Emergency Medical Services Response Time Research Articles

Variation in Out-of-Hospital Cardiac Arrest Survival Across Emergency Medical Service Agencies.

Although studies have reported variation in out-of-hospital cardiac arrest (OHCA) survival by geographic location, little is known about variation in OHCA survival at the level of emergency medical service (EMS) agencies-which may have modifiable practices, unlike counties and regions. We quantified the variation in OHCA survival across EMS agencies and explored whether variation in 2 specific EMS resuscitation practices were associated with survival to hospital admission. Within the Cardiac Arrest Registry to Enhance Survival, a prospective registry representing ≈51% of the US population, we identified 258 342 OHCAs from 764 EMS agencies with >10 OHCA cases annually during 2015 to 2019. Using hierarchical logistic regression, risk-standardized rates of survival to hospital admission were computed for each EMS agency. We quantified inter-agency variation in survival with median odds ratios and assessed the association of 2 resuscitation practices (EMS response time and the proportion of OHCAs with termination of resuscitation without meeting futility criteria) with EMS agency survival rates to hospital admission. Across 764 EMS agencies comprising 258 342 OHCAs, the median risk-standardized rate of survival to hospital admission was 27.3% (interquartile range, 24.5%-30.1%; range: 16.0%-45.6%). The adjusted median odds ratio was 1.35 (95% CI, 1.32-1.39), denoting that the odds of survival of 2 patients with identical covariates varied by 35% at 2 randomly selected EMS agencies. EMS agencies in the lowest quartile of risk-standardized survival had longer EMS response times when compared with the highest quartile (12.0±3.4 versus 9.0±2.6 minutes; P<0.001), and a higher proportion of OHCAs with termination of resuscitation without meeting futility criteria (27.9±16.1% versus 18.9±11.4%; P<0.001). Survival after OHCA varies widely across EMS agencies. EMS response times and termination of resuscitation practices were associated with agency-level rates of survival to hospital admission, suggesting potentially modifiable practices which can improve OHCA survival.

Observational study on implications of the COVID-19-pandemic for cardiopulmonary resuscitation in out-of-hospital cardiac arrest: qualitative and quantitative insights from a model region in Germany

BackgroundThe city of Freiburg has been among the most affected regions by the COVID-19 pandemic in Germany. In out of hospital cardiac arrest (OHCA) care, all parts of the rescue system were exposed to profound infrastructural changes. We aimed to provide a comprehensive overview of these changes in the resuscitation landscape in the Freiburg region.MethodsUtstein-style quantitative data on OHCA with CPR initiated, occurring in the first pandemic wave between February 27th, 2020 and April 30th, 2020 were compared to the same time periods between 2016 and 2019.Additionally, qualitative changes in the entire rescue system were analyzed and described.ResultsIncidence of OHCA with attempted CPR did not significantly increase during the pandemic period (11.1/100.000 inhabitants/63 days vs 10.4/100.000 inhabitants/63 days, p = 1.000). In witnessed cases, bystander-CPR decreased significantly from 57.7% (30/52) to 25% (4/16) (p = 0.043). A severe pre-existing condition (PEC) was documented more often, 66.7% (16/24) vs 38.2% (39/102) there were longer emergency medical services (EMS) response times, more resuscitation attempts terminated on scene, 62.5% (15/24) vs. 34.3% (35/102) and less patients transported to hospital (p = 0.019). Public basic life support courses, an app-based first-responder alarm system, Kids Save Lives activities and a prehospital extracorporeal CPR (eCPR) service were paused during the peak of the pandemic.ConclusionIn our region, bystander CPR in witnessed OHCA cases as well as the number of patients transported to hospital significantly decreased during the first pandemic wave. Several important parts of the resuscitation landscape were paused. The COVID-19 pandemic impedes OHCA care, which leads to additional casualties. Countermeasures should be taken.

Ambulance dispatching and relocation problem considering overcrowding of emergency departments

An important issue in emergency medical services (EMS) is ambulance dispatching and relocation. EMS response time is usually measured by the response time of an ambulance (RTA), the time between receiving a call and the ambulance's arrival at the scene. EMS's success also depends on response time to the patient (RTP), the time between receiving a call and starting the service to the patient in a hospital. This study aims to use RTP to decide about ambulance dispatching and relocation. RTP is affected by the distance of the patient to the chosen hospital and the crowding in the hospital. Thus, this study integrates ambulance dispatching and relocation with hospital selection to better provide both RTA and RTP along with coverage while considering an overcrowded emergency department (ED). A mixed-integer linear programming model is developed to solve the proposed problem. The model's performance and the impact of the ED overcrowding factor have been examined in the context of a real case study from Utrecht, Netherlands. Findings reveal that considering RTP in joint ambulance dispatching and relocation has a 39% positive impact on the patient's average response time. Further, considering ED crowding with RTP results in 91% and 9% improvement in RTP and RTA with the same demand coverage, compared to typical ambulance dispatching and relocation problems, respectively.

Perception and Satisfaction of Patients' Relatives Regarding Emergency Medical Service Response Times: A Cross-Sectional Study.

PurposeDelays in emergency medical service (EMS) directly affect life-threatening emergencies. Delays also indirectly affect the perception and satisfaction of patients and their relatives, which are important qualitative EMS indicators.Patients and MethodsFor this cross-sectional study, data was collected from May 1 to July 31, 2021, through questionnaires developed by the authors. The study sample consisted of relatives of EMS patients. The primary objective was the perceived EMS response time, which was compared to the actual EMS response time. The secondary objective was the relatives’ perceptions and feelings regarding the waiting time.ResultsDuring study period, the sample was 165 relatives of patients managed by EMS. The mean perceived EMS response time of 18.28 ± 8.10 min was significantly longer than the mean actual response time of 14.44 ± 4.86 min (p < 0.001). The positive correlation between the perceived and actual times was low but statistically significant (p < 0.001) with a correlation coefficient of 0.315 (95% CI 0.170–0.446). The overall satisfaction level was high (noverline {rm{x}} ,{rm{ = }},{rm{4}}{rm{.47}}n, standard deviation 0.63). The mean perceived EMS response time compares with the high-to-highest satisfaction levels of relatives was significantly lower than the mean perceived EMS response time compares with the lowest-to-middle satisfaction levels of relatives (17.83 ± 8.05 and 22.50 ± 7.47 min, respectively; p = 0.028).ConclusionThe perceived EMS response time was longer than the actual response time, with a low correlation. However, the relatives’ overall satisfaction level was high.

Influence of hospital capabilities and prehospital time on outcomes of thrombectomy for stroke in Japan from 2013 to 2016

To determine whether increasing thrombectomy-capable hospitals with moderate comprehensive stroke center (CSC) capabilities is a valid alternative to centralization of those with high CSC capabilities. This retrospective, nationwide, observational study used data from the J-ASPECT database linked to national emergency medical service (EMS) records, captured during 2013–2016. We compared the influence of mechanical thrombectomy (MT) use, the CSC score, and the total EMS response time on the modified Rankin Scale score at discharge among patients with acute ischemic stroke transported by ambulance, in phases I (2013–2014, 1461 patients) and II (2015–2016, 3259 patients). We used ordinal logistic regression analyses to analyze outcomes. From phase I to II, MTs increased from 2.7 to 5.5%, and full-time endovascular physicians per hospital decreased. The CSC score and EMS response time remained unchanged. In phase I, higher CSC scores were associated with better outcomes (1-point increase, odds ratio [95% confidence interval]: 0.951 [0.915–0.989]) and longer EMS response time was associated with worse outcomes (1-min increase, 1.007 [1.001–1.013]). In phase II, neither influenced the outcomes. During the transitional shortage of thrombectomy-capable hospitals, increasing hospitals with moderate CSC scores may increase nationwide access to MT, improving outcomes.

Data linkage for crash outcome assessment: Linking police-reported crashes, emergency response data, and trauma registry records

Introduction: Traffic crash reports lack detailed information about emergency medical service (EMS) responses, the injuries, and the associated treatments, limiting the ability of safety analysts to account for that information. Integrating data from other sources can enable a better understanding of characteristics of serious crashes and further explain variance in injury outcomes. In this research, an approach is proposed and implemented to link crash data to EMS run data, patient care reports, and trauma registry data. Method: A heuristic framework is developed to match EMS run reports to crashes through time, location, and other indicators present in both datasets. Types of matches between EMS and crashes were classified. To investigate the fidelity of the match approach, a manual review of a sample of data was conducted. A comparative bias analysis was implemented on several key variables. Results: 72.2% of EMS run reports matched to a crash record and 69.3% of trauma registry records matched with a crash record. Females, individuals between 11 and 20 years old, and individuals involved in single vehicle or head on crashes were more likely to be present in linked data sets. Using the linked data sets, relationships between EMS response time and reported injury in the crash report, and between police-reported injury and injury severity score were examined. Conclusion: Linking data from other sources can greatly enhance the information available to address road safety issues, data quality issues, and more. Linking data has the potential to result in biases that must be investigated as they relate to the use-case for the data. Practical implications: This research resulted in a transferable heuristic approach that can be used to link data sets that are commonly collected by agencies across the world. It also provides guidance on how to check the linked data for biases and errors.

Out-of-hospital cardiac arrest: Does rurality decrease chances of survival?

BackgroundGeographical setting is seldomly taken into account when investigating out-of-hospital cardiac arrest (OHCA). It is a common notion that living in rural areas means a lower chance of fast and effective helpwhen suffering a time-critical event. This retrospective cohort study investigates this hypothesis and compares across healthcare-divided administrative regions. MethodsWe included only witnessed OHCAs to minimize the risk that outcome was predetermined by time to caller arrival and/or recognition. Arrests were divided into public and residential. Residential arrests were categorized according to population density of the area in which they occurred. We investigated incidence, EMS response time and 30-day survival according to area type and subsidiarily by healthcare-divided administrative region. ResultsThe majority (71%) of 8,579 OHCAs were residential, and 53.2% of all arrests occurred in the most densely populated cell group amongst residential arrests. This group had a median EMS response time of six minutes, whereas the most sparsely populated group had a median of 10 minutes. Public arrests also had a median response time of six minutes. 30-day survival was highest in public arrests (38.5%, [95% CI 36.9;40.1]), and varied only slightly with no statistical significance between OHCAs in densely and sparsely populated areas from 14.8% (95% CI 14.4;15.2) and 13.4% (95% CI 12.2;14.7). ConclusionOur study demonstrates that while EMS response times in Denmark are longer in the rural areas, there is no statistically significant decrease in survival compared to the most densely populated areas.

Abstract 23: Population Access To Acute Stroke Expertise In The United States

Backgound: In 2011, nearly 20% of Americans lacked timely access to alteplase-capable hospitals. We update this work by assessing access to stroke centers and emergency departments (EDs) with telestroke capacity. Our objectives are to identify all US EDs with acute stroke capabilities (i.e., in a confirmed stroke center or with telestroke capacity), and to characterize the proportion of the US population with access to an ED with either capacity. Methods: We used the 2019 National ED Inventory-USA to identify all US EDs and characterize stroke capabilities by hospital stroke center status (none, acute stroke ready hospital [ASRH], primary stroke center [PSC], thrombectomy-capable or comprehensive stroke center [TSC/CSC]) and telestroke capacity. We used 2020 US Census data for census block group population and centroid. For each block group, we used ArcGIS to assess whether an ED with stroke expertise was within a 60 minute (min) response and transport time by ground emergency medical services (EMS). To determine the transport time, we used data from actual EMS stroke transports using the 2019 National EMS Information System with median EMS dispatch, response, and scene times in access calculations. Results: Of 5,587 US EDs, 2,563 (46%) were in a stroke center (691 ASRH, 1,505 PSC, 367 TSC/CSC); of these, 55% also had telestroke capacity. Of the 3,024 (54%) that were not a confirmed stroke center, 36% had telestroke. We estimate that 91% of the US population is within 60 min of a confirmed stroke center by ground EMS and 96% is within 60 min of a confirmed stroke center or telestroke ED (Figure). The percentage of the population without access to a confirmed stroke center or telestroke ED varied by region, from 1% in the Middle Atlantic to 9% in the West Mountain. Conclusion: Relative to previous reports, an increasing proportion of the US population has access to acute stroke expertise. While geographic disparities in access remain, telestroke plays an important role in filling this gap.

Effect of time intervals in critical care provided by helicopter emergency medical services on 30-day survival after trauma

BackgroundTrauma is the leading cause of death especially in children and young adults. Prehospital care following trauma emphasizes swift transport to a hospital following initial care. Previous studies have shown conflicting results regarding the effect of time on the survival following major trauma. In our study we investigated the effect of prehospital time-intervals on 30-day mortality on trauma patients that received prehospital critical care. MethodsWe performed a retrospective study on all trauma patients encountered by helicopter emergency medical services in Finland from 2012 to 2018. Patients discharge diagnoses were classed into (1) trauma without traumatic brain injury, (2) isolated traumatic brain injury and (3) trauma with traumatic brain injury. Emergency medical services response time, helicopter emergency medical services response time, on-scene time and transport time were used as time-intervals and age, Glasgow coma scale, hypotension, need for prehospital airway intervention and ICD-10 based Injury Severity Score were used as variables in logistic regression analysis. ResultsMortality data was available for 4,803 trauma cases. The combined 30-day mortality was 12.1% (582/4,803). Patients with trauma without a traumatic brain injury had the lowest mortality, at 4.3% (111/2,605), whereas isolated traumatic brain injury had the highest, at 22.9% (435/1,903). Patients with both trauma and a traumatic brain injury had a mortality of 12.2% (36/295). Following adjustments, no association was observed between time intervals and 30-day mortality. DiscussionOur study revealed no significant association between different timespans and mortality following severe trauma in general. Trends in odds ratios can be interpreted to favor more expedited care, however, no statistical significance was observed. As trauma forms a heterogenous patient group, specific subgroups might require different approaches regarding the prehospital timeframes. Study typeprognostic/therapeutic/diagnostic test.

A retrospective multi-centre cohort study: Pre-hospital survival factors of out-of-hospital cardiac arrest (OHCA) patients in Thailand

ObjectiveThis study aimed to explore significant pre-hospital factors affecting the survivability of Out-of-Hospital Cardiac Arrest (OHCA) patients in countries with developing EMS systems. MethodA retrospective cohort study was conducted examining data from January 1, 2017 to December 31, 2020 from Utstein Registry databases in Thailand, collected through Pan-Asian Resuscitation Outcomes Study (PAROS). Data were collected from three centres, including regional, suburban-capital, and urban-capital hospitals. The primary endpoint of this study was 30-day survival or discharged alive after an OHCA event. The multivariable risk regression was done by modified Poisson regression with robust error variance to explore the association between 30-day survival and pre-hospital factors with potential confounders adjustments. FindingsOf 1,240 OHCA cases transferred by Emergency Medical Services (EMS), 42 patients (3.4%) were discharged alive after 30 days, including 22 (8.6%), 8 (3.0%), and 12 (1.7%) from regional, suburban-capital, and urban-capital centres, respectively. The initial arrest rhythm was 89.7% unshockable, with no significant variations across the three centres. Overall, bystander Cardiopulmonary Resuscitation (CPR) was 40.4%. However, bystander CPR with Automated External Defibrillator (AED) application was 0.8%. Bystander CPR significantly increased 30-day survival probability (aRR 1.88, 95% CI 1.01 to 3.51; p 0.049). Additionally, reducing the EMS response time by one minute significantly increased OHCA survivability (aRR 1.12, 95% CI 1.04 to 1.20; p 0.001). ConclusionsResponse time and bystander CPR are the factors that improve the 30-day survival outcomes of OHCA patients. In contrast, scene time, transport time, and pre-hospital advanced airway management didn’t improve 30-day OHCA survival.

Effects of different crash data variables on EMS response time for a rural county in alabama.

Response time of Emergency Medical Services (EMS) is an important factor related to preventable deaths in road crash incidents. This study focuses on analyzing the effects of different independent variables on the EMS Response Time (ERT). Independent variables considered for this investigation are travel time, day of the week, crash severity, weather, time of the day, and lighting condition. Understanding outcomes resulting from variations of the considered parameters on ERT is crucial to minimize the possibility of adverse outcomes which are tied to different types of injuries, and vital to limit the prospect of fatalities. Crash data used for this study is from a rural county in Alabama where only one EMS control location is available. Results from the analysis indicate that ERT becomes larger as travel time increases. ERT is also larger on weekends than on weekdays. ERT is larger in the evening and night when compared with morning. When the weather is clear or cloudy, the ERT parameter is shorter. But when the weather is extreme, with mist, fog, or rain, the parameter is longer. When roads are dark, ERT is long. When daylight is present, the ERT is shorter. If the crash is fatal, the parameter is longer compared with situations when crash injuries are non-severe.

Pre-Hospital Delay in Patients With Acute Stroke During the Initial Phase of the Coronavirus Disease 2019 Outbreak.

BackgroundWhen a sudden outbreak of an infectious disease occurs, emergency medical services (EMS) response could be negatively affected. The poor prognosis of acute stroke may be largely attributed to delays in treatment. This study aimed to identify the impact of the sudden outbreak of coronavirus disease 2019 (COVID-19) on EMS response for patients with acute stroke.MethodsThis comparative cross-sectional study was conducted in 25 safety centers in Seoul, Korea. We enrolled patients with acute stroke who were transferred to the emergency department by EMS. The study period was from February–April 2020 and the same period in 2019. Patients were divided into two groups, pre-COVID-19 period and early-COVID-19 period, and previously collected patient data were analyzed. We performed comparative analyses of EMS response and clinical outcomes between the groups.ResultsOf 465 patients, 231 (49.7%) had an acute stroke during the study period. There was no significant difference between clinical characteristics of patients with acute stroke before and after the COVID-19 outbreak. EMS response times increased significantly during the early COVID-19 outbreak. The intensive care unit admission rate and mortality rate increased during the early COVID-19 outbreak.ConclusionIn the initial phase after the sudden COVID-19 outbreak, EMS response times for acute stroke were delayed and the clinical outcomes of patients with acute stroke deteriorated.

Improvement of Barranquilla’s EMS response time with the use of GIS

The global emergency medical services (EMS) are complex systems characterized by significant differences in service providers, care pathways, patient care, and quality of care indicators. Therefore, analyzing and improving them is a challenge. Since EMS systems vary from country to country, it isn’t easy to provide common standards and methods for EMS planning. However, the common goal of all service providers is to provide medical care to patients who are critically ill or injured as quickly as possible. This research analyzes the location of ambulances of the emergency medical system (EMS) of Barranquilla through a statistical and geographical study. This analysis considers the accident rate, ambulances’ geolocation, service areas, and accident to hospital driving times. ArcGIS was used for data processing. The aim was to give an adequate response to accidents in the city of Barranquilla, Colombia.

Effect of Prehospital Epinephrine Use on Survival from Out-of-Hospital Cardiac Arrest and on Emergency Medical Services.

This study was to identify the effect of epinephrine on the survival of out-of-hospital cardiac arrest (OHCA) patients and changes in prehospital emergency medical services (EMSs) after the introduction of prehospital epinephrine use by EMS providers. This was a retrospective observational study comparing two groups (epinephrine group and norepinephrine group). We used propensity score matching of the two groups and identified the association between outcome variables regarding survival and epinephrine use, controlling for confounding factors. The epinephrine group was 339 patients of a total 1943 study population. The survival-to-discharge rate and OR (95% CI) of the epinephrine group were 5.0% (p = 0.215) and 0.72 (0.43–1.21) in the total patient population and 4.7% (p = 0.699) and 1.15 (0.55–2.43) in the 1:1 propensity-matched population. The epinephrine group received more mechanical chest compression and had longer EMS response times and scene times than the norepinephrine group. Mechanical chest compression was a negative prognostic factor for survival to discharge and favorable neurological outcomes in the epinephrine group. The introduction of prehospital epinephrine use in OHCA patients yielded no evidence of improvement in survival to discharge and favorable neurological outcomes and adversely affected the practice of EMS providers, exacerbating the factors negatively associated with survival from OHCA.

Exploration of the police response time to motor-vehicle crashes in Pennsylvania, USA

Introduction: After roadway crashes occur, the quick emergency response is essential for minimizing tolls and economic losses. Many studies have analyzed the post-crash emergency medical services response time, but few ones have explored the post-crash police response time. However, the presence of police is the precondition for other agencies to perform their duties safely and smoothly. Method: With Pennsylvania crash data from 2008 to 2017, this study gives an assessment of the post-crash police response time in Pennsylvania. Results: First, we demonstrate that police response time is highly correlated to crash consequences: the longer police response time is positively associated with more fatalities at both individual level and county level. Then, for fatal crashes, a negative binomial model with the police agency-level random effects is built to identify the significant factors influencing the police response time. The results indicate that day of week, illumination, weather, area, roadway type, and roadway location could significantly affect the police response time. Police respond much slower to fatal crashes occurring in rural areas, mid-blocks, turnpikes, adverse weather, on weekends, and at nighttime without streetlights. Police response time shows a decreasing trend since 2016 and varies a lot by police agencies. It is found that many police agencies affiliated to the Pennsylvania State Police, which oversees statewide law enforcement on all interstate and state highways, respond slower than other police agencies. Practical Applications: These findings are expected to provide some new insights for Pennsylvania police agencies to improve their response mechanisms to roadway crashes.

The Ambulance Location Can Influence Emergency Medical Service Response Time: A Literature Review

Factor of the accident was the highest cause of mortality. The mortality or death caused by accident could be avoided through a fast and appropriate first aid. The ambulance was a component of EMS that must reach the incident location in a quick time. This research was aimed to identify the effects of ambulance station location and ambulance response time. In the literature review, four databases were used as EBSCOhost, Proquest, Science Direct, and SpringerLink and through access help from Brawijaya University library. PRISMA method was exerted in this research to select the articles and choose as many as 15 research articles that fulfill inclusion criteria. The response time of EMS was very influential for patient care and safety. The standby ambulance location can affect the officer's response time. The determination of the ambulance location for the EMS service provider was very significant to offer an optimal service.

Abstract 14171: Prehospital Outcomes and Patient Characteristics Associated With PulsePoint Dispatches for Out-of-Hospital Cardiac Arrest in Pittsburgh, Pennsylvania

Background: Mobile phone-based dispatch of volunteers to out-of-hospital cardiac arrest (OHCA) has been shown to increase the likelihood of early chest compressions and AED application. In the United States, limited characterization of patients encountered as a result of such systems exists, including PulsePoint Respond, a smartphone-based volunteer dispatch system. Objective: Examine prehospital case characteristics and outcomes from a multi-year deployment of PulsePoint in Pittsburgh, Pennsylvania. Methods: Case data, including PulsePoint determinant triggers and timing, prehospital electronic health records (EHRs), and computer aided dispatch records were obtained for suspected EMS-treated OHCA cases that did and did not generate PulsePoint alerts within the service area of Pittsburgh EMS for the period July 2016 to October 2020. EHRs were reviewed to determine true OHCA status, and OHCA case characteristics were extracted according to the Utstein template. Key characteristics and the outcome of prehospital return of spontaneous circulation (ROSC) were summarized and compared between cases with and without PulsePoint dispatches. Chi-squared tests were used to determine statistical significance of relationships. Results: There were 1229 OHCA cases overall in the capture period, with an estimated 29.6% occurring in public. Of 840 total PulsePoint dispatches, 68 (8.1%) were for true OHCA. Forty-five (66.2%) of these were witnessed, 43 (63.2%) received bystander CPR, and 17 (25%) had an AED applied prior to first responder arrival. Twenty-seven (39.7%) had an initial shockable rhythm, and 34 (50%) achieved ROSC in the field. Compared to non-PulsePoint dispatch generating OHCA, PulsePoint alert-associated patients were significantly more likely to be male (p=0.024), have bystander CPR/AED application performed (p&lt;0.001), have an initial shockable rhythm (p&lt;0.001), and achieve ROSC (p&lt;0.001). EMS response time, age, ALS response time, and witnessed status were not significantly different. Conclusions: A minority of PulsePoint dispatches in Pittsburgh were triggered by true OHCA. Among cases that did generate a PulsePoint dispatch, case characteristics were prognostically favorable.

Abstract 11399: Time to Anti-Arrhythmic for Out-of-Hospital Cardiac Arrest

Introduction: Initial shockable rhythm is the strongest predictor of good outcomes for patients with out-of-hospital cardiac arrest (OHCA). While preclinical models have shown benefit of anti-arrhythmics, clinical trials have shown a very modest impact of anti-arrhythmic drugs, possibly related to real-life delays in drug administration. Little is known regarding the time to administration of anti-arrhythmic drugs or the association of time to drug and outcome. We utilized a national EMS registry to evaluate the time of drug administration and the association with outcomes. Methods: We evaluated the 2018 and 2019 NEMSIS dataset, including all non-traumatic, adult 911 EMS encounters for cardiac arrests with initial shockable rhythm. We then calculated the time from 911 call to administration of anti-arrhythmic. We excluded cases with time to administration less than 0 or greater than 120 minutes. Stratified by initial antiarrhythmic (amiodarone and lidocaine), we created a mixed-effect logistic regression model evaluating the association between every 5 minute increase in time to antiarrhythmic and ROSC. We modeled EMS agency as a random intercept and adjusted the analysis for age, sex, race, bystander witnessed arrest, location of arrest and EMS response time. We excluded EMS witnessed arrests and cases with missing ROSC data. Results: There were 449,630 adult, non-traumatic cardiac arrests identified with 55,142 patients (12.3%) having an initial shockable rhythm; 17,769 (32.2%) received amiodarone and 2,855 (5.2%) received lidocaine initially. The median time in minutes to initial dose of amiodarone was 20.4 with IQR (16-26.7). The median time in minutes to initial dose of lidocaine administration was 20.2 with IQR (15.7-27.0). Increasing time to initial antiarrhythmic was associated with decreased odds of ROSC for both amiodarone (aOR 0.9; 95% CI 0.9-0.94) and lidocaine (aOR 0.9; 95% CI 0.8-0.96). Conclusion: Time to administration of anti-arrhythmic medication varied, but most patients received the first does of anti-arrhythmic drug more than 20 minutes after the initial 911 call. Time to administration of antiarrhythmic was linked to ROSC.

Abstract 8875: Early Compared to Late Administration of Epinephrine in Adults With Shockable Initial Rhythm Out-of-Hospital Cardiac Arrest

Introduction: The optimal timing of epinephrine administration in shockable initial rhythm out-of-hospital cardiac arrest (OHCA) is unclear. Hypothesis: Early compared to late epinephrine following first electrical defibrillation attempt is associated with better outcomes in shockable initial rhythm OHCA. Methods: We conducted a retrospective study in adults with shockable initial rhythm OHCA from 2011-2015 in North America. We used multivariable logistic regression to assess associations between timing of epinephrine and prehospital return of spontaneous circulation (ROSC), survival to hospital discharge, and hospital discharge with favorable neurological outcome (modified Rankin Scale score≤3). We used propensity-score-matching and subgroup analyses to assess robustness of associations. Results: Of 6416 patients, median age was 64 (IQR: 54-74) years, 5136 (80%) were men, 2226 (35%) received epinephrine within four minutes after first defibrillation, 5119 (80%), 1237 (19%), and 996 (16%) had prehospital ROSC, survival to hospital discharge, and favorable neurological outcome at discharge respectively. Adjusted for confounders, we observed lower odds of prehospital ROSC (OR=0.95, 95%CI 0.94-0.96; p&lt;0.001), survival to hospital discharge (OR=0.91, 95%CI 0.89-0.92; p&lt;0.001), and favorable neurological outcomes at discharge (OR=0.92, 95%CI 0.90-0.93; p&lt;0.001) per minute later epinephrine administration. Compared to epinephrine administration within four minutes following first defibrillation attempt, later epinephrine was associated with lower odds of prehospital ROSC (OR=0.58, 95%CI 0.51-0.68; p&lt;0.001), survival to hospital discharge (OR=0.50, 95%CI 0.43-0.58; p&lt;0.001), and favorable neurological outcome at discharge (OR=0.51, 95%CI 0.43-0.59; p&lt;0.001). Associations remained significant in a well-balanced propensity score matched cohort and subgroup analyses by witness status, EMS response time, and total epinephrine dose. Conclusion: In shockable initial rhythm OHCA, early compared to late epinephrine administration following first defibrillation attempt was associated with better odds of prehospital ROSC, survival to hospital discharge, and hospital discharge with favorable neurological outcome.

Abstract 10508: Variation in Community and Emergency Medical Systems Processes for Out-of-Hospital Cardiac Arrest During the COVID-19 Pandemic: A Systematic Review and Meta-Analysis

Introduction: Bystander cardiopulmonary resuscitation (B-CPR) with early defibrillation and immediate emergency medical services (EMS) care significantly increases a victim's chance of survival from out-of-hospital sudden cardiac arrest (OHCA). Few studies have assessed the overall effect of the COVID-19 pandemic on the prehospital chain of survival. Objectives: We sought to quantify the effect of the COVID-19 pandemic on prehospital processes including B-CPR, bystander defibrillation, community characteristics, and EMS process measures. We hypothesized that B-CPR rates would decrease and OHCA occurring in the home would increase during the pandemic. Methods: We conducted a systematic review and meta-analysis of studies identified through 05/03/2021. We examined 5 bibliographic databases and searched terms including cardiac arrest, OHCA, and COVID-19. Data were abstracted and independently coded. Subgroup analysis and meta-regression analysis were performed. Our primary outcome was B-CPR; our secondary outcomes were community processes and EMS characteristics. Results: The original search yielded 966 articles; 20 articles were included in our analysis. Studies originated from 10 different countries and were retrospective in study design. There was no difference in B-CPR rates during COVID-19 compared to Pre-COVID-19 (OR: 0.94 (0.80-1.11), p=0.46). Patients had a 1.38 (1.11-1.71) higher likelihood of having an OHCA at home during COVID-19 compared to Pre-COVID-19 (p=0.01). Receipt of bystander defibrillation was significantly lower during COVID-19 compared to Pre-COVID-19 (OR: 0.65 (0.48-0.88), p=0.01). There was a significant increase in EMS call to arrival time during COVID-19 compared to Pre-COVID-19 (Mean difference in minutes= 0.27 (0.13-0.40), p&lt;0.01). Statistical heterogeneity was moderate-to-high; findings were robust to sensitivity analyses with no publication bias detected. Conclusion: B-CPR rates remained unchanged during the pandemic, while OHCA in the home increased. Bystander defibrillation decreased, while EMS response time increased during the pandemic. These findings may inform future public programing, particularly to consider interventions to improve the prehospital chain of survival.