How important are delays in treatment for health outcomes? The case of ambulance response time and cardiovascular events

The cost effectiveness of medical treatments is not precisely known due to the compounding effect of multiple determining factors. Ambulance response time (RT) to emergency calls is exploited to learn more about the effect of the timing of treatment on health outcomes. This causal relation is identified by exploiting rainfall at the time of the ambulance run as a shock to RT. The analysis focuses on patients who have undergone a cardiac event and shows that a one-minute increase in average RT leads to 105 more deaths each year in one Italian region. Finally, the economic value of the lives that would be saved by reducing RT is quantified to facilitate policymaking.

Response times in rural areas for emergency medical services, fire and rescue services and voluntary first responders during out-of-hospital cardiac arrests

Aim

To increase survival in out-of-hospital cardiac arrests (OHCA), great efforts are made to improve the number of voluntary first responders (VFR). However, evidence of the potential utility of such efforts is sparse, especially in rural areas. Therefore, the aim was to describe and compare response times for emergency medical services (EMS), fire and rescue services (FRS), and VFR during OHCA in relation to population density.

Methods

This observational and comparative study was based on data including positions and time stamps for VFR and response times for EMS and FRS in a region in southern Sweden.

Results

In total, 285 OHCAs between 1 July 2020 and 31 December 2021 were analysed. VFR had the shortest median response time in comparison to EMS and FRS in all studied population densities. The overall median (Q1-Q3) time gain for VFR was 03:07 (01:39-05:41) minutes. A small proportion (19.2%) of alerted VFR accepted the assignments. This is most problematic in rural and sub-rural areas, where there were low numbers of alerted VFR. Also, FRS had shorter response time than EMS in all studied population densities except in urban areas.

Conclusion

The differences found in median response times between rural and urban areas are worrisome from an equality perspective. More focus should be placed on recruiting VFR, especially in rural areas since VFR can potentially contribute to saving more lives. Also, since FRS has a shorter response time than EMS in rural, sub-rural, and sub-urban areas, FRS should be dispatched more frequently.

Swedish emergency medical dispatch centres' ability to answer emergency medical calls and dispatch an ambulance in response to out-of-hospital cardiac arrest calls in accordance with the American Heart Association performance goals: An observational study

AIM

To investigate the ability of Swedish Emergency Medical Dispatch Centres (EMDCs) to answer medical emergency calls and dispatch an ambulance for out-of-hospital cardiac arrest (OHCA) in accordance with the American Heart Association (AHA) performance goals in a 1-step (call connected directly to the EMDC) and a 2-step (call transferred to regional EMDC) procedure over 10 years, and to assess whether delays may be associated with 30-day survival.

METHOD

Observational data from the Swedish Registry for Cardiopulmonary Resuscitation and EMDC.

RESULTS

A total of 9,174,940 medical calls were answered (1-step). The median answer delay was 7.3 s (interquartile range [IQR], 3.6-14.5 s). Furthermore, 594,008 calls (6.1%) were transferred in a 2-step procedure, with a median answer delay of 39 s (IQR, 30-53 s). A total of 45,367 cases (0.5%, 1-step) were registered as OHCA, with a median answer delay of 7.2 s (IQR, 3.6-14.1 s) (AHA high-performance goal, 10 s). For 1-step procedure, no difference in 30-day survival was found regarding answer delay. For OHCA (1-step), an ambulance was dispatched after a median of 111.9 s (IQR, 81.7-159.9 s). Thirty-day survival was 10.8% (n = 664) when an ambulance was dispatched within 70 s (AHA high-performance) versus 9.3% (n = 2174) > 100 s (AHA acceptable) (p = 0.0013). Outcome data in the 2-step procedure was unobtainable.

CONCLUSION

The majority of calls were answered within the AHA performance goals. When an ambulance was dispatched within the AHA high-performance standard in response to OHCA calls, survival was higher compared with calls when dispatch was delayed.

Sex and out-of-hospital cardiac arrest survival: a systematic review

BACKGROUND

The literature is unresolved on whether female receive advanced cardiac life support less than do male and on whether female have a survival advantage over male after cardiopulmonary resuscitation.

METHODS

We systematically searched PubMed, Embase and Web of Science databases (from inception to 23-April-2022) for papers reporting outcomes in adult male and female after out-of-hospital cardiac arrest. The main study outcome was the rate of adjusted survival to hospital discharge or 30 days. Secondary outcomes included unadjusted survival to hospital discharge and favourable neurological outcome.

RESULTS

A total of 28 studies were included, involving 1,931,123 patients. Female were older than male, their cardiac arrests were less likely to be witnessed and less likely to present with a shockable rhythm. Unadjusted analysis showed that females had a lower likelihood of survival than males (OR 0.68 [0.62-0.74], I² = 97%). After adjustment, no significant difference was identified between male and female in survival at hospital discharge/30 days (OR 1.01 [0.93-1.11], I² = 87%). Data showed that male had a significantly higher likelihood of favorable neurological outcome in unadjusted analysis but this trend disappeared after adjustment. Both the primary outcome (adjusted for several variables) and the secondary outcomes were associated with substantial heterogeneity. The variables examined using meta-regression, subgroup and sensitivity analyses (i.e., study type, location, years, population, quality of adjustment, risk of bias) did not reduce heterogeneity.

CONCLUSIONS

The adjusted rate of survival to hospital discharge/30 days was similar for male and female despite an initial seeming survival advantage for male. The validity of this finding is limited by substantial heterogeneity despite in-depth investigation of its causes, which raises concerns regarding latent inequalities in some reports nonetheless. Further study on this topic may require inclusion of factors not reported in the Utstein template and in-depth analysis of decision-making processes.

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.

The Association of Fire or Police First Responder Initiated Interventions with Out of Hospital Cardiac Arrest Survival

OBJECTIVE

Fire and police first responders are often the first to arrive in medical emergencies and provide basic life support services until specialized personnel arrive. This study aims to evaluate rates of fire or police first responder-initiated cardiopulmonary resuscitation (CPR) and automated external defibrillator (AED) use, as well as their associated impact on out-of-hospital cardiac arrest (OHCA) outcomes.

METHODS

We completed a secondary data analysis of the MI-CARES registry from 2014 to 2019. We reported rates of CPR initiation and AED use by fire or police first responders. Multilevel modeling was utilized to evaluate the relationship between fire/police first responder-initiated interventions and outcomes of interest: ROSC upon emergency department arrival, survival to hospital discharge, and good neurologic outcome.

RESULTS

Our cohort included 25,067 OHCA incidents. We found fire or police first responders initiated CPR in 31.8% of OHCA events and AED use in 6.1% of OHCA events. Likelihood of sustained ROSC on ED arrival after CPR initiated by a fire/police first responder was not statistically different as compared to EMS initiated CPR (aOR 1.01, CI 0.93-1.11). However, fire/police first responder interventions were associated with significantly higher odds of survival to hospital discharge and survival with good neurologic outcome (aOR 1.25, 95% CI 1.08-1.45 and aOR 1.40, 95% CI 1.18-1.65, respectively). Similar associations were see when examining fire or police initiated AED use.

CONCLUSIONS

Fire or police first responders may be an underutilized, potentially powerful mechanism for improving OHCA survival. Future studies should investigate barriers and opportunities for increasing first responder interventions by these groups in OHCA.

A review on initiatives for the management of daily medical emergencies prior to the arrival of emergency medical services

Emergency services worldwide face increasing cost pressure that potentially limits their existing resources. In many countries, emergency services also face the issues of staff shortage-creating extra challenges and constraints, especially during crisis times such as the COVID-19 pandemic-as well as long distances to sparsely populated areas resulting in longer response times. To overcome these issues and potentially reduce consequences of daily (medical) emergencies, several countries, such as Sweden, Germany, and the Netherlands, have started initiatives using new types of human resources as well as equipment, which have not been part of the existing emergency systems before. These resources are employed in response to medical emergency cases if they can arrive earlier than emergency medical services (EMS). A good number of studies have investigated the use of these new types of resources in EMS systems, from medical, technical, and logistical perspectives as their study domains. Several review papers in the literature exist that focus on one or several of these new types of resources. However, to the best of our knowledge, no review paper that comprehensively considers all new types of resources in emergency medical response systems exists. We try to fill this gap by presenting a broad literature review of the studies focused on the different new types of resources, which are used prior to the arrival of EMS. Our objective is to present an application-based and methodological overview of these papers, to provide insights to this important field and to bring it to the attention of researchers as well as emergency managers and administrators.

Different forms of bystander cardiopulmonary resuscitation in out-of-hospital cardiac arrest

Out-of-hospital cardiac arrest (OHCA) is a major cause of death in the Western world with an estimated number of 275 000 treated with resuscitation attempts by the Emergency Medical Services (EMS) in Europe each year. Overall survival rates remain low, and most studies indicate that around 1 out 10 will survive to 30 days. Amongst the strongest factors associated with survival in OHCA is first recorded rhythm amendable to defibrillation, early defibrillation and prompt initiation of cardiopulmonary resuscitation (CPR). Overall, CPR started prior to EMS arrival has repeatedly been shown to be associated with survival rates 2-3 times higher compared with no such initiation. The primary goal of CPR is to generate sufficient blood flow to vital organs, mainly the brain and heart, until restoration of spontaneous circulation can be achieved. Barriers to the initiation of CPR by bystanders in OHCA include fear of being incapable, causing harm, and transmission of infectious diseases. Partly due to these barriers, and low rates of CPR, the concept of CPR with compression only was proposed as a simpler form of resuscitation with the aim to be more widely accepted by the public in the 1990s. But how reliable is the evidence supporting this simpler form of CPR, and are the outcomes after CO-CPR comparable to standard CPR?

Machine learning can support dispatchers to better and faster recognize out-of-hospital cardiac arrest during emergency calls: A retrospective study

AIM

Fast recognition of out-of-hospital cardiac arrest (OHCA) by dispatchers might increase survival. The aim of this observational study of emergency calls was to (1) examine whether a machine learning framework (ML) can increase the proportion of calls recognizing OHCA within the first minute compared with dispatchers, (2) present the performance of ML with different false positive rate (FPR) settings, (3) examine call characteristics influencing OHCA recognition.

METHODS

ML can be configured with different FPR settings, i.e., more or less inclined to suspect an OHCA depending on the predefined setting. ML OHCA recognition within the first minute is evaluated with a 1.5 FPR as the primary endpoint, and other FPR settings as secondary endpoints. ML was exposed to a random sample of emergency calls from 2018. Voice logs were manually audited to evaluate dispatchers time to recognition.

RESULTS

Of 851 OHCA calls, the ML recognized 36% (n = 305) within 1 min compared with 25% (n = 213) by dispatchers. The recognition rate at any time during the call was 86% for ML and 84% for dispatchers, with a median time to recognition of 72 versus 94 s. OHCA recognized by both ML and dispatcher showed a 28 s mean difference in favour of ML (P < 0.001). ML with higher FPR settings reduced recognition times.

CONCLUSION

ML recognized a higher proportion of OHCA within the first minute compared with dispatchers and has the potential to be a supportive tool during emergency calls. The optimal FPR settings need to be evaluated in a prospective study.

Using firefighters as medical first responders to shorten response time in rural areas in Sweden

OBJECTIVE

To map out and describe an earlier response by using firefighters as medical first responders on while waiting for the ambulance and first incident person assignments focusing on frequency, event time and survival >30 days after performed cardiopulmonary resuscitation.

DESIGN

Retrospective descriptive design.

SETTING

Ambulance service in a county of southern Sweden with a population of 200 000 inhabitants (23/km² ).

PARTICIPANTS

Data were collected from four data systems within different organizations; emergency medical communication centre, fire deparment, ambulance services and conty hospital analysis unit.

MAIN OUTCOME MEASURE(S)

Data from 600 while waiting for the ambulance assignments, whereof 120 with first incident person present, collected between 1 January 2012 and 31 December 2016. Between 1 June 2014 and 1 October 2015, the two fire departments were dually dispatched on out-of-hospital cardiac arrests.

RESULTS

Three main findings were made: there was a prolonged process time for dispatching fire fighters on while waiting for the ambulance assignments. Dual dispatches did not shorten the process time for dispatching full-time firefighters, and, in a majority of while waiting for the ambulance assignments where cardiopulmonary resuscitation was performed, firefighters or first incident persons arrived first on the scene.

CONCLUSION

Minimising every minute that delays the performance of life-saving actions is crucial. By dispatching firefighters on while waiting for the ambulance assignments in rural areas, the response time in a majority of assignments was shortened. However, there was substantial delay in dispatching firefighters due to prolonged process time at the emergency medical communication centre. The emergency medical communication centre operator's ability to quickly assess the need for while waiting for the ambulance assignments plays a crucial role in the chain of survival.

Effectiveness of the Dual Dispatch to Cardiac Arrest Policy in Houston, Texas

CONTEXT

Houston policy is to dual dispatch medically trained firefighters, in addition to emergency medical services (EMS) units to out-of-hospital cardiac arrest (OHCA) cases. While believed to improve public health outcomes, no research exists supporting the policy that when firefighters respond before a better-equipped EMS unit, they increase the probability of survival.

OBJECTIVE

To inform EMS policy decisions regarding the effectiveness of dual dispatch by determining the impact of medically trained firefighter dispatch on return of spontaneous circulation (ROSC), a measure of survivability, in OHCA 911 calls while controlling for the subsequent arrival of an EMS unit.

DESIGN

This retrospective study uses logistic regression to determine the association between ROSC and response time for fire apparatus first responders controlling for arrival of the EMS unit.

SETTING

Out-of-hospital cardiac arrest cases in Houston between May 2008 and April 2013 when dual dispatch was used.

PARTICIPANTS

A total of 6961 OHCA cases with the complete data needed for the analysis.

MAIN OUTCOME MEASURES

Logistic regression of the dependence of OHCA survival using the indicator ROSC, as related to the fire first responder response times controlling for subsequent arrival of the EMS.

RESULTS

Fire apparatus arrived first in 46.7% of cases, a median value of 1.5 minutes before an EMS unit. Controlling for subsequent arrival time of EMS has no effect on ROSC achieved by the fire first responder. If the firefighters had not responded, the resulting 1.5-minute increase in response time equates to a decrease in probability of attaining ROSC of 20.1% for cases regardless of presenting heart rhythm and a 47.7% decrease for ventricular fibrillation cases in which bystander cardiopulmonary resuscitation was initiated.

CONCLUSIONS

The firefighter first responder not only improved response time but also greatly increased survivability independent of the arrival time of the better-equipped EMS unit, validating the public health benefit of the dual dispatch policy in Houston.

First-response treatment after out-of-hospital cardiac arrest: a survey of current practices across 29 countries in Europe

Background

In Europe, survival rates after out-of-hospital cardiac arrest (OHCA) vary widely. Presence/absence and differences in implementation of systems dispatching First Responders (FR) in order to arrive before Emergency Medical Services (EMS) may contribute to this variation. A comprehensive overview of the different types of FR-systems used across Europe is lacking.

Methods

A mixed-method survey and information retrieved from national resuscitation councils and national EMS services were used as a basis for an inventory. The survey was sent to 51 OHCA experts across 29 European countries.

Results

Forty-seven (92%) OHCA experts from 29 countries responded to the survey. More than half of European countries had at least one region with a FR-system. Four categories of FR types were identified: (1) firefighters (professional/voluntary); (2) police officers; (3) citizen-responders; (4) others including off-duty EMS personnel (nurses, medical doctors), taxi drivers. Three main roles for FRs were identified: (a) complementary to EMS; (b) part of EMS; (c) instead of EMS. A wide variation in FR-systems was observed, both between and within countries.

Conclusions

Policies relating to FRs are commonly implemented on a regional level, leading to a wide variation in FR-systems between and within countries. Future research should focus on identifying the FR-systems that most strongly influence survival. The large variation in local circumstances across regions suggests that it is unlikely that there will be a ‘one-size fits all’ FR-system for Europe, but examining the role of FRs in the Chain of Survival is likely to become an increasingly important aspect of OHCA research.

Experiences among firefighters and police officers of responding to out-of-hospital cardiac arrest in a dual dispatch programme in Sweden: an interview study

OBJECTIVES

The objective of this study was to explore firefighters' and police officers' experiences of responding to out-of-hospital cardiac arrest (OHCA) in a dual dispatch programme.

DESIGN

A qualitative interview study with semi-structured, open-ended questions where critical incident technique (CIT) was used to collect recalled cardiac arrest situations from the participants' narratives. The interviews where transcribed verbatim and analysed with inductive content analysis.

SETTING

The County of Stockholm, Sweden.

PARTICIPANTS

Police officers (n=10) and firefighters (n=12) participating in a dual dispatch programme with emergency medical services in case of suspected OHCA of cardiac or non-cardiac origin.

RESULTS

Analysis of 60 critical incidents was performed resulting in three consecutive time sequences (preparedness, managing the scene and the aftermath) with related categories, where first responders described the complexity of the cardiac arrest situation. Detailed information about the case and the location was crucial for the preparedness, and information deficits created stress, frustration and incorrect perceptions about the victim. The technical challenges of performing cardiopulmonary resuscitation and managing the airway was prominent and the need of regular team training and education in first aid was highlighted.

CONCLUSIONS

Participating in dual dispatch in case of suspected OHCA was described as a complex technical and emotional process by first responders. Providing case discussions and opportunities to give, and receive feedback about the case is a main task for the leadership in the organisations to diminish stress among personnel and to improve future OHCA missions.

Application of a Dual-Dispatch System for Out-of-Hospital Cardiac Arrest Patients: Will More Hands Save More Lives?

BACKGROUND

Recovery after out-of-hospital cardiac arrest (OHCA) is difficult, and emergency medical services (EMS) systems apply various strategies to improve outcomes. Multi-dispatch is one means of providing high-quality cardiopulmonary resuscitation (CPR), but no definitive best-operation guidelines are available. We assessed the effects of a basic life support (BLS)-based dual-dispatch system for OHCA.

METHODS

This prospective observational study of 898 enrolled OHCA patients, conducted in Daegu, Korea from March 1, 2015 to June 30, 2016, involved patients > 18 years old with suspected cardiac etiology OHCA. In Daegu, EMS started a BLS-based dual-dispatch system in March 2015, for cases of cardiac arrest recognition by a dispatch center. We assessed the association between dual-dispatch and OHCA outcomes using multivariate logistic regressions. We also analyzed the effect of dual-dispatch according to the stratified on-scene time.

RESULTS

Of 898 OHCA patients (median, 69.0 years; 65.5% men), dual-dispatch was applied in 480 (53.5%) patients. There was no difference between the single-dispatch group (SDG) and the dual-dispatch group (DDG) in survival at discharge and neurological outcomes (survival discharge, P = 0.176; neurological outcomes, P = 0.345). In the case of less than 10 minutes of on-scene time, the adjusted odds ratio was 1.749 (95% confidence interval [CI], 0.490-6.246) for survival discharge and 6.058 (95% CI, 1.346-27.277) for favorable neurological outcomes in the DDG compared with the SDG.

CONCLUSION

Dual-dispatch was not associated with better OHCA outcomes for the entire study population, but showed favorable neurological outcomes when the on-scene time was less than 10 minutes.

Association Between Driving Distance From Nearest Fire Station and Survival of Out-of-Hospital Cardiac Arrest

Background

Firefighter first responders dispatched in parallel with emergency medical services (EMS) personnel for out‐of‐hospital cardiac arrests (OHCA) can provide early defibrillation to improve survival. We examined whether survival following first responder defibrillation differed according to driving distance from nearest fire station to OHCA site.

Methods and Results

From the CARES (Cardiac Arrest Registry to Enhance Survival) registry, we identified non‐EMS witnessed OHCAs of presumed cardiac cause from 2010 to 2014 in Durham, Mecklenburg, and Wake counties, North Carolina. We used logistic regression to estimate the association between calculated driving distances (≤1, 1–1.5, 1.5–2, and >2 miles) and survival to hospital discharge following first responder defibrillation compared with defibrillation by EMS personnel. In total, 5020 OHCAs were included in the study. First responders more often applied the first automated external defibrillators at the shortest distances (≤1 mile) versus longest distances (>2 miles) (53.4% versus 46.6%, respectively, P<0.001). When compared with EMS defibrillation, first responder defibrillation within 1 mile and 1 to 1.5 miles of the nearest fire station was associated with increased survival to hospital discharge (odds ratio 2.01 [95% confidence interval 1.46–2.78] and odds ratio 1.61 [95% confidence interval 1.10–2.35], respectively). However, at the longest distances (1.5–2.0 and >2.0 miles), survival following first responder defibrillation did not differ from EMS defibrillation (odds ratio 0.77 [95% confidence interval 0.48–1.21] and odds ratio 0.97 [95% confidence interval 0.67–1.41], respectively).

Conclusions

Shorter driving distance from nearest fire station to OHCA location was associated with improved survival following defibrillation by first responders. These results suggest that the location of first responder units should be considered when organizing prehospital systems of OHCA care.

Different defibrillation strategies in survivors after out-of-hospital cardiac arrest

BACKGROUND

In the last decade, there has been a rapid increase in the dissemination of automated external defibrillators (AEDs) for prehospital defibrillation of out-of-hospital cardiac arrest patients. The aim of this study was to study the association between different defibrillation strategies on survival rates over time in Copenhagen, Stockholm, Western Sweden and Amsterdam, and the hypothesis was that non-EMS defibrillation increased over time and was associated with increased survival.

METHODS

We performed a retrospective analysis of four prospectively collected cohorts of out-of-hospital cardiac arrest patients between 2008 and 2013. Emergency medical service (EMS)-witnessed arrests were excluded.

RESULTS

A total of 22 453 out-of-hospital cardiac arrest patients with known survival status were identified, of whom 2957 (13%) survived at least 30 days postresuscitation. Of all survivors with a known defibrillation status, 2289 (81%) were defibrillated, 1349 (59%) were defibrillated by EMS, 454 (20%) were defibrillated by a first responder AED and 429 (19%) were defibrillated by an onsite AED and 57 (2%) were unknown. The percentage of survivors defibrillated by first responder AEDs (from 13% in 2008 to 26% in 2013, p<0.001 for trend) and onsite AEDs (from 14% in 2008 to 30% in 2013, p<0.001 for trend) increased. The increased use of these non-EMS AEDs was associated with the increase in survival rate of patients with a shockable initial rhythm.

CONCLUSION

Survivors of out-of-hospital cardiac arrest are increasingly defibrillated by non-EMS AEDs. This increase is primarily due to a large increase in the use of onsite AEDs as well as an increase in first-responder defibrillation over time. Non-EMS defibrillation accounted for at least part of the increase in survival rate of patients with a shockable initial rhythm.

The challenges and possibilities of public access defibrillation

Out-of-hospital cardiac arrest (OHCA) is a major health problem that affects approximately four hundred and thousand patients annually in the United States alone. It is a major challenge for the emergency medical system as decreased survival rates are directly proportional to the time delay from collapse to defibrillation. Historically, defibrillation has only been performed by physicians and in-hospital. With the development of automated external defibrillators (AEDs), rapid defibrillation by nonmedical professionals and subsequently by trained or untrained lay bystanders has become possible. Much hope has been put to the concept of Public Access Defibrillation with a massive dissemination of public available AEDs throughout most Western countries. Accordingly, current guidelines recommend that AEDs should be deployed in places with a high likelihood of OHCA. Despite these efforts, AED use is in most settings anecdotal with little effect on overall OHCA survival. The major reasons for low use of public AEDs are that most OHCAs take place outside high incidence sites of cardiac arrest and that most OHCAs take place in residential settings, currently defined as not suitable for Public Access Defibrillation. However, the use of new technology for identification and recruitment of lay bystanders and nearby AEDs to the scene of the cardiac arrest as well as new methods for strategic AED placement redefines and challenges the current concept and definitions of Public Access Defibrillation. Existing evidence of Public Access Defibrillation and knowledge gaps and future directions to improve outcomes for OHCA are discussed. In addition, a new definition of the different levels of Public Access Defibrillation is offered as well as new strategies for increasing AED use in the society.

Dispatch of Firefighters and Police Officers in Out-of-Hospital Cardiac Arrest: A Nationwide Prospective Cohort Trial Using Propensity Score Analysis

Background

Dispatch of basic life support–trained first responders equipped with automated external defibrillators in addition to advanced life support–trained emergency medical services personnel in out‐of‐hospital cardiac arrest (OHCA) has, in some minor cohort studies, been associated with improved survival. The aim of this study was to evaluate the association between basic life support plus advanced life support response and survival in OHCA at a national level.

Methods and Results

This prospective cohort study was conducted from January 1, 2012, to December 31, 2014. People who experienced OHCA in 9 Swedish counties covered by basic life support plus advanced life support response were compared with a propensity‐matched contemporary control group of people who experienced OHCA in 12 counties where only emergency medical services was dispatched, providing advanced life support. Primary outcome was survival to 30 days. The analytic sample consisted of 2786 pairs (n=5572) derived from the total cohort of 7308 complete cases. The median time from emergency call to arrival of emergency medical services or first responder was 9 minutes in the intervention group versus 10 minutes in the controls (P<0.001). The proportion of patients admitted alive to the hospital after resuscitation was 31.4% (875/2786) in the intervention group versus 24.9% (694/2786) in the controls (conditional odds ratio, 1.40; 95% confidence interval, 1.24–1.57). Thirty‐day survival was 9.5% (266/2786) in the intervention group versus 7.7% (214/2786) in the controls (conditional odds ratio, 1.27; 95% confidence interval, 1.05–1.54).

Conclusions

In this nationwide interventional trial, using propensity score matching, dispatch of first responders in addition to emergency medical services in OHCA was associated with a moderate, but significant, increase in 30‐day survival.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02184468.

Use of a geographic information system to identify differences in automated external defibrillator installation in urban areas with similar incidence of public out-of-hospital cardiac arrest: a retrospective registry-based study

OBJECTIVES

Early defibrillation in out-of-hospital cardiac arrest (OHCA) is of importance to improve survival. In many countries the number of automated external defibrillators (AEDs) is increasing, but the use is low. Guidelines suggest that AEDs should be installed in densely populated areas and in locations with many visitors. Attempts have been made to identify optimal AED locations based on the incidence of OHCA using geographical information systems (GIS), but often on small datasets and the studies are seldom reproduced. The aim of this paper is to investigate if the distribution of public AEDs follows the incident locations of public OHCAs in urban areas of Stockholm County, Sweden.

METHOD

OHCA data were obtained from the Swedish Register for Cardiopulmonary Resuscitation and AED data were obtained from the Swedish AED Register. Urban areas in Stockholm County were objectively classified according to the pan-European digital mapping tool, Urban Atlas (UA). Furthermore, we reclassified and divided the UA land cover data into three classes (residential, non-residential and other areas). GIS software was used to spatially join and relate public AED and OHCA data and perform computations on relations and distance.

RESULTS

Between 1 January 2012 and 31 December 2014 a total of 804 OHCAs occurred in public locations in Stockholm County and by December 2013 there were 1828 AEDs available. The incidence of public OHCAs was similar in residential (47.3%) and non-residential areas (43.4%). Fewer AEDs were present in residential areas than in non-residential areas (29.4% vs 68.8%). In residential areas the median distance between OHCAs and AEDs was significantly greater than in non-residential areas (288 m vs 188 m, p<0.001).

CONCLUSION

The majority of public OHCAs occurred in areas classified in UA as 'residential areas' with limited AED accessibility. These areas need to be targeted for AED installation and international guidelines need to take geographical location into account when suggesting locations for AED installation.

Survival in ventricular fibrillation with emphasis on the number of defibrillations in relation to other factors at resuscitation

INTRODUCTION

Mortality after out of hospital cardiac arrest (OHCA) is high and a shockable rhythm is a key predictor of survival. A concomitant need for repeated shocks appears to be associated with less favorable outcome.

AIM

To, among patients found in ventricular fibrillation (VF) or pulseless ventricular tachycardia (pVT) describe: (a) factors associated with 30-day survival with emphasis on the number of defibrillatory shocks delivered; (b) the distribution of and the characteristics of patients in relation to the number of defibrillatory shocks that were delivered.

METHODS

Patients who were reported to The Swedish Register for Cardiopulmonary Resuscitation (SRCR) between January 1 1990 and December 31 2015 and who were found in VF/pVT took part in the survey.

RESULTS

In all there were 19,519 patients found in VF/pVT. The 30-day survival decreased with an increasing number of shocks among all patients regardless of witnessed status and regardless of time period in the survey. In a multivariate analysis there were 12 factors that were associated with the chance of 30-day survival one of which was the number of shocks that was delivered. For each shock that was added the chance of survival decreased. Factors associated with an increased 30-day survival included CPR before arrival of EMS, female sex, cardiac etiology and year of OHCA (increasing survival over years). Factors associated with a decreased chance of 30-day survival included: increasing age, OHCA at home, the use of adrenaline and intubation and an increased delay to CPR, defibrillation and EMS arrival.

CONCLUSION

Among patients found in VF/pVT, 7.5% required more than 10 shocks. For each shock that was added the chance of 30-day survival decreased. There was an increase in 30-day survival over time regardless of the number of shocks. On top of the number of defibrillations, eleven further factors were associated with 30-day survival.

Home healthcare nurses’ experiences of being on stand by as a first responder in a ‘While Waiting For the Ambulance’ assignment

The aim of the study is to describe experiences of the ‘While Waiting for the Ambulance’ (WWFA) assignment, as described by home healthcare nurses (HHCNs). Since the early 1990s, municipal resources in Sweden, preferably firefighters, have been dispatched on WWFA. In order to further assist the local residents on an island in the southwest of Sweden, HHCNs have recently begun accompanying firefighters on WWFA. A reflective lifeworld approach was used for data analysis including in-depth interviews with eight HHCNs. When WWFA was established, the HHCNs experienced lack of clarity in where their responsibilities start and end. A split role is described, and there is a paradox in that the responders are meant to collaborate toward saving lives, when the assignment itself has a lack of collaborative structure. Ethical dilemmas and inner emotional worries led to the nurses expressing a need for support before, during and after WWFA.

The first single responders in Sweden - Evaluation of a pre-hospital single staffed unit

BACKGROUND

Single responder (SR) systems have been implemented in several countries. When the very first SR system in Sweden was planned, it was criticised because of concerns about sending single emergency nurses out on alerts. In the present study, the first Swedish SR unit was studied in order to register waiting times and assess the working environment.

METHOD

Quantitative data were collected from the ambulance dispatch register. Data on the working environment were collected using a questionnaire sent to the SR staff.

RESULTS

The SR system reduced the average patient waiting time from 26 to 13min. It also reduced the number of ambulance transports by 35% following triage of patient(s) priority determined by the SR. The staff perceived the working environment to be adequate.

CONCLUSION

The SR unit was successful in that it reduced waiting times to prehospital health care. Contrary to expectations, it proved to be an adequate working environment. There is good reason to believe that SR systems will spread throughout the country. In order to enhance in depth the statistical analysis, additional should be collected over a longer time period and from more than one SR unit.

Impact of an emergency medical dispatch system on survival from out-of-hospital cardiac arrest: a population-based study

Background

In countries where a single public emergency telephone number is not in operation, different emergency telephone numbers corresponding to multiple dispatch centres (police, fire, emergency medical service) may create confusion for the population about the most appropriate service to call. In particular, out-of-hospital cardiac arrest (OHCA) requires a prompt and effective response. We compare two different dispatch systems on OHCA patient survival at 30 days in a national system with multiple emergency telephone numbers.

Methods

We conducted an observational retrospective study of 6871 patients aged 18 years or older with presumed OHCA of cardiac origin between 2005 and 2013 in three counties of the Northern French Alps region. One county had a single dispatch centre combining medical and fire emergencies, and two had multiple dispatch centres. Propensity score matching analyses were performed to compare patient survival at 30 days.

Results

A total of 2257 emergency calls for OHCA were managed by a single dispatch centre and 4614 by a multiple dispatch centre. A single dispatch centre was associated with an increase in survival (adjusted odds ratio [OR] for all patients: 1.7; 95 % confidence interval [CI] = 1.3–2.2; p <0.001; adjusted OR for propensity-matched patients: 2.0; 95 % CI = 1.2–3.4; p = 0.012).

Conclusions

A single dispatch centre was associated with a markedly improved increase of survival among OHCA patients at 30 days in a system with several emergency telephone numbers.

Electronic supplementary material

The online version of this article (doi:10.1186/s13049-016-0247-y) contains supplementary material, which is available to authorized users.

Home Care Providers to the Rescue: A Novel First-Responder Programme

AIM

To describe the implementation of a novel first-responder programme in which home care providers equipped with automated external defibrillators (AEDs) were dispatched in parallel with existing emergency medical services in the event of a suspected out-of-hospital cardiac arrest (OHCA).

METHODS

We evaluated a one-year prospective study that trained home care providers in performing cardiopulmonary resuscitation (CPR) and using an AED in cases of suspected OHCA. Data were collected from cardiac arrest case files, case files from each provider dispatch and a survey among dispatched providers. The study was conducted in a rural district in Denmark.

RESULTS

Home care providers were dispatched to 28 of the 60 OHCAs that occurred in the study period. In ten cases the providers arrived before the ambulance service and subsequently performed CPR. AED analysis was executed in three cases and shock was delivered in one case. For 26 of the 28 cases, the cardiac arrest occurred in a private home. Ninety-five per cent of the providers who had been dispatched to a cardiac arrest reported feeling prepared for managing the initial resuscitation, including use of AED.

CONCLUSION

Home care providers are suited to act as first-responders in predominantly rural and residential districts. Future follow-up will allow further evaluation of home care provider arrivals and patient survival.

The survival benefit of dual dispatch of EMS and fire-fighters in out-of-hospital cardiac arrest may differ depending on population density--a prospective cohort study

BACKGROUND

Outcome after out-of-hospital cardiac arrest (OHCA) varies between contexts. Dual dispatching of fire-fighters or police in addition to emergency medical services (EMS) has the potential to increase survival, but the effect in urban vs. rural areas is unknown. The aim of this study was to determine the effects of dual dispatching on response times and outcome in regions with different population density.

METHODS AND RESULTS

The study design was a prospective cohort study of EMS-treated OHCAs from 2004 (historical controls, only EMS dispatch) and 2006-2009 (intervention, dual dispatch of EMS and fire-fighters), with data on exact geographical coordinates. Patients were divided into four subgroups depending on population density: rural (<250 persons/km2), suburban (250-2999/km2), urban (3000-5999/km2) and downtown (≥6000/km2). Totally, 2513 OHCAs were included (historical controls, n=571 and intervention, n=1942). Median time to arrival of first unit shortened significantly in all subgroups, ranging from 0.8 to 3.2 min, with the main time gain in the rural area. There were significant differences in 30-day survival between the historical controls vs. the intervention group in the suburban population (3.1% vs. 7.0%, p=0.02) and in downtown (4.1 vs. 14.6, p=0.04). In the urban population the difference was 2.7 vs. 6.9% (p=0.06) and in the rural population (4.7 vs. 5.3, p=0.82).

CONCLUSIONS

Dual dispatch of fire-fighters and EMS in OHCA significantly reduced response times in all studied regions. The 30-day survival increased significantly in the downtown and suburban populations, while a limited impact was seen in the rural areas.

Improved outcome in Sweden after out-of-hospital cardiac arrest and possible association with improvements in every link in the chain of survival

AIMS

To describe out-of-hospital cardiac arrest (OHCA) in Sweden from a long-term perspective in terms of changes in outcome and circumstances at resuscitation.

METHODS AND RESULTS

All cases of OHCA (n = 59,926) reported to the Swedish Cardiac Arrest Register from 1992 to 2011 were included. The number of cases reported (n/100,000 person-years) increased from 27 (1992) to 52 (2011). Crew-witnessed cases, cardiopulmonary resuscitation prior to the arrival of the emergency medical service (EMS), and EMS response time increased (P < 0.0001). There was a decrease in the delay from collapse to calling for the EMS in all patients and from collapse to defibrillation among patients found in ventricular fibrillation (P < 0.0001). The proportion of patients found in ventricular fibrillation decreased from 35 to 25% (P < 0.0001). Thirty-day survival increased from 4.8 (1992) to 10.7% (2011) (P < 0.0001), particularly among patients found in a shockable rhythm and patients with return of spontaneous circulation (ROSC) at hospital admission. Among patients hospitalized with ROSC in 2008-2011, 41% underwent therapeutic hypothermia and 28% underwent percutaneous coronary intervention. Among 30-day survivors in 2008-2011, 94% had a cerebral performance category score of 1 or 2 at discharge from hospital and the results were even better if patients were found in a shockable rhythm.

CONCLUSION

From a long-term perspective, 30-day survival after OHCA in Sweden more than doubled. The increase in survival was most marked among patients found in a shockable rhythm and those hospitalized with ROSC. There were improvements in all four links in the chain of survival, which might explain the improved outcome.

The implementation of a dual dispatch system in out-of-hospital cardiac arrest is associated with improved short and long term survival

AIMS

To determine the impact of a dual dispatch system, using fire fighters as first responders, in out-of-hospital cardiac arrest (OHCA) on short (30 days) and long term (three years) survival, and, to investigate the potential differences regarding in-hospital factors and interventions between the patient groups, such as the use of therapeutic hypothermia and cardiac catheterization.

METHODS AND RESULTS

OHCAs from 2004 (historical controls) and 2006-2009 (intervention period) were included. During the intervention period, fire fighters equipped with automated external defibrillators (AEDs) were dispatched in suspected OHCA. Logistic regression analyses of outcome data included: the intervention with dual dispatch, sex, age, location, aetiology, witnessed status, bystander-cardiopulmonary resuscitation, first rhythm and therapeutic hypothermia. In total, 2581 OHCAs were included (historical controls n=620, intervention period n=1961). Fire fighters initiated cardiopulmonary resuscitation and connected an AED before emergency medical services' arrival in 41% of the cases. The median time from dispatch to arrival of first responder or emergency medical services shortened from 7.7 in the control period to 6.7 min in the intervention period (p<0.001). The 30-day survival improved from 3.9% to 7.6% (p=0.001), adjusted odds ratio 2.8 (confidence interval 1.6-4.9). Survival to three years increased from 2.4% to 6.5% (p<0.001), adjusted odds ratio 3.8 (confidence interval 1.9-7.6). In the logistic regression analysis including in-hospital factors we found no outcome benefit of therapeutic hypothermia.

CONCLUSIONS

The implementation of a dual dispatch system using fire fighters in OHCA was associated with increased 30-day and three-year survival. No major differences in the in-hospital treatment were seen between the studied patient groups.

Out-of-hospital cardiac arrest: 10 years of progress in research and treatment

Cardiac disease is the most common cause of mortality in Western countries, with most deaths due to out-of-hospital cardiac arrest (OHCA). In Sweden, 5000-10 000 OHCAs occur annually. During the last decade, the time from cardiac arrest to start of cardiopulmonary resuscitation (CPR) and defibrillation has increased, whereas survival has remained unchanged or even increased. Resuscitation of OHCA patients is based on the 'chain-of-survival' concept, including early (i) access, (ii) CPR, (iii) defibrillation, (iv) advanced cardiac life support and (v) post-resuscitation care. Regarding early access, agonal breathing, telephone-guided CPR and the use of 'track and trigger systems' to detect deterioration in patients' condition prior to an arrest are all important. The use of compression-only CPR by bystanders as an alternative to standard CPR in OHCA has been debated. Based on recent findings, guidelines recommend telephone-guided chest compression-only CPR for untrained rescuers, but trained personnel are still advised to give standard CPR with both compressions and ventilation, and the method of choice for this large group remains unclear and demands for a randomized study. Data have shown the benefit of public access defibrillation for dispatched rescuers (e.g. police and fire fighters) but data are not as strong for the use of automated defibrillators (AEDs) by trained or untrained rescuers. Postresuscitation, use of therapeutic hypothermia, the importance of specific prognostic survival factors in the intensive care unit and the widespread use of percutaneous coronary intervention have all been considered. Despite progress in research and improved treatment regimens, most patients do not survive OHCA. Particular areas of interest for improving survival include (i) identification of high-risk patients prior to their arrest (e.g. early warning symptoms and genes); (ii) increased use of bystander CPR training (e.g. in schools) and simplified CPR techniques; (iii) better identification of high-incidence sites and better recruitment of AEDs (via mobile phone solutions?); (iv) improved understanding of the use of therapeutic hypothermia; (v) determining which patients should undergo immediate coronary angiography on hospital admission; and (vi) clarifying the importance of extracorporeal membrane oxygenation during CPR.

Dual dispatch early defibrillation in out-of-hospital cardiac arrest in a mixed urban-rural population

AIMS

The effects of a system based on minimally trained first responders (FR) dispatched simultaneously with the emergency medical services (EMS) of the local hospital in a mixed urban and rural area in Northwestern Switzerland were examined.

METHODS AND RESULTS

In this prospective study 500 voluntary fire fighters received a 4-h training in basic-life-support using automated-external-defibrillation (AED). FR and EMS were simultaneously dispatched in a two-tier rescue system. During the years 2001-2008, response times, resuscitation interventions and outcomes were monitored. 1334 emergencies were included. The FR reached the patients (mean age 60.4 ± 19 years; 65% male) within 6 ± 3 min after emergency calls compared to 12 ± 5 min by the EMS (p<0.0001). Seventy-six percent of the 297 OHCAs occurred at home. Only 3 emergencies with resuscitation attempts occurred at the main railway station equipped with an on-site AED. FR were on the scene before arrival of the EMS in 1166 (87.4%) cases. Of these, the FR used AED in 611 patients for monitoring or defibrillation. CPR was initiated by the FR in 164 (68.9% of 238 resuscitated patients). 124 patients were defibrillated, of whom 93 (75.0%) were defibrillated first by the FR. Eighteen patients (of whom 13 were defibrillated by the FR) were discharged from hospital in good neurological condition.

CONCLUSIONS

Minimally trained fire fighters integrated in an EMS as FR contributed substantially to an increase of the survival rate of OHCAs in a mixed urban and rural area.

Developing an analytical tool for evaluating EMS system design changes and their impact on cardiac arrest outcomes: combining geographic information systems with register data on survival rates

Background

Out-of-hospital cardiac arrest (OHCA) is a frequent and acute medical condition that requires immediate care. We estimate survival rates from OHCA in the area of Stockholm, through developing an analytical tool for evaluating Emergency Medical Services (EMS) system design changes. The study also is an attempt to validate the proposed model used to generate the outcome measures for the study.

Methods and results

This was done by combining a geographic information systems (GIS) simulation of driving times with register data on survival rates. The emergency resources comprised ambulance alone and ambulance plus fire services. The simulation model predicted a baseline survival rate of 3.9 per cent, and reducing the ambulance response time by one minute increased survival to 4.6 per cent. Adding the fire services as first responders (dual dispatch) increased survival to 6.2 per cent from the baseline level. The model predictions were validated using empirical data.

Conclusion

We have presented an analytical tool that easily can be generalized to other regions or countries. The model can be used to predict outcomes of cardiac arrest prior to investment in EMS design changes that affect the alarm process, e.g. (1) static changes such as trimming the emergency call handling time or (2) dynamic changes such as location of emergency resources or which resources should carry a defibrillator.

Favourable cost-benefit in an early defibrillation programme using dual dispatch of ambulance and fire services in out-of-hospital cardiac arrest

AIMS

Out-of-hospital cardiac arrest is fatal without treatment, and time to defibrillation is an extremely important factor in relation to survival. We performed a cost-benefit analysis of dual dispatch defibrillation by ambulance and fire services in the County of Stockholm, Sweden.

METHODS AND RESULTS

A cost-benefit analysis was performed to evaluate the effects of dual dispatch defibrillation. The increased survival rates were estimated from a real-world implemented intervention, and the monetary value of a life (<euro> 2.2 million) was applied to this benefit by using results from a recent stated-preference study. The estimated costs include defibrillators (including expendables/maintenance), training, hospitalisation/health care, fire service call-outs, overhead resources and the dispatch centre. The estimated number of additional saved lives was 16 per year, yielding a benefit-cost ratio of 36. The cost per quality-adjusted life years (QALY) was estimated to be <euro> 13,000, and the cost per saved life was <euro> 60,000.

CONCLUSIONS

The intervention of dual dispatch defibrillation by ambulance and fire services in the County of Stockholm had positive economic effects. For the cost-benefit analysis, the return on investment was high and the cost-effectiveness showed levels below the threshold value for economic efficiency used in Sweden. The cost-utility analysis categorises the cost per QALY as medium.

Characteristics of lifesaving from drowning as reported by the Swedish Fire and Rescue Services 1996-2010

AIM

We aimed to describe characteristics associated with rescue from drowning as reported by the Swedish Fire and Rescue Services (SFARS) and their association with survival from the Out of Hospital Cardiac Arrest (OHCA) registry.

METHOD

This retrospective study is based on the OHCA registry and the Swedish Civil Contingencies Agency (SCCA) registry. All emergency calls (1996-2010) where the SFARS were dispatched were included (n=7175). For analysis of survival, OHCAs that matched events from the SCCA registry were included (n=250).

RESULTS

Calls to lakes and ponds were predominant (35% of all calls reported). Rescues were more likely in cold water, <10 °C (45%), in open water (80%) and in April-September (68%). Median delay from a call to arrival of rescue services was 8min, while it was 9 min for rescue diving units. Of all OHCA cases, the victim was found at the surface in 47% and underwater in 38%. In events where rescue divers were used, victims were significantly younger than in non-diving cardiac arrests and the mean diving depth was 6.3±5.8 m. Overall survival to one month was 5.6% (13% in diving and 4.7% in non-diving cases; p=0.07).

CONCLUSION

In half of more than 7000 drowning-related calls to the SFARS during 15 years of practice, water rescue was needed. In all treated OHCA cases, the majority were found at the surface. Only in a small percentage did rescue diving take place. In these cases, survival did not appear to be poorer than in non-diving cases.