Association between prehospital prognostic factors and out-of-hospital cardiac arrest: Effect of rural-urban disparities

Cost-effectiveness analysis of a 'Termination of Resuscitation' protocol for the management of out-of-hospital cardiac arrest

BACKGROUND

Historically in Singapore, all out-of-hospital cardiac arrests (OHCA) were transported to hospital for pronouncement of death. A 'Termination of Resuscitation' (TOR) protocol, implemented from 2019 onwards, enables emergency responders to pronounce death at-scene in Singapore. This study aims to evaluate the cost-effectiveness of the TOR protocol for OHCA management.

METHODS

Adopting a healthcare provider's perspective, a Markov model was developed to evaluate three competing options: No TOR, Observed TOR reflecting existing practice, and Full TOR if TOR is exercised fully. The model had a cycle duration of 30 days after the initial state of having a cardiac arrest, and was evaluated over a 10-year time horizon. Probabilistic sensitivity analysis was performed to account for uncertainties. The costs per quality adjusted life years (QALY) was calculated.

RESULTS

A total of 3,695 OHCA cases eligible for the TOR protocol were analysed; mean age of 73.0 ± 15.5 years. For every 10,000 hypothetical patients, Observed TOR and Full TOR had more deaths by approximately 19 and 31 patients, respectively, compared to No TOR. Full TOR had the least costs and QALYs at $19,633,369 (95% Uncertainty Interval (UI) 19,469,973 to 19,796,764) and 0 QALYs. If TOR is exercised for every eligible case, it could expect to save approximately $400,440 per QALY loss compared to No TOR, and $821,151 per QALY loss compared to Observed TOR.

CONCLUSION

The application of the TOR protocol for the management of OHCA was found to be cost-effective within acceptable willingness-to-pay thresholds, providing some justification for sustainable adoption.

Rural cardiac arrest care and outcomes in Texas

INTRODUCTION

Out-of-hospital cardiac arrest (OHCA) victims in rural communities have worse outcomes despite higher rates of bystander cardiopulmonary resuscitation (CPR) than urban communities. In this retrospective cohort study we attempt to evaluate selected aspects of the continuum of care, including post-arrest care, for rural OHCA victims, and we investigated factors that could contribute to rural areas having higher rates of bystander CPR.

METHODS

We analyzed 2014-2020 Texas Cardiac Arrest Registry to Enhance Survival (TX-CARES) data for adult OHCAs. We linked TX-CARES data to census tract data and stratified OHCAs into urban and rural events. We created a mixed-model logistic regression to compare cardiac arrest characteristics, pre-hospital care, and post-arrest care between rural and urban settings. We adjusted for confounders and modeled census tract as a random intercept. We then compared different regression models evaluating the association between response time and bystander CPR.

RESULTS

We included 1202 rural and 28,288 urban cardiac arrests. Comparing rural to urban OHCAs, rates of bystander CPR were significantly higher in rural communities (49.6% v 40.6%, aOR 1.3 95% CI 1.1-1.5). The median response time for rural (11.5 min) was longer than urban (7.3 min). The occurrence of an ambulance response time of <10 min was notably less common in rural communities when compared to urban areas (aOR 0.2, 95% CI 0.2-0.2). For post-arrest care the rates of percutaneous coronary intervention (PCI) were higher in rural than urban communities (aOR 1.7, 95% CI 1.01-2.8). The rates of AED and TTM were similar between urban and rural communities. Survival to hospital discharge was significantly lower in rural communities than urban communities (aOR 0.6, 95% CI 0.4-0.7). Although not significant, rural communities had lower rate of survival with a cognitive performance score (CPC) of 1 or 2 (aOR 0.7, 05% CI 0.6-1.003). We identified no association between response time and bystander CPR.

CONCLUSION

Patients in rural areas of Texas have lower survival after OHCA compared to patients in urban areas, despite having significantly greater rates of bystander CPR and PCI. We did not find a link between response time and bystander CPR rates.

Standardizing post-cardiac arrest care across rural-urban settings - qualitative findings on proposed post-cardiac arrest learning community intervention

BACKGROUND

Standardization of post-cardiac arrest care between emergency department arrival and intensive care unit admission can be challenging, particularly for rural centers, which can experience significant delays in interfacility transfer. One approach to addressing this issue is to form a post-cardiac arrest learning community (P-CALC) consisting of emergency department (ED) and intensive care unit (ICU) physicians and nurses who use data, shared resources, and collaboration to improve post-cardiac arrest care. MaineHealth, the largest regional health system in Maine, launched its P-CALC in 2022.

OBJECTIVE

To explore P-CALC participants' perspectives on current post-cardiac arrest care, attitudes toward implementing a P-CALC intervention, perceived barriers and facilitators to intervention implementation, and implementation strategies.

METHODS

We conducted semi-structured, individual, qualitative interviews with 16 staff from seven system EDs spanning the rural-urban spectrum. Directed content analysis was used to discern key themes in transcribed interviews.

RESULTS

Participants highlighted site- and system-level factors influencing current post-cardiac arrest care. They expressed both positive attitudes and concerns about the P-CALC intervention. Multiple facilitators and barriers were identified in regard to the intervention implementation. Five proposed implementation strategies emerged as important factors to move the intervention forward.

CONCLUSIONS

Implementation of a P-CALC intervention to effect system-wide improvements in post-cardiac arrest care is complex. Understanding providers' perspectives on current care practices, feasibility of quality improvement, and potential intervention impacts is essential for program development.

The Influence of Cardiac Arrest Floor-Level Location within a Building on Survival Outcomes

This nationwide, population-based observational study investigated the association between the floor level of out-of-hospital cardiac arrest (OHCA) incidence and survival outcomes in South Korea, notable for its significant high-rise apartment living. Data were collected retrospectively from OHCA patients through the South Korean Out-of-Hospital Cardiac Arrest Surveillance database. The study incorporated cases that included the OHCA's building floor information. The primary outcome assessed was survival to discharge, analyzed using multivariate logistic regression, and the secondary outcome was favorable neurological outcome. Among 36,977 patients, a total of 29,729 patients were included, and 1680 patients were survivors. A weak yet significant correlation between floor level and hospital arrival time was observed. Interestingly, elevated survival rates were noted among patients from higher floors despite extended emergency medical service response times. Multivariate analysis identified age, witnessed OHCA, shockable rhythm, and prehospital return of spontaneous circulation (ROSC) as primary determinants of survival to discharge. The floor level's impact on survival was less substantial than anticipated, suggesting residential emergency response enhancements should prioritize witness interventions, shockable rhythm management, and prehospital ROSC rates. The study underscores the importance of bespoke emergency response strategies in high-rise buildings, particularly in urban areas, and the potential of digital technologies to optimize response times and survival outcomes.

How do current police practices impact trauma care in the prehospital setting? A scoping review

Objective

In the United States, police are often important co-responders to 911 calls with emergency medical services for medical emergencies. To date, there remains a lack of a comprehensive understanding of the mechanisms by which police response modifies time to in-hospital medical care for traumatically injured patients. Further, it remains unclear if differentials exist within or between communities. A scoping review was performed to identify studies evaluating prehospital transport of traumatically injured patients and the role or impact of police involvement.

Methods

PubMed, SCOPUS, and Criminal Justice Abstracts databases were utilized to identify articles. English-language, US-based, peer-reviewed articles published on or prior to March 30, 2022 were eligible for inclusion.

Results

Of 19,437 articles initially identified, 70 articles were selected for full review and 17 for final inclusion. Key findings included (1) current law enforcement practices involving scene clearance introduce the potential for delayed patient transport but to date there is little research quantifying delays; (2) police transport protocols may decrease transport times; and (3) there are no studies examining the potential impact of scene clearance practices at the patient or community level.

Conclusions

Our results highlight that police are often the first on scene when responding to traumatic injuries and have an active role via scene clearance or, in some systems, patient transport. Despite the significant potential for impact on patient well-being, there remains a paucity of data examining and driving current practices.

Urban-suburb disparities in pre-hospital emergency medical resources and response time among patients with out-of-hospital cardiac arrest: A mixed-method cross-sectional study

Aim

To investigate (1) the association between pre-hospital emergency medical resources and pre-hospital emergency medical system (EMS) response time among patients with Out-of-hospital cardiac arrest (OHCA); (2) whether the association differs between urban and suburbs.

Methods

Densities of ambulances and physicians were independent variables, respectively. Pre-hospital emergency medical system response time was dependent variable. Multivariate linear regression was used to investigate the roles of ambulance density and physician density in pre-hospital EMS response time. Qualitative data were collected and analyzed to explore reasons for the disparities in pre-hospital resources between urban areas and suburbs.

Results

Ambulance density and physician density were both negatively associated with call to ambulance dispatch time, with odds ratios (ORs) 0.98 (95% confidence interval [CI] 0.96-0.99; P = 0.001) and 0.97 (95% CI; 0.93-0.99; P < 0.001), respectively. ORs of ambulance density and physician density in association with total response time were 0.99 (95% CI: 0.97-0.99; P = 0.013) and 0.90 (95% CI: 0.86-0.99; P = 0.048). The effect of ambulance density on call to ambulance dispatch time in urban areas was 14% smaller than that in suburb areas and that on total response time in urban areas was 3% smaller than the effect in suburbs. Similar effects were identified for physician density on urban-suburb disparities in call to ambulance dispatch time and total response time. The main reasons summarized from stakeholders for a lack of physicians and ambulances in suburbs included low income, poor personal incentive mechanisms, and inequality in financial distribution of the healthcare system.

Conclusion

Improving pre-hospital emergency medical resources allocation can reduce system delay and narrow urban-suburb disparity in EMS response time for OHCA patients.

The incidence and outcomes of out-of-hospital cardiac arrest in metropolitan versus rural locations: A systematic review and meta-analysis

BACKGROUND/AIMS

Rurality poses a unique challenge to the management of out-of-hospital cardiac arrest (OHCA) when compared to metropolitan (metro) locations. We conducted a systematic review of published literature to understand how OHCA incidence, management and survival outcomes vary between metro and rural areas.

METHODS

We included studies comparing the incidence or survival of ambulance attended OHCA in metropolitan and rural areas, from a search of five databases from inception until 9th March 2022. The primary outcomes of interest were cumulative incidence and survival (return of spontaneous circulation, survival to hospital discharge (or survival to 30 days)). Meta-analyses of OHCA survival were undertaken.

RESULTS

We identified 28 studies (30 papers- total of 823,253 patients) across 13 countries of origin. The definition of rurality varied markedly. There was no clear difference in OHCA incidence between metro and rural locations. Whilst there was considerable statistical heterogeneity between studies, the likelihood of return of spontaneous circulation on arrival at hospital was lower in rural than metro locations (OR = 0.53, 95% CI 0.40, 0.70; I² = 89%; 5 studies; 90,934 participants), as was survival to hospital discharge/survival to 30 days (OR = 0.52, 95% CI 0.38, 0.71; I² = 95%; 15 studies; 18,837 participants).

CONCLUSIONS

Overall, while incidence did not vary, the odds of OHCA survival to hospital discharge were approximately 50% lower in rural areas compared to metro areas. This suggests an opportunity for improvement in the prehospital management of OHCA within rural locations. This review also highlighted major challenges in standardising the definition of rurality in the context of cardiac arrest research.

Prehospital Time Interval for Urban and Rural Emergency Medical Services: A Systematic Literature Review

The aim of this study was to discuss the differences in pre-hospital time intervals between rural and urban communities regarding emergency medical services (EMS). A systematic search was conducted through various relevant databases, together with a manual search to find relevant articles that compared rural and urban communities in terms of response time, on-scene time, and transport time. A total of 37 articles were ultimately included in this review. The sample sizes of the included studies was also remarkably variable, ranging between 137 and 239,464,121. Twenty-nine (78.4%) reported a difference in response time between rural and urban areas. Among these studies, the reported response times for patients were remarkably variable. However, most of them (number (n) = 27, 93.1%) indicate that response times are significantly longer in rural areas than in urban areas. Regarding transport time, 14 studies (37.8%) compared this outcome between rural and urban populations. All of these studies indicate the superiority of EMS in urban over rural communities. In another context, 10 studies (27%) reported on-scene time. Most of these studies (n = 8, 80%) reported that the mean on-scene time for their populations is significantly longer in rural areas than in urban areas. On the other hand, two studies (5.4%) reported that on-scene time is similar in urban and rural communities. Finally, only eight studies (21.6%) reported pre-hospital times for rural and urban populations. All studies reported a significantly shorter pre-hospital time in urban communities compared to rural communities. Conclusions: Even with the recently added data, short pre-hospital time intervals are still superior in urban over rural communities.

Clinical Validation of Cardiac Arrest Hospital Prognosis (CAHP) Score and MIRACLE2 Score to Predict Neurologic Outcomes after Out-of-Hospital Cardiac Arrest

Background. Out-of-hospital cardiac arrest (OHCA) remains a challenge for emergency physicians, given the poor prognosis. In 2020, MIRACLE2, a new and easier to apply score, was established to predict the neurological outcome of OHCA. Objective. The aim of this study is to compare the discrimination of MIRACLE2 score with cardiac arrest hospital prognosis (CAHP) score for OHCA neurologic outcomes. Methods. This retrospective cohort study was conducted between January 2015 and December 2019. Adult patients (>17 years) with cardiac arrest who were brought to the hospital by an emergency medical service crew were included. Deaths due to trauma, burn, drowning, resuscitation not initiated due to pre-ordered “do not resuscitate” orders, and patients who did not achieve return of spontaneous circulation were excluded. Receiver operating characteristic curve analysis with Youden Index was performed to calculate optimal cut-off values for both scores. Results. Overall, 200 adult OHCA cases were analyzed. The threshold of the MIRACLE2 score for favorable neurologic outcomes was 5.5, with an area under the curve (AUC) value of 0.70 (0.61−0.80, p < 0.001); the threshold of the CAHP score was 223.4, with an AUC of 0.77 (0.68−0.86, p < 0.001). On setting the MIRACLE2 score cut-off value, we documented 64.7% sensitivity (95% confidence interval [CI], 56.9−71.9%), 66.7.0% specificity (95% CI, 48.2−82.0%), 90.8% positive predictive value (PPV; 95% CI, 85.6−94.2%), and 27.2% negative predictive value (NPV; 95% CI, 21.4−33.9%). On establishing a CAHP cut-off value, we observed 68.2% sensitivity (95% CI, 60.2−75.5%), 80.6% specificity (95% CI, 62.5−92.6%), 94.6% PPV (95% CI, 88.6%−98.0%), and 33.8% NPV (95% CI, 23.2−45.7%) for unfavorable neurologic outcomes. Conclusions. The CAHP score demonstrated better discrimination than the MIRACLE2 score, affording superior sensitivity, specificity, PPV, and NPV; however, the CAHP score remains relatively difficult to apply. Further studies are warranted to establish scores with better discrimination and ease of application.

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.

Pre-hospital Prognostic Factors of Out-of-Hospital Cardiac Arrest: The Difference Between Pediatric and Adult

The prognosis of out-of-hospital cardiac arrest (OHCA) is very poor. Although several pre-hospital factors are associated with survival, the different association of pre-hospital factors with OHCA outcomes in pediatric and adult groups remain unclear. To assess the association of pre-hospital factors with OHCA outcomes among pediatric and adult groups, a retrospective observational study was conducted using the emergency medical service (EMS) database in Kaohsiung from January 2015 to December 2019. Pre-hospital factors, underlying diseases, and OHCA outcomes were collected for the pediatric (Age ≤ 20) and adult groups. Kaplan-Meier type plots and multivariable logistic regression were used to analyze the association between pre-hospital factors and outcomes. In total, 7,461 OHCAs were analyzed. After adjusting for EMS response time, bystander CPR, attended by EMT-P, witness, and pre-hospital defibrillation, we found that age [odds ratio (OR) = 0.877, 95% confidence interval (CI): 0.764-0.990, p = 0.033], public location (OR = 7.681, 95% CI: 1.975-33.428, p = 0.003), and advanced airway management (AAM) (OR = 8.952; 95% CI, 1.414-66.081; p = 0.02) were significantly associated with survival till hospital discharge in pediatric OHCAs. The results of Kaplan-Meier type plots with log-rank test showed a significant difference between the pediatric and adult groups in survival for 2 h (p < 0.001), 24 h (p < 0.001), hospital discharge (p < 0.001), and favorable neurologic outcome (p < 0.001). AAM was associated with improved survival for 2 h (p = 0.015), 24 h (p = 0.023), and neurologic outcome (p = 0.018) only in the pediatric group. There were variations in prognostic factors between pediatric and adult patients with OHCA. The prognosis of the pediatric group was better than that of the adult group. Furthermore, AAM was independently associated with outcomes in pediatric patients, but not in adult patients. Age and public location of OHCA were independently associated with survival till hospital discharge in both pediatric and adult patients.