HIV status and lay bystander cardiopulmonary resuscitation initiation for witnessed cardiac arrest.

INTRODUCTION: Early initiation of cardiopulmonary resuscitation (CPR) by bystanders of out-of-hospital cardiac arrest (OHCA) significantly improves survival and neurological outcomes. However, misconceptions about human immunodeficiency virus (HIV) transmission risk during CPR can deter lay bystanders from performing resuscitation. The aim of this study was to compare the rate of CPR initiation by lay bystanders who witnessed OHCA in subjects with and without HIV infection. METHODS: We analysed data from the two French cardiac arrest registries (SDEC and RéAC) from 2012 to 2020. We identified HIV-positive individuals from the French National Health Insurance database for the SDEC registry, and directly from the RéAC registry data. We used logistic regression models to assess the association between CPR initiation by lay bystanders and the victim's HIV status. RESULTS: Of 58,177 witnessed OHCA cases, 192 (0.3%) occurred in HIV-positive subjects. These individuals were younger, more often male, and presented more shockable initial rhythms compared with subjects without HIV. Overall, there was no difference in the CPR initiation rate according to the HIV status (57.3% vs 47.6%, adjusted odds ratio 1.11, 95% confidence interval 0.83-1.48). The CPR initiation rate also did not differ by location between victims with or without HIV (home: 57.7% vs 45.4%; public places: 56.0% vs 53.6%; p for interaction = 0.46). Survival and neurological outcomes at hospital discharge did not differ based on the HIV status. CONCLUSIONS: This study revealed that the rate of CPR initiation by lay bystanders did not differ between HIV and non-HIV subjects during OHCA.

Regional variation in accessibility of automated external defibrillators in British Columbia.

OBJECTIVES: Bystander-applied Automated External Defibrillators (AED) improve outcomes for out-of-hospital cardiac arrest. AED placement is often driven by private enterprise or non-for-profit agencies, which may result in inequitable access. We sought to compare AED availability between four regions in British Columbia (BC). METHODS: We identified AEDs (confirmed to be operational) and emergency medical system (EMS)-treated out-of-hospital cardiac arrests (OHCA) from provincial registries. We compared AED availability between BC's four most populous regions. The primary outcome was the total regional weekly accessible AED-hours per 100,000 population. We also examined: AEDs per 100,000 population and per km2, the ratio of AEDs to OHCA, and the distance from each OHCA to the closest AED. RESULTS: From provincial registries, we included 879 AEDs from BC's four most populous regions, where 9333 EMS-treated OHCA occurred over a 5-year period. The most common AED location types were stores, public community centres, and office buildings. Ten percent of AEDs were accessible for all hours. Weekly accessible AED-hours/100,000 population in the four regions were: 3845, 1734, 1594, and 1299. AEDs/100,000 population ranged from 22 to 48, and AEDs/km2 ranged from 0.0048 to 0.20. The number of OHCAs per AED per year ranged from 1.1 to 2.8. The median OHCA-to-closest AED distance ranged from 503 (IQR 244, 947) to 925 (IQR 455, 1501) metres. The regional mean accessibility of individual AEDs ranged between 59 and 79 h per week. CONCLUSION: BC's four most populous regions demonstrate substantial variability in AED accessibility. Further benefit could be derived from AEDs if placed in locations accessible all hours. Our data may encourage community planning efforts to use data-based strategies to systematically place AEDs in optimal locations with strategies to maximize accessibility.

ABSTRAIT: OBJECTIFS: Les défibrillateurs externes automatisés (DEA) appliqués par les témoins améliorent les résultats en cas d'arrêt cardiaque hors hôpital. Le placement des DEA est souvent dirigé par une entreprise privée ou des organismes sans but lucratif, ce qui peut entraîner un accès inéquitable. Nous avons cherché à comparer la disponibilité des DEA entre quatre régions de la Colombie-Britannique. MéTHODES: Nous avons identifié les DEA (dont la mise en service a été confirmée) et les SMU (système médical d'urgence) traités par arrêt cardiaque hors hôpital (AHC) dans les registres provinciaux. Nous avons comparé la disponibilité des DEA entre les quatre régions les plus peuplées de la Colombie-Britannique. Le résultat principal était le nombre total d'heures de DEA accessibles hebdomadaires par région pour 100000 habitants. Nous avons également examiné : les DEA par 100000 habitants et par km2, le rapport entre les DEA et l'AHCA, et la distance entre chaque AHCA et le DEA le plus proche. RéSULTATS: À partir des registres provinciaux, nous avons inclus 879 DEA des quatre régions les plus peuplées de la Colombie-Britannique, où 9333 OHCA traités par les SMU se sont produits sur une période de 5 ans. Les types de DEA les plus courants étaient les magasins, les centres communautaires publics et les immeubles de bureaux. Dix pour cent des DEA étaient accessibles toutes les heures. La population hebdomadaire accessible en heures AED/100000 habitants dans les quatre régions était de 3845, 1734, 1594 et 1299. Le nombre de DEA/100 000 habitants variait de 22 à 48, et le nombre de DEA/km2 variait de 0,018 à 0,018. Le nombre de CASO par DEA par année variait de 1,1 à 2,8. La distance médiane entre le DEA OHCA et le DEA le plus proche variait de 503 mètres (IQR 244, 947) à 925 mètres (IQR 455, 1501). L'accessibilité moyenne régionale des DEA individuels variait entre 59 et 79 heures par semaine. CONCLUSION: Les quatre régions les plus populeuses de la Colombie-Britannique présentent une variabilité importante de l'accessibilité aux DEA. D'autres avantages pourraient découler des DEA s'ils sont placés dans des endroits accessibles toutes les heures. Nos données peuvent encourager les efforts de planification communautaire à utiliser des stratégies fondées sur les données pour placer systématiquement les DEA dans des endroits optimaux avec des stratégies pour maximiser l'accessibilité.

Improving EMS response times for out-of-hospital cardiac arrest in urban areas using drone-like vertical take-off and landing air ambulances: An international, simulation-based cohort study.

BACKGROUND: Advances in vertical take-off and landing (VTOL) technologies may enable drone-like crewed air ambulances to rapidly respond to out-of-hospital cardiac arrest (OHCA) in urban areas. We estimated the impact of incorporating VTOL air ambulances on OHCA response intervals in two large urban centres in France and Canada. METHODS: We included adult OHCAs occurring between Jan. 2017-Dec. 2018 within Greater Paris in France and Metro Vancouver in Canada. Both regions utilize tiered OHCA response with basic (BLS)- and advanced life support (ALS)-capable units. We simulated incorporating 1-2 ALS-capable VTOL air ambulances dedicated to OHCA response in each study region, and computed time intervals from call reception by emergency medical services (EMS) to arrival of the: (1) first ALS unit ("call-to-ALS arrival interval"); and (2) first EMS unit ("call-to-first EMS arrival interval"). RESULTS: There were 6,217 OHCAs included during the study period (3,760 in Greater Paris and 2,457 in Metro Vancouver). Historical median call-to-ALS arrival intervals were 21 min [IQR 16-29] in Greater Paris and 12 min [IQR 9-17] in Metro Vancouver, while median call-to-first EMS arrival intervals were 11 min [IQR 8-14] and 7 min [IQR 5-8] respectively. Incorporating 1-2 VTOL air ambulances improved median call-to-ALS arrival intervals to 7-9 min and call-to-first EMS arrival intervals to 6-8 min in both study regions (all P < 0.001). CONCLUSION: VTOL air ambulances dedicated to OHCA response may improve EMS response intervals, with substantial improvements in ALS response metrics.

Out-of-hospital cardiac arrests occurring at school in France: A nation-wide retrospective cohort study from the RéAC registry.

AIM: We sought to describe the characteristics of at-school out-of-hospital cardiac arrests cases, subsequent basic life support, as well as ultimate patient outcomes. METHODS: This was a nation-wide, multicentre, retrospective cohort study from the French national population-based RéAC out-of-hospital cardiac arrest registry (July 2011 - March 2023). We compared the characteristics and outcomes of cases occurring at schools vs. in other public places. RESULTS: Of the 149,088 national out-of-hospital cardiac arrests, 25,071 were public: 86 (0.3%) and 24,985 (99.7%) in schools and other public places, respectively. At-school out-of-hospital cardiac arrests, in comparison to other public places, were: significantly younger (median: 42.5 vs. 58 years, p < 0.001); more commonly of a medical cause (90.7% vs. 63.8%, p < 0.001), more commonly bystander-witnessed (93.0% vs. 73.4%, p < 0.001) and recipients of bystander cardiopulmonary resuscitation (78.8% vs. 60.6%, p = 0.001) with shorter median no-flow durations (2 min. vs. 7 min.); with greater bystander automated external defibrillator application (38.9% vs. 18.4%) and defibrillation (23.6%, vs. 7.9%; all p < 0.001). At-school patients had greater rates of return of spontaneous circulation than out-of-school ones (47.7%, vs. 31.8%; p = 0.002), higher rates of survival at arrival at hospital (60.5% vs. 30.7%; p < 0.001) and at 30-days (34.9% vs. 11.6%; p < 0.001), and survival with favourable neurological outcomes at 30 days (25.9% vs. 9.2%; p < 0.001). CONCLUSION: At-school out-of-hospital cardiac arrests were rare in France, however demonstrated favourable prognostic features and outcomes. The use of automated external defibrillators in at-school cases, while more common than cases occurring elsewhere, should be improved.

The association of the post-resuscitation on-scene interval and patient outcomes after out-of-hospital cardiac arrest.

BACKGROUND: After resuscitation from out-of-hospital cardiac arrest (OHCA) by Emergency Medical Services (EMS), the amount of time that should be dedicated to pre-transport stabilization is unclear. We examined whether the time spent on-scene after return of spontaneous circulation (ROSC) was associated with patient outcomes. METHODS: We examined consecutive adult EMS-treated OHCAs from the British Columbia Cardiac Arrest registry (January 1/2019-June 1/2021) that had on-scene ROSC (sustained to scene departure). The primary outcome was favourable neurological outcome (Cerebral Performance Category ≤ 2) at hospital discharge; secondary outcomes were re-arrest during transport and hospital-discharge survival. Using adjusted logistic regression models, we estimated the association between the post-resuscitation on-scene interval (divided into quartiles) and outcomes. RESULTS: Of 1653 cases, 611 (37%) survived to hospital discharge, and 523 (32%) had favourable neurological outcomes. The median post-resuscitation on-scene interval was 18.8 minutes (IQR:13.0-25.5). Compared to the first post-resuscitation on-scene interval quartile, neither the second (adjusted odds ratio [AOR] 1.19; 95% CI 0.72-1.98), third (AOR 1.10; 95% CI 0.67-1.81), nor fourth (AOR 1.54; 95% CI 0.93-2.56) quartiles were associated with favourable neurological outcomes; however, the fourth quartile was associated with a greater odds of hospital-discharge survival (AOR 1.73; 95% CI 1.05-2.85), and both the third (AOR 0.40; 95% CI 0.22-0.72) and fourth (AOR 0.44;95% CI 0.24-0.81) quartiles were associated with a lower odds of intra-transport re-arrest. CONCLUSION: Among resuscitated OHCAs, increased post-resuscitation on-scene time was not associated with improved neurological outcomes, but was associated with improved survival to hospital discharge and decreased intra-transport re-arrest.

Accuracy of a Prehospital Triage Protocol in Predicting In-Hospital Mortality and Severe Trauma Cases among Older Adults.

Background: Prehospital trauma triage tools are not tailored to identify severely injured older adults. Our trauma triage protocol based on a three-tier trauma severity grading system (A, B, and C) has never been studied in this population. The objective was to assess its accuracy in predicting in-hospital mortality among older adults (≥65 years) and to compare it to younger patients. Methods: A retrospective multicenter cohort study, from 2011 to 2021. Consecutive adult trauma patients managed by a mobile medical team were prospectively graded A, B, or C according to the initial seriousness of their injuries. Accuracy was evaluated using sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios. Results: 8888 patients were included (14.1% were ≥65 years). Overall, 10.1% were labeled Grade A (15.2% vs. 9.3% among older and younger adults, respectively), 21.9% Grade B (27.9% vs. 20.9%), and 68.0% Grade C (56.9% vs. 69.8%). In-hospital mortality was 7.1% and was significantly higher among older adults regardless of severity grade. Grade A showed lower sensitivity (50.5 (43.7; 57.2) vs. 74.6 (69.8; 79.1), p < 0.0001) for predicting mortality among older adults compared to their younger counterparts. Similarly, Grade B was associated with lower sensitivity (89.5 (84.7; 93.3) vs. 97.2 (94.8; 98.60), p = 0.0003) and specificity (69.4 (66.3; 72.4) vs. 74.6 (73.6; 75.7], p = 0.001) among older adults. Conclusions: Our prehospital trauma triage protocol offers high sensitivity for predicting in-hospital mortality including older adults.

Risk factors and mortality associated with undertriage after major trauma in a physician-led prehospital system: a retrospective multicentre cohort study.

PURPOSE: To assess the incidence of undertriage in major trauma, its determinant, and association with mortality. METHODS: A multicentre retrospective cohort study was conducted using data from a French regional trauma registry (2011-2017). All major trauma (Injury Severity Score ≥ 16) cases aged ≥ 18 years and managed by a physician-led mobile medical team were included. Those transported to a level-II/III trauma centre were considered as undertriaged. Multivariable logistic regression was used to identify factors associated with undertriage. RESULTS: A total of 7110 trauma patients were screened; 2591 had an ISS ≥ 16 and 320 (12.4%) of these were undertriaged. Older patients had higher risk for undertriage (51-65 years: OR = 1.60, 95% CI [1.11; 2.26], p = 0.01). Conversely, injury mechanism (fall from height: 0.62 [0.45; 0.86], p = 0.01; gunshot/stab injuries: 0.45 [0.22; 0.90], p = 0.02), on-scene time (> 60 min: 0.62 [0.40; 0.95], p = 0.03), prehospital endotracheal intubation (0.53 [0.39; 0.71], p < 0.001), and prehospital focussed assessment with sonography [FAST] (0.15 [0.08; 0.29], p < 0.001) were associated with a lower risk for undertriage. After adjusting for severity, undertriage was not associated with a higher risk of mortality (1.22 [0.80; 1.89], p = 0.36). CONCLUSIONS: In our physician-led prehospital EMS system, undertriage was higher than recommended. Advanced aged was identified as a risk factor highlighting the urgent need for tailored triage protocol in this population. Conversely, the potential benefit of prehospital FAST on triage performance should be furthered explored as it may reduce undertriage. Fall from height and penetrating trauma were associated with a lower risk for undertriage suggesting that healthcare providers should remain vigilant of the potential seriousness of trauma associated with low-energy mechanisms.

Pediatric and adult Out-of-Hospital cardiac arrest incidence within and near public schools in British Columbia: Missed opportunities for Systematic AED deployment strategies.

BACKGROUND: Systematic automated external defibrillator(AED) placement in schools may improve pediatric out-of-hospital cardiac arrest(OHCA) survival. To estimate their utility, we identified school-located pediatric and adult OHCAs to estimate the potential utilization of school-located AEDs. Further, we identified all OHCAs within an AED-retrievable distance of the school by walking, biking, and driving. METHODS: We used prospectively collected data from the British Columbia(BC) Cardiac Arrest Registry(2013-2020), and geo-plotted all OHCAs and schools(n = 824) in BC. We identified adult and pediatric(age < 18 years) OHCAs occurring in schools, as well as nearby OHCAs for which a school-based externally-placed AED could be retrieved by a bystander prior to emergency medical system(EMS) arrival. RESULTS: Of 16,409 OHCAs overall in the study period, 28.6 % occurred during school hours. There were 301 pediatric OHCAs. 5(1.7 %) occurred in schools, of whom 2(40 %) survived to hospital discharge. Among both children and adults, 28(0.17 %) occurred in schools(0.0042/school/year), of whom 21(75 %) received bystander resuscitation, 4(14 %) had a bystander AED applied, and 14(50 %) survived to hospital discharge. For each AED, an average of 0.29 OHCAs/year(95 % CI 0.21-0.37), 0.93 OHCAs/year(95 % CI 0.69-1.56) and 1.69 OHCAs/year(95 % CI 1.21-2.89) would be within the potential retrieval distance of a school-located AED by pedestrian, cyclist and automobile retrieval, respectively, using the median EMS response times. CONCLUSION: While school-located OHCAs were uncommon, outcomes were favourable. 11.1% to 60.9% of all OHCAs occur within an AED-retrievable distance to a school, depending on retrieval method. Accessible external school-located AEDs may improve OHCA outcomes of school children and in the surrounding community.

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.

AIM: To 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. METHODS: This 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). RESULTS: A 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). CONCLUSIONS: Accessibility of public AEDs was globally poor in Metro Vancouver and Rhône, and even poorer in Metro Vancouver's socioeconomically deprived areas.

Incremental gains in response time with varying base location types for drone-delivered automated external defibrillators.

INTRODUCTION: Drone-delivered automated external defibrillators (AEDs) may reduce delays to defibrillation for out-of-hospital cardiac arrests (OHCAs). We sought to determine how integration of drones and selection of drone bases between emergency service stations (i.e., paramedic, fire, police) would affect 9-1-1 call-to-arrival intervals. METHODS: We identified all treated OHCAs in southern Vancouver Island, British Columbia, Canada from Jan. 2014 to Dec. 2020. We developed mathematical models to select 1-5 optimal drone base locations from each of: paramedic stations, fire stations, police stations, or an unrestricted grid-based set of points to minimize drone travel time to OHCAs. We evaluated models on the estimated first response interval assuming that drones were integrated with existing OHCA response. We compared median response intervals with historical response, as well as across drone base locations. RESULTS: A total of 1610 OHCAs were included in the study with a historical median response interval of 6.4 minutes (IQR 5.0-8.6). All drone-integrated response systems significantly reduced the median response interval to 4.2-5.4 minutes (all P < 0.001), with grid-based stations using 5 drones resulting in the lowest response interval (4.2 minutes). Median response times between drone base location types differed by 6-16 seconds, all comparisons of which were statistically significant (all P < 0.02). CONCLUSION: Integrating drone-delivered AEDs into OHCA response may reduce first response intervals, even with a small quantity of drones. Implementing drone response with only one emergency service resulted in similar response metrics regardless of the emergency service hosting the drone base and was competitive with unrestricted drone base locations.

Utilization and cost-effectiveness of school and community center AED deployment models in Canadian cities.

BACKGROUND: The optimal locations and cost-effectiveness of placing automated external defibrillators (AEDs) for out-of-hospital cardiac arrest (OHCAs) in urban residential neighbourhoods are unclear. METHODS: We used prospectively collected data from 2016 to 2018 from the British Columbia OHCA Registry to examine the utilization and cost-effectiveness of hypothetical AED deployment in municipalities with a population of over 100 000. We geo-plotted OHCA events using seven hypothetical deployment models where AEDs were placed at the exteriors of public schools and community centers and fetched by bystanders. We calculated the "radius of effectiveness" around each AED within which it could be retrieved and applied to an individual prior to EMS arrival, comparing automobile and pedestrian-based retrieval modes. For each deployment model, we estimated the number of OHCAs within the "radius of effectiveness". RESULTS: We included 4017 OHCAs from ten urban municipalities. The estimated radius of effectiveness around each AED was 625 m for automobile and 240 m for pedestrian retrieval. With AEDs placed outside each school and community center, 2567 (64%) and 605 (15%) of OHCAs fell within the radii of effectiveness for automobile and pedestrian retrieval, respectively. For each AED, there was an average of 1.20-2.66 and 0.25-0.61 in-range OHCAs per year for automobile retrieval and pedestrian retrieval, respectively, depending on the deployment model. All of our proposed surpassed the cost-effectiveness threshold of 0.125 OHCA/AED/year provided > 5.3-11.6% in-range AEDs were brought-to-scene. CONCLUSIONS: The systematic deployment of AEDs at schools and community centers in urban neighbourhoods may result in increased application and be a cost-effective public health intervention.

Rationale, development and implementation of the ReACanROC registry for out-of-hospital cardiac arrests in France and Canada.

France and Canada prehospital systems and care delivery in out-of-hospital cardiac arrests (OHCAs) show substantial differences. This article aims to describe the rationale, design, implementation and expected research implications of the international, population-based, France-Canada registry for OHCAs, namely ReACanROC, which is built from the merging of two nation-wide, population-based, Utstein-style prospectively implemented registries for OHCAs attended to by emergency medical services. Under the supervision of an international steering committee and research network, the ReACanROC dataset will be used to run in-depth analyses on the differences in organisational, practical and geographic predictors of survival after OHCA between France and Canada. ReACanROC is the first Europe-North America registry ever created to meet this goal. To date, it covers close to 80 million people over the two countries, and includes approximately 200 000 cases over a 10-year period.

Prehospital predictors for return of spontaneous circulation in traumatic cardiac arrest.

BACKGROUND: Traumatic cardiac arrests (TCAs) are associated with high mortality and the majority of deaths occur at the prehospital scene. The aim of the present study was to assess, in a prehospital physician-led emergency medical system, the factors associated with sustained return of spontaneous circulation (ROSC) in TCA, including advanced life procedures. The secondary objectives were to assess factors associated with 30-day survival in TCA, evaluate neurological recovery in survivors, and describe the frequency of organ donation among patients experiencing a TCA. METHODS: We conducted a retrospective study of all TCA patients included in the French nationwide cardiac arrest registry from July 2011 to November 2020. Multivariable logistic regression analysis was used to identify factors independently associated with ROSC. RESULTS: A total of 120,045 out-of-hospital cardiac arrests were included in the registry, among which 4,922 TCA were eligible for analysis. Return of spontaneous circulation was sustained on-scene in 21.1% (n = 1,037) patients. Factors significantly associated with sustained ROSC were not-asystolic initial rhythms (pulseless electric activity (odds ratio [OR], 1.81; 95% confidence interval [CI], 1.40-2.35; p < 0.001), shockable rhythm (OR, 1.83; 95% CI, 1.12-2.98; p = 0.016), spontaneous activity (OR, 3.66; 95% CI, 2.70-4.96; p < 0.001), and gasping at the mobile medical team (MMT) arrival (OR, 1.40; 95% CI, 1.02-1.94; p = 0.042). The MMT interventions significantly associated with ROSC were as follows: intravenous fluid resuscitation (OR, 3.19; 95% CI, 2.69-3.78; p < 0.001), packed red cells transfusion (OR, 2.54; 95% CI, 1.84-3.51; p < 0.001), and external hemorrhage control (OR, 1.74; 95% CI, 1.31-2.30; p < 0.001). Among patients who survived (n = 67), neurological outcome at Day 30 was favorable (cerebral performance categories 1-2) in 72.2% cases (n = 39/54) and 1.4% (n = 67/4,855) of deceased patients donated one or more organ. CONCLUSION: Sustained ROSC was frequently achieved in patients not in asystole at MMT arrival, and higher ROSC rates were achieved in patients benefiting from specific advanced life support interventions. Organ donation was somewhat possible in TCA patients undergoing on-scene resuscitation. LEVEL OF EVIDENCE: Prognostic and epidemiologic, Level III.

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

BACKGROUND: There is substantial regional variation in out-of-hospital cardiac arrest (OHCA) survival. We investigated whether regional emergency medical services (EMS) intra-arrest transport (IAT) practices are associated with patient outcomes. METHODS: We performed a secondary analysis of a multi-center North American clinical trial dataset, which enrolled EMS-treated adult OHCA cases from 49 regional population-based clusters. The exposure of interest was regional-level intra-arrest transport (IAT), calculated as the proportion of cases in each cluster transported to hospital prior to return of spontaneous circulation, examined as quartiles and as a continuous variable. Multilevel mixed-effects logistic regression modeling estimated the association between regional IAT with survival to hospital discharge and favorable neurologic status (modified Rankin Scale ≤ 3) at hospital discharge. RESULTS: Of 26,148 subjects (median age 68 years; 36% female; 23% shockable initial rhythm) 2424 (9.3%), survived to hospital discharge and 1993 (7.6%) had favourable neurological outcomes. Across regional clusters, IAT ranged from 0.84% to 75% (quartiles <6.2%, 6.2-19.6%, 19.6-30.4%, and ≥30.4%). For each quartile, 13.3%, 7.9%, 7.4%, and 4.8% survived, and 10.4%, 7.8%, 7.4%, and 4.8% had favourable neurological status. Regional IAT (per 10% change) was associated with decreased probability of survival (AOR 0.86, 95% CI 0.82-0.91) and favorable neurological outcome (AOR 0.80, 95% CI 0.76-0.85). CONCLUSION: Treatment within a region that utilizes IAT less frequently was associated with improved clinical outcomes at hospital discharge. These findings may account for some of the known regional variation in OHCA outcomes.

The association of pH values during the first 24 h with neurological status at hospital discharge and futility among patients with out-of-hospital cardiac arrest.

STUDY OBJECTIVE: Post-resuscitation prognostic biomarkers for out-of-hospital cardiac arrest (OHCA) outcomes have not been fully elucidated. We examined the association of acid-base blood values (pH) with patient outcomes and calculated the pH test performance to predict prognosis. METHODS: This was a post-hoc analysis of data from the continuous chest compression trial, which enrolled non-traumatic adult emergency medical system-treated OHCA in Canada and the United States. We examined cases who survived a minimum of 24 h post hospital arrival. The independent variables of interest were initial pH, final pH, and the change in pH (δpH). The primary outcome was neurological status at hospital discharge, with favorable status defined as modified Rankin Scale (mRS) ≤ 3. We reported adjusted odds ratios for favorable neurological outcome using multivariable logistic regression models. We calculated the test performance of increasing pH thresholds in 0.1 increments to predict unfavorable neurological status (defined as mRS >3) at hospital discharge. RESULTS: We included 4189 patients. 32% survived to hospital discharge with favorable neurological status. In the adjusted analysis, higher initial pH (OR 6.82; 95% CI 3.71-12.52) and higher final pH (OR 7.99; 95% CI 3.26-19.62) were associated with higher odds of favorable neurological status. pH thresholds with highest positive predictive values were initial pH < 6.8 (92.5%; 95% CI 86.2 %-98.8%) and final pH < 7.0 (100%; 95% CI 95.2 %-100%). CONCLUSION: In patients with OHCA, pH values were associated with patients' subsequent neurological status at hospital discharge. Final pH may be clinically useful to predict unfavorable neurological status at hospital discharge.

EMS Access Constraints And Response Time Delays For Deprived Critically Ill Patients Near Paris, France.

Increased emergency medical services (EMS) response times and areas of low socioeconomic status are both associated with poorer outcomes for several time-sensitive medical conditions attended to by medical personnel before a patient is hospitalized. We evaluated the association between EMS response times, area deprivation level, and on-scene access constraints encountered by EMS in a large urban area in France. We conducted a multicenter prospective cohort study of EMS dispatches occurring in the forty-seven cities in a region southeast of Paris. We fit multilevel mixed-effects linear regression models for multivariate assessment of the predictors of EMS response times and then used multivariate logistic regression on outcomes among a subgroup of patients presenting with out-of-hospital cardiac arrest. We found evidence that access constraints were more frequently encountered by EMS in the most deprived areas compared to less deprived ones, and were associated with increased EMS response times until patient contact and with poorer outcomes from cardiac arrest. Strategies to anticipate and overcome access constraints should be implemented to improve outcomes for emergent conditions attended to by prehospital medical teams.