Out-of-hospital Cardiac Arrest Recognition Research Articles

Pediatric Out-of-Hospital Cardiac Arrest: The Role of the Telecommunicator in Recognition of Cardiac Arrest and Delivery of Bystander Cardiopulmonary Resuscitation.

Telecommunicator CPR (T-CPR), whereby emergency dispatch facilitates cardiac arrest recognition and coaches CPR over the telephone, is an important strategy to increase early recognition and bystander CPR in adult out-of-hospital cardiac arrest (OHCA). Little is known about this treatment strategy in the pediatric population. We investigated the role of T-CPR and related performance among pediatric OHCA. This study was a retrospective cohort investigation of OHCA among individuals <18 years in King County, Washington, from April 1, 2013, to December 31, 2019. We reviewed the 911 audio recordings to determine if and how bystander CPR was delivered (unassisted or T-CPR), key time intervals in recognition of arrest, and key components of T-CPR delivery. Of the 185 eligible pediatric OHCAs, 23% (n=43) had bystander CPR initiated unassisted, 59% (n=109) required T-CPR, and 18% (n=33) did not receive CPR before emergency medical services arrival. Among all cases, cardiac arrest was recognized by the telecommunicator in 89% (n=165). Among those receiving T-CPR, the median (interquartile range) interval from start of call to OHCA recognition was 59 seconds (38-87) and first CPR intervention was 115 seconds (94-162). When stratified by age (≤8 versus >8), the older age group was less likely to receive CPR before emergency medical services arrival (88% versus 69%, P=0.002). For those receiving T-CPR, bystanders spent a median of 207 seconds (133-270) performing CPR. The median compression rate was 93 per minute (82-107) among those receiving T-CPR. T-CPR is an important strategy to increase early recognition and early CPR among pediatric OHCA.

Investigating characteristics of patients and healthcare Visits Prior to Out-of-Hospital Cardiac Arrest in Two Tertiary Hospitals in Oman

Introduction The high incidence of out of hospital cardiac arrest (OHCA) as well as its low survival rates are contributing to the burden on public health. Emerging evidence have recognized prodromal symptoms and patterns of healthcare use suggesting the possibility of predicting these cardiac events despite the general belief that they are merely sudden. Our study aimed to identify the characteristics of patients who present in OHCA and the utilization pattern of healthcare facilities by these patients in the period preceding the cardiac arrest. Methods This is a retrospective study which included adult OHCA patients who presented at two emergency departments (ED) in Muscat, Oman between 2016 and 2020. The ED visits that occurred within the six months preceding the arrest were investigated. Descriptive statistics and frequency tables were used to report the baseline characteristics of all patients. Associations were tested using chi-square test. Results The final cohort consisted of 822 patients with mean age of 60.2 years. The male and female percentages were 65.7% and 34.3% respectively. Less than 10% survived to hospital discharge. About two thirds of all recorded ED visits occurred in the three months immediately before the arrest. A significant association was observed between the frequency of pre-OHCA visits and cardiopulmonary resuscitation (CPR) outcome among patients (P-value = 0.000004). Conclusion Over a quarter of the cohort subjects have approached ED prior to the arrest. Patients are more likely to seek medical attention before the arrest complaining mainly of cardiac and respiratory symptoms. The chances of survival after receiving CPR were higher for those with higher number of visits prior to the arrest. Having a unified system to document and monitor frequent emergency presentations as well as demographics of the patients concerned will aid in the pattern recognition and prevention of OHCA in many subjects.

Evaluation of Telephone Cardiopulmonary Resuscitation Performance in Current Practice in Saudi Arabia.

Out-of-hospital cardiac arrest (OHCA) is a global health problem with a low survival rate. Telephone cardiopulmonary resuscitation (T-CPR) guidance by emergency medical services (EMS) dispatchers can improve CPR performance and, consequently, survival rates. Accordingly, the American Heart Association (AHA) has released performance standards for T-CPR in current practice to improve its quality. However, no study has examined T-CPR performance in Saudi Arabia. Therefore, this study aims to evaluate T-CPR performance in the Saudi Arabian EMS system. A retrospective observation of OHCA calls in current practice was conducted in Riyadh, Saudi Arabia. OHCA calls were reviewed to identify those that met the selection criteria. Variables collected included return of spontaneous circulation (ROSC), OHCA recognition rate, time from EMS call receipt to location acquisition, to OHCA recognition and to commencement of CPR. A total of 308 OHCA cases were reviewed, and 100 calls were included. ROSC was identified in 10% of the included calls. OHCA was correctly recognized in 62% of the calls. The time to OHCA identification and CPR performance from EMS call receipt were found to be 303 s and 367 s, respectively. T-CPR performance in Saudi Arabia is below AHA standards. However, this is similar to what has been reported in the literature. Avoiding any unnecessary call transfer during OHCA calls and prompt identification of callers' locations could improve T-CPR performance.

A Qualitative Analysis of the Experiences of EMS Clinicians in Recognizing and Treating Witnessed Cardiac Arrests

Background Survival from out of hospital cardiac arrest (OHCA) increases when effective cardiopulmonary resuscitation (CPR) and defibrillation are performed early. Patients who suffer OHCA in front of emergency medical services (EMS) clinicians have greater likelihood of survival, but little is known about how EMS clinicians think about and experience those events. We sought to understand how EMS clinicians assessed patients who devolved to cardiac arrest in their presence and uncover the perceived barriers and facilitators associated with recognizing and treating witnessed OHCAs. Methods EMS clinicians who had attended an EMS-witnessed OHCA and consented to participate were interviewed within 72 hours of the index case. Transcripts of the interviews were coded through the consolidated framework for implementation research to understand enabling and constraining factors involved and the predictability and anticipation of OHCA and subsequent management of patient care. Utstein data points, interventions, and associated times were extracted from the medical records. Results We interviewed 29 EMS clinicians who attended 27 EMS-witnessed OHCAs. Twenty-six (96.3%) of the EMS-witnessed OHCAs were preceded by prodromal symptoms and were classified as predictable. Of the predictable cases, clinicians anticipated 53.8% of them and attributed the prodromes of other cases to serious but not peri-arrest etiologies. Participants described various environmental, crew, and intrapersonal enabling and constraining factors associated with recognizing and treating EMS-witnessed OHCAs. Environmental elements included issues of safety and physical locations, crew elements included familiarity with their partners and working with them in the past, and intrapersonal elements included abilities to collect information and stress associated with responding to and managing the calls. Conclusion Recognition and treatment of EMS-witnessed OHCAs are influenced by numerous environmental, crew, and intrapersonal factors. Future training and education on OHCA should include diverse locations, situations, and crew make-up, along with nontraditional patient complaints to broaden experiences associated with cardiac arrest management.

Out of hospital cardiac arrest: experience of a bystander CPR training program in Karachi, Pakistan

BackgroundNearly 90% of out-of-hospital cardiac arrest (OHCA) patients are witnessed, yet only 2.3% received bystander cardiopulmonary resuscitation (CPR) in Pakistan. This study aimed to determine retention of knowledge and skills of Hands-Only CPR among community participants in early recognition of OHCA and initiation of CPR in Karachi, Pakistan.MethodsPre and post-tests were conducted among CPR training participants from diverse non-health-related backgrounds from July 2018 to October 2019. Participants were tested for knowledge and skills of CPR before training (pre-test), immediately after training (post-test), and 6 months after training (re-test). All the participants received CPR training through video and scenario-based demonstration using manikins. Post-training CPR skills of the participants were assessed using a pre-defined performance checklist. The facilitator read out numerous case scenarios to the participants, such as drowning, poisoning, and road traffic injuries, etc., and then asked them to perform the critical steps of CPR identified in the scenario on manikins. The primary outcome was the mean difference in the knowledge score and skills of the participants related to the recognition of OHCA and initiation of CPR.ResultsThe pre and post-tests were completed by 652 participants, whereas the retention test after 6 months was completed by 322 participants. The mean knowledge score related to the recognition of OHCA, and initiation of CPR improved significantly (p < 0.001) from pre-test [47.8/100, Standard Deviation (SD) ±13.4] to post-test (70.2/100, SD ±12.1). Mean CPR knowledge after 6 months (retention) reduced slightly from (70.2/100, ±12.1) to (66.5/100, ±10.8). CPR skill retention for various components (check for scene safety, check for response, check for breathing and correct placement of the heel of hands) deteriorated significantly (p < 0.001) from 77.9% in the post-test to 72.8% in re-test. Participants performed slightly better on achieving an adequate rate of chest compressions from 73.1% in post-test to 76.7% in re-test (p 0.27).ConclusionCommunity members with non-health backgrounds can learn and retain CPR skills, allowing them to be effective bystander CPR providers in OHCA situations. We recommend mass population training in Pakistan for CPR to increase survival from OHCA.

Out-of-Hospital Cardiac Arrest Detection by Machine Learning Based on the Phonetic Characteristics of the Caller's Voice.

Out-of-hospital cardiac arrest (OHCA) is a major public health issue. The prognosis is closely related to the time from collapse to return of spontaneous circulation. Resuscitation efforts are frequently initiated at the request of emergency call center professionals who are specifically trained to identify critical conditions over the phone. However, 25% of OHCAs are not recognized during the first call. Therefore, it would be interesting to develop automated computer systems to recognize OHCA on the phone. The aim of this study was to build and evaluate machine learning models for OHCA recognition based on the phonetic characteristics of the caller's voice. All patients for whom a call was done to the emergency call center of Rennes, France, between 01/01/2017 and 01/01/2019 were eligible. The predicted variable was OHCA presence. Predicting variables were collected by computer-automatized phonetic analysis of the call. They were based on the following voice parameters: fundamental frequency, formants, intensity, jitter, shimmer, harmonic to noise ratio, number of voice breaks, and number of periods. Three models were generated using binary logistic regression, random forest, and neural network. The area under the curve (AUC) was the primary outcome used to evaluate each model performance. 820 patients were included in the study. The best model to predict OHCA was random forest (AUC=74.9, 95% CI=67.4-82.4). Machine learning models based on the acoustic characteristics of the caller's voice can recognize OHCA. The integration of the acoustic parameters identified in this study will help to design decision-making support systems to improve OHCA detection over the phone.

Unrecognized cardiac arrests: A one-year review of audio from emergency medical dispatch calls.

Immediate recognition of out-of-hospital cardiac arrest (OHCA) by Emergency Medical Dispatch (EMD) operators is crucial to facilitate timely initiation of telephone cardiopulmonary resuscitation (T-CPR) and to enable the appropriate level of Emergency Medical Services (EMS) response. The goal of this study was to identify patterns that can increase EMD-level recognition of cardiac arrests prior to EMS arrival. The Combined Communications Center in Alachua County, Florida provided audio recordings of all emergency calls from January 1, 2018 to November 16, 2018 dispatched as a chief complaint other than OHCA, but later identified as cardiac arrest. A multi-disciplinary medical team transcribed and analyzed the calls to determine common themes and trends. Out of an initial 81 calls meeting inclusion criteria, 69 were immediately recognized as OHCA by EMDs, leaving 12 calls of unrecognized OHCA. In 11 of 12 calls respiratory issues were described to EMD. In 10 of 12 calls the subject was described as unconscious, and in the other 2 calls, the subject lost consciousness during the call. Lack of recognition of OHCA by EMD occurred in most calls due to difficulty communicating the subject's respiratory status. Further emphasis should be placed on identifying non-viable respirations in unconscious patients in EMD training and algorithms to increase recognition of OHCA and initiation of T-CPR. A multi-year review of a comparable dataset from geographically and socioeconomically diverse regions in the United States can validate and expand these preliminary trends.

A mixed methods analysis of caller-emergency medical dispatcher communication during 9–1–1 calls for out-of-hospital cardiac arrest

ObjectiveRecognition of out-of-hospital cardiac arrest (OHCA) during 9–1–1 calls is critically important, but little is known about how laypersons and emergency medical dispatchers (EMDs) communicate. We sought to describe 9–1–1 calls for OHCA. MethodsWe performed a mixed-methods, retrospective analysis of 9–1–1 calls for OHCA victims in a large urban emergency medical services (EMS) system using a random sampling of cases containing the term “cardiopulmonary resuscitation” (CPR) in the EMS electronic report. A constant comparison qualitative approach with four independent reviewers continued until thematic saturation was achieved. Quantitative analysis employed computational linguistics. Callers’ emotional states were rated using the emotional content and cooperation score (ECCS). ResultsThematic saturation was achieved after 46 calls. Three “OHCA recognition” themes emerged [ 1) disparate OHCA terms used, 2) OHCA mimics create challenges, 3) EMD questions influence recognition]. Three “CPR facilitation” themes emerged [ 1) directive language may facilitate CPR, 2) specific instructions assist CPR, 3) caller’s emotions affect CPR initiation]. Callers were generally “anxious but cooperative.” Callers saying “pulse” was associated with OHCA recognition. ConclusionCommunication characteristics appear to influence OHCA recognition and CPR facilitation. Practice implicationsDispatch protocols that acknowledge characteristics of callers’ communication may improve OHCA recognition and CPR facilitation.

Urban-Rural Differences in Cardiac Arrest Outcomes: A Retrospective Population-Based Cohort Study

BackgroundApproximately 10% of people who suffer an out-of-hospital cardiac arrest (OHCA) treated by paramedics survive to hospital discharge. Survival differs by up to 19.2% between urban centres and rural areas. Our goal was to investigate the differences in OHCA survival between urban centres and rural areas. MethodsThis was a retrospective cohort study of OHCA patients treated by Nova Scotia Emergency Medical Services (EMS) in 2017. Cases of traumatic, expected, and noncardiac OHCA were excluded. Data were collected from the Emergency Health Service electronic patient care record system and the discharge abstract database. Geographic information system analysis classified cases as being in urban centres (population > 1000 people) or rural areas, using 2016 Canadian Census boundaries. The primary outcome was survival to hospital discharge. Multivariable logistic regression covariates were age, sex, bystander resuscitation, whether the arrest was witnessed, public location, and preceding symptoms. ResultsA total of 510 OHCAs treated by Nova Scotia Emergency Medical Services were included for analysis. A total of 12% (n = 62) survived to discharge. Patients with OHCAs in urban centres were 107% more likely to survive than those with OHCAs in rural areas (adjusted odds ratio = 2.1; 95% confidence interval = 1.1 to 3.8; P = 0.028). OHCAs in urban centres had a significantly shorter mean time to defibrillation of shockable rhythm (11.2 minutes ± 6.2) vs those in rural areas (17.5 minutes ± 17.3). ConclusionsNova Scotia has an urban vs rural disparity in OHCA care that is also seen in densely populated OHCA centres. Survival is improved in urban centres. Further improvements in overall survival, especially in rural areas, may arise from community engagement in OHCA recognition and optimized healthcare delivery.

Swedish dispatchers’ compliance with the American Heart Association performance goals for dispatch-assisted cardiopulmonary resuscitation and its association with survival in out-of-hospital cardiac arrest: A retrospective study

AimWe aimed 1) to investigate how Swedish dispatchers perform during emergency calls in accordance with the American Heart Association (AHA) goals for dispatcher-assisted cardiopulmonary resuscitation (DA-CPR), 2) calculate the potential impact on 30-day survival. MethodsThis observational study includes a random sample of 1000 out-of-hospital cardiac arrest (OHCA) emergency ambulance calls during 2018 in Sweden. Voice logs were audited to evaluate dispatchers’ handling of emergency calls according to the AHA performance goals. Number of possible additional survivors was estimated assuming the timeframes of the AHA performance goals was achieved. ResultsA total of 936 cases were included. An OHCA was recognized by a dispatcher in 79% (AHA goal 75%). In recognizable OHCA, dispatchers recognized 85% (AHA goal 95%). Dispatch-directed compressions were given in 61% (AHA goal 75%). Median time to OHCA recognition was 113 s [interquartile range (IQR), 62, 204 s] (AHA goal < 60 s). The first dispatch-directed compression was performed at a median time of 240 s [IQR, 176, 332 s] (AHA goal < 90 s). If eligible patients receive dispatch-directed compressions within the AHA 90 s goal, 73 additional lives may be saved; if all cases are recognized within the AHA 60 s goal, 25 additional lives may be saved. ConclusionsThe AHA policy statement serves as a benchmark for all emergency medical dispatch centres (EMDC). Additional effort is needed at Swedish EMDC to achieve AHA goals for DA-CPR. Our study suggests that if EMDC further optimize handling of OHCA calls in accordance with AHA goals, many more lives may be saved.

“I’m sorry, my English not very good”: Tracking differences between Language-Barrier and Non-Language-Barrier emergency ambulance calls for Out-of-Hospital Cardiac Arrest

BackgroundOne-fifth of Australia’s population do not speak English at home. International studies have found emergency calls with language barriers (LB) result in longer delays to out-of-hospital cardiac arrest (OHCA) recognition, and lower rates of bystander cardiopulmonary resuscitation (CPR) and survival. This study compared LB and non-LB OHCA call time intervals in an Australian emergency medical service (EMS). MethodsThe retrospective cohort study measured time intervals from call commencement for primary outcomes: (1) address acquisition; (2) OHCA recognition; (3) CPR initiation; (4) telecommunicator CPR (t-CPR) compressions, in all identified LB calls and a 2:1 random sample of non-LB EMS calls from January to June 2019. Results for time intervals #1, 2, and 4 were benchmarked against the American Heart Association’s (AHA) t-CPR minimal acceptable time standards. Patient survival outcomes were compared. ResultsWe identified 50 (14%) LB calls from a cohort of 353 calls. LB calls took longer than non-LB calls (n=100) for: address acquisition (median 29 vs 14 secs, p<0.001), OHCA recognition (103 vs 85 secs, p=0.02), and CPR initiation (206 vs 164 secs, p=0.01), but not for t-CPR compressions (292 vs 248 secs, p=0.12). Rates of OHCA recognition and 30-day-survival did not differ but smaller proportions of LB calls met the AHA standards. ConclusionTime delays found in LB calls point to phases of the call which need further qualitative investigation to understand how to improve communication. Overall, training call-takers for LB calls may assist caller understanding and cooperation during OHCAs.

Description of call handling in emergency medical dispatch centres in Scandinavia: recognition of out-of-hospital cardiac arrests and dispatcher-assisted CPR

BackgroundThe European resuscitation council have highlighted emergency medical dispatch centres as an important key player for early recognition of Out-of-Hospital Cardiac Arrest (OHCA) and in providing dispatcher assisted cardiopulmonary resuscitation (CPR) before arrival of emergency medical services. Early recognition is associated with increased bystander CPR and improved survival rates. The aim of this study is to describe OHCA call handling in emergency medical dispatch centres in Copenhagen (Denmark), Stockholm (Sweden) and Oslo (Norway) with focus on sensitivity of recognition of OHCA, provision of dispatcher-assisted CPR and time intervals when CPR is initiated during the emergency call (NO-CPRprior), and to describe OHCA call handling when CPR is initiated prior to the emergency call (CPRprior).MethodsBaseline data of consecutive OHCA eligible for inclusion starting January 1st 2016 were collected from respective cardiac arrest registries. A template based on the Cardiac Arrest Registry to Enhance Survival definition catalogue was used to extract data from respective cardiac arrest registries and from corresponding audio files from emergency medical dispatch centres. Cases were divided in two groups: NO-CPRprior and CPRprior and data collection continued until 200 cases were collected in the NO-CPRprior-group.ResultsNO-CPRprior OHCA was recognised in 71% of the calls in Copenhagen, 83% in Stockholm, and 96% in Oslo. Abnormal breathing was addressed in 34, 7 and 98% of cases and CPR instructions were started in 50, 60, and 80%, respectively. Median time (mm:ss) to first chest compression was 02:35 (Copenhagen), 03:50 (Stockholm) and 02:58 (Oslo). Assessment of CPR quality was performed in 80, 74, and 74% of the cases. CPRprior comprised 71 cases in Copenhagen, 9 in Stockholm, and 38 in Oslo. Dispatchers still started CPR instructions in 41, 22, and 40% of the calls, respectively and provided quality assessment in 71, 100, and 80% in these respective instances.ConclusionsWe observed variations in OHCA recognition in 71–96% and dispatcher assisted-CPR were provided in 50–80% in NO-CPRprior calls. In cases where CPR was initiated prior to emergency calls, dispatchers were less likely to start CPR instructions but provided quality assessments during instructions.

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

AimFast 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. MethodsML 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. ResultsOf 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. ConclusionML 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.

Multi-centre implementation of an Educational program to improve the Cardiac Arrest diagnostic accuracy of ambulance Telecommunicators and survival outcomes for sudden cardiac arrest victims: the EduCATe study design and methodology

BackgroundSudden cardiac death remains a leading cause of mortality in Canada, resulting in more than 35,000 deaths annually. Most cardiac arrest victims collapse in their own home (85% of the time) and 50% are witnessed by a family member or bystander. Survivors have a quality of life similar to the general population, but the overall survival rate for out-of-hospital cardiac arrest (OHCA) rarely exceeds 8%. Victims are almost four times more likely to survive when receiving bystander CPR, but bystander CPR rates have remained low in Canada over the past decade, not exceeding 15–25% until recently. Telecommunication-assisted CPR instructions have been shown to significantly increase bystander CPR rates, but agonal breathing may be misinterpreted as a sign of life by 9–1-1 callers and telecommunicators, and is responsible for as much as 50% of missed OHCA diagnoses.We sought to improve the ability and speed with which ambulance telecommunicators can recognize OHCA over the phone, initiate timely CPR instructions, and improve survival.MethodsIn this multi-center national study, we will implement and evaluate an educational program developed for ambulance telecommunicators using a multiple baseline interrupted time-series design. We will compare outcomes 12 months before and after the implementation of a 20-min theory-based educational video addressing barriers to recognition of OHCA while in the presence of agonal breathing. Participating Canadian sites demonstrated prior ability to collect standardized data on OHCA. Data will be collected from eligible 9–1-1 recordings, paramedic documentation and hospital medical records. Eligible cases will include suspected or confirmed OHCA of presumed cardiac origin in patients of any age with attempted resuscitation.DiscussionThe ability of telecommunication-assisted CPR instructions to improve bystander CPR and survival rates for OHCA victims is undeniable. The ability of telecommunicators to recognize OHCA over the phone is unequivocally impeded by relative lack of training on agonal breathing, and reluctance to initiate CPR instructions when in doubt. Our pilot data suggests the potential impact of this project will be to increase absolute OHCA recognition and bystander CPR rates by at least 10%, and absolute out-of-hospital cardiac arrest survival by 5% or more.Trial registrationProspectively registered on March 28, 2019 at ClinicalTrials.gov identifier: NCT03894059.

Assessment of a quality improvement programme to improve telephone dispatchers’ accuracy in identifying out-of-hospital cardiac arrest

IntroductionEarly recognition of out-of-hospital cardiac arrest (OHCA) by the medical dispatcher is a prerequisite for an effective chain of survival, leading to rapid dispatch of emergency medical services. AimTo analyse and compare the accuracy of the Emergency Medical Dispatch Centre in identifying OHCA before and after an educational intervention. MethodsA quality-assessment study collecting data from prehospital medical voice logs in Southern Denmark during two periods. Baseline data and post-interventional data were obtained during December, January, and February 2017/2018 and 2019/2020, respectively. We imposed an intervention consisting of a specifically targeted education in quick assessment of OHCA and instructions regarding telephone-assisted-CPR.The primary outcome measure was the dispatcher's ability to recognise OHCA. Secondary outcome measures were time from contact with the caller to the dispatcher formulated essential questions related to the NO-NO-GO algorithm. These questions included an assessment of the patients’ consciousness and respiratory efforts and if both negative, would ideally lead to the dispatcher initiating telephone-assisted-CPR. All data was analysed in accordance with the recommendations and performance goals made by Resuscitation Academy. ResultsBaseline data included 209 calls. Post-interventional data was based on 208 calls.The sensitivity for recognition of OHCA was 82.3% (95% CI: 76.4–87.2%) before and 92.7% (95% CI: 88.2–95.8%) after the intervention (p=0.0014). The median duration of calls before recognition of OHCA was 68 and 56s before and after the intervention (p=0.097). ConclusionAfter the period of intervention, the accuracy of OHCA recognition by dispatchers improved. The median time to identify OHCA or recognise the first compression did not differ significantly. This indicates that continuing education and quality assessment may be beneficial and necessary.

‘I think he’s dead’: A cohort study of the impact of caller declarations of death during the emergency call on bystander CPR

BackgroundIn emergency calls for out-of-hospital cardiac arrest (OHCA), dispatchers are instrumental in the provision of bystander cardiopulmonary resuscitation (CPR) through the recruitment of the caller. We explored the impact of caller perception of patient viability on initial recognition of OHCA by the dispatcher, rates of bystander CPR and early patient survival outcomes. MethodsWe conducted a retrospective cohort study of 422 emergency calls where OHCA was recognised by the dispatcher and resuscitation was attempted by paramedics. We used the call recordings, dispatch data, and electronic patient care records to identify caller statements that the patient was dead, initial versus delayed recognition of OHCA by the dispatcher, caller acceptance to perform CPR, provision of bystander-CPR, prehospital return of spontaneous circulation (ROSC), and ROSC on arrival at the Emergency Department. ResultsInitial recognition of OHCA by the dispatcher was more frequent in cases with a declaration of death by the caller than in cases without (92%, 73/79 vs. 66%, 227/343, p < 0.001). Callers who expressed such a view (19% of cases) were more likely to decline CPR (38% vs. 10%, adjusted odds ratio 4.59, 95% confidence interval 2.49–8.52, p < 0.001). Yet, 15% (12/79) of patients described as non-viable by callers achieved ROSC. ConclusionCaller statements that the patient is dead are helpful for dispatchers to recognise OHCA early, but potentially detrimental when recruiting the caller to perform CPR. There is an opportunity to improve the rate of bystander-CPR and patient outcomes if dispatchers are attentive to caller statements about viability.

Predictors of recognition of out of hospital cardiac arrest by emergency medical services call handlers in England: a mixed methods diagnostic accuracy study

BackgroundThe aim of this study was to identify key indicator symptoms and patient factors associated with correct out of hospital cardiac arrest (OHCA) dispatch allocation. In previous studies, from 3% to 62% of OHCAs are not recognised by Emergency Medical Service call handlers, resulting in delayed arrival at scene.MethodsRetrospective, mixed methods study including all suspected or confirmed OHCA patients transferred to one acute hospital from its associated regional Emergency Medical Service in England from 1/7/2013 to 30/6/2014. Emergency Medical Service and hospital data, including voice recordings of EMS calls, were analysed to identify predictors of recognition of OHCA by call handlers. Logistic regression was used to explore the role of the most frequently occurring (key) indicator symptoms and characteristics in predicting a correct dispatch for patients with OHCA.ResultsA total of 39,136 dispatches were made which resulted in transfer to the hospital within the study period, including 184 patients with OHCA. The use of the term ‘Unconscious’ plus one or more of symptoms ‘Not breathing/Ineffective breathing/Noisy breathing’ occurred in 79.8% of all OHCAs, but only 72.8% of OHCAs were correctly dispatched as such. ‘Not breathing’ was associated with recognition of OHCA by call handlers (Odds Ratio (OR) 3.76). The presence of key indicator symptoms ‘Breathing’ (OR 0.29), ‘Reduced or fluctuating level of consciousness’ (OR 0.24), abnormal pulse/heart rate (OR 0.26) and the characteristic ‘Female patient’ (OR 0.40) were associated with lack of recognition of OHCA by call handlers (p-values < 0.05).ConclusionsThere is a small proportion of calls in which cardiac arrest indicators are described but the call is not dispatched as such. Stricter adherence to dispatch protocols may improve call handlers’ OHCA recognition. The existing dispatch protocol would not be improved by the addition of further terms as this would be at the expense of dispatch specificity.

Effect of Machine Learning on Dispatcher Recognition of Out-of-Hospital Cardiac Arrest During Calls to Emergency Medical Services

Emergency medical dispatchers fail to identify approximately 25% of cases of out-of-hospital cardiac arrest (OHCA), resulting in lost opportunities to save lives by initiating cardiopulmonary resuscitation. To examine how a machine learning model trained to identify OHCA and alert dispatchers during emergency calls affected OHCA recognition and response. This double-masked, 2-group, randomized clinical trial analyzed all calls to emergency number 112 (equivalent to 911) in Denmark. Calls were processed by a machine learning model using speech recognition software. The machine learning model assessed ongoing calls, and calls in which the model identified OHCA were randomized. The trial was performed at Copenhagen Emergency Medical Services, Denmark, between September 1, 2018, and December 31, 2019. Dispatchers in the intervention group were alerted when the machine learning model identified out-of-hospital cardiac arrest, and those in the control group followed normal protocols without alert. The primary end point was the rate of dispatcher recognition of subsequently confirmed OHCA. A total of 169 049 emergency calls were examined, of which the machine learning model identified 5242 as suspected OHCA. Calls were randomized to control (2661 [50.8%]) or intervention (2581 [49.2%]) groups. Of these, 336 (12.6%) and 318 (12.3%), respectively, had confirmed OHCA. The mean (SD) age among of these 654 patients was 70 (16.1) years, and 419 of 627 patients (67.8%) with known gender were men. Dispatchers in the intervention group recognized 296 confirmed OHCA cases (93.1%) with machine learning assistance compared with 304 confirmed OHCA cases (90.5%) using standard protocols without machine learning assistance (P = .15). Machine learning alerts alone had a significantly higher sensitivity than dispatchers without alerts for confirmed OHCA (85.0% vs 77.5%; P < .001) but lower specificity (97.4% vs 99.6%; P < .001) and positive predictive value (17.8% vs 55.8%; P < .001). This randomized clinical trial did not find any significant improvement in dispatchers' ability to recognize cardiac arrest when supported by machine learning even though artificial intelligence did surpass human recognition. ClinicalTrials.gov Identifier: NCT04219306.

Rapid recognition of out-of-hospital cardiac arrest by emergency medical dispatchers is associated with improved survival

Abstract Background Emergency medical dispatchers' (EMD) recognition of out-of-hospital cardiac arrest (OHCA) is an essential part of the first link in the Chain of Survival. However, it is unknown whether the time-to-recognition of OHCA by EMD during an emergency call is associated with survival. Purpose To investigate the effect of time-to-recognition on 30-day survival among patients with recognised OHCA. Methods We linked data on OHCAs occurring in the Capital Region of Denmark from 2016 through 2017 to records of corresponding emergency calls. We defined recognition as dispatching an ambulance with an appropriate priority level and subsequently defined time-to-recognition as the time from start of the call to the time of dispatching the ambulance. Among patients with recognised OHCA, we performed uni- and multivariate logistic regression to investigate the association of time-to-recognition and 30-day survival and reported odds ratios (OR) with 95% confidence intervals (CI). Results Among 2,382 patients with OHCA, 94.2% were recognised, in which median age was 73.6 years, 61.6% were males and median time-to-recognition was 0.8 minutes (interquartile range 0.7 minutes). Patients for whom time-to-recognition was up to (but not including) one minute had more than three-fold higher probability of surviving 30 days (15.5%) compared to patients for whom time-to-recognition was three or more minutes (4.5%) (Figure 1). Time-to-recognition was significantly associated with 30-day survival: OR 0.75 per minute (95% CI 0.62–0.91, P&amp;lt;0.005), and results were similar in the adjusted analysis: OR 0.72 per minute (95% CI 0.58–0.90, P&amp;lt;0.005). Conclusion Rapid recognition of OHCA by EMD resulted in improved survival rate of patients. This was particularly evident when time-to-recognition was three or more minutes. Figure 1 Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): Hjerteforeningen

Phone CPR and barriers affecting life-saving seconds

ABSTRACT Objectives: Phone cardiopulmonary resuscitation (CPR) increases the rate of bystander CPR to patients suffering from an out-of-hospital cardiac arrest (OHCA). This study analyzed the effectiveness of the ALERT protocol for instructing laypeople in bystander CPR. Methods: All 244 phone CPR calls to the emergency medical communication center in Leuven during a one-year period were analyzed. Time to recognition of OHCA and to start of phone CPR was evaluated and compared to the recommendations set up by the American Heart Association (AHA). Barriers that delayed or prevented phone CPR were identified. Results: Time to recognition of OHCA and to start of chest compressions was below the benchmark set by the AHA in 37% and 32% of the calls, respectively. The most common barriers that delayed the start of phone CPR were irrelevant questioning by the dispatcher and difficulties moving the patient. In 52 calls, phone CPR was not initiated. In 54% of these calls, this was due to the bystander’s inability to move the patient to the floor or to perform CPR. In 44% the bystander’s lack of motivation hindered the start of CPR. Conclusions: The ALERT protocol plays a key role in bystander-CPR. Despite the increased CPR rates and reduced time to start chest compressions since its implementation, further improvement is required. Based on the barriers detected, intensive training of dispatchers is an important next step. Furthermore, adding an alternative track to the protocol for immovable patients might be worth considering.