Out-of-hospital cardiac arrest phone detection: Those who most need chest compressions are the most difficult to recognize

Optimising telecommunicator recognition of out-of-hospital cardiac arrest: A scoping review

Aim

To summarize existing literature and identify knowledge gaps regarding barriers and enablers of telecommunicators' recognition of out-of-hospital cardiac arrest (OHCA).

Methods

This scoping review was undertaken by an International Liaison Committee on Resuscitation (ILCOR) Basic Life Support scoping review team and guided by the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for scoping reviews (PRISMA-ScR). Studies were eligible for inclusion if they were peer-reviewed and explored barriers and enablers of telecommunicator recognition of OHCA. We searched Ovid MEDLINE® and Embase and included articles from database inception till June 18th, 2024.

Results

We screened 9,244 studies and included 62 eligible studies on telecommunicator recognition of OHCA. The studies ranged in methodology. The majority were observational studies of emergency calls. The barriers most frequently described to OHCA recognition were breathing status and agonal breathing. The most frequently tested enabler for recognition was a variety of dispatch protocols focusing on breathing assessment. Only one randomized controlled trial (RCT) was identified, which found no difference in OHCA recognition with the addition of machine learning alerting telecommunicators in suspected OHCA cases.

Conclusion

Most studies were observational, assessed barriers to recognition of OHCA and compared different dispatch protocols. Only one RCT was identified. Randomized trials should be conducted to inform how to improve telecommunicator recognition of OHCA, including recognition of pediatric OHCAs and assessment of dispatch protocols.

Trends in survival from out-of-hospital cardiac arrest with a shockable rhythm and its association with bystander resuscitation: a retrospective study

OBJECTIVE

Over 300 000 cases of out-of-hospital cardiac arrests (OHCAs) occur each year in the USA and Europe. Despite decades of investment and research, survival remains disappointingly low. We report the trends in survival after a ventricular fibrillation/pulseless ventricular tachycardia OHCA, over a 13-year period, in a French urban region, and describe the simultaneous evolution of the rescue system.

METHODS

We investigated four 18-month periods between 2005 and 2018. The first period was considered baseline and included patients from the randomised controlled trial 'DEFI 2005'. The three following periods were based on the Paris Sudden Death Expertise Center Registry (France). Inclusion criteria were non-traumatic cardiac arrests treated with at least one external electric shock with an automated external defibrillator from the basic life support team and resuscitated by a physician-staffed ALS team. Primary outcome was survival at hospital discharge with a good neurological outcome.

RESULTS

Of 21 781 patients under consideration, 3476 (16%) met the inclusion criteria. Over all study periods, survival at hospital discharge increased from 12% in 2005 to 25% in 2018 (p<0.001), and return of spontaneous circulation at hospital admission increased from 43% to 58% (p=0.004).Lay-rescuer cardiopulmonary resuscitation (CPR) and telephone CPR (T-CPR) rates increased significantly, but public defibrillator use remained limited.

CONCLUSION

In a two-tiered rescue system, survival from OHCA at hospital discharge doubled over a 13-year study period. Concomitantly, the system implemented an OHCA patient registry and increased T-CPR frequency, despite a consistently low rate of public defibrillator use.

Barriers to the Initiation of Telecommunicator-CPR during 9-1-1 Out-of-Hospital Cardiac Arrest Calls: A Qualitative Study

INTRODUCTION

Fewer than 10% of individuals who suffer out-of-hospital cardiac arrest (OHCA) survive with good neurologic function. Bystander CPR more than doubles the chance of survival, and telecommunicator-CPR (T-CPR) during a 9-1-1 call substantially improves the frequency of bystander CPR.

OBJECTIVE

We examined the barriers to initiation of T-CPR.

METHODS

We analyzed the 9-1-1 call audio from 65 EMS-treated OHCAs from a single US 9-1-1 dispatch center. We initially conducted a thematic analysis aimed at identifying barriers to the initiation of T-CPR. We then conducted a conversation analysis that examined the interactions between telecommunicators and bystanders during the recognition phase (i.e., consciousness and normal breathing).

RESULTS

We identified six process themes related to barriers, including incomplete or delayed recognition assessment, delayed repositioning, communication gaps, caller emotional distress, nonessential questions and assessments, and caller refusal, hesitation, or inability to act. We identified three suboptimal outcomes related to arrest recognition and delivery of chest compressions, which are missed OHCA identification, delayed OHCA identification and treatment, and compression instructions not provided following OHCA identification. A primary theme observed during missed OHCA calls was incomplete or delayed recognition assessment and included failure to recognize descriptors indicative of agonal breathing (e.g., "snoring", "slow") or to confirm that breathing was effective in an unconscious victim.

CONCLUSIONS

We observed that modifiable barriers identified during 9-1-1 calls where OHCA was missed, or treatment was delayed, were often related to incomplete or delayed recognition assessment. Repositioning delays were a common barrier to the initiation of chest compressions.

Assessment of telecommunicator cardiopulmonary resuscitation performance during out-of-hospital cardiac arrest using a standardized tool for audio review

OBJECTIVE

Telecommunicator cardiopulmonary resuscitation (T-CPR) is a critical component of optimized out-of-hospital cardiac arrest (OHCA) care. We assessed a pilot tool to capture American Heart Association (AHA) T-CPR measures and T-CPR coaching by telecommunicators using audio review.

METHODS

Using a pilot tool, we conducted a retrospective review of 911 call audio from 65 emergency medical services-treated out-of-hospital cardiac arrest (OHCA) patients. Data collection included events (e.g., OHCA recognition), time intervals, and coaching quality measures. We calculated summary statistics for all performance and quality measures.

RESULTS

Among 65 cases, the patients' mean age was 64.7 years (SD: 14.6) and 17 (26.2%) were women. Telecommunicator recognition occurred in 72% of cases (47/65). Among 18 non-recognized cases, reviewers determined 12 (66%) were not recognizable based on characteristics of the call. Median time-to-recognition was 76 seconds (n = 40; IQR:39-138), while median time-to-first-instructed-compression was 198 seconds (n = 26; IQR:149-233). In 36 cases where coaching was needed, coaching on compression-depth occurred in 27 (75%); -rate in 28 (78%); and chest recoil in 10 (28%) instances. In 30 cases where repositioning was needed, instruction to position the patient's body flat occurred in 18 (60%) instances, on-back in 22 (73%) instances, and on-ground in 22 (73%) instances.

CONCLUSIONS

Successful collection of data to calculate AHA T-CPR measures using a pilot tool for audio review revealed performance near AHA benchmarks, although coaching instructions did not occur in many instances. Application of this standardized tool may aid in T-CPR quality review.

The “unclear problem” category: an analysis of its patient and dispatch characteristics and its trend over time

Background

An effective emergency medical dispatch process is vital to provide appropriate prehospital care to patients. It increases patient safety and ensures the sustainable use of medical resources. Although Copenhagen has a sophisticated emergency medical services (EMS) system with a significant focus on public welfare, more than 10% of emergency cases are still being categorized as an "unclear problem category" (UPC) and are thus not categorized as "symptom-specific". Therefore, the objective of this research is to gain a better understanding of the patient and dispatch characteristics of emergency cases categorized as "unclear".

Methods

This register-based study based on medical emergency cases data describes patient and dispatch characteristics of emergency cases categorized as “unclear” through the use of numbers and proportions. Moreover, these cases were compared to non UPC cases. Use of UPC was stratified by month to determine the impact of alerting medical dispatchers to reduce its use.

Results

From 296,398 included cases UPC accounted for 11.4% of the cases. The median age of those triaged with the UPC was 66 years vs 58 years for individuals triaged with other symptom-specific categories.

Moreover, after having been triaged with the UPC, 9,661 (34.7%) of the dispatched EMS vehicles ended up being cancelled. Sensitizing medical dispatchers about the use of the UPC likely contributed to the decreased use of the UPC over time.

Conclusion

The UPC has different dispatch characteristics than the symptom-specific categories, with potential negative effects on the medical dispatch process. Moreover, the median age of individuals triaged with the UPC is higher than those triaged with symptom-specific categories. Nonetheless, the use of the UPC decreased throughout the study period after the medical dispatchers were alerted about the implications of its use.

Can Video Assistance Improve the Quality of Pediatric Dispatcher-Assisted Cardiopulmonary Resuscitation?

OBJECTIVES

This study aimed to evaluate the impact of adding video conferencing to dispatcher-assisted telephone cardiopulmonary resuscitation (CPR) on pediatric bystander CPR quality.

METHODS

We conducted a prospective, randomized manikin study among volunteers with no CPR training and among bachelor nurses. Volunteers randomly received either video or audio assistance in a 6-minute pediatric cardiac arrest scenario. The main outcome measures were the results of the Cardiff Test to assess compression and ventilation performance.

RESULTS

Of 255 candidates assessed for eligibility, 120 subjects were randomly assigned to 1 of the 4 following groups: untrained telephone-guided (U-T; n = 30) or video-guided (U-V; n = 30) groups and trained telephone-guided (T-T; n = 30) or video-guided (T-V; n = 30) groups. Cardiac arrest was appropriately identified in 86.7% of the U-T group and in 100% in the other groups (P = 0.0061). Hand positioning was adequate in 76.7% of T-T, 80% of T-V, and 60% of U-V, as compared with 23.4% of the U-T group (P = 0.0001). Fewer volunteers managed to deliver 2 rescue breaths/cycle (P = 0.0001) in the U-T (16.7%) compared with the U-V (43.3%), the T-T (56.7%), and the T-V groups (60%).Subjects in the video groups had a lower fraction of minute to ventilate as compared with the telephone groups (P = 0.0005).

CONCLUSIONS

In dispatcher-instructed children CPR simulation, using video assistance improves cardiac arrest recognition and CPR quality with more appropriate chest compression technique and ventilation delivering. The long interruptions in chest compression combined with the mixed success rate to deliver proper ventilation raise question about ventilation quality and its effectiveness.

Features of Emergency Medical System calls that facilitate or inhibit Emergency Medical Dispatcher recognition that a patient is in, or at imminent risk of, cardiac arrest: A systematic mixed studies review

Aim

To identify and appraise evidence relating to the features of an Emergency Medicine System call interaction that enable, or inhibit, an Emergency Medical Dispatcher’s recognition that a patient is in out-of-hospital cardiac arrest, or at imminent risk of out-of-hospital cardiac arrest.

Methods

All study designs were eligible for inclusion. Data sources included Medline, BNI, CINAHL, EMBASE, PubMed, Cochrane Database of Systematic Reviews, AMED and OpenGrey. Stakeholder resources were screened and experts in resuscitation were asked to review the studies identified. Studies were appraised using the Mixed Methods Appraisal Tool. Synthesis was completed using a segregated mixed research synthesis approach.

Results

Thirty-two studies were included in the review. Three main themes were identified: Key features of the Emergency Medical Service call interaction; Managing the Emergency Medical Service call; Emotional distress.

Conclusion

A dominant finding is the difficulty in recognising abnormal/agonal breathing during the Emergency Medical Service call. The interaction between the caller and the Emergency Medical Dispatcher is critical in the recognition of patients who suffer an out-of-hospital cardiac arrest. Emergency Medical Dispatchers adapt their approach to the Emergency Medical Service call, and regular training for Emergency Medical Dispatchers is recommended to optimise out-of-hospital cardiac arrest recognition. Further research is required with a focus on the Emergency Medical Service call interaction of patients who are alive at the time of the Emergency Medical Service call and who later deteriorate into OHCA.

PROSPERO registration: CRD42019155458.

Assessment of breathing in cardiac arrest: a randomised controlled trial of three teaching methods among laypersons

Background

The aim of this trial was to compare a video- and a simulation-based teaching method to the conventional lecture-based method, hypothesizing that the video- and simulation-based teaching methods would lead to improved recognition of breathing patterns during cardiac arrest.

Methods

In this Danish, investigator-initiated, stratified, randomised controlled trial, adult laypersons (university students, military conscripts and elderly retirees) participating in European Resuscitation Council Basic Life Support courses were randomised to receive teaching on how to recognise breathing patterns using a lecture- (usual practice), a video-, or a simulation-based teaching method. The primary outcome was recognition of breathing patterns in nine videos of actors simulating normal breathing, no breathing, and agonal breathing (three of each). We analysed outcomes using logistic regression models and present results as odds ratios (ORs) with 95% confidence intervals (CIs) and P-values from likelihood ratio tests.

Results

One hundred fifty-three participants were included in the analyses from February 2, 2018 through May 21, 2019 and recognition of breathing patterns was statistically significantly different between the teaching methods (P = 0.013). Compared to lecture-based teaching (83% correct answers), both video- (90% correct answers; OR 1.77, 95% CI: 1.19–2.64) and simulation-based teaching (88% correct answers; OR 1.48; 95% CI: 1.01–2.17) led to significantly more correct answers. Video-based teaching was not statistically significantly different compared to simulation-based teaching (OR 1.20; 95% CI: 0.78–1.83).

Conclusion

Video- and simulation-based teaching methods led to improved recognition of breathing patterns among laypersons participating in adult Basic Life Support courses compared to the conventional lecture-based teaching method.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12873-021-00513-4.

Development of a Performance Assessment Scale for Simulated Dispatcher-Assisted Cardiopulmonary Resuscitation (Telephone-CPR): A Multi-Center Randomized Simulation-Based Clinical Trial

INTRODUCTION

Dispatchers should be trained to interrogate bystanders with strict protocols to elicit information focused on recognizing cardiac arrest and should provide telephone cardiopulmonary resuscitation (CPR) instructions in all cases of suspected cardiac arrest. While an objective assessment of training outcomes is needed, there is no performance assessment scale for simulated dispatcher-assisted CPR.

STUDY OBJECTIVE

The aim of the study was to create a valid and reliable performance assessment scale for simulated dispatcher-assisted CPR.

METHODS

In this prospective, randomized, controlled, multi-centric simulation-based trial (registration number TCTR20210130002), the scale was developed according to the European Resuscitation Council (ERC) and American Heart Association (AHA) Guidelines 2015 and revised by experts. The performance of 48 dispatchers' telephone-CPR and of 48 bystanders carrying out CPR on a manikin was assessed by two independent evaluators using the scale and using a SkillReporter (PC) software to provide CPR objective performance. Continuous variables were described as mean (SD) and categorical variables as numbers and percentage (%). Comparative analysis between two groups used a Student t-test or a non-parametric test of Mann-Whitney. The internal structure of the scale was evaluated, including internal consistency using α Cronbach coefficient, and reproducibility using intraclass correlation coefficient (ICC) and linear correlation coefficient (R2) calculation.

RESULTS

The scale included three different parts: two sections for dispatchers' (32 items) and bystanders' CPR performance (15 items) assessment, and a third part recording times. There was excellent internal consistency (α Cronbach coefficient = 0.77) and reproducibility (ICC = 0.93; R² = 0.86). For dispatchers' performance assessment, α Cronbach coefficient = 0.76; ICC = 0.91; R2 = 0.84. For bystanders' performance assessment, α Cronbach coefficient = 0.75; ICC = 0.93; R2 = 0.87. Reproducibility was excellent for nine items, good for 19 items, and moderate for 19 items. No item had poor reproducibility. There was no significant difference between dispatch doctors' and medical dispatch assistants' performances (33.0 [SD = 4.7] versus 32.3 [SD = 3.2] out of 52, respectively; P = .70) or between trained and untrained bystanders to follow the instructions (14.3 [SD = 2.0] versus 13.9 [SD = 1.8], respectively; P = .64). Objective performance (%) was significantly higher for trained bystanders than for untrained bystanders (67.4 [SD = 14.5] versus 50.6 [SD = 19.3], respectively; P = .03).

CONCLUSION

The scale was valid and reliable to assess performance for simulated dispatcher-assisted CPR. To the authors' knowledge, no other valid performance tool currently exists. It could be used in simulated telephone-CPR training programs to improve performance.

[Basic life support]

The European Resuscitation Council has produced these basic life support guidelines, which are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. The topics covered include cardiac arrest recognition, alerting emergency services, chest compressions, rescue breaths, automated external defibrillation (AED), cardiopulmonary resuscitation (CPR) quality measurement, new technologies, safety, and foreign body airway obstruction.

Activation of citizen responders to out-of-hospital cardiac arrest

PURPOSE OF REVIEW

To discuss different approaches to citizen responder activation and possible future solutions for improved citizen engagement in out-of-hospital cardiac arrest (OHCA) resuscitation.

RECENT FINDINGS

Activating volunteer citizens to OHCA has the potential to improve OHCA survival by increasing bystander cardiopulmonary resuscitation (CPR) and early defibrillation. Accordingly, citizen responder systems have become widespread in numerous countries despite very limited evidence of their effect on survival or cost-effectiveness. To date, only one randomized trial has investigated the effect of citizen responder activation for which the outcome was bystander CPR. Recent publications are of observational nature with high risk of bias. A scoping review published in 2020 provided an overview of available citizen responder systems and their differences in who, when, and how to activate volunteer citizens. These differences are further discussed in this review.

SUMMARY

Implementation of citizen responder programs holds the potential to improve bystander intervention in OHCA, with advancing technology offering new improvement possibilities. Information on how to best activate citizen responders as well as the effect on survival following OHCA is warranted to evaluate the cost-effectiveness of citizen responder programs.

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

European Resuscitation Council Guidelines 2021: Systems saving lives

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

European Resuscitation Council Guidelines 2021: Basic Life Support

The European Resuscitation Council has produced these basic life support guidelines, which are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. The topics covered include cardiac arrest recognition, alerting emergency services, chest compressions, rescue breaths, automated external defibrillation (AED), CPR quality measurement, new technologies, safety, and foreign body airway obstruction.

Diagnosis of out-of-hospital cardiac arrest by emergency medical dispatch: A diagnostic systematic review

INTRODUCTION

Cardiac arrest is a time-sensitive condition requiring urgent intervention. Prompt and accurate recognition of cardiac arrest by emergency medical dispatchers at the time of the emergency call is a critical early step in cardiac arrest management allowing for initiation of dispatcher-assisted bystander CPR and appropriate and timely emergency response. The overall accuracy of dispatchers in recognizing cardiac arrest is not known. It is also not known if there are specific call characteristics that impact the ability to recognize cardiac arrest.

METHODS

We performed a systematic review to examine dispatcher recognition of cardiac arrest as well as to identify call characteristics that may affect their ability to recognize cardiac arrest at the time of emergency call. We searched electronic databases for terms related to "emergency medical dispatcher", "cardiac arrest", and "diagnosis", among others, with a focus on studies that allowed for calculating diagnostic test characteristics (e.g. sensitivity and specificity). The review was consistent with Grading of Recommendations, Assessment, Development and Evaluation (GRADE) method for evidence evaluation.

RESULTS

We screened 2520 article titles, resulting in 47 studies included in this review. There was significant heterogeneity between studies with a high risk of bias in 18 of the 47 which precluded performing meta-analyses. The reported sensitivities for cardiac arrest recognition ranged from 0.46 to 0.98 whereas specificities ranged from 0.32 to 1.00. There were no obvious differences in diagnostic accuracy between different dispatching criteria/algorithms or with the level of education of dispatchers.

CONCLUSION

The sensitivity and specificity of cardiac arrest recognition at the time of emergency call varied across dispatch centres and did not appear to differ by dispatch algorithm/criteria used or education of the dispatcher, although comparisons were hampered by heterogeneity across studies. Future efforts should focus on ways to improve sensitivity of cardiac arrest recognition to optimize patient care and ensure appropriate and timely resource utilization.

Adult Basic Life Support: International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations

This 2020 International Consensus on Cardiopulmonary Resuscitation (CPR) and Emergency Cardiovascular Care Science With Treatment Recommendations on basic life support summarizes evidence evaluations performed for 20 topics that were prioritized by the Basic Life Support Task Force of the International Liaison Committee on Resuscitation. The evidence reviews include 16 systematic reviews, 3 scoping reviews, and 1 evidence update. Per agreement within the International Liaison Committee on Resuscitation, new or revised treatment recommendations were only made after a systematic review.

Systematic reviews were performed for the following topics: dispatch diagnosis of cardiac arrest, use of a firm surface for CPR, sequence for starting CPR (compressions-airway-breaths versus airway-breaths-compressions), CPR before calling for help, duration of CPR cycles, hand position during compressions, rhythm check timing, feedback for CPR quality, alternative techniques, public access automated external defibrillator programs, analysis of rhythm during chest compressions, CPR before defibrillation, removal of foreign-body airway obstruction, resuscitation care for suspected opioid-associated emergencies, drowning, and harm from CPR to victims not in cardiac arrest.

The topics that resulted in the most extensive task force discussions included CPR during transport, CPR before calling for help, resuscitation care for suspected opioid-associated emergencies, feedback for CPR quality, and analysis of rhythm during chest compressions. After discussion of the scoping reviews and the evidence update, the task force prioritized several topics for new systematic reviews.

Adult Basic Life Support: 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations

This2020 International Consensus on Cardiopulmonary Resuscitation(CPR)and Emergency Cardiovascular Care Science With Treatment Recommendationson basic life support summarizes evidence evaluations performed for 22 topics that were prioritized by the Basic Life Support Task Force of the International Liaison Committee on Resuscitation. The evidence reviews include 16 systematic reviews, 5 scoping reviews, and 1 evidence update. Per agreement within the International Liaison Committee on Resuscitation, new or revised treatment recommendations were only made after a systematic review.

Systematic reviews were performed for the following topics: dispatch diagnosis of cardiac arrest, use of a firm surface for CPR, sequence for starting CPR (compressions-airway-breaths versus airway-breaths-compressions), CPR before calling for help, duration of CPR cycles, hand position during compressions, rhythm check timing, feedback for CPR quality, alternative techniques, public access automated external defibrillator programs, analysis of rhythm during chest compressions, CPR before defibrillation, removal of foreign-body airway obstruction, resuscitation care for suspected opioid-associated emergencies, drowning, and harm from CPR to victims not in cardiac arrest.

The topics that resulted in the most extensive task force discussions included CPR during transport, CPR before calling for help, resuscitation care for suspected opioid-associated emergencies, feedback for CPR quality, and analysis of rhythm during chest compressions. After discussion of the scoping reviews and the evidence update, the task force prioritized several topics for new systematic reviews.

Mobile Smartphone Technology Is Associated With Out-of-hospital Cardiac Arrest Survival Improvement: The First Year "Greater Paris Fire Brigade" Experience

BACKGROUND

Out-of-hospital cardiac arrest (OHCA) remains associated with very high mortality. Accelerating the initiation of efficient cardiopulmonary resuscitation (CPR) is widely perceived as key to improving outcomes. The main goal was to determine whether identification and activation of nearby first responders through a smartphone application named Staying Alive (SA) can improve survival following OHCA in a large urban area (Paris).

METHODS

We conducted a nonrandomized cohort study of all adults with OHCA managed by the Greater Paris Fire Brigade during 2018, irrespective of mobile application usage. We compared survival data in cases where SA did or did not lead to the activation of nearby first responders. During dispatch, calls for OHCA were managed with or without SA. The intervention group included all cases where nearby first responders were successfully identified by SA and actively contributed to CPR. The control group included all other cases. We compared survival at hospital discharge between the intervention and control groups. We analyzed patient data, CPR metrics, and first responders' characteristics.

RESULTS

Approximately 4,107 OHCA cases were recorded in 2018. Among those, 320 patients were in the control group, whereas 46 patients, in the intervention group, received first responder-initiated CPR. After adjustment for confounders, survival at hospital discharge was significantly improved for patients in the intervention group (35% vs. 16%, adjusted odds ratio = 5.9, 95% confidence interval = 2.1 to 16.5, p < 0.001). All CPR metrics were improved in the intervention group.

CONCLUSIONS

We report that mobile smartphone technology was associated with OHCA survival through accelerated initiation of efficient CPR by first responders in a large urban area.

Hypoxemia Index Associated with Prehospital Intubation in COVID-19 Patients

BACKGROUND

There exists a need for prognostic tools for the early identification of COVID-19 patients requiring prehospital intubation. Here we investigated the association between a prehospital Hypoxemia Index (HI) and the need for intubation among COVID-19 patients in the prehospital setting.

METHODS

We retrospectively analyzed COVID-19 patients initially cared for by a Paris Fire Brigade advanced life support (ALS) team in the prehospital setting between 8th March and 18th April of 2020. We assessed the association between HI and prehospital intubation using receiver operating characteristic (ROC) curve analysis and logistic regression model analysis after propensity score matching. Results are expressed as odds ratio (OR) and 95% confidence interval (CI).

RESULTS

We analyzed 300 consecutive COVID-19 patients (166 males (55%); mean age, 64 ± 18 years). Among these patients, 45 (15%) were deceased on the scene, 34 (11%) had an active care restriction, and 18 (6%) were intubated in the prehospital setting. The mean HI value was 3.4 ± 1.9. HI was significantly associated with prehospital intubation (OR, 0.24; 95% CI: 0.12-0.41, p < 10^-3) with a corresponding area under curve (AUC) of 0.91 (95% CI: 0.85-0.98). HI significantly differed between patients with and without prehospital intubation (1.0 ± 1.0 vs. 3.6 ± 1.8, respectively; p < 10^-3). ROC curve analysis defined the optimal HI threshold as 1.3. Bivariate analysis revealed that HI <1.3 was significantly, positively associated with prehospital intubation (OR, 38.38; 95% CI: 11.57-146.54; p < 10^-3). Multivariate logistic regression analysis demonstrated that prehospital intubation was significantly associated with HI (adjusted odds ratio (ORa), 0.20; 95% CI: 0.06-0.45; p < 10^-3) and HI <3 (ORa, 51.08; 95% CI: 7.83-645.06; p < 10^-3). After adjustment for confounders, the ORa between HI <1.3 and prehospital intubation was 3.6 (95% CI: 1.95-5.08; p < 10^-3).

CONCLUSION

An HI of <1.3 was associated with a 3-fold increase in prehospital intubation among COVID-19 patients. HI may be a useful tool to facilitate decision-making regarding prehospital intubation of COVID-19 patients initially cared for by a Paris Fire Brigade ALS team. Further prospective studies are needed to confirm these preliminary results.

Prehospital management of acute respiratory distress in suspected COVID-19 patients

BACKGROUND

In December 2019, coronavirus disease (COVID-19) emerged in China and became a world-wide pandemic in March 2020. Emergency services and intensive care units (ICUs) were faced with a novel disease with unknown clinical characteristics and presentations. Acute respiratory distress (ARD) was often the chief complaint for an EMS call. This retrospective study evaluated prehospital ARD management and identified factors associated with the need of prehospital mechanical ventilation (PMV) for suspected COVID-19 patients.

METHODS

We included 256 consecutive patients with suspected COVID-19-related ARD that received prehospital care from a Paris Fire Brigade BLS or ALS team, from March 08 to April 18, 2020. We performed multivariate regression to identify factors predisposing to PMV.

RESULTS

Of 256 patients (mean age 60 ± 18 years; 82 (32%) males), 77 (30%) had previous hypertension, 31 (12%) were obese, and 49 (19%) had diabetes mellitus. Nineteen patients (7%) required PMV. Logistic regression observed that a low initial pulse oximetry was associated with prehospital PMV (ORa = 0.86, 95%CI: 0.73-0.92; p = 0.004).

CONCLUSIONS

This study showed that pulse oximetry might be a valuable marker for rapidly determining suspected COVID-19-patients requiring prehospital mechanical ventilation. Nevertheless, the impact of prehospital mechanical ventilation on COVID-19 patients outcome require further investigations.

Simplified instructional phrasing in dispatcher-assisted cardiopulmonary resuscitation - when 'less is more'

INTRODUCTION

In our national emergency dispatch centre, the standard protocol for dispatcher-assisted cardiopulmonary resuscitation (DACPR) in out-of-hospital cardiac arrests (OHCAs) involves the instruction "push 100 times a minute 5 cm deep". As part of quality improvement, the instruction was simplified to "push hard and fast".

METHODS

We analysed all dispatcher-diagnosed OHCAs over four months in 2018: January to February ("push 100 times a minute 5 cm deep") and August to September ("push hard and fast"). We also performed secondary per-protocol analysis based on the protocol used: (a) standard (n = 48); (b) simplified (n = 227); and (c) own words (n = 231).

RESULTS

506 cases were included, 282 in the 'before' group and 224 in the 'after' group. Adherence to the protocol was 15.2% in the 'before' phase and 72.8% in the 'after' phase (p < 0.001). The mean time between instruction and first compression for the 'before' and 'after' groups was 34.36 seconds and 26.83 seconds, respectively (p < 0.001). Time to first compression was 238.62 seconds and 218.83 seconds in the 'before' and 'after' groups, respectively (p = 0.016). In the per-protocol analysis, the interval between instruction and compression was 37.19 seconds, 28.31 seconds and 32.40 seconds in the standard protocol, simplified protocol and 'own words' groups, respectively (p = 0.005). The need for paraphrasing was 60.4% in the standard protocol group and 81.5% in the simplified group (p < 0.001).

CONCLUSION

Simplified instructions were associated with a shorter interval between instruction and first compression. Efforts should be directed at simplifying DACPR instructions.

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

Introduction:

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

Methods:

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

Results:

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

Conclusion:

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

Improving emergency call detection of Out-of-Hospital Cardiac Arrests in the Greater Paris area: Efficiency of a global system with a new method of detection

AIM

The detection of cardiac arrests by dispatchers allows telephone-assisted cardiopulmonary resuscitation (t-CPR) and improves Out-of-Hospital Cardiac Arrest (OHCA) survival. To enhance the OHCA detection rate, in 2012, the Paris Fire Brigade dispatch center created an original technique called "Hand On Belly" (HoB). The new algorithm that resulted has become a central point in a broader program for dispatch-assisted cardiac arrests.

METHODS

This is a repeated cross-sectional study with retrospective data of four 15-day call samples recorded from 2012 to 2018. We included all calls from OHCAs cared for by Basic Life Support (BLS) teams and excluded calls where the dispatcher was not in contact directly with a witness. The primary endpoint was the successful detection of an OHCA by the dispatcher; the secondary endpoints were successful t-CPR and measurements of the different time intervals related to the call. Logistic regressions were performed to assess parameters associated with detecting OHCAs and initiating t-CPR.

RESULTS

From 2012 to 2018, among the detectable OCHAs, the proportion correctly identified increased from 54% to 93%; the rate of t-CPRs from 51% to 84%. OHCA detection and t-CPR initiation were both associated with HoB breathing assessments (adjustedOR: 89, 95%CI: 31-299, and adjustedOR: 11.2, 95%CI: 1.4-149, respectively). Over the study period, the times to answering calls and the time to sending BLS teams were shorter than those recommended by international guidelines; however, the times to OHCA recognition and starting t-CPR delivery were longer.

CONCLUSIONS

The HoB effectively facilitated OHCA detection in our system, which has achieved very high performance levels.

Maternal out-of-hospital cardiac arrest: A retrospective observational study

AIM

Out-of-hospital cardiac arrests (OHCAs) in pregnant women are rare events. In this study, we aimed to describe a cohort of pregnant women who experienced OHCAs in a large urban area, and received treatment by the prehospital teams in a two-tiered emergency response system.

METHODS

This retrospective study included pregnant women over 18 years of age who experienced OHCAs. The analysed variables included maternal age, gestational age, variables specific to the rescue system, number of shocks delivered by an automatic external defibrillator, and rates of maternal and neonatal survival.

RESULTS

Over the 5-year study period, 19,515 OHCAs occurred, 16 of which were in pregnant women. These 16 patients had a median age of 31 years [interquartile range (IQR): 28-35] and a median gestational age of 20 weeks [IQR: 10-33]. Three patients (18.8%) had an initial rhythm of ventricular fibrillation. Only one patient underwent thrombolysis. Of the 16 patients, 6 (38%) died after resuscitation on the scene. The remaining 10 were transported to the hospital, of whom 5 achieved circulation through a mechanical CPR device. Only 2 patients were alive 30days after OHCA.

CONCLUSIONS

Over half of the pregnant women who experienced OHCA were at least 20 weeks pregnant. Analysis of the prehospital medical data suggests that the current recommendations are difficult to apply in an out-of-hospital environment. Specific recommendations for this situation must be developed.

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

Background

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

Methods and Results

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

Conclusions

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

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.

'She's sort of breathing': What linguistic factors determine call-taker recognition of agonal breathing in emergency calls for cardiac arrest?

BACKGROUND

In emergency ambulance calls, agonal breathing remains a barrier to the recognition of out-of-hospital cardiac arrest (OHCA), initiation of cardiopulmonary resuscitation, and rapid dispatch. We aimed to explore whether the language used by callers to describe breathing had an impact on call-taker recognition of agonal breathing and hence cardiac arrest.

METHODS

We analysed 176 calls of paramedic-confirmed OHCA, stratified by recognition of OHCA (89 cases recognised, 87 cases not recognised). We investigated the linguistic features of callers' response to the question "is s/he breathing?" and examined the impact on subsequent coding by call-takers.

RESULTS

Among all cases (recognised and non-recognised), 64% (113/176) of callers said that the patients were breathing (yes-answers). We identified two categories of yes-answers: 56% (63/113) were plain answers, confirming that the patient was breathing ("he's breathing"); and 44% (50/113) were qualified answers, containing additional information ("yes but gasping"). Qualified yes-answers were suggestive of agonal breathing. Yet these answers were often not pursued and most (32/50) of these calls were not recognised as OHCA at dispatch.

CONCLUSION

There is potential for improved recognition of agonal breathing if call-takers are trained to be alert to any qualification following a confirmation that the patient is breathing.

[Knowledge of the population about leading symptoms of cardiovascular emergencies and the responsibility and accessibility of medical facilities in emergencies : Results of the KZEN study in Western Palatinate]

BACKGROUND

The Westpfalz is a mainly rural region in the southwestern part of the German state of Rhineland-Palatinate with 527,000 inhabitants and demonstrates a higher than average cardiovascular mortality compared to the rest of Germany. The reasons are not known. Our study attempted to investigate whether significant deficits in knowledge of the population on cardiovascular emergencies, the accessibility of emergency medical services (EMS) or the different responsibilities and abilities of the medical facilities could be held responsible for this. These factors are of the utmost importance for the timely initiation and administration of curative therapeutic strategies.

METHODS

We conducted standardized telephone interviews with 1126 inhabitants of Westpfalz as a representative sample of the population in the study area. The interviewees were asked about demographic data, participation in first aid courses, knowledge of emergency telephone numbers and the different responsibilities of preclinical emergency physicians which are a part of the EMS and the doctor-on-call system for non-life-threatening conditions (ÄBD). Moreover, we asked about the leading symptoms of myocardial infarction and stroke. Finally, we enquired how the respondents would react in fictitious cardiovascular emergencies.

RESULTS

Of the participants 651 (57.8%) were female and 475 (42.2%) male. The mean age in our study was 51 ± 18 years and 1002 of the participants (89%) had some formal first aid training. The current telephone number of the EMS system (112) was known to 29.5% of the interviewees and 15.4% could only recall the old number (19222) which is no longer in use. In the case of participants who gave the correct telephone number the first aid course took place 10 years ago (median), whereas for participants who did not know the correct number, the course dated back 15 years (median, p < 0.01). The telephone number 116117 of the ÄBD, usually a family physician, was familiar to only 23 of the people interviewed (2.0%). The basic differences in the functions and responsibilities of the ÄBD and the emergency physician within the EMS were known to only 235 participants (20.2%), 231 (20.5%) were not able to name a single leading symptom of a myocardial infarction and 354 did not know a leading symptom (31.4%) of stroke. In the fictitious case report of an unconscious patient with respiratory arrest (as a sign of cardiac arrest) 96.8% of the interviewees would have correctly informed the EMS, for patients with acute coronary syndrome 81.8% and for a stroke patient 76.8% (cardiac arrest vs. acute coronary syndrome: p < 0.001, cardiac arrest vs. stroke: p < 0.001, acute coronary syndrome vs. stroke: p = 0.005).

CONCLUSION AND RECOMMENDATIONS

A large proportion of the population were found to be ignorant about the telephone numbers for medical emergency calls and the different functions of the ÄBD and emergency physicians within the EMS. Moreover, our results indicate that a significant percentage of the population would neither be in a position to recognize a stroke or myocardial infarction in an emergency situation nor be informed enough to communicate with the correct part of the emergency system. The association of these deficits with the time elapsed since the last first aid course should be reason enough to continuously motivate the population, especially at risk patients and their relatives, to repeat such courses several times. Furthermore, digital media should be used more intensively in providing first aid instructions. In our opinion, this study clearly shows that in Germany a uniform number for medical emergency calls is mandatory.

Long-Term Prognostic Value of Gasping During Out-of-Hospital Cardiac Arrest

BACKGROUND

Gasping is a natural reflex that enhances oxygenation and circulation during cardiopulmonary resuscitation (CPR).

OBJECTIVES

This study sought to assess the relationship between gasping during out-of-hospital cardiac arrest and 1-year survival with favorable neurological outcomes.

METHODS

The authors prospectively collected incidence of gasping on all evaluable subjects in a multicenter, randomized, controlled, National Institutes of Health-funded out-of-hospital cardiac arrest clinical trial from August 2007 to July 2009. The association between gasping and 1-year survival with favorable neurological function, defined as a Cerebral Performance Category (CPC) score ≤2 was estimated using multivariable logistic regression.

RESULTS

The rates of 1-year survival with a CPC score of ≤2 were 5.4% (98 of 1,827) overall, and 20% (36 of 177) and 3.7% (61 of 1,643) for individuals with and without spontaneous gasping or agonal respiration during CPR, respectively. In multivariable analysis, 1-year survival with CPC ≤2 was independently associated with younger age (odds ratio [OR] for 1 SD increment 0.57; 95% confidence interval [CI]: 0.43 to 0.76), gasping during CPR (OR: 3.94; 95% CI: 2.09 to 7.44), shockable initial recorded rhythm (OR: 16.50; 95% CI: 7.40 to 36.81), shorter CPR duration (OR: 0.31; 95% CI: 0.19 to 0.51), lower epinephrine dosage (OR: 0.47; 95% CI: 0.25 to 0.87), and pulmonary edema (OR: 3.41; 95% CI: 1.53 to 7.60). Gasping combined with a shockable initial recorded rhythm had a 57-fold higher OR (95% CI: 23.49 to 136.92) of 1-year survival with CPC ≤2 versus no gasping and no shockable rhythm.

CONCLUSIONS

Gasping during CPR was independently associated with increased 1-year survival with CPC ≤2, regardless of the first recorded rhythm. These findings underscore the importance of not terminating resuscitation prematurely in gasping patients and the need to routinely recognize, monitor, and record data on gasping in all future cardiac arrest trials and registries.

Simulation training to improve 9-1-1 dispatcher identification of cardiac arrest: A randomized controlled trial

BACKGROUND

The objective of this study was to test the effectiveness of simulation training, using actors to make mock calls, on improving Emergency Medical Dispatchers' (EMDs) ability to recognize the need for, and reduce the time to, telephone-assisted CPR (T-CPR) in simulated and real cardiac arrest 9-1-1 calls.

METHODS

We conducted a parallel prospective randomized controlled trial with n=157 EMDs from thirteen 9-1-1 call centers. Study participants were randomized within each center to intervention (i.e., completing 4 simulation training sessions over 12-months) or control (status quo). After the intervention period, performance on 9 call processing skills and 2 time-intervals were measured in 2 simulation assessment calls for both arms. Six of the 13 call centers provided recordings of real cardiac arrest calls taken by study participants during the study period.

RESULTS

Of the N=128 EMDs who completed the simulation assessment, intervention participants (n=66) performed significantly better on 6 of 9 call processing skills and started T-CPR 23s faster (73 vs 91s respectively, p<0.001) compared to participants in the control arm (n=62). In real cardiac arrest calls, EMDs who completed 3 or 4 training sessions were more likely to recognize the need for T-CPR for more challenging cardiac arrest calls than EMDs who completed fewer than 3, including controls who completed no training (68% vs 53%, p=0.018).

CONCLUSIONS

Simulation training improves call processing skills and reduces time to T-CPR in simulated call scenarios, and may improve the recognition of the need for T-CPR in more challenging real-life cardiac arrest calls.

CLINICAL TRIAL REGISTRATION

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

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.

'Tell me exactly what's happened': When linguistic choices affect the efficiency of emergency calls for cardiac arrest

BACKGROUND

Clear and efficient communication between emergency caller and call-taker is crucial to timely ambulance dispatch. We aimed to explore the impact of linguistic variation in the delivery of the prompt "okay, tell me exactly what happened" on the way callers describe the emergency in the Medical Priority Dispatch System^®.

METHODS

We analysed 188 emergency calls for cases of paramedic-confirmed out-of-hospital cardiac arrest. We investigated the linguistic features of the prompt "okay, tell me exactly what happened" in relation to the format (report vs. narrative) of the caller's response. In addition, we compared calls with report vs. narrative responses in the length of response and time to dispatch.

RESULTS

Callers were more likely to respond with a report format when call-takers used the present perfect ("what's happened") rather than the simple past ("what happened") (Adjusted Odds Ratio [AOR] 4.07; 95% Confidence Interval [95%CI] 2.05-8.28, p<0.001). Reports were significantly shorter than narrative responses (9s vs. 18s, p<0.001), and were associated with less time to dispatch (50s vs. 58s, p=0.002).

CONCLUSION

These results suggest that linguistic variations in the way the scripted sentences of a protocol are delivered can have an impact on the efficiency with which call-takers process emergency calls. A better understanding of interactional dynamics between caller and call-taker may translate into improvements of dispatch performance.

Recognising out-of-hospital cardiac arrest during emergency calls increases bystander cardiopulmonary resuscitation and survival

BACKGROUND

Initiation of early bystander cardiopulmonary resuscitation (CPR) depends on bystanders' or medical dispatchers' recognition of out-of-hospital cardiac arrest (OHCA). The primary aim of our study was to investigate if OHCA recognition during the emergency call was associated with bystander CPR, return of spontaneous circulation (ROSC), and 30-day survival. Our secondary aim was to identify patient-, setting-, and dispatcher-related predictors of OHCA recognition.

METHODS

We performed an observational study of all OHCA patients' emergency calls in the Capital Region of Denmark from 01/01/2013-31/12/2013. OHCAs were collected from the Danish Cardiac Arrest Registry and the Mobile Critical Care Unit database. Emergency call recordings were identified and evaluated. Multivariable logistic regression analyses were applied to all OHCAs and witnessed OHCAs only to analyse the association between OHCA recognition and bystander CPR, ROSC, and 30-day survival. Univariable logistic regression analyses were applied to identify predictors of OHCA recognition.

RESULTS

We included 779 emergency calls in the analyses. During the emergency calls, 70.1% (n=534) of OHCAs were recognised; OHCA recognition was positively associated with bystander CPR (odds ratio [OR]=7.84, 95% confidence interval [CI]: 5.10-12.05) in all OHCAs; and ROSC (OR=1.86, 95% CI: 1.13-3.06) and 30-day survival (OR=2.80, 95% CI: 1.58-4.96) in witnessed OHCA. Predictors of OHCA recognition were addressing breathing (OR=1.76, 95% CI: 1.17-2.66) and callers located by the patient's side (OR=2.16, 95% CI: 1.46-3.19).

CONCLUSIONS

Recognition of OHCA during emergency calls was positively associated with the provision of bystander CPR, ROSC, and 30-day survival in witnessed OHCA.

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

Background

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

Methods

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

Results

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

Conclusion

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

Effect of bystander CPR initiation prior to the emergency call on ROSC and 30day survival-An evaluation of 548 emergency calls

BACKGROUND

This study aimed at evaluating if time for initiation of bystander cardiopulmonary resuscitation (CPR) - prior to the emergency call (CPR_prior) versus during the emergency call following dispatcher-assisted CPR (CPR_during) - was associated with return of spontaneous circulation (ROSC) and 30-day survival. The secondary aim was to identify predictors of CPR_prior.

METHODS

This observational study evaluated out-of-hospital cardiac arrests (OHCA) occurring in the Capital Region of Denmark from 01.01.2013 to 31.12.2013. OHCAs were linked to emergency medical dispatch centre records and corresponding emergency calls were evaluated. Multivariable logistic regression analyses were applied to evaluate the association between time for initiation of bystander CPR, ROSC, and 30-day survival. Univariable logistic regression analyses were applied to identify predictors of CPR_prior.

RESULTS

The study included 548 emergency calls for OHCA patients receiving bystander CPR, 34.9% (n=191) in the CPR_prior group and 65.1% (n=357) in the CPR_during group. Multivariable analyses showed no difference in ROSC (OR=0.88, 95% CI: 0.56-1.38) or 30-day survival (OR=1.14, 95% CI: 0.68-1.92) between CPR_prior and CPR_during. Predictors positively associated with CPR_prior included witnessed OHCA and healthcare professional bystanders. Predictors negatively associated with CPR_prior included residential location, solitary bystanders, and bystanders related to the patient.

CONCLUSIONS

The majority of bystander CPR (65%) was initiated during the emergency call, following dispatcher-assisted CPR instructions. Whether bystander CPR was initiated prior to emergency call versus during the emergency call following dispatcher-assisted CPR was not associated with ROSC or 30-day survival. Dispatcher-assisted CPR was especially beneficial for the initiation of bystander CPR in residential areas.

Factors impacting upon timely and adequate allocation of prehospital medical assistance and resources to cardiac arrest patients

AIM

Explore, understand and address issues that impact upon timely and adequate allocation of prehospital medical assistance and resources to out-of-hospital cardiac arrest (OHCA) patients.

METHODS

Mixed-methods design obtaining data for one year in three emergency medical communication centres (EMCC); Oslo-Akershus (OA), Vestfold-Telemark (VT) and Østfold (Ø). Data collection included quantitative data from analysis of dispatch logs, ambulance records and audio files. Qualitative data were collected through in-depth interviews and non-participant observations.

RESULTS

OA-, VT- and Ø-EMCC responded to 1095 OHCAs and 579 of these calls were included for further analysis (333, 143 and 103, respectively). There were significant site differences in their recognition of OHCA (89, 94 and 78%, respectively, p<0.001), provision of CPR instructions (83, 83 and 61%, respectively, p<0.001), time from call answered to initial CPR instructions (1.4min (1.2, 1.6), 1.1min (0,9, 1.2) and 1.3 (1.2, 1.7) respectively, p=0.002). The most frequent reason for delayed or failed recognition of OHCA was misinterpretation of agonal breathing. Interviews and observations revealed individual differences in protocol use, interrogation strategy and assessment of breathing. Use of protocol was only part of decision making, dispatchers trusted their own clinical experience and intuition, and used assumptions about the patient and the situation as part of decision making.

CONCLUSION

Agonal breathing continues to be the main barrier to recognition of cardiac arrest. Individual differences among dispatchers' strategies can directly impact on performance, mainly due to the wide definition of cardiac arrest and lack of uniform tools for assessment of breathing.