Effect of Implementation of Cardiopulmonary Resuscitation-Targeted Multi-Tier Response System on Outcomes After Out-of-Hospital Cardiac Arrest: A Before-and-After Population-Based Study

Dual-dispatch protocols and return of spontaneous circulation in patients with out-of-hospital cardiac arrest: a nationwide observational study

OBJECTIVE

The Korean National Fire Agency conducted a pilot project examining Advanced Life Support (ALS) protocols, including epinephrine administration, to improve survival among patients suffering out-of-hospital cardiac arrest (OHCA). In this study, we aimed to evaluate the effects of the Korean National Fire Agency ALS protocol on prehospital return of spontaneous circulation (ROSC) in patients with OHCA.

METHODS

This study included patients with adult-presumed cardiac arrest between January and December 2020. The main factor of interest was ambulance type according to ALS protocol, which was divided into dedicated ALS ambulance (DA), smartphone-based ALS ambulance (SALS), and non-DA, and the main analysis factor was prehospital ROSC. Multivariate logistic regression analysis was performed.

RESULTS

During the study period, a total of 18,031 adult patients with OHCA was treated by the emergency medical services, including 7,520 DAs (41.71%), 2,622 SALSs (14.54%), and 7,889 non-DAs (43.75%). The prehospital ROSC ratio was 13.19% for DA, 11.17% for SALS, and 7.91% for non-DA (P<0.01). Compared with that of the DA group, the odds ratios (95% confidence interval) for prehospital ROSC ratio were 0.97 (0.82-1.15) in the SALS group and 0.57 (0.50-0.65) in the non-DA group. The prehospital ROSC ratio of the DA group was higher than those of the non-DA group and the SALS group.

CONCLUSION

ALS protocol intervention was associated with prehospital ROSC rates. Therefore, continuous efforts to promote systemic implementation of the ALS protocol to improve OHCA outcomes are necessary.

Establishing the Korean Out-of-Hospital cardiac arrest registry (KOHCAR)

Background

The Korean out-of-hospital cardiac arrest registry (KOHCAR) serves as the basis for a chain of survival monitoring and quality improvement programs for out-of-hospital cardiac arrest (OHCA). This study describes the development history and current status of KOHCAR.

Methods/design

The KOHCAR, initiated in 2008, is a population-based OHCA registry that captures all emergency medical service (EMS)-assessed OHCA cases, regardless of etiology. The KOHCAR represents complete nationwide data and aligns with South Korea's comprehensive plan for cardiovascular disease, which has a legal basis. The KOHCAR is a collaboration between the National Fire Agency (NFA) and the Korea Disease Control and Prevention Agency (KDCA). The NFA identifies OHCA patients and provides prehospital information after integrating various EMS records, whereas the KDCA collects hospital information and clinical outcomes through a medical record review. Comprehensive Utstein variables, including patient and arrest characteristics, prehospital and hospital management, and survival outcomes, were collected.

Discussion

The KOHCAR has significantly contributed to improving OHCA survival rates in South Korea; however, the COVID-19 pandemic has posed challenge. To address the post-pandemic survival rate decline, there is a need to enhance data utilization, expand data sources, and tailor communication with diverse stakeholders.

Sex Disparities in Prehospital Advanced Cardiac Life Support in Out-of-Hospital Cardiac Arrest in South Korea

OBJECTIVE

Sex disparities have been reported in the prehospital and in-hospital care among patients with out-of-hospital cardiac arrest (OHCA). The aim of this study was to investigate the association between sex and prehospital advanced cardiac life support (ACLS) interventions provided by emergency medical services (EMS).

METHODS

This was a cross-sectional observational study using a nationwide OHCA registry in South Korea. The study included adult OHCAs with presumed cardiac etiology from January 2016 to December 2019. The main exposure was the sex of the victim, and the primary outcomes were prehospital ACLS interventions, including advanced airway management (AAM), intravenous access (IV), and epinephrine (EPI) administration. Multivariable logistic regression analysis accounted for age group, health insurance, comorbidities, place of arrest, urbanization level, witness status, bystander CPR and initial rhythm was performed to calculate adjusted odds ratios (AORs) with 95% confidence intervals (95% CIs).

RESULTS

Among 71,154 eligible patients, females with OHCA received less prehospital ACLS interventions than males: risk difference, (95% CIs) -2.76 (-3.41;-2.11) for AAM, -6.03 (-6.79;-5.27) for IV, and -3.81 (-4.37;-3.25) for EPI. In multivariable logistic regression analysis, female sex was significantly associated with a lower probability of prehospital ACLS provision: AOR, (95% CIs) 0.87 (0.84-0.91) for AAM, 0.85 (0.82-0.88) for IV, and 0.81 (0.77-0.84) for EPI.

CONCLUSION

Compared to male patients, female patients were less likely to receive prehospital ACLS. This offers opportunities for EMS systems to reduce disparities and to improve compliance with OHCA resuscitation guidelines and outcomes through quality improvement and educational interventions.

The number and level of first-contact emergency medical services crew and clinical outcomes in out-of-hospital cardiac arrest with dual dispatch response

OBJECTIVE

This study aimed to evaluate the association between the number and level of emergency medical technicians (EMTs) in the first-contact emergency medical services (EMS) unit and the clinical outcomes of out-of-hospital cardiac arrest (OHCA) with a dual dispatch response.

METHODS

Adult nontraumatic EMS-treated OHCAs between 2015 and 2018 in a nationwide database, were enrolled. The main exposure was the number and certification level of first-contact EMS crew: three versus two members, proportion of EMT intermediate level (EMT-I) over 50% versus under or equal to 50%. Good neurologic recovery was selected as the primary outcome. Multilevel multivariable logistic regression analysis was conducted to calculate adjusted odds ratios and confidence intervals.

RESULTS

A total of 26,867 patients were enrolled and analyzed. Good neurologic recovery was different across the study groups: 5.4% in the two-member crews, 7.2% in the three-member crews, 5.9% in the low EMT-I proportion crews, and 6.8% in the high EMT-I proportion crews. In the main analysis, statistically significant differences for favorable outcomes were found between the three-member and two-member crews, and the high EMT-I proportion and low EMT-I proportion crews; for good neurologic recovery, adjusted odds ratios (95% confidence interval) were 1.23 (1.06-1.43) for three-member crews, and 1.28 (1.17-1.40) for a high EMT-I proportion.

CONCLUSION

The higher number and level of first-contact EMS crew was associated with better neurologic recovery in adult nontraumatic OHCA with a dual-dispatched EMS response.

Effects of a designated ambulance team response on prehospital return of spontaneous circulation and advanced cardiac life support of out-of-hospital cardiac arrest: A nationwide natural experimental study

OBJECTIVES

This study aimed to investigate the effects of adding advanced cardiac life support (ACLS) training to an existing basic life support program and the operation of a designated team response for patients with out-of-hospital cardiac arrest (OHCA) on prehospital return of spontaneous circulation (ROSC) and ACLS management.

METHODS

A natural experimental study was conducted for emergency medical service (EMS)-treated adult patients with OHCA in 2020. In 2019, a quarter of the EMS clinicians were trained in a 3-day ACLS courses, and they were designated to be dispatched first in suspected OHCA. Some were dispatched only to major emergencies, such as OHCA and myocardial infarction (dedicated team), while others were dispatched to all emergencies with priority to major ones (non-dedicated team). The exposure was the ambulance response type: dedicated, no-dedicated, and basic teams (others). The primary outcome was prehospital ROSC. The secondary outcomes were prehospital ACLS (advanced airway management and intravenous access). A multivariable logistic regression analysis was conducted to investigate the effect of ambulance response type on study outcomes.

RESULTS

Among 23,512 eligible patients with OHCA, 54.8% (12,874) were treated by the basic team, 36.5% (8,580) by the non-dedicated ACLS team, and 8.8% (2,058) were treated by the dedicated ACLS team. Prehospital ROSC was greater for the designated team than for the basic team (dedicated ACLS team 13.8%, non-dedicated ACLS team 11.3%, and basic team 6.7%) (p <0.01). In the final logistic regression analysis, compared with the basic team, the designated ACLS team was associated with a higher probability of prehospital ROSC (AOR (95% CIs), 1.88 (1.68-2.09) compared to the non-dedicated ACLS team, and 2.46 (2.09-2.90) compared to the dedicated ACLS team), prehospital advanced airway management (1.72 (1.57-1.87) and 1.73 (1.48-2.03), respectively), and intravenous access (2.29 (2.16-2.43) and 2.76 (2.50-3.04), respectively).

CONCLUSION

Additional ACLS training and operation of a designated OHCA team response were associated with higher rates of prehospital ROSC and prehospital ACLS provision. However, further research is needed to find the optimal operation for EMS to improve survival outcomes.

Impact of crowding in local ambulance demand on call-to-ambulance scene arrival in out-of-hospital cardiac arrest

BACKGROUND

Rapid emergency medical service (EMS) response is an important prognostic factor in out-of-hospital cardiac arrest (OHCA). This study aims to evaluate the association between local hourly EMS demand and ambulance response in OHCA.

METHODS

OHCA occurring in 24 districts of Seoul from 2013 to 2018 was analyzed. Hourly ambulance demand per ambulance in each local district of patient location at the hour of cardiac arrest was calculated as the crowding index. The crowding index was categorized according to quartiles (1Q: ≤0.43, 2Q: 0.44-0.67, 3Q: 0.68-0.99, 4Q: ≥1.0 calls/h\r/ambulance). The primary outcome was ambulance dispatched within 1 km of the OHCA scene. Multivariable logistic regression analysis was performed to test the association between the local hourly ambulance demand and outcomes.

RESULTS

A total of 26,479 patients were analyzed. The rate of ambulance dispatched within 1 km decreased according to the crowding quartile (1Q: 31.3%, 2Q: 30.0%, 3Q: 28.8%, and 4Q: 26.6%). Compared to 1Q, adjusted odds ratios (95% CIs) of dispatch distance within 1 km in 2Q, 3Q, and 4Q were 0.92 (0.86-0.99), 0.86 (0.80-0.94), and 0.77 (0.71-0.84), respectively.

CONCLUSION

Crowding in local ambulance demand was associated with less ambulance dispatched within 1 km and delayed response to the scene in OHCA. Strategies to mitigate and adjust to ambulance demand crowding may be considered for better EMS response performance.

Location of out-of-hospital cardiac arrest and the awareness time interval: a nationwide observational study

AIMS

A short awareness time interval (ATI, time from witnessing the arrest to calling for help) and bystander cardiopulmonary resuscitation (CPR) are important factors affecting neurological recovery after out-of-hospital cardiac arrest (OHCA). This study investigated the association of the location of OHCA with the length of ATI and bystander CPR.

METHODS

This population-based observational study used the nationwide Korea OHCA database and included all adults with layperson-witnessed OHCA with presumed cardiac aetiology between 2013 and 2017. The exposure was the location of OHCA (public places, private housing and nursing facilities). The primary outcome was short ATI, defined as <4 min from witnessing to calling for emergency medical service (EMS). The secondary outcome was the frequency of provision of bystander CPR. Multivariable logistic regression analysis was performed to evaluate the association of location of OHCA with study outcomes.

RESULTS

Of 30 373 eligible OHCAs, 66.6% occurred in private housing, 24.0% occurred in public places and 9.4% occurred in nursing facilities. In 67.3% of the cases, EMS was activated within 4 min of collapse, most frequently in public places (public places 77.0%, private housing 64.2% and nursing facilities 64.8%; p<0.01). The overall rate of bystander CPR was 65.5% with highest in nursing facilities (77.0%), followed by public places (70.1%) and private housing 62.3%; p<0.01). Compared with public places, the adjusted ORs (AORs) (95% CIs) for a short ATI were 0.58 (0.54 to 0.62) in private housing and 0.62 (0.56 to 0.69) in nursing facilities. The AORs (95% CIs) for bystander CPR were 0.75 (0.71 to 0.80) in private housing and 1.57 (1.41 to 1.75) in nursing facilities.

CONCLUSION

OHCAs in private housing and nursing facilities were less likely to have immediate EMS activation after collapse than in public places. A public education is needed to increase the awareness of necessity of prompt EMS activation.

A Systematic Review and Meta-Analysis of the Implementation of High-Performance Cardiopulmonary Resuscitation on Out-of-Hospital Cardiac Arrest Outcomes

Despite numerous technological and medical advances, out-of-hospital cardiac arrests (OHCAs) still suffer from suboptimal survival rates and poor subsequent neurological and functional outcomes amongst survivors. Multiple studies have investigated the implementation of high-quality prehospital resuscitative efforts, and across these studies, different terms describing high-quality resuscitative efforts have been used, such as high-performance CPR (HP CPR), multi-tiered response (MTR) and minimally interrupted cardiac resuscitation (MICR). There is no universal definition for HP CPR, and dissimilar designs have been employed. This systematic review thus aimed to review current evidence on HP CPR implementation and examine the factors that may influence OHCA outcomes. Eight studies were systematically reviewed, and seven were included in the final meta-analysis. Random-effects meta-analysis found a significantly improved likelihood of prehospital return of spontaneous circulation (pooled odds ratio (OR) = 1.46, 95% CI: 1.16 to 1.82, p < 0.001), survival-to-discharge (pooled OR = 1.32, 95% CI: 1.16 to 1.50, p < 0.001) and favourable neurological outcomes (pooled OR = 1.24, 95% CI: 1.11 to 1.39, p < 0.001) with HP CPR or similar interventions. However, the studies had generally high heterogeneity (I² greater than 50%) and overall moderate-to-severe risk for bias. Moving forward, a randomised, controlled trial is necessary to shed light on the subject.

Type of bystander and rate of cardiopulmonary resuscitation in nursing home patients suffering out-of-hospital cardiac arrest

AIM

We investigated bystander cardiopulmonary resuscitation (CPR) provision rate and survival outcomes of out-of-hospital cardiac arrest (OHCA) patients in nursing homes by bystander type.

METHODS

A population-based observational study was conducted for nursing home OHCAs during 2013-2018. The exposure was the bystander type: medical staff, non-medical staff, or family. The primary outcome was bystander CPR provision rate; the secondary outcomes were prehospital return of spontaneous circulation (ROSC) and survival to discharge. Multivariable logistic regression analysis which corrected for various demographic and clinical characteristics evaluated bystander type impact on study outcomes. Bystander CPR rate trend was investigated by bystander type.

RESULTS

Of 8281 eligible OHCA patients, 26.0%, 70.8%, and 3.2% cases were detected by medical staff, non-medical staff, and family, respectively. Provision rate of bystander CPR was 69.9% and rate of bystander defibrillation was 0.4% in total. Bystander CPR was provided by medical staff, non-medical staff, and families in 74.8%, 68.9%, and 52.1% respectively. Total survival rate was 2.2%, out of which, 3.3% was for medical staff, 3.2% for non-medical staff, and 0.6% for family. Compared to the results of detection by medical staff, the adjusted odds ratios (95% CIs) for provision of bystander CPR were 0.56 (0.49-0.63) for detection by non-medical staff and 0.33 (0.25-0.44) for detection by family. The bystander CPR rates of all three groups increased over time, and among them, the medical staff group increased the most. For prehospital ROSC and survival to discharge, no significant differences were observed according to bystander type.

CONCLUSION

Although OHCA was detected more often by non-medical staff, they provided bystander CPR less frequently than the medical staff did. To improve survival outcome of nursing home OHCA, bundle interventions including increasing the usage of automated external defibrillators and expanding CPR training for non-medical staff in nursing home are needed.