Out-of-hospital Cardiac Arrest Location Research Articles

Out-of-hospital cardiac arrest - does location affect ROSC?

Abstract Introduction Out-of-hospital cardiac arrest (OHCA) is a significant public health problem, with hundreds of thousands of cases occurring annually in the UE and the USA. While overall survival rates remain low, studies indicate that the location of OHCA plays a critical role in survival outcomes. The discrepancy in survival rates between public and non-public locations can be stark, with public OHCA showing a notably higher chance of the return of spontaneous circulation (ROSC). This exploratory study aims to investigate the effect of OHCA location (public vs non-public) on ROSC in Poland. Methods The study was a retrospective analysis of patient records, focusing on cases handled by the Polish EMS from January 2021 to June 2022. This research utilized data from the National Emergency Medical Services. From a total of 4,925,214 EMS calls, 54,190 patients diagnosed with cardiac arrest (CA, ICD 10-I46), where paramedics initiated CPR on-site, were initially selected from the database. The study excluded patients whose CAs were due to suicide attempts, criminal acts, trauma and cases that lacked initial rhythm data of CA. Ultimately, data from 33,636 patients were analyzed. Data preprocessing was performed with Python 3.10.6 and STATISTICA 13.3. The α value used for statistical inference was 0.05. Results A higher frequency of CAs was in public places among younger individuals (p < 0.001). In public locations, we have also observed a lower prevalence of diabetes and higher incidences of myocardial infarction and return of spontaneous circulation (ROSC) in cases of CA (31.53 vs 35.79%). The odds of ROSC were modulated by age depending on the CA location – each subsequent increase in age by one year decreased the odds by 1.62% in at-home cases (p < 0.001) or by 0.40% upon public incidence (p ≈ 0.009). (Table 1). In multi-factor-adjusted logistic regression models, it is evident that the initial rhythm of VF/pVT significantly increases the likelihood of ROSC by more than 3.7 times compared to the Asystole/PEA rhythm, regardless of location. Obesity notably decreases ROSC chances in home incidents, unlike public cases. In public location CAs, conditions like stroke or myocardial infarction significantly increased ROSC odds. Additionally, the impact of age on ROSC probability varies with the location of the cardiac arrest, showing different rates of decrease with each additional year of age in home versus public incidents. Conclusion Patients with OHCA were statistically more likely to achieve ROSC if the CA occurred in a public location. In addition, if the initial rhythm was VF/pVT, the odds of ROSC were almost four times higher for both public and non-public locations. The odds of ROSC decreased with each additional year of age, regardless of the location of the CA. In addition, the presence of myocardial infarction increased the odds of ROSC in public locations. In non-public locations, obesity was associated with decreased odds of ROSC.

A retrospective comparison of mechanical cardio-pulmonary ventilation and manual bag valve ventilation in non-traumatic out-of-hospital cardiac arrests: A study from the Belgian cardiac arrest registry

BackgroundThe optimal ventilation modalities to manage out-of-hospital cardiac arrest (OHCA) remain debated. A specific pressure mode called cardio-pulmonary ventilation (CPV) may be used instead of manual bag ventilation (MBV). We sought to analyse the association between mechanical CPV and return of spontaneous circulation (ROSC) in non-traumatic OHCA. MethodsMBV and CPV were retrospectively identified in patients with non-traumatic OHCA from the Belgian Cardiac Arrest Registry. We used a two-level mixed-effects multivariable logistic regression analysis to determine the association between the ventilation modalities and outcomes. The primary and secondary study criteria were ROSC and survival with a Cerebral Performance Category (CPC) score of 1 or 2 at 30 days. Age, sex, initial rhythm, no-flow duration, low-flow duration, OHCA location, use of a mechanical chest compression device and Rankin status before arrest were used as covariables. ResultsBetween January 2017 and December 2021, 2566 patients with OHCA who fulfilled the inclusion criteria were included. 298 (11.6%) patients were mechanically ventilated with CPV whereas 2268 were manually ventilated. The use of CPV was associated with greater probability of ROSC both in the unadjusted (odds ratio: 1.28, 95% confidence interval [CI]: 1.01–1.63; p = 0.043) and adjusted analyses (adjusted odds ratio [aOR]: 2.16, 95%CI 1.37–3.41; p = 0.001) but not with a lower CPC score (aOR: 1.44, 95%CI 0.72–2.89; p = 0.31). ConclusionsCompared with MBV, CPV was associated with an increased risk of ROSC but not with improved an CPC score in patients with OHCA. Prospective randomised trials are needed to challenge these results.

Volunteer Responder Interventions in Out-of-Hospital Cardiac Arrest in Urban, Suburban, and Rural Areas.

Patients with out-of-hospital cardiac arrest (OHCA) in rural areas experience longer emergency response times and have lower survival rates compared with patients in urban areas. Volunteer responders might improve care and outcomes for patients with OHCA specifically in rural areas. Therefore, we investigated volunteer responder interventions based on the degree of urbanization. We included 1310 OHCAs from 3 different regions in Denmark where volunteer responders had arrived at the OHCA location. The location was classified as urban, suburban, or rural according to the Eurostat Degree of Urbanization Tool. A logistic regression model was used to examine associations between the degree of urbanization and volunteer responder arrival before emergency medical services, cardiopulmonary resuscitation, or defibrillation. We found the odds for volunteer responder arrival before emergency medical services more than doubled in rural areas (odds ratio [OR], 2.60 [95% CI, 1.91-3.53]) and suburban areas (OR, 2.05 [95% CI, 1.56-2.69]) compared with urban areas. In OHCA cases where volunteer responders arrived first, odds for bystander cardiopulmonary resuscitation was tripled in rural areas (OR, 3.83 [95% CI, 1.64-8.93]) and doubled in suburban areas (OR, 2.27 [95% CI, 1.17-4.41]) compared with urban areas. Bystander defibrillation was more common in suburban areas (OR, 1.53 [95% CI, 1.02-2.31]), where almost 1 out of 4 patients received bystander defibrillation, compared with urban areas. Volunteer responders are significantly more likely to arrive before emergency medical services in rural and suburban areas than in urban areas. Patients with OHCA received more cardiopulmonary resuscitation in rural and suburban areas and more defibrillation in suburban areas than in urban areas.

AMplitude Spectral Area (AMSA) is associated with one-year survival with good neurological outcome in out-of-hospital cardiac arrest

Abstract Background Patients resuscitated from Out-of-Hospital Cardiac Arrest (OHCA) with shockable rhythms are reported to have better survival rates. Amplitude spectral area (AMSA) of ventricular fibrillation (VF), a surrogate for the metabolic status of the myocardium, can predict shock success and return of spontaneous circulation (ROSC). There is minimal evidence regarding its role in predicting survival from OHCA, and the evidence that exists is limited to survival at discharge. Purpose To test the hypothesis that the first, the maximum, the minimum and the average values of AMSA are associated with one-year survival with good neurological outcome in OHCA patients. Methods All the OHCAs with at least one shockable rhythm, that occurred from January 2015 to December 2020 and collected from an Utstein-style database, were considered. AMSA values were calculated by retrospectively analyzing the data collected by the monitors/defibrillators used and by using a 2-second pre-shock ECG interval. The first, the maximum, the minimum and the average AMSA values during resuscitation were computed. Data were analyzed by using Cox regression analysis. Results 250 patients (84% male, median age 67 [57-77] years) with at least one computable AMSA value were included; 12% achieved ROSC and 9.4% survived at one year with good neurological outcome, defined as Cerebral Performance Category (CPC) ≤ 2. The first, the maximum, the minimum and the average values of AMSA were higher in patients alive one year after OHCA with CPC≤2 (first: 11.6 [9.9-14.7] vs 7.8 [5.1-11.8]; max: 15.4 [12-20] vs 9.9 [6.2-14.4]; min: 9.9 [8.5-12.2] vs 6.1 [4.3-9.6]; avg: 12.5 [10.7-15.2] vs 8.3 [5.5-12]; all p <0.01). These values showed similar areas under the curve of the receiver operating characteristic (ROC) curve for one-year survival with good neurological outcome (first: 0.77; max: 0.76; min: 0.78; avg: 0.78, p=ns). In univariable model, the survival probability with good neurological outcome was significantly lower in the first tertile (T1) of AMSA compared to the third one (T3; p<0.05; figure). In multivariable analysis, after correction for sex, presence of bystander CPR, age, EMS arrival time, witnessed status, OHCA location, the use of mechanical CPR and the total amount of epinephrine administrated, AMSA was significantly associated with probability of death or poor neurologic outcome [HR 0.5 (95%CI 0.3-0.9), p=0.03]. Conclusions This is the first study to evaluate the association between AMSA values and one-year survival with good neurological outcome. We found that AMSA is independently associated with one-year survival with­ good neurological outcome in OHCA patients and that the first, the maximum, the minimum and the average of AMSA values all have similar prediction power in survival rate with CPC≤2.

Acute SARS-CoV-2 Infection and Incidence and Outcomes of Out-of-Hospital Cardiac Arrest

Little is known about how COVID-19 affects the incidence or outcomes of out-of-hospital cardiac arrest (OHCA), and it is possible that more generalized factors beyond SARS-CoV-2 infection are primarily responsible for changes in OHCA incidence and outcome. To assess whether COVID-19 is associated with OHCA incidence and outcomes. This retrospective cohort study was conducted in Seattle and King County, Washington. Participants included persons aged 18 years or older with nontraumatic OHCA attended by emergency medical services (EMS) between January 1, 2018, and December 31, 2021. Data analysis was performed from November 2022 to March 2023. Prepandemic (2018-2019) and pandemic (2020-2021) periods and SARS-CoV-2 infection. The primary outcomes were OHCA incidence and patient outcomes (ie, survival to hospital discharge). Mediation analysis was used to determine the percentage change in OHCA incidence and outcomes between prepandemic and pandemic periods that was attributable to acute SARS-CoV-2 infection vs conventional Utstein elements related to OHCA circumstances (ie, witness status and OHCA location) and resuscitation care (ie, bystander cardiopulmonary resuscitation, early defibrillation, and EMS response intervals). There were a total of 13 081 patients with OHCA (7102 dead upon EMS arrival and 5979 EMS treated). Among EMS-treated patients, the median (IQR) age was 64.0 (51.0-75.0) years, 3864 (64.6%) were male, and 1027 (17.2%) survived to hospital discharge. The total number of patients with OHCA increased by 19.0% (from 5963 in the prepandemic period to 7118 in the pandemic period), corresponding to an incidence increase from 168.8 to 195.3 events per 100 000 person-years. Of EMS-treated patients with OHCA during the pandemic period, 194 (6.2%) were acutely infected with SARS-CoV-2 compared with 7 of 191 EMS-attended but untreated patients with OHCA (3.7%). In time-series correlation analysis, there was a positive correlation between community SARS-CoV-2 incidence and overall OHCA incidence (r = 0.27; P = .01), as well as OHCA incidence with acute SARS-CoV-2 infection (r = 0.43; P < .001). The survival rate during the pandemic period was lower than that in the prepandemic period (483 patients [15.4%] vs 544 patients [19.2%]). During the pandemic, those with OHCA and acute SARS-CoV-2 infection had lower likelihood of survival compared with those without acute infection (12 patients [6.2%] vs 471 patients [16.0%]). SARS-CoV-2 infection itself accounted for 18.5% of the pandemic survival decline, whereas Utstein elements mediated 68.2% of the survival decline. In this cohort study of COVID-19 and OHCA, a substantial proportion of the higher OHCA incidence and lower survival during the pandemic was not directly due to SARS-CoV-2 infection but indirect factors that challenged OHCA prevention and treatment.

The Association of Prehospital End-Tidal Carbon Dioxide with Survival Following Out-of-Hospital Cardiac Arrest

Objective End tidal carbon dioxide (ETCO2) is often used to assess ventilation and perfusion during cardiac arrest resuscitation. However, few data exist evaluating the relationship between ETCO2 values and mortality in the context of contemporary resuscitation practices. We aimed to explore the association between ETCO2 and mortality following out-of-hospital cardiac arrest (OHCA). Methods We used the 2018–2021 ESO annual datasets to query all non-traumatic OHCA patients with attempted resuscitation. Patients with documented DNR/POLST, EMS-witnessed arrest, ROSC after bystander CPR only, or < 2 documented ETCO2 values were excluded. The lowest and highest ETCO2 values recorded during the total prehospital interval, in addition to the pre- and post-ROSC intervals for resuscitated patients, were calculated. Multivariable logistic regression models adjusted for age, sex, initial rhythm, witnessed status, bystander CPR, etiology, OHCA location, sodium bicarbonate administration, number of milligrams of epinephrine administered, and response interval were used to evaluate the association between measures of ETCO2 and mortality. Results Hospital outcome data were available for 14,122 patients, and 2,209 (15.6%) were classified as surviving to discharge. Compared to patients with maximum prehospital ETCO2 values of 30–40 mmHg, odds of mortality were increased for patients with maximum prehospital ETCO2 values of <20 mmHg (aOR: 3.5 [2.1, 5,9]), 20–29 mmHg (aOR: 1.5 [1.1, 2.1]), and >50 mmHg (aOR: 1.5 [1.2, 1.8]). After 20 minutes of ETCO2 monitoring, <12% of patients had ETCO2 values <10 mmHg. This cutpoint was 96.7% specific and 6.9% sensitive for mortality. Conclusion In this dataset, both high and low ETCO2 values were associated with increased mortality. Contemporary resuscitation practices may make low ETCO2 values uncommon, and field termination decision algorithms should not use ETCO2 values in isolation.

Racial and ethnic disparities in the provision of bystander CPR after witnessed out-of-hospital cardiac arrest in the United States

ObjectiveTo evaluate the association between race/ethnicity and the odds of receiving bystander cardiopulmonary resuscitation (bCPR) after witnessed out-of-hospital cardiac arrest (OHCA). MethodsFor this cross-sectional retrospective study, data were obtained from the National Emergency Medical Services Information System database for adults (≥18 years) with a witnessed non-traumatic OHCA in the year 2021. Patients were separated into two groups including Black/Hispanic and White. The primary outcome was the odds of receiving bCPR. We excluded traumatic etiology, do-not-resuscitate orders, and arrest in a healthcare facility or wilderness location. Multiple logistic regression controlling for known covariates was utilized and analyses were stratified by public versus non-public location, median household income, and rural, suburban, or urban setting. ResultsA total of 64,007 witnessed OHCAs were included. When compared to White, the Black/Hispanic group were younger (62 vs 67 years) and more often female (40% vs 33%), in neighborhoods with the lowest median household income (31% vs 13%) and in an urban setting (92% vs 80%). Overall, bystander CPR rates were 60% and 67% for the Black/Hispanic and White groups, respectively. Multiple logistic regression stratified by OHCA location found that the Black/Hispanic group had a decreased odds of receiving bCPR compared to the White group both in the home (adjusted OR [aOR] 0.77; 95% CI 0.74–0.81) and in public (aOR 0.69; 95% CI 0.64–0.76). This difference persisted throughout neighborhoods of different socioeconomic status and across the rural–urban spectrum. ConclusionsRacial/ethnic disparities exist for Black and Hispanic persons in the odds of receiving bCPR after a witnessed non-traumatic OHCA regardless of public or private setting, neighborhood income level, or population density.

A retrospective comparison of the King Laryngeal Tube and iGel supraglottic airway devices: A study for the CARES surveillance group

ObjectiveSupraglottic airway devices are increasingly used during the resuscitation of out-of-hospital cardiac arrest (OHCA) patients in the United States and worldwide. In this study, we aimed to compare the neurologic outcomes of OHCA patients managed with the King Laryngeal Tube (King LT) to the neurologic outcomes of patients managed with the iGel. MethodsWe used the Cardiac Arrest Registry to Enhance Survival (CARES) public use research dataset for our analysis. Non-traumatic OHCA cases with attempted EMS resuscitation enrolled from 2013-2021 were included. We used two-level mixed effects multivariable logistic regression analyses with treating EMS agency as the random effect to determine the association between supraglottic airway device and outcome. The primary outcome was survival with a Cerebral Performance Category (CPC) score of 1 or 2 at discharge. Secondary outcomes included survival to hospital admission and survival to hospital discharge. Age, sex, calendar year of OHCA, initial ECG rhythm, witnessed status (unwitnessed, bystander witnessed, 9-1-1 responder witnessed), bystander CPR, response interval, and OHCA location (private/home, public, institutional) were used as covariables. ResultsIn comparison to use of the King LT, use of the iGel was associated with greater neurologically favorable survival (aOR: 1.45 [1.33, 1.58]). In addition, use of the iGel was associated with greater survival to hospital admission (1.07 [1.02, 1.12]) and survival to hospital discharge (1.35 [1.26, 1.46]). ConclusionsThis study adds to the body of literature suggesting that use of the iGel during OHCA resuscitation is associated with better outcomes than use of the King LT.

Termination of resuscitation in out-of-hospital cardiac arrest in women and men: An ESCAPE-NET project

AimWomen have less favorable resuscitation characteristics than men. We investigated whether the Advanced Life Support Termination of Resuscitation rule (ALS-TOR) performs equally in women and men. Additionally, we studied whether adding or removing criteria from the ALS-TOR improved classification into survivors and non-survivors. MethodsWe analyzed 6,931 female and 14,548 male out-of-hospital cardiac arrest (OHCA) patients from Dutch and Swedish registries, and validated in 10,772 female and 21,808 male Danish OHCA patients. Performance measures were calculated for ALS-TOR in relation to 30-day survival. Recursive partitioning analysis was performed with the ALS-TOR criteria, as well as age, comorbidities, and additional resuscitation characteristics (e.g. initial rhythm, OHCA location). Finally, we explored if we could reduce the number of ALS-TOR criteria without loss of prognostic value. ResultsThe ALS-TOR had a specificity and positive predictive value (PPV) of ≥99% in both women and men (e.g. PPV 99.9 in men). Classification by recursive partitioning analysis showed a high sensitivity but a PPV below 99%, thereby exceeding the acceptable miss rate of 1%. A combination of no return of spontaneous circulation (ROSC) before transport to the hospital and unwitnessed OHCA resulted in nearly equal specificity and PPV, higher sensitivity, and a lower transport rate to the hospital than the ALS-TOR. ConclusionFor both women and men, the ALS-TOR has high specificity and low miss rate for predicting 30-day OHCA survival. We could not improve the classification with additional characteristics. Employing a simplified version may decrease the number of futile transports to the hospital.

Out-of-hospital cardiac arrests in the city of Cape Town metropole of the Western Cape province of South Africa: a spatio-temporal analysis.

The incidence of out-of-hospital cardiac arrest (OHCA) is expected to increase in sub-Saharan Africa along with the incidence of cardiovascular disease. In low-resource settings (LRS), OHCA carries a negligible survival rate. Interventions to improve OHCA survival might not be cost effective for many LRS, and therefore need to be targeted to areas of high incidence. The aim of this study was to describe the temporal and geographic distribution of OHCA in the City of Cape Town, South Africa, and their proximity to percutaneous coronary intervention (PCI) resources. In this retrospective study, OHCA data between 1 January and 31 December 2018 were extracted from public and one private emergency medical services in the Western Cape. For temporal analysis, distribution of OHCA according to time of day, day of the week and month of the year were subjected to chi-squared testing. For geospatial analysis, cluster and outlier, and hotspot analyses were performed. Proximity analysis was employed to determine the driving time from OHCA location to the closest PCI-capable facility. A total of 929 patients with OHCA received an emergency medical services response in the City of Cape Town, corresponding to an annual prevalence of 23.2 per 100 000 persons. The distribution of OHCA incidence was not explained by month of the year (p = 0.08) or day of the week (p = 0.67). A statistically significant variation in OHCA incidence was explained by time of day (p < 0.01) with 30% (n = 279) of all OHCAs occurring from 05:00 to 09:59. Geospatial analysis yielded a large area of hotspots (99% confidence interval) over the centre of the metropole, Cape Flats and southern suburbs. The median (interquartile range) driving time from the incident to the closest PCI-capable facility was 10:22 (08:05) minutes. Incidents of OHCA occurred predominantly at home during the mid-morning, with hotspots around the city centre and residential suburbs of Cape Town. While the incidents occurred close to PCI-capable facilities, some areas remained underserved and access to PCI for OHCA victims may be impossible due to socio-economic factors. With an increase in OHCA incidence expected, it is essential that contextual, cost-effective management interventions be developed and implemented.

Association between location of out-of-hospital cardiac arrest, on-scene socioeconomic status, and accessibility to public automated defibrillators in two large metropolitan areas in Canada and France

AimTo compare walking access times to automated external defibrillators (AEDs) between area-level quintiles of socioeconomic status (SES) in out-of-hospital cardiac arrest (OHCA) cases occurring in 2 major urban regions of Canada and France. MethodsThis was an international, multicenter, retrospective cohort study of adult, non-traumatic OHCA cases in the metropolitan Vancouver (Canada) and Rhône County (France) regions that occurred between 2014 and 2018. We calculated area-level SES for each case, using quintiles of country-specific scores (Q5 = most deprived). We identified AED locations from local registries. The primary outcome was the simulated walking time from the OHCA location to the closest AED (continuous and dichotomized by a 3-minute 1-way threshold). We fit multivariate models to analyze the association between OHCA-to-AED walking time and outcomes (Q5 vs others). ResultsA total of 6,187 and 3,239 cases were included from the Metro Vancouver and Rhône County areas, respectively. In Metro Vancouver Q5 areas (vs Q1-Q4), areas, AEDs were farther from (79 % over 400 m from case vs 67 %, p < 0.001) and required longer walking times to (97 % above 3 min vs 91 %, p < 0.001) cases. In Rhône Q5 areas, AEDs were closer than in other areas (43 % over 400 m from case vs 50 %, p = 0.01), yet similarly poorly accessible (85 % above 3 min vs 86 %, p = 0.79). In multivariate models, AED access time ≥ 3 min was associated with decreased odds of survival at hospital discharge in Metro Vancouver (odds ratio 0.41, 95 % CI [0.23–0.74], p = 0.003). ConclusionsAccessibility of public AEDs was globally poor in Metro Vancouver and Rhône, and even poorer in Metro Vancouver’s socioeconomically deprived areas.

Development of smartphone applications for bystander cardiopulmonary resuscitation in the prehospital setting in Thailand

Objective The survival of out-of-hospital cardiac arrest (OHCA) patients depends on early bystander chest compression and rapid public access defibrillation. This study aimed to design and develop a smartphone application for bystander cardiopulmonary resuscitation (BCPR) in a prehospital setting in Thailand. Methods The four steps of the study were planning, development, evaluation, and production of applications through online meetings and submission of a linked questionnaire to 19 experts for consensus. Results Among the total of 19 experts, 93% strongly agreed with the development of the smartphone application. They agreed with the operating modes as follows: 100% with emergency calls by number and video calls, 100% with dispatchers and bystanders to locate OHCA and automated external de­fibrillator (AED), 94% with teaching of BCPR by video, 88% with pediatric cardiopulmonary resuscitation (CPR), 100% with tracking of real-time feedback to BCPR by voice, 88% with contacting bystanders by phone number, 83% with applications that can transmit signals from OHCA to nearby bystanders within 400 m, and 89% with first aid for daily life. Consequently, the application’s main operating modes are emergency calls, identification of OHCA and AED locations, responder call, and first aid. Conclusion We designed and developed a new smartphone application for BCPR in Thailand. The following study will test a smartphone application for training and outcome measures in Bangkok, Thailand. Keywords: Out-of-hospital cardiac arrest, Cardiopulmonary resuscitation, Smartphone

Drones delivering automated external defibrillators—Integrating unmanned aerial systems into the chain of survival: A simulation study in rural Germany

BackgroundCommunity first responders (CFR) improve survival in out-of-hospital cardiac arrest (OHCA) but are often hampered by limited availability of public access defibrillation. Unmanned aerial systems (UAS) delivering automated external defibrillators (AED) directly to an OHCA site could help overcome this. We evaluated the feasibility of integrating UAS into the chain of survival in rural Northeast Germany. MethodsThis simulation study explored UAS-AED delivery combined with a smartphone-based CFR dispatch. Five OHCA locations (A–E) were randomly selected. We routed a flight corridor to each of these sites from a corresponding UAS base; 50 OHCA scenarios with 10 flights per corridor were scheduled. All steps were accurately simulated, from a bystander finding the patient, making an emergency call, conducting dispatcher-assisted cardiopulmonary resuscitation, and simultaneous CFR plus UAS deployment, to the bystander and CFR interacting with UAS and AED. This process was time-tracked and video-recorded until defibrillation. ResultsWe performed 46 OHCA simulations. Missions were flown autonomously but needed pilot assistance during landing. Distances (km) and average time intervals from alert to defibrillation (td in min:sec ± SD) were 0.4 (6:02 ± 0:56), 2.29 (6:53 ± 0:19), 4.0 (8:54 ± 0:25), 7.43 (14:51 ± 1:055), and 9.79 (15:51 ± 1:16) for routes A to E, respectively. All participants were able to retrieve the AED within seconds after UAS landing and interacted safely with the UAS and AED. ConclusionsIntegrating airborne AED delivery into the chain of survival appeared feasible and safe but remains an experimental technology. Linking this with CFR potentially improves the availability of early public-access defibrillation, particularly in rural regions.

Abstract 11964: Citizen Responders Provide Emotional Support for Relatives to Out-of-Hospital Cardiac Arrest Patients

Introduction: A citizen responder (CR) system to activate volunteer citizens by a smartphone application (HeartRunner) to nearby cardiac arrests was implemented in 2017 in the Capital Region of Denmark. Participating in resuscitation may not only involve provision of cardio-pulmonary resuscitation (CPR) but also include provision of emotional support for relatives to the cardiac arrest patient. We examined the proportion of CR who reported provision of support to relatives to out-of-hospital cardiac arrest (OHCA) patients during resuscitation attempt. Hypothesis: We hypothesized that CR not only deliver CPR but also provide emotional support to relatives of OHCA patients. Methods: All CR activated by the HeartRunner app received a follow-up questionnaire 90 minutes after the alarm including questions about how CRs participated in resuscitation and whether they provided emotional support to relatives present during the resuscitation attempt. All surveys from March 12, 2020 to June 1, 2021, from CR who accepted an alarm and arrived at the cardiac arrest location were included. Results: A total of 1,868 CR responded to the survey (median age 37 years (IQR 28-37). Half (54.4%) were male and 23.9% health care professionals. CRs arrived before the emergency medical services (EMS) in almost 1/3 (28.9%) of OHCA cases with CR activation, with 227 CRs (41.9%) performing CPR and 139 (25.7%) attaching an automated external defibrillator. In total, more than 433 CRs (23.2%) reported provision of support for relatives at the OHCA location. Even though a higher proportion of support was observed among CR who arrived before the EMS, almost 12% reported provision of support to relatives even when arriving after EMS (Figure). Conclusions: Citizen responders provide not only resuscitative efforts but offer emotional support to relatives to OHCA patients. Citizen responders may be an important resource for both EMS personnel and relatives who are present at the cardiac arrest scene.

Impact of the COVID-19 pandemic on emergency medical service response to out-of-hospital cardiac arrests in Taiwan: a retrospective observational study

BackgroundEmergency medical service (EMS) personnel have high COVID-19 risk during resuscitation. The resuscitation protocol for patients with out-of-hospital cardiac arrest (OHCA) was modified in response to the COVID-19 pandemic. However,...

First Description of a Helicopter-Borne ECPR Team for Remote Refractory Out-of-Hospital Cardiac Arrest

Introduction: Access time to extracorporeal cardiopulmonary resuscitation (ECPR) refractory out of hospital cardiac arrest (OHCA) is a crucial factor. In our region, some patients are not eligible to this treatment due to the impossibility to reach the hospital with reasonable delay (ideally 60 min). In order to increase accessibility for patients far from ECPR centers, we developed a helicopter-borne ECPR-team which is sent out to the patient for ECPR implementation on the scene of the OHCA. Methods: We conducted a retrospective monocentric study to evaluate this strategy. The team is triggered by the local emergency medical service and heliborne on the site of the OHCA. All consecutive patients implemented with ECPR by our heliborne ECPR team from January 2014 to December 2017 were included. We analyzed usual CA characteristics, different times (no-flow, low-flow, time between OHCA and dispatch…), and patient outcome. Results: During this 4-year study period, 33 patients were included. Mean age was 43.9 years. Mean distance from the ECPR-team base to OHCA location was 41 km. Mean low-flow time was 110 minutes. Five patients survived with good neurological outcome; 6 patients developed brain death and became organ donors. Conclusion: These results show the possibility to make ECPR accessible for patients far from ECPR centers. Survival rate is non negligible, especially in the absence of therapeutic alternative. An earlier trigger of the ECPR-team could reduce the low-flow time and probably increase survival. This strategy improves equity of access to ECPR and needs to be confirmed by further studies.

Outcomes of out-of-hospital cardiac arrest in relation to prehospital care services in Hospital Canselor Tuanku Muhriz: A prospective study

Background: The role of prehospital care (PHC) services in out-of-hospital cardiac arrest (OHCA) is well established in developed countries. The American Heart Association has defined PHC as the ‘chain of survival’ between public and advanced medical care. For developing countries such as Malaysia, the importance of PHC services in OHCA is evolving; however, data are lacking. Objective: This study aimed to investigate OHCA outcomes in relation to PHC services in Hospital Canselor Tuanku Muhriz, Kuala Lumpur, Malaysia. Method: This was a prospective study conducted on OHCA cases attended by the PHC staff of Hospital Canselor Tuanku Muhriz. Independent variables were patient background, OHCA nature, and PHC interventions, while dependent variables were patient outcomes. Results: A total of 82 OHCA cases were identified. The survival rate to admission was 12.2% (n = 10), while the survival rate to discharge was 1.2% (n = 1) with cerebral performance categories of 1 or 2. The mean ambulance response time was 14.91 min. Among the variables, only OHCA location and adrenaline administration show significant association with OHCA outcome. OHCA location was significant in both outcomes (admission χ2(4) = 16.354, p &lt; 0.03, Cramer&apos;s V = 0.447, discharge χ2(4) = 19.741, p &lt; 0.001, Cramer&apos;s V = 0.491). However, adrenaline administration was significant only for survival to admission (χ2(1) = 3.776, p &lt; 0.052, Cramer&apos;s V = 0.215) but not for survival to discharge (χ2(1) = 0.964, p &lt; 0.326). Conclusion: Improvement in ambulance response time, public availability of automated external defibrillator, and public awareness of early cardiac arrest and cardiopulmonary resuscitation are required to increase the survivability of OHCA in developing countries.

Abstract 148: A Machine Learning-based Dispatch Rule for Drone-delivered Defibrillators

Introduction: Drone-delivered defibrillators may reduce response time for out-of-hospital cardiac arrest (OHCA). However, an optimal dispatch rule is not yet known. Methods: We identified all suspected OHCAs in Peel Region, Ontario, Canada from Jan. 2014 to Dec. 2019. We trained a neural network model to predict emergency medical services (EMS) response times using OHCA location, distance from responding ambulance, day of week and time of day. Instead of least-squares loss, our model optimized a loss function that penalized weighted errors in the dispatch decision (type I/II error). Assuming drones were deployed from three bases in the region, we calculated drone response time to each suspected OHCA using real drone specifications. Our dispatch rule dispatched a drone when its calculated response time was shorter than the predicted EMS response time. Response time was calculated as the minimum of the drone and EMS response times. The performance of our dispatch rule was compared on out-of-sample OHCAs using 5-fold cross validation to the baseline cases of (1) no drones, and (2) drone dispatch to every suspected OHCA. Statistical analysis on the median response times was performed using a right-tailed sign test. Results: We identified 4774 suspected OHCAs with a median historical EMS response time of 6.0 minutes. Using our dispatch rule, median response time was significantly shorter at 3.9 minutes (P&lt;0.001). Drones were dispatched to 3803 cases (79.7%) and of those, drone response was faster than EMS in 3076 cases (80.9%). When the drone was not dispatched, it would have been slower than EMS in 856 cases (88.1%). Sending a drone to every suspected OHCA resulted in an identical median response time of 3.9 minutes (P&lt;0.001), with drones arriving before EMS in 3191 cases (66.8%). Conclusion: A machine learning-based dispatch rule can achieve similar response times as a policy that dispatches a drone to all suspected OHCAs, while dispatching drones less frequently.

Gender-specific differences in return-to-spontaneous circulation and outcome after out-of-hospital cardiac arrest: Results of sixteen-year-state-wide initiatives

AimSeveral studies reported a lower proportion of laypeople cardio-pulmonary resuscitation (CPR) in female victims of out-of-hospital cardiac arrest (OHCA). We aimed to verify how sixteen-years of state-wide initiatives impacted on gender-differences in OHCA treatment and survival. MethodsAll the 2481 consecutive OHCAs of presumed cardiac origin occurred between 2002 and 2018 in the Swiss Ticino Canton and in which a resuscitation was attempted, were included. Emergency medical system (EMS)-witnessed OHCAs were excluded. ResultsTime from call to CPR decreased from 9-min in 2002–2006 to 5-min in 2015–2018 (p<0.01) and until 2014, it was longer in women. Survival to discharge increased overall from 11% in 2002–2006 to 23% in 2015–2018 (p<0.001) related to telephone-assisted CPR development (period 2011–2014) and first responder and layperson recruitment via a mobile application (period 2015–2018). In males, survival increased from 12% to 25% (p=0.001) with a statistically significant increase in odds of survival in 2007–2010 (OR 1.6 95%CI 1.1–2.3; p=0.001), in 2011–2014 (OR 2 95%CI 1.4–2.8; p=0.001), and in 2015–2018 (2.4 95%CI 1.7–3.3; p=0.001) compared to 2002–2006. On the other hand, in females, survival increased from 7% to 18% (p<0.001), with a corresponding increase in the odds of survival of almost 3 times from 2002–2006 to 2015–2018 time period (OR 2.9 95%CI 1.5–5.8, p=0.001). No difference in survival probability was observed according to gender when adjusted for age, presenting rhythm, year-groups, OHCA location, EMS arrival time, witnessed status and laypeople-CPR. ConclusionsState-wide initiatives can significantly increase the chances of survival in both male and female victims of OHCAs, by increasing the probability to receive CPR in a shorter time span.

Pre-hospital factors and survival after out-of-hospital cardiac arrest according to population density, a nationwide study

AimThis study aimed to examine the impact of population density on bystander cardiopulmonary resuscitation (CPR) and survival after out-of-hospital cardiac arrest (OHCA). MethodsThrough the Danish Cardiac Arrest Registry (2001–2013), OHCAs ≥18 years of presumed cardiac cause were identified, and divided according to the OHCA location in four population density groups (inhabitants/km2) based on urban/rural area-definitions: low (<300/km2), medium (300–1499/km2), high (1500–2999/km2), very high (>3000/km2). The association between population density, bystander cardiopulmonary resuscitation (CPR) and survival was examined using logistic regression, adjusted for age, sex, comorbitidies and calendar-year. Results18,248 OHCAs were identified. Patients in areas of high compared to low population density were older, more often female, had more comorbidities, more witnessed arrests (very high: 59.6% versus low: 55.0%), shorter response time (very high: 10min versus low: 14min), but less bystander CPR (very high: 34.3% versus low: 45.1%). Thirty-day survival was higher in areas of higher population density (very high: 10.2% vs. low 5.3%), also in best-cases of witnessed arrests with bystander CPR and response time <10min (very high: 33.6% versus low: 13.8%). The same trends were found in adjusted analyses with lower odds for bystander CPR (odds ratio [OR] 0.55 95% confidence interval [CI] 0.46–0.66) and higher odds for 30-day survival (OR 2.78, 95%CI 1.95–3.96) in the highest population density areas compared to low. ConclusionsHaving an OHCA in higher populated areas were found associated with less bystander CPR, but higher survival. Identification of area-related factors can help target future pre-hospital care.