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.

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.

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.

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.

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.

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.

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.

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.

Bayesian Analysis of the Pragmatic Airway Resuscitation Trial.

STUDY OBJECTIVE: Intubation and laryngeal tube insertion are common airway management strategies in out-of-hospital cardiac arrest. Bayesian analysis offers an alternate statistical approach to assess the results of a trial. We use Bayesian analysis to compare the effectiveness of initial laryngeal tube versus initial intubation strategies on outcomes after out-of-hospital cardiac arrest in the Pragmatic Airway Resuscitation Trial. METHODS: We performed a post hoc Bayesian analysis of the Pragmatic Airway Resuscitation Trial. We defined prior distributions representing neutral or skeptical estimates of laryngeal tube benefit. Using Bayesian log binomial models, we fit models for 72-hour survival, hospital survival, and hospital survival with favorable neurologic status. We estimated the posterior probability (the probability of observing an effect difference between treatment groups) of the benefit of laryngeal tube over intubation on out-of-hospital cardiac arrest outcomes. RESULTS: The parent trial enrolled 3,004 patients (1,505 laryngeal tube, 1,499 intubation). Under a neutral prior distribution (relative risk 1.0), laryngeal tube was better than intubation (72-hour survival risk difference 1.8% [95% credible interval {CrI} -0.9% to 4.5%], posterior probability 91%; hospital survival 1.4% [95% CrI -0.4% to 3.4%], posterior probability 93%; and hospital survival with favorable neurologic status 0.7% [95% CrI -0.5% to 2.1%], posterior probability 86%). Under a skeptical prior distribution (relative risk 0.83 to 0.92), laryngeal tube was also better than intubation (72-hour survival risk difference 1.7% [95% CrI -0.9% to 4.3%], posterior probability 89%; hospital survival 1.3% [95% CrI -0.5% to 3.3%], posterior probability 91%; and hospital survival with favorable neurologic status 0.6% [95% CrI -0.5% to 2.0%], posterior probability 82%). CONCLUSION: Under various prior assumptions, post hoc Bayesian analysis of the Pragmatic Airway Resuscitation Trial confirmed better out-of-hospital cardiac arrest outcomes with a strategy of initial laryngeal tube than initial intubation.

Effect of a Strategy of Initial Laryngeal Tube Insertion vs Endotracheal Intubation on 72-Hour Survival in Adults With Out-of-Hospital Cardiac Arrest: A Randomized Clinical Trial.

Importance: Emergency medical services (EMS) commonly perform endotracheal intubation (ETI) or insertion of supraglottic airways, such as the laryngeal tube (LT), on patients with out-of-hospital cardiac arrest (OHCA). The optimal method for OHCA advanced airway management is unknown. Objective: To compare the effectiveness of a strategy of initial LT insertion vs initial ETI in adults with OHCA. Design, Setting, and Participants: Multicenter pragmatic cluster-crossover clinical trial involving EMS agencies from the Resuscitation Outcomes Consortium. The trial included 3004 adults with OHCA and anticipated need for advanced airway management who were enrolled from December 1, 2015, to November 4, 2017. The final date of follow-up was November 10, 2017. Interventions: Twenty-seven EMS agencies were randomized in 13 clusters to initial airway management strategy with LT (n = 1505 patients) or ETI (n = 1499 patients), with crossover to the alternate strategy at 3- to 5-month intervals. Main Outcomes and Measures: The primary outcome was 72-hour survival. Secondary outcomes included return of spontaneous circulation, survival to hospital discharge, favorable neurological status at hospital discharge (Modified Rankin Scale score ≤3), and key adverse events. Results: Among 3004 enrolled patients (median [interquartile range] age, 64 [53-76] years, 1829 [60.9%] men), 3000 were included in the primary analysis. Rates of initial airway success were 90.3% with LT and 51.6% with ETI. Seventy-two hour survival was 18.3% in the LT group vs 15.4% in the ETI group (adjusted difference, 2.9% [95% CI, 0.2%-5.6%]; P = .04). Secondary outcomes in the LT group vs ETI group were return of spontaneous circulation (27.9% vs 24.3%; adjusted difference, 3.6% [95% CI, 0.3%-6.8%]; P = .03); hospital survival (10.8% vs 8.1%; adjusted difference, 2.7% [95% CI, 0.6%-4.8%]; P = .01); and favorable neurological status at discharge (7.1% vs 5.0%; adjusted difference, 2.1% [95% CI, 0.3%-3.8%]; P = .02). There were no significant differences in oropharyngeal or hypopharyngeal injury (0.2% vs 0.3%), airway swelling (1.1% vs 1.0%), or pneumonia or pneumonitis (26.1% vs 22.3%). Conclusions and Relevance: Among adults with OHCA, a strategy of initial LT insertion was associated with significantly greater 72-hour survival compared with a strategy of initial ETI. These findings suggest that LT insertion may be considered as an initial airway management strategy in patients with OHCA, but limitations of the pragmatic design, practice setting, and ETI performance characteristics suggest that further research is warranted. Trial Registration: ClinicalTrials.gov Identifier: NCT02419573.

Improvements in Out-of-Hospital Cardiac Arrest Survival from 1998 to 2013.

OBJECTIVES: Out-of-hospital cardiac arrest (OHCA) remains a major public health burden. Aggregate OHCA survival to hospital discharge has reportedly remained unchanged at 7.6% for almost 30 years from 1970 to 2008. We examined the trends in adult OHCA survival over a 16-year period from 1998 to 2013 within a single EMS agency. METHODS: Observational cohort study of adult OHCA patients treated by Tualatin Valley Fire & Rescue (TVF&R) from 1998 to 2013. This is an ALS first response fire agency that maintains an active Utstein style cardiac arrest registry and serves a population of approximately 450,000 in 9 incorporated cities in Oregon. Primary outcomes were survival to hospital discharge in all patients and in the subgroup with witnessed ventricular fibrillation/pulseless ventricular tachycardia (VF/VT). The impact of key covariates on survival was assessed using univariate logistic regression. These included patient factors (age and sex), event factors (location of arrest, witnessed status, and first recorded cardiac arrest rhythm), and EMS system factors (response time interval, bystander CPR, and non-EMS AED shock). We used multivariate logistic regression to examine the impact of year increment on survival after multiple imputation for missing data. Sensitivity analysis was performed with complete cases. RESULTS: During the study period, 2,528 adult OHCA had attempted field resuscitation. The survival rate for treated cases increased from 6.7% to 18.2%, with witnessed VF/VT cases increasing from 14.3% to 31.4% from 1998 to 2013. Univariate analysis showed that younger age, male sex, public location of arrest, bystander or EMS witnessed event, initial rhythm of pulseless electrical activity (PEA) or VF/VT, bystander CPR, non-EMS AED shock, and a shorter EMS response time were independently associated with survival. After adjustment for covariates, the odds of survival increased by 9% (OR 1.09, 95%CI: 1.05-1.12) per year in all treated cases, and by 6% (OR 1.06, 95% 1.01-1.10) per year in witnessed VF/VT subgroups. Findings remained consistent on sensitivity analysis. CONCLUSIONS: Overall survival from treated OHCA has increased over the last 16 years in this community. These survival increases demonstrate that OHCA is a treatable condition that warrants further investigation and investment of resources.

Chest compression rates and survival following out-of-hospital cardiac arrest.

OBJECTIVE: Guidelines for cardiopulmonary resuscitation recommend a chest compression rate of at least 100 compressions/min. A recent clinical study reported optimal return of spontaneous circulation with rates between 100 and 120/min during cardiopulmonary resuscitation for out-of-hospital cardiac arrest. However, the relationship between compression rate and survival is still undetermined. DESIGN: Prospective, observational study. SETTING: Data is from the Resuscitation Outcomes Consortium Prehospital Resuscitation IMpedance threshold device and Early versus Delayed analysis clinical trial. PARTICIPANTS: Adults with out-of-hospital cardiac arrest treated by emergency medical service providers. INTERVENTIONS: None. MEASUREMENTS MAIN RESULTS: Data were abstracted from monitor-defibrillator recordings for the first five minutes of emergency medical service cardiopulmonary resuscitation. Multiple logistic regression assessed odds ratio for survival by compression rate categories (<80, 80-99, 100-119, 120-139, ≥140), both unadjusted and adjusted for sex, age, witnessed status, attempted bystander cardiopulmonary resuscitation, location of arrest, chest compression fraction and depth, first rhythm, and study site. Compression rate data were available for 10,371 patients; 6,399 also had chest compression fraction and depth data. Age (mean±SD) was 67±16 years. Chest compression rate was 111±19 per minute, compression fraction was 0.70±0.17, and compression depth was 42±12 mm. Circulation was restored in 34%; 9% survived to hospital discharge. After adjustment for covariates without chest compression depth and fraction (n=10,371), a global test found no significant relationship between compression rate and survival (p=0.19). However, after adjustment for covariates including chest compression depth and fraction (n=6,399), the global test found a significant relationship between compression rate and survival (p=0.02), with the reference group (100-119 compressions/min) having the greatest likelihood for survival. CONCLUSIONS: After adjustment for chest compression fraction and depth, compression rates between 100 and 120 per minute were associated with greatest survival to hospital discharge.

Early versus later rhythm analysis in patients with out-of-hospital cardiac arrest.

BACKGROUND: In a departure from the previous strategy of immediate defibrillation, the 2005 resuscitation guidelines from the American Heart Association-International Liaison Committee on Resuscitation suggested that emergency medical service (EMS) personnel could provide 2 minutes of cardiopulmonary resuscitation (CPR) before the first analysis of cardiac rhythm. We compared the strategy of a brief period of CPR with early analysis of rhythm with the strategy of a longer period of CPR with delayed analysis of rhythm. METHODS: We conducted a cluster-randomized trial involving adults with out-of-hospital cardiac arrest at 10 Resuscitation Outcomes Consortium sites in the United States and Canada. Patients in the early-analysis group were assigned to receive 30 to 60 seconds of EMS-administered CPR and those in the later-analysis group were assigned to receive 180 seconds of CPR, before the initial electrocardiographic analysis. The primary outcome was survival to hospital discharge with satisfactory functional status (a modified Rankin scale score of ≤3, on a scale of 0 to 6, with higher scores indicating greater disability). RESULTS: We included 9933 patients, of whom 5290 were assigned to early analysis of cardiac rhythm and 4643 to later analysis. A total of 273 patients (5.9%) in the later-analysis group and 310 patients (5.9%) in the early-analysis group met the criteria for the primary outcome, with a cluster-adjusted difference of -0.2 percentage points (95% confidence interval, -1.1 to 0.7; P=0.59). Analyses of the data with adjustment for confounding factors, as well as subgroup analyses, also showed no survival benefit for either study group. CONCLUSIONS: Among patients who had an out-of-hospital cardiac arrest, we found no difference in the outcomes with a brief period, as compared with a longer period, of EMS-administered CPR before the first analysis of cardiac rhythm. (Funded by the National Heart, Lung, and Blood Institute and others; ROC PRIMED ClinicalTrials.gov number, NCT00394706.).

A trial of an impedance threshold device in out-of-hospital cardiac arrest.

BACKGROUND: The impedance threshold device (ITD) is designed to enhance venous return and cardiac output during cardiopulmonary resuscitation (CPR) by increasing the degree of negative intrathoracic pressure. Previous studies have suggested that the use of an ITD during CPR may improve survival rates after cardiac arrest. METHODS: We compared the use of an active ITD with that of a sham ITD in patients with out-of-hospital cardiac arrest who underwent standard CPR at 10 sites in the United States and Canada. Patients, investigators, study coordinators, and all care providers were unaware of the treatment assignments. The primary outcome was survival to hospital discharge with satisfactory function (i.e., a score of ≤3 on the modified Rankin scale, which ranges from 0 to 6, with higher scores indicating greater disability). RESULTS: Of 8718 patients included in the analysis, 4345 were randomly assigned to treatment with a sham ITD and 4373 to treatment with an active device. A total of 260 patients (6.0%) in the sham-ITD group and 254 patients (5.8%) in the active-ITD group met the primary outcome (risk difference adjusted for sequential monitoring, -0.1 percentage points; 95% confidence interval, -1.1 to 0.8; P=0.71). There were also no significant differences in the secondary outcomes, including rates of return of spontaneous circulation on arrival at the emergency department, survival to hospital admission, and survival to hospital discharge. CONCLUSIONS: Use of the ITD did not significantly improve survival with satisfactory function among patients with out-of-hospital cardiac arrest receiving standard CPR. (Funded by the National Heart, Lung, and Blood Institute and others; ROC PRIMED ClinicalTrials.gov number, NCT00394706.).