Variation in survival after out-of-hospital cardiac arrest between receiving hospitals in Japan: an observational study

Pakistan's Emergency Medical Services (EMS) system & out-of-hospital-cardiac-arrest (OHCA): A narrative review of an EMS system of a low middle income country in context of OHCA

Pakistan's Emergency Medical Services (EMS) are a critical component of its healthcare system, providing pre-hospital emergency care across a nation with over 220 million people. This article explores the evolutionary journey of Pakistan's EMS, highlighting both the challenges it faces and the strides it has made, with a specific emphasis on patients experiencing out-of-hospital cardiac arrest (OHCA). To extract relevant information, we searched MEDLINE & Embase data bases using MeSH terms "Emergency Medical Services" OR "EMS" AND "Out-of-Hospital-Cardiac-Arrest" OR "OHCA" AND "Pakistan". In addition, we also retrieved information from the EMS leadership in Pakistan through e-mails. We delve into the significance of key performance indicators for OHCA, advocate for the establishment of OHCA registries to improve patient outcomes, address regional disparities in pre-hospital care, and acknowledge the gradual progress of the EMS system.

Mediators of the Association Between Socioeconomic Status and Survival After Out-of-Hospital Cardiac Arrest: A Systematic Review

Low socioeconomic status (SES) is associated with poor outcomes after out-of-hospital cardiac arrest (OHCA). Patient characteristics, care processes, and other contextual factors may mediate the association between SES and survival after OHCA. Interventions that target these mediating factors may reduce disparities in OHCA outcomes across the socioeconomic spectrum. This systematic review identified and quantified mediators of the SES-survival after OHCA association. Electronic databases (MEDLINE, Embase, PubMed, Web of Science) and grey literature sources were searched from inception to July or August 2023. Observational studies of OHCA patients that conducted mediation analyses to evaluate potential mediators of the association between SES (defined by income, education, occupation, or a composite index) and survival outcomes were included. A total of 10 studies were included in this review. Income (n = 9), education (n = 4), occupation (n = 1), and composite indices (n = 1) were used to define SES. The proportion of OHCA cases that had bystander involvement, presented with an initial shockable rhythm, and survived to hospital discharge or 30 days increased with higher SES. Common mediators of the SES-survival association that were evaluated included initial rhythm (n = 6), emergency medical services response time (n = 5), and bystander cardiopulmonary resuscitation (n = 4). Initial rhythm was the most important mediator of this association, with a median percent excess risk explained of 37.4% (range 28.6%-40.0%; n = 5; 1 study reported no mediation) and mediation proportion of 41.8% (n = 1). To mitigate socioeconomic disparities in outcomes after OHCA, interventions should target potentially modifiable mediators, such as initial rhythm, which may involve improving bystander awareness of OHCA and the need for prompt resuscitation.

Three-year trends in out-of-hospital cardiac arrest across the world: second report from the International Liaison Committee on Resuscitation (ILCOR)

BACKGROUND

The International Liaison Committee on Resuscitation (ILCOR) Research and Registries Working Group previously reported data on systems of care and outcomes of out-of-hospital cardiac arrest (OHCA) in 2015 from 16 national and regional registries. To describe the temporal trends with updated data on OHCA, we report the characteristics of OHCA from 2015 through 2017.

METHODS

We invited national and regional population-based OHCA registries for voluntary participation and included emergency medical services (EMS)-treated OHCA. We collected descriptive summary data of core elements of the latest Utstein style recommendation during 2016 and 2017 at each registry. For registries that participated in the previous 2015 report, we also extracted the 2015 data.

RESULTS

Eleven national registries in North America, Europe, Asia, and Oceania, and 4 regional registries in Europe were included in this report. Across registries, the estimated annual incidence of EMS-treated OHCA was 30.0-97.1 individuals per 100,000 population in 2015, 36.4-97.3 in 2016, and 40.8-100.2 in 2017. The provision of bystander cardiopulmonary resuscitation (CPR) varied from 37.2% to 79.0% in 2015, from 2.9% to 78.4% in 2016, and from 4.1% to 80.3% in 2017. Survival to hospital discharge or 30-day survival for EMS-treated OHCA ranged from 5.2% to 15.7% in 2015, from 6.2% to 15.8% in 2016, and from 4.6% to 16.4% in 2017.

CONCLUSION

We observed an upward temporal trend in provision of bystander CPR in most registries. Although some registries showed favourable temporal trends in survival, less than half of registries in our study demonstrated such a trend.

The epidemiology of out-of-hospital cardiac arrest in Australia and New Zealand: A binational report from the Australasian Resuscitation Outcomes Consortium (Aus-ROC)

INTRODUCTION

The Australasian Resuscitation Outcomes Consortium (Aus-ROC) out-of-hospital cardiac arrest (OHCA) Epistry (Epidemiological Registry) now covers 100% of Australia and New Zealand (NZ). This study reports and compares the Utstein demographics, arrest characteristics and outcomes of OHCA patients across our region.

METHODS

We included all OHCA cases throughout 2019 as submitted to the Epistry by the eight Australian and two NZ emergency medical services (EMS). We calculated crude and age-standardised incidence rates and performed a national and EMS regional comparison.

RESULTS

We obtained data for 31,778 OHCA cases for 2019: 26,637 in Australia and 5,141 in NZ. Crude incidence was 107.9 per 100,000 person-years in Australia and 103.2/100,000 in NZ. Overall, the majority of OHCAs occurred in adults (96%), males (66%), private residences (76%), were unwitnessed (63%), of presumed medical aetiology (83%), and had an initial monitored rhythm of asystole (64%). In non-EMS-witnessed cases, 38% received bystander CPR and 2% received public defibrillation. Wide variation was seen between EMS regions for all OHCA demographics, arrest characteristics and outcomes. In patients who received an EMS-attempted resuscitation (13,664/31,778): 28% (range across EMS=13.1% to 36.7%) had return of spontaneous circulation (ROSC) at hospital arrival and 13% (range across EMS=9.9% to 20.7%) survived to hospital discharge/30-days. Survival in the Utstein comparator group (bystander-witnessed in shockable rhythm) varied across the EMS regions between 27.4% to 42.0%.

CONCLUSION

OHCA across Australia and NZ has varied incidence, characteristics and survival. Understanding the variation in survival and modifiable predictors is key to informing strategies to improve outcomes.

Initial Outcomes and Survival of Out-of-Hospital Cardiac Arrest: EuReCa Serbia Multicenter Cohort Study

Introduction Although the global survival rate of patients after out-of-hospital cardiac arrest (OHCA) has increased in the previous years, there still remain significant multifactorial public health challenges with many important aspects influencing the overall survival rate of these patients. The objective of this article is to analyze basic epidemiological parameters of OHCA in Serbia and to evaluate the influence of pre-hospitalization factors on the survival of OHCA patients. Methods Data on OHCA within the EuReCa Serbia Registry was collected according to the EuReCa Study protocol during the period October 1, 2014 - December 31, 2019, and included basic demographic data of the patients, data related to OHCA prior to hospital arrival, as well as data regarding subsequent hospitalization. Results The study included 6,266 EuReCa events (54% males), with a median age of 73 years [interquartile range (IQR) 63-82]. Cardiac arrest was witnessed in 3,111 out of 6,266 cases (49.6%), of which 2,725 cases (87.6%) were witnessed by bystanders and 286 cases (12.4%) by the emergency medical service (EMS) team. Resuscitation measures were attempted in 2,097 of 3,111 (67.4%) witnessed OHCA cases. Bystander cardiopulmonary resuscitation (CPR) was initiated in 288 cases within the bystander-witnessed group of 2,725 cases (10.6%). An initial shockable rhythm was detected in 323 out of 3,111 witnessed cases (10.4%). Any return of spontaneous circulation (ROSC) prior to hospital arrival was observed in 441 out of 2,097 cases where CPR was initiated (21.0%). Within the group of 2,097 events where CPR was initiated, in 287 cases the patient was transported to the hospital with ROSC (13.7%). An automated external defibrillator (AED) was used by bystanders in three cases. The collapse in locations other than the place of residence [p < 0.01; odds ratio (OR) 3.928], attempt to initiate CPR by a bystander (p < 0.01; OR 2.169), and presence of initial shockable rhythm (p = 0.01; OR 2.070) were observed as significant predictors of any ROSC in OHCA patients. Out of 287 patients hospitalized with ROSC, 54 (18.8%) were discharged alive. Conclusion Collapse outside of residence place, bystander CPR initiation, and initially detected shockable rhythm are important predictors of ROSC prior to hospital arrival and overall survival. Key factors of CPR-providing performance observed in this study were witnessing OHCA, CPR initiated by a bystander, presence of initial shockable rhythm, and any ROSC prior to hospital arrival.

European Resuscitation Council Guidelines 2021: Epidemiology of cardiac arrest in Europe

In this section of the European Resuscitation Council Guidelines 2021, key information on the epidemiology and outcome of in and out of hospital cardiac arrest are presented. Key contributions from the European Registry of Cardiac Arrest (EuReCa) collaboration are highlighted. Recommendations are presented to enable health systems to develop registries as a platform for quality improvement and to inform health system planning and responses to cardiac arrest.

Response Time Threshold for Predicting Outcomes of Patients with Out-of-Hospital Cardiac Arrest

Ambulance response time is a prognostic factor for out-of-hospital cardiac arrest (OHCA), but the impact of ambulance response time under different situations remains unclear. We evaluated the threshold of ambulance response time for predicting survival to hospital discharge for patients with OHCA. A retrospective observational analysis was conducted using the emergency medical service (EMS) database (January 2015 to December 2019). Prehospital factors, underlying diseases, and OHCA outcomes were assessed. Receiver operating characteristic (ROC) curve analysis with Youden Index was performed to calculate optimal cut-off values for ambulance response time that predicted survival to hospital discharge. In all, 6742 cases of adult OHCA were analyzed. After adjustment for confounding factors, age (odds ratio [OR] = 0.983, 95% confidence interval [CI]: 0.975-0.992, p < 0.001), witness (OR = 3.022, 95% CI: 2.014-4.534, p < 0.001), public location (OR = 2.797, 95% CI: 2.062-3.793, p < 0.001), bystander cardiopulmonary resuscitation (CPR, OR = 1.363, 95% CI: 1.009-1.841, p=0.044), EMT-paramedic response (EMT-P, OR = 1.713, 95% CI: 1.282-2.290, p < 0.001), and prehospital defibrillation using an automated external defibrillator ([AED] OR = 3.984, 95% CI: 2.920-5.435, p < 0.001) were statistically and significantly associated with survival to hospital discharge. The cut-off value was 6.2 min. If the location of OHCA was a public place or bystander CPR was provided, the threshold was prolonged to 7.2 min and 6.3 min, respectively. In the absence of a witness, EMT-P, or AED, the threshold was reduced to 4.2, 5, and 5 min, respectively. The adjusted OR of EMS response time for survival to hospital discharge was 1.217 (per minute shorter, CI: 1.140-1299, p < 0.001) and 1.992 (<6.2 min, 95% CI: 1.496-2.653, p < 0.001). The optimal response time threshold for survival to hospital discharge was 6.2 min. In the case of OHCA in public areas or with bystander CPR, the threshold was prolonged, and without witness, the optimal response time threshold was shortened.

Association between prehospital prognostic factors on out-of-hospital cardiac arrest in different age groups

Background

The prognosis of out-of-hospital cardiac arrest (OHCA) is very poor. While several prehospital factors are known to be associated with improved survival, the impact of prehospital factors on different age groups is unclear. The objective of the study was to access the impact of prehospital factors and pre-existing comorbidities on OHCA outcomes in different age groups.

Methods

A retrospective observational analysis was conducted using the emergency medical service (EMS) database from January 2015 to December 2019. We collected information on prehospital factors, underlying diseases, and outcome of OHCAs in different age groups. Kaplan-Meier type survival curves and multivariable logistic regression were used to analyze the association between modifiable pre-hospital factors and outcomes.

Results

A total of 4188 witnessed adult OHCAs were analyzed. For the age group 1 (age ≦75 years old), after adjustment for confounding factors, EMS response time (odds ratio [OR] = 0.860, 95% confidence interval [CI]: 0.811–0.909, p < 0.001), public location (OR = 1.843, 95% CI: 1.179–1.761, p < 0.001), bystander CPR (OR = 1.329, 95% CI: 1.007–1.750, p = 0.045), attendance by an EMT-Paramedic (OR = 1.666, 95% CI: 1.277–2.168, p < 0.001), and prehospital defibrillation by automated external defibrillator (AED)(OR = 1.666, 95% CI: 1.277–2.168, p < 0.001) were prognostic factors for survival to hospital discharge in OHCA patients. For the age group 2 (age > 75 years old), age (OR = 0.924, CI:0.880–0.966, p = 0.001), EMS response time (OR = 0.833, 95% CI: 0.742–0.928, p = 0.001), public location (OR = 4.290, 95% CI: 2.450–7.343, p < 0.001), and attendance by an EMT-Paramedic (OR = 2.702, 95% CI: 1.704–4.279, p < 0.001) were independent prognostic factors for survival to hospital discharge in OHCA patients.

Conclusions

There were variations between younger and older OHCA patients. We found that bystander CPR and prehospital defibrillation by AED were independent prognostic factors for younger OHCA patients but not for the older group.

Early risk stratification after resuscitation from cardiac arrest

Emergency clinicians often resuscitate cardiac arrest patients, and after acute resuscitation, clinicians face multiple decisions regarding disposition. Recent evidence suggests that out-of-hospital cardiac arrest patients with return of spontaneous circulation have higher odds of survival to hospital discharge, long-term survival, and improved functional outcomes when treated at centers that can provide advanced multidisciplinary care. For community clinicians, a high volume cardiac arrest center may be hours away. While current guidelines recommend against neurological prognostication in the first hours or days after return of spontaneous circulation, there are early findings suggestive of irrecoverable brain injury in which the patient would receive no benefit from transfer. In this Concepts article, we describe a simplified approach to quickly evaluate neurological status in cardiac arrest patients and identify findings concerning for irrecoverable brain injury. Characteristics of the arrest and resuscitation, initial neurological assessment, and brain computed tomography together can identify patients with high likelihood of irrecoverable anoxic injury. Patients who may benefit from centers with access to continuous electroencephalography are discussed. This approach can be used to identify patients who may benefit from rapid transfer to cardiac arrest centers versus those who may benefit from care close to home. Risk stratification also can provide realistic expectations for recovery to families.