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

Observational Study of Words Used by Emergency Callers and Their Impact on the Recognition of an Out-Of-Hospital Cardiopulmonary Arrest by the Medical Dispatcher

BACKGROUND

Survival of victims of out-of-hospital cardiopulmonary arrest (CA) is related to the time and quality of cardiopulmonary resuscitation (CPR).1 Considering that most CAs occur outside the hospital setting, it is evident that the early recognition of this condition is the cornerstone of the chain of survival. Current literature on the theme is still scarce.

OBJECTIVES

To analyze categories and subcategories of words and expressions spontaneously used by laypeople during emergency calls for CA and their relationship with the recognition of this event by the medical dispatcher.

METHODS

This was a cross-sectional study, with analysis of calls made by laypeople due to suspected CA to emergency medical services in Brazil. The expressions used were classified into six categories and 31 subcategories. Univariate and multivariate models were used to assess the strength of the association of categories and subcategories of words and expressions with the presumption of CA. The level of significance was set at 5%. Results: A total of 284 calls were included, and after applying the inclusion criteria, 101 calls were analyzed. The categories "cardiovascular/perfusion status" (p=0.019) and "general status" (p=0.011) were identified as confounding factors for the recognition of CA, and the subcategories "breathing difficulty" (p=0.023), "verbal unresponsiveness" (p=0.034), "facial coloration" (p=0.068) and "feeling unwell" (p=0.013) were also considered as confounders. On the other hand, the subcategories "not breathing" (p=0.010); "spatial position" (p=0.016), and "cardiovascular emergencies" (p=0.045) were identified as facilitating factors for the recognition of CA.

CONCLUSION

Categories and subcategories of expressions used by emergency callers for CA can influence the timely recognition of this condition by the medical dispatcher.

Current trends in the management of out of hospital cardiac arrest (OHCA)

Sudden cardiac arrest remains a relevant problem with a significant number of deaths worldwide. Although survival rates have more than tripled over the last 20 years (4% in 2001 vs. 14% in 2020), survival rates with good neurological outcomes remain persistently low, representing a major socioeconomic problem. Every minute of delay from patient collapse to start cardiopulmonary resuscitation (CPR) and early defibrillation reduces the chance of survival by approximately 10-12%. Therefore, the time to treatment is a crucial factor in the prognosis of patients with out-of-hospital cardiac arrest (OHCA). Research teams working in the pre-hospital setting are therefore looking for ways to improve the transmission of information from the site of an emergency event and to make it easier for emergency medical dispatch centres (EMDC) to recognise life-threatening conditions with minimal deviation. For emergency unit procedures already at the scene of the event, methods are being sought to efficiently and temporarily replace a non-functioning cardiopulmonary system. In the case of traumatic cardiac arrest (TCA), the focus is mainly on effective affecting non-compressible haemorrhage.

Performance of the Medical Priority Dispatch System® in Identifying Patients Requiring Chest Compressions at Overdose Prevention Services: A Retrospective Cohort Study

BACKGROUND AND AIMS

The Medical Priority Dispatch System (MPDS)® is used to triage 9-1-1 calls according to acuity, with certain coding receiving telecommunicator cardiopulmonary resuscitation (T-CPR) for suspected out-of-hospital cardiac arrest (OHCA). However, this may be challenging for those with drug poisoning emergencies, who may resemble OHCA. We sought to examine the performance of the system to correctly identify cases requiring T-CPR, specifically at overdose prevention services (OPS).

METHODS

This retrospective cohort study included patients attended by the provincial emergency medical system (EMS) (May 1, 2019-January 31, 2023). We calculated the diagnostic performance of MPDS® assessment of whether the case required T-CPR instructions against the gold standard of whether the patient was found pulseless on EMS clinician arrival. We compared performance among subgroups, specifically OPS vs other locations and drug poisoning-classified cases vs other case classifications.

RESULTS

Comparing OPS to other locations, the sensitivity of MPDS® was similar (66.7% vs 62.4%, p = 0.4), with lower specificity (87.3% vs 98.1%, p < 0.01) and positive predictive value (0.3% vs 35.7%, p < 0.01) and higher negative predictive value (99.9% vs 99.4%, p < 0.01). The negative likelihood ratio of MPDS® was 0.381 at OPS locations, compared with 0.383 at other locations, while the positive likelihood ratio was 5.24, compared with 32.36. In patients with drug poisoning emergencies, compared with other 9-1-1 events, MPDS® had higher sensitivity (83.6% vs 60.6%, p < 0.01) but lower specificity (77.6% vs 98.9%, p < 0.01) and positive predictive value (10.5% vs 48.5%, p < 0.01), and similar negative predictive value (99.33% vs 99.35%, p = 0.03). The negative likelihood ratio of MPDS® was 0.212 in drug poisoning emergencies compared with 0.398 for all other presentations, and the positive likelihood ratio was 3.73 compared with 57.88.

DISCUSSION AND CONCLUSIONS

The ability of MPDS® to correctly identify patients needing telecommunicator cardiopulmonary resuscitation instructions differed between OPS settings and other locations, frequently recommending T-CPR for patients not suffering OHCA at an OPS. Different strategies developed in collaboration with people who use substances are required to better tailor dispatch instructions prior to EMS arrival to avoid delays in life-saving interventions.

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

Objectives

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.

Methods

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.

Results

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.

Conclusion

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.

Dispatcher-assisted BLS for lay bystanders: A pilot study comparing video streaming via smart glasses and telephone instructions

OBJECTIVE

To determine whether dispatcher assistance via smart glasses improves bystander basic life support (BLS) performance compared with standard telephone assistance in a simulated out-of-hospital cardiac arrest (OHCA) scenario.

METHODS

Pilot study in which 28 lay people randomly assigned to a smart glasses-video assistance (SG-VA) intervention group or a smartphone-audio assistance (SP-AA) control group received dispatcher guidance from a dispatcher to provide BLS in an OHCA simulation. SG-VA rescuers received assistance via a video call with smart glasses (Vuzix, Blade) connected to a wireless network, while SP-AA rescuers received instructions over a smartphone with the speaker function activated. BLS protocol steps, quality of chest compressions, and performance times were compared.

RESULTS

Nine of the 14 SG-VA rescuers correctly completed the BLS protocol compared with none of the SP-AA rescuers (p = 0.01). A significantly higher number of SG-VA rescuers successfully opened the airway (13 vs. 5, p = 0.002), checked breathing (13 vs. 8, p = 0.03), correctly positioned the automatic external defibrillator pads (14 vs.6, p = 0.001), and warned bystanders to stay clear before delivering the shock (12 vs. 0, p < 0.001). No significant differences were observed for performance times or chest compression quality. The mean compression rate was 104 compressions per minute in the SG-VA group and 98 compressions per minute in the SP-AA group (p = 0.46); mean depth of compression was 4.5 cm and 4.4 cm (p = 0.49), respectively.

CONCLUSIONS

Smart glasses could significantly improve dispatcher-assisted bystander performance in an OHCA event. Their potential in real-life situations should be evaluated.

When the machine is wrong. Characteristics of true and false predictions of Out-of-Hospital Cardiac arrests in emergency calls using a machine-learning model

BACKGROUND

A machine-learning model trained to recognize emergency calls regarding Out-of-Hospital Cardiac Arrest (OHCA) was tested in clinical practice at Copenhagen Emergency Medical Services (EMS) from September 2018 to December 2019. We aimed to investigate emergency call characteristics where the machine-learning model failed to recognize OHCA or misinterpreted a call as being OHCA.

METHODS

All emergency calls were linked to the dispatch database and verified OHCAs were identified by linkage to the Danish Cardiac Arrest Registry. Calls with either false negative or false positive predictions of OHCA were evaluated by trained auditors. Descriptive analyses were performed with absolute numbers and percentages reported.

RESULTS

The machine-learning model processed 169,236 calls to Copenhagen EMS and suspected 5,811 (3.4%) of the calls as OHCA, resulting in 84.5% sensitivity and 97.1% specificity. Among OHCAs not recognised by machine-learning model, a condition completely different from OHCA was presented by caller in 31% of the cases. In 28% of unrecognised calls, patient was reported breathing normally, and language barriers were identified in 23% of the cases. Among falsely suspected OHCA, the patient was reported unconscious in 28% of the cases, and in 13% of the false positive cases the machine-learning model interpreted calls regarding dead patients with irreversible signs of death as OHCA.

CONCLUSION

Continuous optimization of the language model is needed to improve the prediction of OHCA and thereby improve sensitivity and specificity of the machine-learning model on recognising OHCA in emergency telephone calls.

Real-time video communication between ambulance paramedic and scene - a simulation-based study

Introduction

Telemedicine has been widely used in various medical settings including in Emergency Medical Services (EMS). The goal of this study was to assess the possible roles of real-time video communication between paramedics and bystanders at scenes of emergency, in the analysis and treatment of patients.

Methods

44 experienced paramedics participated in a simulation. Participants communicated with the experimenter presenting video clips showing patients that simulated three emergency scenarios: trauma, an unresponsive patient with cardiac arrest, and an opiate overdose. The simulation sessions were conducted through Zoom™, recorded, and then analyzed to document participants’ questions, requests, instructions, and their timings during each scenario.

Results

The trauma scenario was assessed most promptly, with instructions to handle the bleeding provided by all paramedics. In the unresponsive patient with cardiac arrest scenario, most of the participants achieved a correct initial diagnosis, and in the opiate overdose scenario over half of paramedics sought visual clinical clues for the differential diagnoses of loss of consciousness and their causes. Additional results show the type of assessment, treatment and diagnosis participants provided in each scenario, and their confidence about situation.

Conclusions

The findings show that direct video communication between paramedic and scene may facilitate correct diagnosis, provision of instructions for treatment, and early preparation of medications or equipment. These may decrease time to correct diagnosis and lifesaving treatment and impact patient morbidity and mortality. Moreover, the findings highlight the difference between incidents with higher visual clarity, such as trauma, and conditions that require an extended diagnosis to reveal, such as unresponsive patients. This may also increase the paramedics’ mental preparedness for what is expected at the scene.

Emergency medical dispatchers' experiences of managing emergency calls: a qualitative interview study

OBJECTIVES

To explore the emergency medical dispatchers (EMDs) experiences of managing emergency medical calls.

DESIGN

A qualitative interview study with an inductive approach. EMDs were interviewed individually using a semistructured interview guide. The verbatim transcripts were analysed using a qualitative content analysis.

SETTING

EMDs, without a professional background as registered nurses, were recruited from emergency medical communication centers (EMCCs) within Sweden.

PARTICIPANTS

To achieve a varied description of EMDs' experiences, participants were included from several EMCCs nationally, using a convenience sampling. Interviews were performed up until saturation of data, resulting in 13 EMDs from 7 EMCCs being interviewed. All the EMDs were women, ranging in age from 28 to 61 years (mean 42 years), and had worked in emergency medical dispatching between 1 and 13.5 years (mean 6.5 years).

RESULTS

The analysis revealed the main category-to attentively manage a multifaceted, interactive task-made up of three categories: utilize creativity to gather information, continuously process and assess complex information, and engage in the professional role. The content of each category was reflected in several subcategories further described and illustrated with representative quotes.

CONCLUSIONS

Managing emergency medical calls was experienced by EMDs to attentively manage a multifaceted interactive task. Core parts were described as: the ability to utilize creativity to gather information, continuously process and asses complex information, and engage in the professional role. Our results could be beneficial for emergency care managers when designing training programmes and organising EMD work and the EMD work environment, including further development of dispatch protocols and implementation of regular feedback sessions. Moreover, the results indicate that aspects such as self-awareness and emotional challenges encountered during EMD work could be important matters to discuss during staff evaluations.

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

Aim

We 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.

Methods

This 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.

Results

A 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.

Conclusions

The 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.

Dispatcher-assisted CPR can it do harm as well as good?

Outcomes for patients with out-of-hospital cardiac arrest can be improved by bystander cardiopulmonary resuscitation (CPR). Dispatcher-assisted CPR increases both the likelihood of CPR being performed, and the chance of survival for the arrested patient. Due to the urgency of the situation, CPR may be advised in patients who are subsequently found not to be in cardiac arrest. Ng and colleagues look at whether bystander CPR causes harm in this group of patients.

Discrimination between the presence and absence of spontaneous circulation using smartphone seismocardiography: A preliminary investigation

BACKGROUND

Seismocardiography measures the vibrations produced by the beating heart using an accelerometer sensor placed on the chest. We evaluated the ability of smartphone seismocardiography to distinguish between the presence and absence of spontaneous circulation.

METHODS

Seismocardiography signals were obtained using a smartphone placed on the sternum in a convenience sample of 60 adult patients (30 comatose patients with spontaneous circulation and 30 deceased patients). The maximum, minimum, and standard deviation (SD) of acceleration values for head-to-foot, right-to-left, and dorsoventral axes and the three axis-root mean square (RMS) of the acceleration signals were calculated. Blinded observers (n = 156) were each asked to determine the presence or absence of spontaneous circulation based on seismocardiography video clips for each of the 60 patients.

RESULTS

The seismocardiography revealed periodic large positive peaks in the patients with spontaneous circulation, which were absent in the patients without spontaneous circulation. For each of the four output measurements (three independent axes plus the three-axis RMS), the acceleration maxima and SD were significantly higher and the minima significantly lower in the patients with spontaneous circulation than in those without spontaneous circulation (all P < 0.001 except the minimum of three axis-RMS results [P = 0.009]). The observers accurately identified the seismocardiography signals from patients without spontaneous circulation, with a sensitivity of 97.6% (95% confidence interval, 97.0%-98.2%) and a specificity of 98.4% (95% confidence interval, 97.8%-99.0%).

CONCLUSIONS

In conclusion, blinded observers accurately distinguished between seismocardiography signals from patients with and without spontaneous circulation.

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?

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

BACKGROUND

The 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-CPR_prior), and to describe OHCA call handling when CPR is initiated prior to the emergency call (CPR_prior).

METHODS

Baseline 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-CPR_prior and CPR_prior and data collection continued until 200 cases were collected in the NO-CPR_prior-group.

RESULTS

NO-CPR_prior 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. CPR_prior 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.

CONCLUSIONS

We observed variations in OHCA recognition in 71-96% and dispatcher assisted-CPR were provided in 50-80% in NO-CPR_prior 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.

Temporal trends in neurologically intact survival after paediatric bystander-witnessed out-of-hospital cardiac arrest: A nationwide population-based observational study

AIM

Trends in neurologically intact survival after paediatric out-of-hospital cardiac arrest (OHCA) remain unclear. In the present study, we aimed to determine trends in 1-month neurologically intact survival after paediatric OHCA over time.

METHODS

We reviewed the data of 5461 children (aged < 18 years) who experienced bystander-witnessed OHCA and were included in the nationwide Japanese registry from 2005 to 2017. Patients were divided into three groups according to study period: 2005-2010, 2011-2015, and 2016-2017. We analysed the trends in 1-month neurologically intact survival rates over time.

RESULTS

The risk-adjusted odds of 1-month neurologically intact survival (odds ratio, 1.86; 95% confidence interval, 1.41-2.44) were significantly improved by 2016-2017 compared with baseline. Similar improvements in 1-month neurologically intact survival rates were observed with both standard bystander cardiopulmonary resuscitation (CPR) with rescue breaths and chest compression-only bystander CPR (P for trend < 0.05 and < 0.001, respectively). In the subgroup analyses by aetiology, the 1-month neurologically intact survival rate in patients with OHCA of non-traumatic origin significantly increased from 11.8%-15.1% to 19.7% (P for trend < 0.001) but not in those with OHCA of traumatic origin (from 4.9% to 3.4% to 4.1%; P for trend = 0.29).

CONCLUSION

The 1-month neurologically intact survival rate significantly increased from 2005 to 2017 in Japanese children with bystander-witnessed OHCA, regardless of bystander CPR type; This increase was noted in patients with OHCA of non-traumatic origin but not in those with OHCA of traumatic origin.

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.

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.

Unrecognized Out of Hospital Cardiac Arrest Symptoms during Thailand’s Emergency Medical Services

BACKGROUND: To improve survival rate, the main focus of adult cardiac arrest management includes rapid recognition, prompt administration of cardiopulmonary resuscitation (CPR), defibrillation for shockable rhythms, post-return of spontaneous circulation (ROSC) care, and identification and treatment of underlying causes. This study aimed to identify the determinants of unrecognized cardiac arrest, and to study the recognition rate of out-of-hospital cardiac arrest (OHCA) by emergency medical services call handlers. METHODS: We included OHCA patients who were transferred to hospital via Emergency Medical Services (EMS) of Srinagarind hospital, Khon Kaen, Thailand, from 1st January 2020 to 31st December 2020. The primary outcome was to identify symptoms that lead to an unrecognized cardiac arrest by the EMS call handlers. Secondary outcomes were to identify the recognition rate of OHCA by emergency medical services call handlers, and assess the outcome of CPR performed on OHCA patients. RESULTS: There were a total of 58 patients in the present study, 26 patients (44.8%) and 32 patients (55.2%) belonged to the unrecognized and recognized cardiac arrest groups, respectively. The most common symptoms that led to unrecognized cardiac arrest were a state of unconsciousness (46.2%), major trauma (15.4%), and seizure-like activity (11.5%). The rate of ROSC was higher in the unrecognized cardiac arrest group (34.6% vs. 15.6%) but the rate of survival to hospital discharge was higher in the recognized cardiac arrest group (6.3% vs 0%). CONCLUSIONS: Falling unconscious is the most common symptom of unrecognized OHCA cases seen by EMS in Thailand. Basic life support, especially an immediate assessment of a patient’s respiratory status should be taught in health programs in school or through public service channels.

Improving the Appropriateness of Advanced Life Support Teams' Dispatch: A Before-After Study

BACKGROUND AND IMPORTANCE

The dispatch of Advanced Life Support (ALS) teams in Emergency Medical Services (EMS) is still a hardly studied aspect of prehospital emergency logistics. In 2015, the dispatch algorithm of Emilia Est Emergency Operation Centre (EE-EOC) was implemented and the dispatch of ALS teams was changed from primary to secondary based on triage of dispatched vehicles for high-priority interventions when teams with Immediate Life Support (ILS) skills were dispatched.

OBJECTIVES

This study aimed to evaluate the effects on the appropriateness of ALS teams' intervention and their employment time, and to compare sensitivity and specificity of the algorithm implementation.

DESIGN

This was a retrospective before-after observational study.

SETTINGS AND PARTICIPANTS

Primary dispatches managed by EE-EOC involving ambulances and/or ALS teams were included. Two groups were created on the basis of the years of intervention (2013-2014 versus 2017-2018).

INTERVENTION

A switch from primary to secondary dispatch of ALS teams in case of high-priority dispatches managed by ILS teams was implemented.

OUTCOMES

Appropriateness of ALS team intervention, total task time of ALS vehicles, and sensitivity and specificity of the algorithm were reviewed.

RESULTS

The study included 242,501 emergency calls that generated 56,567 red code dispatches. The new algorithm significantly increased global sensitivity and specificity of the system in terms of recognition of potential need of ALS intervention and the specificity of primary ALS dispatch. The appropriateness of ALS intervention was significantly increased; total tasking time per day for ALS and the number of critical dispatches without ALS available were reduced.

CONCLUSION

The revision of the dispatch criteria and the extension of the two-tiered dispatch for ALS teams significantly increased the appropriateness of ALS intervention and reduced both the global tasking time and the number of high-priority dispatches without ALS teams available.

Knowledge and attitudes to cardiopulmonary resuscitation (CPR)- a cross-sectional population survey in Sweden

Aim of the study

Rates of bystander CPR are increasing, yet mortality after out-of-hospital cardiac arrest (OHCA) remains high. The aim of this survey was to explore public knowledge and attitudes to CPR. Our hypotheses were that recent CPR training (< 5 years) would be associated with a high-quality response in a case vignette of OHCA with agonal breathing, and associated with an interest to become a smartphone app responder in suspected OHCA.

Methods

Data were collected through a web survey. Respondents (≥18 years) in Skåne County, Sweden were members of a panel created by a market research company. Data were weighted with respect to gender, age, municipalities and level of education to increase generalisability to the general population.

Results

A total of 1060 eligible answers were analysed. Seventy-six percent of non-healthcare professionals (n = 912) had participated in a CPR course at some time in life, 58 percent during the previous five years. The recommended CPR algorithm was known by 57 percent, whereas knowledge of the location of the nearest automated external defibrillator (AED) in a home environment was poor. Recent CPR training (< 5 years) did not favour high-quality response in a case vignette of OHCA with agonal breathing, but was one predictor of wanting to become a smartphone app responder.

Conclusion

This study highlights possible areas of improvement in CPR training, which might improve OHCA identification and facilitate knowledge retention. The potential to recruit smartphone app responders seems promising in certain groups.

Cardiac arrhythmias in the emergency settings of acute coronary syndrome and revascularization: an European Heart Rhythm Association (EHRA) consensus document, endorsed by the European Association of Percutaneous Cardiovascular Interventions (EAPCI), and European Acute Cardiovascular Care Association (ACCA)

Despite major therapeutic advances over the last decades, complex supraventricular and ventricular arrhythmias (VAs), particularly in the emergency setting or during revascularization for acute myocardial infarction (AMI), remain an important clinical problem. Although the incidence of VAs has declined in the hospital phase of acute coronary syndromes (ACS), mainly due to prompt revascularization and optimal medical therapy, still up to 6% patients with ACS develop ventricular tachycardia and/or ventricular fibrillation within the first hours of ACS symptoms. Despite sustained VAs being perceived predictors of worse in-hospital outcomes, specific associations between the type of VAs, arrhythmia timing, applied treatment strategies and long-term prognosis in AMI are vague. Atrial fibrillation (AF) is the most common supraventricular tachyarrhythmia that may be asymptomatic and/or may be associated with rapid haemodynamic deterioration requiring immediate treatment. It is estimated that over 20% AMI patients may have a history of AF, whereas the new-onset arrhythmia may occur in 5% patients with ST elevation myocardial infarction. Importantly, patients who were treated with primary percutaneous coronary intervention for AMI and developed AF have higher rates of adverse events and mortality compared with subjects free of arrhythmia. The scope of this position document is to cover the clinical implications and pharmacological/non-pharmacological management of arrhythmias in emergency presentations and during revascularization. Current evidence for clinical relevance of specific types of VAs complicating AMI in relation to arrhythmia timing has been discussed.

Impact of dispatcher assisted CPR on ROSC rates: A National Cohort Study

INTRODUCTION

Out of hospital cardiac arrest (OHCA) is a leading cause of mortality. Bystander CPR is associated with increased OHCA survival rates. Dispatcher assisted CPR (DA-CPR) increases rates of bystander CPR, shockable rhythm prevalence, and improves ROSC rates. The aim of this article was to quantify and qualify DA-CPR (acceptance/rejection), ROSC, shockable rhythms, and associations between factors as seen in MDA, Israel, during 2018.

METHODS

All 2018 OHCA incidents in Israel's national EMS database were studied retrospectively. We identified rates and reasons for DA-CPR acceptance or rejection. Reasons DA-CPR was rejected/non-feasible by caller were categorized into 5 groups. ROSC was the primary outcome. We created two study groups: 1) No DA-CPR (n = 542). 2) DA-CPR & team CPR (n = 1768).

RESULTS

DA-CPR was accepted by caller 76.5% of incidents. In group 1, ROSC rates were significantly lower compared to patients in group 2 (12.4% vs. 21.3% p < .001). Group 1 had 12.4% shockable rhythms vs. 17.1% in group 2 (DA-CPR and team CPR). Of the total 369 shockable cases, 42.3% (156) achieved ROSC, in the non-shockable rhythms only 14.8% achieved ROSC.

CONCLUSIONS

OHCA victims receiving dispatcher assisted bystander CPR have higher rates of ROSC and more prevalence of shockable rhythms. MDA dispatchers offer DA-CPR and it is accepted 76.5% of the time. MDA patients receiving DA-CPR had higher ROSC rates and more shockable rhythms. MDA's age demographic is high, possibly affecting ROSC and shockable rhythm rates.

Delays in recognition of the need for telephone-assisted CPR due to caller descriptions of chief complaint

BACKGROUND

The objective of this study was to test if caller descriptions of chief complaint delays emergency medical dispatchers' (EMDs) recognition of the need for telephone-assisted CPR (T-CPR).

METHODS

We conducted an analysis of N = 433 cardiac arrest calls from six large call centers in the United States. Calls were abstracted for initial chief complaint description: caller reports (1) correct medical condition (CMC); (2) incorrect medical condition (IMC), or (3) signs/symptoms only (SS), as well the time interval between call pickup and recognition of the need for T-CPR. In addition, we abstracted if EMDs asked questions related to the caller's chief complaint (rather than, or before), asking about patients' consciousness and breathing status.

RESULTS

The majority of cardiac arrest calls (60%) were reported as SS. Median time to recognition of the need for T-CPR was 64 s for SS chief complaints, 47 s for CMC chief complaints, and 100 s for IMC chief complaints. EMDs pursued chief complaint descriptions for 9% of the calls with SS chief complaints, 41% of the calls with IMC chief complaints, and 19% of the calls with CMC chief complaints. Median time to recognition of the need for CPR for calls in which the chief complaint description was pursued was 166 s compared to 62 s for calls in which the chief complaint description was not pursued.

CONCLUSION

Caller chief complaint description affects the time to recognition of the need for T-CPR.

CLINICAL TRIAL REGISTRATION

http://www.clinicaltrials.gov Trial # NCT01972087.

Emergency medical dispatch services across Pan-Asian countries: a web-based survey

Background

Dispatch services (DS’s) form an integral part of emergency medical service (EMS) systems. The role of a dispatcher has also evolved into a crucial link in patient care delivery, particularly in dispatcher assisted cardio-pulmonary resuscitation (DACPR) during out-of-hospital cardiac arrest (OHCA). Yet, there has been a paucity of research into the emerging area of dispatch science in Asia. This paper compares the characteristics of DS’s, and state of implementation of DACPR within the Pan-Asian Resuscitation Outcomes (PAROS) network.

Methods

A cross-sectional descriptive survey addressing population characteristics, DS structures and levels of service, state of DACPR implementation (including protocols and quality improvement programs) among PAROS DS’s.

Results

9 DS’s responded, representing a total of 23 dispatch centres from 9 countries that serve over 80 million people. Most PAROS DS’s operate a tiered dispatch response, have implemented medical oversight, and tend to be staffed by dispatchers with a predominantly medical background. Almost all PAROS DS’s have begun tracking key EMS indicators. 77.8% (n = 7) of PAROS DS’s have introduced DACPR. Of the DS’s that have rolled out DACPR, 71.4% (n = 5) provided instructions in over one language. All DS’s that implemented DACPR and provided feedback to dispatchers offered feedback on missed OHCA recognition. The majority of DS’s (83.3%; n = 5) that offered DACPR and provided feedback to dispatchers also implemented corrective feedback, while 66.7% (n = 4) offered positive feedback. Compression-only CPR was the standard instruction for PAROS DS’s. OHCA recognition sensitivity varied widely in PAROS DS’s, ranging from 32.6% (95% CI: 29.9–35.5%) to 79.2% (95% CI: 72.9–84.4%). Median time to first compression ranged from 120 s to 220 s.

Conclusions

We found notable variations in characteristics and state of DACPR implementation between PAROS DS’s. These findings will lay the groundwork for future DS and DACPR studies in the PAROS network.

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.

Dispatcher-assisted cardiopulmonary resuscitation for traumatic patients with out-of-hospital cardiac arrest

Background

Resuscitation efforts for traumatic patients with out-of-hospital cardiac arrest (OHCA) are not always futile. Dispatcher-assisted cardiopulmonary resuscitation (DA-CPR) during emergency calls could increase the rate of bystander cardiopulmonary resuscitation (CPR) and thus may enhance survival and neurologic outcomes of non-traumatic OHCA. This study aimed to examine the effectiveness of DA-CPR for traumatic OHCA.

Methods

A retrospective cohort study was conducted using an Utstein-style population database with data from January 1, 2014, to December 31, 2016, in Tainan City, Taiwan. Voice recordings of emergency calls were retrospectively retrieved and reviewed. The primary outcome was an achievement of sustained (≥2 h) return of spontaneous circulation (ROSC); the secondary outcomes were prehospital ROSC, ever ROSC, survival at discharge and favourable neurologic status at discharge. Statistical significance was set at a p-value of less than 0.05.

Results

A total of 4526 OHCA cases were enrolled. Traumatic OHCA cases (n = 560, 12.4%), compared to medical OHCA cases (n = 3966, 87.6%), were less likely to have bystander CPR (10.7% vs. 31.7%, p < 0.001) and initially shockable rhythms (7.1% vs. 12.5%, p < 0.001). Regarding DA-CPR performance, traumatic OHCA cases were less likely to have dispatcher recognition of cardiac arrest (6.3% vs. 42.0%, p < 0.001), dispatcher initiation of bystander CPR (5.4% vs. 37.6%, p < 0.001), or any dispatcher delivery of CPR instructions (2.7% vs. 20.3%, p < 0.001). Stepwise logistic regression analysis showed that witnessed cardiac arrests (aOR 1.70, 95% CI 1.10–2.62; p = 0.017) and transportation to level 1 centers (aOR 1.99, 95% CI 1.27–3.13; p = 0.003) were significantly associated with achievement of sustained ROSC in traumatic OHCA cases, while DA-CPR-related variables were not (All p > 0.05).

Conclusions

DA-CPR was not associated with better outcomes for traumatic OHCA in achieving a sustained ROSC. The DA-CPR program for traumatic OHCAs needs further studies to validate its effectiveness and practicability, especially in the communities where rules for the termination of resuscitation in prehospital settings do not exist.

Interventional studies performed in emergency medical communication centres: systematic review

We aimed to both quantitatively and qualitatively describe interventional research performed in emergency medical communication centres. We conducted a systematic review of articles published in MEDLINE, Cochrane Central Register of Controlled Trials and Web of Science. Studies evaluating therapeutic or organizational interventions directed by call centres in the context of emergencies were included. Studies of call centre management for general practice or nonhealthcare agencies were excluded. We assessed general characteristics and methodological information for each study. Quality was evaluated by the Cochrane Risk of Bias tool or the Newcastle-Ottawa Scale. Among 3896 articles screened, we retained 59; 41 studies were randomized controlled trials (69%) and 18 (31%) were before-after studies; 41 (69%) took place in a single centre. For 33 (56%), 22 (37%) and 4 (7%) studies, the models used were simulation training, patient-based or experimental, respectively. The main topic was cardiac arrests (n = 45, 76%), with outcome measures of cardiopulmonary resuscitation quality and dispatch assistance. Among randomized controlled trials, risk of bias was unclear or high for selective reporting for 37 (90%) studies, low for blinding of outcomes for 34 (83%) and low for incomplete outcomes for 31 (76%). Regarding before-after studies, quality was high in 9 (50%) studies. Few interventional studies have been performed in call centres. Studies mainly involved simulation and focussed on cardiac arrest. The quality of studies needs improvement to allow for a better recognition and understanding of emergency medical call control.

Machine learning as a supportive tool to recognize cardiac arrest in emergency calls

BACKGROUND

Emergency medical dispatchers fail to identify approximately 25% of cases of out of hospital cardiac arrest, thus lose the opportunity to provide the caller instructions in cardiopulmonary resuscitation. We examined whether a machine learning framework could recognize out-of-hospital cardiac arrest from audio files of calls to the emergency medical dispatch center.

METHODS

For all incidents responded to by Emergency Medical Dispatch Center Copenhagen in 2014, the associated call was retrieved. A machine learning framework was trained to recognize cardiac arrest from the recorded calls. Sensitivity, specificity, and positive predictive value for recognizing out-of-hospital cardiac arrest were calculated. The performance of the machine learning framework was compared to the actual recognition and time-to-recognition of cardiac arrest by medical dispatchers.

RESULTS

We examined 108,607 emergency calls, of which 918 (0.8%) were out-of-hospital cardiac arrest calls eligible for analysis. Compared with medical dispatchers, the machine learning framework had a significantly higher sensitivity (72.5% vs. 84.1%, p < 0.001) with lower specificity (98.8% vs. 97.3%, p < 0.001). The machine learning framework had a lower positive predictive value than dispatchers (20.9% vs. 33.0%, p < 0.001). Time-to-recognition was significantly shorter for the machine learning framework compared to the dispatchers (median 44 seconds vs. 54 s, p < 0.001).

CONCLUSIONS

A machine learning framework performed better than emergency medical dispatchers for identifying out-of-hospital cardiac arrest in emergency phone calls. Machine learning may play an important role as a decision support tool for emergency medical dispatchers.

Emergency medical dispatch recognition, clinical intervention and outcome of patients in traumatic cardiac arrest from major trauma: an observational study

OBJECTIVES

The aim of this study is to describe the demographics of reported traumatic cardiac arrest (TCA) victims, prehospital resuscitation and survival to hospital rate.

SETTING

Helicopter Emergency Medical Service (HEMS) in south-east England, covering a resident population of 4.5 million and a transient population of up to 8 million people.

PARTICIPANTS

Patients reported on the initial 999 call to be in suspected traumatic cardiac arrest between 1 July 2016 and 31 December 2016 within the trust's geographical region were identified. The inclusion criteria were all cases of reported TCA on receipt of the initial emergency call. Patients were subsequently excluded if a medical cause of cardiac arrest was suspected.

OUTCOME MEASURES

Patient records were analysed for actual presence of cardiac arrest, prehospital resuscitation procedures undertaken and for survival to hospital rates.

RESULTS

112 patients were reported to be in TCA on receipt of the 999/112 call. 51 (46%) were found not to be in TCA on arrival of emergency medical services. Of the 'not in TCA cohort', 34 (67%) received at least one advanced prehospital medical intervention (defined as emergency anaesthesia, thoracostomy, blood product transfusion or resuscitative thoracotomy). Of the 61 patients in actual TCA, 10 (16%) achieved return-of-spontaneous circulation. In 45 (88%) patients, the HEMS team escorted the patient to hospital.

CONCLUSION

A significant proportion of patients reported to be in TCA on receipt of the emergency call are not in actual cardiac arrest but are critically unwell requiring advanced prehospital medical intervention. Early activation of an enhanced care team to a reported TCA call allows appropriate advanced resuscitation. Further research is warranted to determine which interventions contribute to improved TCA survival.

Witnessed out-of-hospital cardiac arrest- effects of emergency dispatch recognition

BACKGROUND

Survival from an out-of-hospital cardiac arrest (OHCA) depends on the sequence of interventions in "the chain of survival". If OHCA is recognized in the emergency medical communication centre (EMCC), the proper emergency medical service (EMS) should be dispatched and cardiopulmonary resuscitation (CPR) instructions should be given to a bystander. The study aimed to examine the impact of OHCA recognition in the EMCC on survival rates and the main elements of the chain of survival.

METHODS

Data from the Helsinki University Hospital's registry of OHCA patients between 1997 and 2013 were studied. Altogether, 2054 EMCC-handled and bystander-witnessed OHCA proven events of cardiac origin were analysed.

RESULTS

In 80.5% of the victims, two EMS units were correctly dispatched and the OHCA was classified as recognized. Achieved return of spontaneous circulation (ROSC) and survival to hospital discharge were 49% and 23%, respectively, if cardiac arrest was recognized by the EMCC and 40% and 16% when it was not (P = 0.003 and 0.002). Dispatchers gave CPR instructions in 60% of the recognized OHCA cases. Bystander-performed CPR increased over time and was given in 58% of the recognized OHCAs and also in 17% of the unrecognized events. EMS delays were shorter if OHCA was recognized as opposed to unrecognized (8 min with an IQR 6.5-10 min vs. 9 min with an IQR 6.5-11 min; P = 0.001).

CONCLUSIONS

Recognition of OHCA by the EMCC was significantly associated with an increased rate of bystander-performed CPR, reduced EMS response time, and increased OHCA patient ROSC and survival rates.

Revisiting traumatic cardiac arrest: should CPR be initiated?

OBJECTIVES

Traumatic cardiac arrest (TCA) represents a unique problem, and poses difficult challenges in the care of trauma patients. Although the literature has suggested that attempted resuscitation from TCA in trauma is futile and consumptive of medical and human resources, studies have recently demonstrated that the outcome of TCA is comparable cardiac arrest secondary to non-traumatic events. The objective of this study was to determine the incidence, predictors, and outcomes following TCA.

METHODS

We retrospectively reviewed 124 adult patients with TCA over a period of 5 years (July 2010 to June 2014). Cardiopulmonary resuscitation (CPR) occurred either in the field, en route, or in the emergency department at our Level I Trauma Center. Patients' demographics, clinical data, CPR-related variables, and outcomes were extracted from both the electronic and paper medical records.

RESULTS

The median age of the group was 37 (IQR 38), and the median ISS was 37 (IQR 50). The most common cardiac rhythm observed was pulseless electrical activity (PEA, 55%). While 31.4% of patients achieved a return of spontaneous circulation (ROSC), only 7.3% survived with a complete neurological recovery (CNR). In blunt injury patients, the mortality rate after CPR was higher in motor-vehicle-related injuries than falls from heights (93.1 vs 72.3%, OR 5.06, 95% CI 0.95-27.0, p < 0.05). In penetrating injuries, the mortality rate after CPR was higher in patients with trauma to the torsos than those suffering injuries to the head, neck, face, and extremities combined (100 vs 81.3%, OR 0.049, 95% CI 0.0024-1.008, p < 0.001). Two variables predicted failure of CPR were prolonged time interval hospital transport (OR 0.42, 95% CI 0.22-0.80, p < 0.01) and high injury severity score (OR 0.97, 95% CI 0.94-1.00, p < 0.05). However, CPR duration/location (out-of-hospital or in-hospital), head injury, and day/night shifts in ED were not associated with the above outcome. When comparing age groups, the mortality was significantly higher in patients < 65 years than those ≥ 65 years (OR 0.2619, 95% CI 0.09485-0.9703, p = 0.0182).

CONCLUSION

Although survival after CPR among trauma patients continues to have dismal outcomes, advanced cardiac life support should be initiated regardless of the initial EKG rhythm. Ultimately, both a rapid response time and transport to the ED are of the utmost importance to survival.

The linguistic and interactional factors impacting recognition and dispatch in emergency calls for out-of-hospital cardiac arrest: a mixed-method linguistic analysis study protocol

INTRODUCTION

Emergency telephone calls placed by bystanders are crucial to the recognition of out-of-hospital cardiac arrest (OHCA), fast ambulance dispatch and initiation of early basic life support. Clear and efficient communication between caller and call-taker is essential to this time-critical emergency, yet few studies have investigated the impact that linguistic factors may have on the nature of the interaction and the resulting trajectory of the call. This research aims to provide a better understanding of communication factors impacting on the accuracy and timeliness of ambulance dispatch.

METHODS AND ANALYSIS

A dataset of OHCA calls and their corresponding metadata will be analysed from an interdisciplinary perspective, combining linguistic analysis and health services research. The calls will be transcribed and coded for linguistic and interactional variables and then used to answer a series of research questions about the recognition of OHCA and the delivery of basic life-support instructions to bystanders. Linguistic analysis of calls will provide a deeper understanding of the interactional dynamics between caller and call-taker which may affect recognition and dispatch for OHCA. Findings from this research will translate into recommendations for modifications of the protocols for ambulance dispatch and provide directions for further research.

ETHICS AND DISSEMINATION

The study has been approved by the Curtin University Human Research Ethics Committee (HR128/2013) and the St John Ambulance Western Australia Research Advisory Group. Findings will be published in peer-reviewed journals and communicated to key audiences, including ambulance dispatch professionals.

Neurologic Recovery After Cardiac Arrest: a Multifaceted Puzzle Requiring Comprehensive Coordinated Care

OPINION STATEMENT

Surviving cardiac arrest (CA) requires a longitudinal approach with multiple levels of responsibility, including fostering a culture of action by increasing public awareness and training, optimization of resuscitation measures including frequent updates of guidelines and their timely implementation into practice, and optimization of post-CA care. This clearly goes beyond resuscitation and targeted temperature management. Brain-directed physiologic goals should dictate the post-CA management, as accumulating evidence suggests that the degree of hypoxic brain injury is the main determinant of survival, regardless of the etiology of arrest. Early assessment of the need for further hemodynamic and electrophysiologic cardiac interventions, adjusting ventilator settings to avoid hyperoxia/hypoxia while targeting high-normal to mildly elevated PaCO₂, maintaining mean arterial blood pressures >65 mmHg, evaluating for and treating seizures, maintaining euglycemia, and aggressively pursuing normothermia are key steps in reducing the bioenergetic failure that underlies secondary brain injury. Accurate neuroprognostication requires a multimodal approach with standardized assessments accounting for confounders while recognizing the importance of a delayed prognostication when there is any uncertainty regarding outcome. The concept of a highly specialized post-CA team with expertise in the management of post-CA syndrome (mindful of the brain-directed physiologic goals during the early post-resuscitation phase), TTM, and neuroprognostication, guiding the comprehensive care to the CA survivor, is likely cost-effective and should be explored by institutions that frequently care for these patients. Finally, providing tailored rehabilitation care with systematic reassessment of the needs and overall goals is key for increasing independence and improving quality-of-life in survivors, thereby also alleviating the burden on families. Emerging evidence from multicenter collaborations advances the field of resuscitation at an incredible pace, challenging previously well-established paradigms. There is no more room for "conventional wisdom" in saving the survivors of cardiac arrest.