In the per-protocol population, 3026 patients were randomly assigned to amiodarone (974), lidocaine (993), or placebo (1059); of those, 24.4%, 23.7%, and 21.0%, respectively, survived to hospital discharge. The difference in survival rate for amiodarone versus placebo was 3.2 percentage points (95% confidence interval [CI], -0.4 to 7.0; P=0.08); for lidocaine versus placebo, 2.6 percentage points (95% CI, -1.0 to 6.3; P=0.16); and for amiodarone versus lidocaine, 0.7 percentage points (95% CI, -3.2 to 4.7; P=0.70). Neurologic outcome at discharge was similar in the three groups. There was heterogeneity of treatment effect with respect to whether the arrest was witnessed (P=0.05); active drugs were associated with a survival rate that was significantly higher than the rate with placebo among patients with bystander-witnessed arrest but not among those with unwitnessed arrest. More amiodarone recipients required temporary cardiac pacing than did recipients of lidocaine or placebo. CONCLUSIONS: Overall, neither amiodarone nor lidocaine resulted in a significantly higher rate of survival or favorable neurologic outcome than the rate with placebo among patients with out-of-hospital cardiac arrest due to initial shock-refractory ventricular fibrillation or pulseless ventricular tachycardia. (Funded by the National Heart, Lung, and Blood Institute and others; ClinicalTrials.gov number, NCT01401647.).