Emergency dispatch process and patient outcome in bystander-witnessed out-of-hospital cardiac arrest with a shockable rhythm

Outcomes of Out-of-Hospital Cardiac Arrest with Initial Shockable Rhythm: The Role of Bystander and Dispatch-Guided CPR in Sarajevo's Physician-Led Emergency Medical Teams

Background

The Out-of-hospital cardiac arrest (OHCA) remains a major public health challenge worldwide, with survival outcomes heavily influenced by early intervention. The presence of an initial shockable rhythm significantly increases the likelihood of survival when combined with timely cardiopulmonary resuscitation (CPR) and defibrillation.

Objective

To analyze patient outcomes and the incidence of bystander and dispatch-guided CPR in cases of OHCA with an initial shockable rhythm treated by physician-led emergency medical teams in Bosnia and Herzegovina.

Methods

Data for this study were collected over a 5-year period, from January 2019 to September 2023, using the Utstein protocol. Hospital records were analyzed to determine patient outcomes, with a focus on the 30-day survival rate and favorable neurological outcomes. Instances of dispatch-guided and bystander CPR were recorded for each case based on available patient records.

Results

In this study, 1,020 patients were included, with 151 cases (14.8%) having an initial shockable rhythm, of which 14.3% of males and 4.4% of females achieved return of spontaneous circulation (ROSC). ROSC rates varied by year, with the highest in 2019 (20.4%) and 2022 (17.9%). Thirty-day survival with a good neurological outcome was observed in a small percentage of cases. The initial shockable rhythm was found to be statistically significant (p<0.001) for achieving a good neurological outcome after 30 days. Dispatch-guided CPR was attempted in 12.9% of cases, with success in 1.9%. Bystander CPR was performed in 1.4% of cases, and only one case involved the use of an automated external defibrillator (AED). The median response time for successful resuscitations was 2 minutes, while for unsuccessful resuscitations, it was 6 minutes. The findings emphasize the role of age, initial rhythm, and response time in determining outcomes for OHCA patients.

Conclusion

The promising survival rate of OHCA patients, despite limited bystander CPR, highlights the impact of short response times and skilled physician-led teams, underscoring the need for public education and a unified registry to address gaps and better understand OHCA epidemiology in Bosnia and Herzegovina.

Medical emergencies at sea: an analysis of ambulance-supported and autonomously performed operations by lifeboat crews

BACKGROUND

Very little data is available about the involvement of lifeboat crews in medical emergencies at sea. The aim of this study is to analyze the medical operations at sea performed by the Royal Netherlands Sea Rescue Institution (KNRM).

METHODS

This is a retrospective descriptive analysis of all medical operations at sea performed by the KNRM between January 2017 and January 2020. The operations were divided in three groups: with ambulance crew aboard the lifeboat, ambulance crew on land waiting for the arrival of the lifeboat, and autonomous operations (without ambulance crew involvement). The main outcome measures were circumstances, encountered medical problems, follow-up and crew departure time.

RESULTS

The KNRM performed 282 medical operations, involving 361 persons. Operations with ambulance crew aboard the lifeboat (n = 39; 42 persons) consisted mainly of persons with serious trauma or injuries; 32 persons (76.2%) were transported to a hospital. Operations with ambulance crew on land (n = 153; 188 persons) mainly consisted of situations where time was essential, such as persons who were still in the water, with risk of drowning (n = 45, 23.9%), on-going resuscitations (n = 9, 4.8%) or suicide attempts (n = 7, 3.7%). 101 persons (53,7%) were transported to a hospital. All persons involved in the autonomous operations (n = 90; 131 persons) had minor injuries. 38 persons (29%) needed additional medical care, mainly for (suspected) fractures or stitches. In 115 (40.8%) of all operations lifeboat crews did not know that there was a medical problem at the time of departure. Crew departure time in operations with ambulance crew aboard the lifeboat (13.7 min, min. 0, max. 25, SD 5.74 min.) was significantly longer than in operations with ambulance crew on land (7.7 min, min. 0, max 21, SD 4.82 min., p < 0.001).

CONCLUSION

This study provides new information about the large variety of medical emergencies at sea and the way that lifeboat and ambulance crews are involved. Crew departure time in operations with ambulance crew aboard the lifeboat was significantly longer than in operations with ambulance crew on land. This study may provide useful indications for improvement of future medical operations at sea, such as triage, because in 40.8% of operations, it was not known at the time of departure that there was a medical problem.

Potential to enhance telephone cardiopulmonary resuscitation with improved instructions - findings from a simulation-based manikin study with lay rescuers

BACKGROUND

Telephone-Cardiopulmonary Resuscitation (T-CPR) significantly increases rate of bystander resuscitation and improves patient outcomes after out-of-hospital cardiac arrest (OHCA). Nevertheless, securing correct execution of instructions remains a difficulty. ERC Guidelines 2021 recommend standardised instructions with continuous evaluation. Yet, there are no explicit recommendations on a standardised wording of T-CPR in the German language. We investigated, whether a modified wording regarding check for breathing in a German T-CPR protocol improved performance of T-CPR.

METHODS

A simulation study with 48 OHCA scenarios was conducted. In a non-randomised trial study lay rescuers were instructed using the real-life-CPR protocol of the regional dispatch centre and as the intervention a modified T-CPR protocol, including specific check for breathing (head tilt-chin lift instructions). Resuscitation parameters were assessed with a manikin and video recordings.

RESULTS

Check for breathing was performed by 64.3% (n = 14) of the lay rescuers with original wording and by 92.6% (n = 27) in the group with modified wording (p = 0.035). In the original wording group the head tilt-chin manoeuvre was executed by 0.0% of the lay rescuers compared to 70.3% in the group with modified wording (p < 0.001). The average duration of check for breathing was 1 ± 1 s in the original wording group and 4 ± 2 s in the group with modified wording (p < 0.001). Other instructions (e.g. check for consciousness and removal of clothing) were well performed and did not differ significantly between groups. Quality of chest compression did not differ significantly between groups, with the exception of mean chest compression depth, which was slightly deeper in the modified wording group.

CONCLUSION

Correct check for breathing seems to be a problem for lay rescuers, which can be decreased by describing the assessment in more detail. Hence, T-CPR protocols should provide standardised explicit instructions on how to perform airway assessment. Each protocol should be evaluated for practicability.

Understanding the Importance of the Lay Responder Experience in Out-of-Hospital Cardiac Arrest: A Scientific Statement From the American Heart Association

Bystander cardiopulmonary resuscitation (CPR) is critical to increasing survival from out-of-hospital cardiac arrest. However, the percentage of cases in which an individual receives bystander CPR is actually low, at only 35% to 40% globally. Preparing lay responders to recognize the signs of sudden cardiac arrest, call 9-1-1, and perform CPR in public and private locations is crucial to increasing survival from this public health problem. The objective of this scientific statement is to summarize the most recent published evidence about the lay responder experience of training, responding, and dealing with the residual impact of witnessing an out-of-hospital cardiac arrest. The scientific statement focuses on the experience-based literature of actual responders, which includes barriers to responding, experiences of doing CPR, use of an automated external defibrillator, the impact of dispatcher-assisted CPR, and the potential for postevent psychological sequelae. The large body of qualitative and observational studies identifies several gaps in crucial knowledge that, if targeted, could increase the likelihood that those who are trained in CPR will act. We suggest using the experience of actual responders to inform more contextualized training, including the implications of performing CPR on a family member, dispelling myths about harm, training and litigation, and recognition of the potential for psychologic sequelae after the event.

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?

Impact of dispatcher-assisted cardiopulmonary resuscitation on neurologically intact survival in out-of-hospital cardiac arrest: a systematic review

Background

Dispatcher-assisted cardiopulmonary resuscitation (DA-CPR) increases neurologically intact survival in out-of-hospital cardiac arrest (OHCA) according to several studies. This systematic review summarizes neurologically intact survival outcomes of DA-CPR in comparison with bystander-initiated CPR and no bystander CPR in OHCA.

Methods

The systematic review was conducted according to the PRISMA guidelines. All studies including adult and/or pediatric OHCAs that compared DA-CPR with bystander-initiated CPR or no bystander CPR were included. Primary outcome was neurologically intact survival at discharge, one-month or longer. Studies were searched for in PubMed (MEDLINE), EMBASE, and the Cochrane Library databases. The risk of bias was evaluated using the Newcastle-Ottawa Scale.

Results

The search string generated 4742 citations of which 33 studies were eligible for inclusion. Due to overlapping study populations, the review included 14 studies. All studies were observational. The study populations were heterogeneous and included adult, pediatric and mixed populations. Some studies reported only witnessed cardiac arrests, arrests of cardiac ethiology, and/or shockable rhythm. The individual studies scored between six and nine on the Newcastle-Ottawa Scale of risk of bias. The median neurologically intact survival at hospital discharge with DA-CPR was 7.0% (interquartile range (IQR): 5.1–10.8%), with bystander-initiated CPR 7.5% (IQR: 6.6–10.2%), and with no bystander CPR 4.4% (IQR: 2.0–9.0%) (four studies). At one-month neurologically intact survival with DA-CPR was 3.1% (IQR: 1.6–3.4%), with bystander-initiated CPR 5.7% (IQR: 5.0–6.0%), and with no bystander CPR 2.5% (IQR: 2.1–2.6%) (three studies).

Conclusion

Both DA-CPR and bystander-initiated CPR increase neurologically intact survival compared with no bystander CPR. However, DA-CPR demonstrates inferior outcomes compared with bystander-initiated CPR. Early CPR is crucial, thus in cases where bystanders have not initiated CPR, DA-CPR provides an opportunity to improve neurologically intact survival following OHCA. Variability in OHCA outcomes across studies and multiple confounding factors were identified.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13049-021-00875-5.

Rapid dispatch for out-of-hospital cardiac arrest is associated with improved survival

AIM

As proxy for initiation of the first link in the Chain of Survival by the dispatcher, we aimed to investigate the effect of time to first dispatch on 30-day survival among patients with OHCA ultimately receiving the highest-level emergency medical response.

METHODS

We linked data on all OHCA unwitnessed by emergency medical services (EMS) treated by Copenhagen EMS from 2016 through 2018 to corresponding emergency call records. Among patients receiving highest priority emergency response, we calculated time to dispatch as time from start of call to time of first dispatch.

RESULTS

We included 3548 patients with OHCA. Of these, 94.1% received the highest priority response (median time to dispatch 0.84 min, 25th-75th percentile 0.58-1.24 min). Patients with time to dispatch within one minute compared to three or more minutes were more likely to receive bystander cardiopulmonary resuscitation (77.3 vs 54.2%), bystander defibrillation (11.5 vs 6.5%) and defibrillation by emergency medical services (24.1 vs 7.5%) and were 2.6-fold more likely to survive 30 days after the OHCA (P = 0.004). Results from multivariate logistic regression were similar: odds ratio (OR) of survival 0.83 per minute increase (95% confidence interval 0.70-1.00, P = 0.04). However, survival was similar between those who received highest priority response and those who did not: OR of survival 0.88 (95% confidence interval 0.53-1.46, P = 0.61).

CONCLUSION

Rapid time to dispatch among patients with highest priority response was significantly associated with a higher probability of 30-day survival following OHCA.

European Resuscitation Council Guidelines 2021: Systems saving lives

The European Resuscitation Council (ERC) has produced these Systems Saving Lives guidelines, which are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. The topics covered include chain of survival, measuring performance of resuscitation, social media and smartphones apps for engaging community, European Restart a Heart Day, World Restart a Heart, KIDS SAVE LIVES campaign, lower-resource setting, European Resuscitation Academy and Global Resuscitation Alliance, early warning scores, rapid response systems, and medical emergency team, cardiac arrest centres and role of dispatcher.

Part 7: Systems of Care: 2020 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care

Survival after cardiac arrest requires an integrated system of people, training, equipment, and organizations working together to achieve a common goal. Part 7 of the 2020 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care focuses on systems of care, with an emphasis on elements that are relevant to a broad range of resuscitation situations. Previous systems of care guidelines have identified a Chain of Survival, beginning with prevention and early identification of cardiac arrest and proceeding through resuscitation to post-cardiac arrest care. This concept is reinforced by the addition of recovery as an important stage in cardiac arrest survival. Debriefing and other quality improvement strategies were previously mentioned and are now emphasized. Specific to out-of-hospital cardiac arrest, this Part contains recommendations about community initiatives to promote cardiac arrest recognition, cardiopulmonary resuscitation, public access defibrillation, mobile phone technologies to summon first responders, and an enhanced role for emergency telecommunicators. Germane to in-hospital cardiac arrest are recommendations about the recognition and stabilization of hospital patients at risk for developing cardiac arrest. This Part also includes recommendations about clinical debriefing, transport to specialized cardiac arrest centers, organ donation, and performance measurement across the continuum of resuscitation situations.

Identifying the relative importance of predictors of survival in out of hospital cardiac arrest: a machine learning study

Introduction

Studies examining the factors linked to survival after out of hospital cardiac arrest (OHCA) have either aimed to describe the characteristics and outcomes of OHCA in different parts of the world, or focused on certain factors and whether they were associated with survival. Unfortunately, this approach does not measure how strong each factor is in predicting survival after OHCA.

Aim

To investigate the relative importance of 16 well-recognized factors in OHCA at the time point of ambulance arrival, and before any interventions or medications were given, by using a machine learning approach that implies building models directly from the data, and arranging those factors in order of importance in predicting survival.

Methods

Using a data-driven approach with a machine learning algorithm, we studied the relative importance of 16 factors assessed during the pre-hospital phase of OHCA. We examined 45,000 cases of OHCA between 2008 and 2016.

Results

Overall, the top five factors to predict survival in order of importance were: initial rhythm, age, early Cardiopulmonary Resuscitation (CPR, time to CPR and CPR before arrival of EMS), time from EMS dispatch until EMS arrival, and place of cardiac arrest. The largest difference in importance was noted between initial rhythm and the remaining predictors. A number of factors, including time of arrest and sex were of little importance.

Conclusion

Using machine learning, we confirm that the most important predictor of survival in OHCA is initial rhythm, followed by age, time to start of CPR, EMS response time and place of OHCA. Several factors traditionally viewed as important, e.g. sex, were of little importance.

Impact of Dispatcher-Assisted Bystander Cardiopulmonary Resuscitation with Out-of-Hospital Cardiac Arrest: A Systemic Review and Meta-Analysis

OBJECTIVE

This systemic review and meta-analysis was conducted to explore the impact of dispatcher-assisted bystander cardiopulmonary resuscitation (DA-BCPR) on bystander cardiopulmonary resuscitation (BCPR) probability, survival, and neurological outcomes with out-of-hospital cardiac arrest (OHCA).

METHODS

Electronically searching of PubMed, Embase, and Cochrane Library, along with manual retrieval, were done for clinical trials about the impact of DA-BCPR which were published from the date of inception to December 2018. The literature was screened according to inclusion and exclusion criteria, the baseline information, and interested outcomes were extracted. Two reviewers assessed the methodological quality of the included studies. Pooled odds ratio (OR) and 95% confidence interval (CI) were calculated by STATA version 13.1.

RESULTS

In 13 studies, 235,550 patients were enrolled. Compared with no dispatcher instruction, DA-BCPR tended to be effective in improving BCPR rate (I2 = 98.2%; OR = 5.84; 95% CI, 4.58-7.46; P <.01), return of spontaneous circulation (ROSC) before admission (I2 = 36.0%; OR = 1.17; 95% CI, 1.06-1.29; P <.01), discharge or 30-day survival rate (I2 = 47.7%; OR = 1.25; 95% CI, 1.06-1.46; P <.01), and good neurological outcome (I2 = 30.9%; OR = 1.24; 95% CI, 1.04-1.48; P = .01). However, no significant difference in hospital admission was found (I2 = 29.0%; OR = 1.09; 95% CI, 0.91-1.30; P = .36).

CONCLUSION

This review shows DA-BPCR plays a positive role for OHCA as a critical section in the life chain. It is effective in improving the probability of BCPR, survival, ROSC before admission, and neurological outcome.

Spontaneous trigger words associated with confirmed out-of-hospital cardiac arrest: a descriptive pilot study of emergency calls

BACKGROUND

According to the International Liaison Committee on Resuscitation (ILCOR), the trigger words used by callers that are associated with cardiac arrest constitute a scientific knowledge gap. This study was designed to find hypothetical trigger words in emergency calls in order to improve the specificity of out-of-hospital cardiac arrest recognition.

METHODS

In this descriptive pilot study conducted in a Finnish hospital district, linguistic contents of 80 emergency calls of dispatcher-suspected or EMS-encountered out-of-hospital cardiac arrests between January 1, 2017 and May 31, 2017 were analysed. Spontaneous trigger words used by callers were transcribed and grouped into 36 categories. The association between the spontaneous trigger words and confirmed true cardiac arrests was tested with logistic regression.

RESULTS

Of the suspected cardiac arrests, 51 (64%) were confirmed as true cardiac arrests when ambulance personnel met the patient. A total of 291 spontaneous trigger words were analysed. 'Is not breathing' (n = 9 [18%] in the true cardiac arrest group vs n = 1 [3%] in the non-cardiac arrest group, odds ratio [OR] 6.00, 95% confidence interval [CI] 0.72-50.0), 'the patient is blue' (n = 9 [18%] vs n = 1 [3%], OR 6.00, 95% CI 0.72-50.0), 'collapsed or fallen down' (n = 12 [24%] vs n = 2 [7%], OR 4.15, 95% CI 0.86-20.1) and 'is wheezing' (n = 17 [33%] vs n = 5 [17%], OR 2.40, 95% CI 0.78-7.40) were frequently used to describe true cardiac arrest. 'Is snoring' was associated with a false suspicion of cardiac arrest (n = 1 [2%] vs n = 6 [21%], OR 0.08, 95% CI 0.009-0.67).

CONCLUSIONS

In our pilot study, no trigger word was associated with confirmed cardiac arrest. 'Is wheezing' was a frequently used spontaneous trigger word among later confirmed cardiac arrest victims.

2019 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations: Summary From the Basic Life Support; Advanced Life Support; Pediatric Life Support; Neonatal Life Support; Education, Implementation, and Teams; and First Aid Task Forces

The International Liaison Committee on Resuscitation has initiated a continuous review of new, peer-reviewed, published cardiopulmonary resuscitation science. This is the third annual summary of the International Liaison Committee on Resuscitation International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations. It addresses the most recent published resuscitation evidence reviewed by International Liaison Committee on Resuscitation Task Force science experts. This summary addresses the role of cardiac arrest centers and dispatcher-assisted cardiopulmonary resuscitation, the role of extracorporeal cardiopulmonary resuscitation in adults and children, vasopressors in adults, advanced airway interventions in adults and children, targeted temperature management in children after cardiac arrest, initial oxygen concentration during resuscitation of newborns, and interventions for presyncope by first aid providers. Members from 6 International Liaison Committee on Resuscitation task forces have assessed, discussed, and debated the certainty of the evidence on the basis of the Grading of Recommendations, Assessment, Development, and Evaluation criteria, and their statements include consensus treatment recommendations. Insights into the deliberations of the task forces are provided in the Justification and Evidence to Decision Framework Highlights sections. The task forces also listed priority knowledge gaps for further research.

Dispatcher Identification of Out-of-Hospital Cardiac Arrest and Neurologically Intact Survival: A Retrospective Cohort Study

Introduction:

To date, there are no published data on the association of patient-centered outcomes and accurate public-safety answering point (PSAP) dispatch in an American population. The goal of this study is to determine if PSAP dispatcher recognition of out-of-hospital cardiac arrest (OHCA) is associated with neurologically intact survival to hospital discharge.

Methods:

This retrospective cohort study is an analysis of prospectively collected Quality Assurance/Quality Improvement (QA/QI) data from the San Antonio Fire Department (SAFD; San Antonio, Texas USA) OHCA registry from January 2013 through December 2015. Exclusion criteria were: Emergency Medical Services (EMS)-witnessed arrest, traumatic arrest, age <18 years old, no dispatch type recorded, and missing outcome data. The primary exposure was dispatcher recognition of cardiac arrest. The primary outcome was neurologically intact survival (defined as Cerebral Performance Category [CPC] 1 or 2) to hospital discharge. The secondary outcomes were: bystander cardiopulmonary resuscitation (CPR), automated external defibrillator (AED) use, and prehospital return of spontaneous return of circulation (ROSC).

Results:

Of 3,469 consecutive OHCA cases, 2,569 cases were included in this analysis. The PSAP dispatched 1,964/2,569 (76.4%) of confirmed OHCA cases correctly. The PSAP dispatched 605/2,569 (23.6%) of confirmed OHCA cases as another chief complaint. Neurologically intact survival to hospital discharge occurred in 99/1,964 (5.0%) of the recognized cardiac arrest group and 28/605 (4.6%) of the unrecognized cardiac arrest group (OR = 1.09; 95% CI, 0.71–1.70). Bystander CPR occurred in 975/1,964 (49.6%) of the recognized cardiac arrest group versus 138/605 (22.8%) of the unrecognized cardiac arrest group (OR = 3.34; 95% CI, 2.70–4.11).

Conclusion:

This study found no association between PSAP dispatcher identification of OHCA and neurologically intact survival to hospital discharge. Dispatcher identification of OHCA remains an important, but not singularly decisive link in the OHCA chain of survival.

2019 American Heart Association Focused Update on Systems of Care: Dispatcher-Assisted Cardiopulmonary Resuscitation and Cardiac Arrest Centers: An Update to the American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care

Survival after out-of-hospital cardiac arrest requires an integrated system of care (chain of survival) between the community elements responding to an event and the healthcare professionals who continue to care for and transport the patient for appropriate interventions. As a result of the dynamic nature of the prehospital setting, coordination and communication can be challenging, and identification of methods to optimize care is essential. This 2019 focused update to the American Heart Association systems of care guidelines summarizes the most recent published evidence for and recommendations on the use of dispatcher-assisted cardiopulmonary resuscitation and cardiac arrest centers. This article includes the revised recommendations that emergency dispatch centers should offer and instruct bystanders in cardiopulmonary resuscitation during out-of-hospital cardiac arrest and that a regionalized approach to post-cardiac arrest care may be reasonable when comprehensive postarrest care is not available at local facilities.

A systematic review and meta-analysis of the effect of dispatcher-assisted CPR on outcomes from sudden cardiac arrest in adults and children

BACKGROUND

Dispatcher-assisted cardiopulmonary resuscitation (DA-CPR) has been reported in individual studies to significantly increase the rate of bystander CPR and survival from cardiac arrest.

METHODS

We undertook a systematic review and meta-analysis to evaluate the impact of DA-CPR programs on key clinical outcomes following out-of-hospital cardiac arrest. We searched the PubMED, EMBASE, CINAHL, ERIC and Cochrane Central Register of Controlled Trials databases from inception until July 2018. Eligible studies compared systems with and without dispatcher-assisted CPR programs. The results of included studies were classified into 3 categories for the purposes of more accurate analysis: comparison of outcomes in systems with DA-CPR programs, case-based comparison of DA-CPR to bystander CPR, and case-based comparisons of DA-CPR to no CPR before EMS arrival. The GRADE system was used to assess certainty of evidence at an outcome level. We used random-effects models to produce summary effect sizes across all outcomes.

RESULTS

Of 5531 citations screened, 33 studies were eligible for inclusion. All included studies were observational. Evidence certainty across all outcomes was assessed as low or very low. In system-level and patient-level comparisons, the provision of DA-CPR compared with no DA-CPR was consistently associated with improved outcome across all analyses. Comparison of DA-CPR to bystander CPR produced conflicting results. Findings were consistent across sensitivity analyses and the pediatric sub-group.

CONCLUSION

These results support the recommendation that dispatchers provide CPR instructions to callers for adults and children with suspected OHCA. Review registration: PROSPERO- CRD42018091427.

Response time in the emergency services. Systematic review

The growth of the urban population raises concern about municipal public managers in the sense of providing emergency medical services (EMS) that are aligned with the needs of prehospital emergency medical care demanded by the population. The literature review aims at presenting the response time of emergency medical services in several parts of the world and discussing some factors that interfere in the result of this indicator such as GDP (Gross Domestic Product) percentage spent on health and life expectancy of countries. The study will also show that in some of the consulted articles, authors suggest to EMS recommendations for decreasing the response time using simulations, heuristics and metaheuristics. Response time is a basic indicator of emergency medical services, in such a way that researchers use the descriptive statistics to evaluate this parameter. Europe and the USA outstand in the publication of studies that present this information. Some articles use stochastic and mathematical methods to suggest models that simulate scenarios of response time reduction and suggest such proposals to the local EMS. Countries in which the response time was identified have a high index of human development and life expectancy between 74.7 and 83.7 years.

Recognition of out-of-hospital cardiac arrest during emergency calls - a systematic review of observational studies

Background

The medical dispatcher plays an essential role as part of the first link in the Chain of Survival, by recognising the out-of-hospital cardiac arrest (OHCA) during the emergency call, dispatching the appropriate first responder or emergency medical services response, performing dispatcher assisted cardiopulmonary resuscitation, and referring to the nearest automated external defibrillator. The objective of this systematic review was to evaluate and compare studies reporting recognition of OHCA patients during emergency calls.

Methods

This systematic review was reported in compliance with the PRISMA guidelines. We systematically searched MEDLINE, Embase and the Cochrane Library on 4 November 2015. Observational studies, reporting the proportion of clinically confirmed OHCAs that was recognised during the emergency call, were included. Two authors independently screened abstracts and full-text articles for inclusion. Data were extracted and the risk of bias within studies was assessed using the QUADAS-2 tool for quality assessment of diagnostic accuracy studies.

Results

A total of 3,180 abstracts were screened for eligibility and 53 publications were assessed in full-text. We identified 16 studies including 6,955 patients that fulfilled the criteria for inclusion in the systematic review. The studies reported recognition of OHCA with a median sensitivity of 73.9% (range: 14.1–96.9%). The selection of study population and the definition of “recognised OHCA” (threshold for positive test) varied greatly between the studies, resulting in high risk of bias. Heterogeneity in the studies precluded meta-analysis.

Conclusion

Among the 16 included studies, we found a median sensitivity for OHCA recognition of 73.9% (range: 14.1–96.9%). However, great heterogeneity between study populations and in the definition of “recognised OHCA”, lead to insufficient comparability of results. Uniform and transparent reporting is required to ensure comparability and development towards best practice.

Recognition of out-of-hospital cardiac arrest by medical dispatchers in emergency medical dispatch centres in two countries

INTRODUCTION

Survival after out-of-hospital cardiac arrest (OHCA) remains low. Early recognition by emergency medical dispatchers is essential for an effective chain of actions, leading to early cardiopulmonary resuscitation, use of an automated external defibrillator and rapid dispatching of the emergency medical services.

AIM

To analyse and compare the accuracy of OHCA recognition by medical dispatchers in two countries.

METHOD

An observational register-based study collecting data from national cardiac arrest registers in Denmark and Sweden during a six-month period in 2013. Data were analysed in two steps; registry data were merged with electronically registered emergency call data from the emergency medical dispatch centres in the two regions. Cases with missing or non-OHCA dispatch codes were analysed further by auditing emergency call recordings using a uniform data collection template.

RESULTS

The sensitivity for recognition of OHCA was 40.9% (95% CI: 37.1-44.7%) in the Capital Region of Denmark and 78.4% (95% CI: 73.2-83.0%) in the Skåne Region in Sweden (p<0.001). With additional data from the emergency call recordings, the sensitivity was 80.7% (95% CI: 77.7-84.3%) and 86.0% (95% CI: 81.3-89.8%) for the two regions (p=0.06). The majority of the non-recognised OHCA were dispatched with the highest priority.

CONCLUSION

The accuracy of OHCA recognition was high and comparable. We identified large differences in data registration practices despite the use of similar dispatch tools. This raises a discussion of definitions and transparency in general in scientific reporting of OHCA recognition, which is essential if used as quality indicator in emergency medical services.