A novel protocol for dispatcher assisted CPR improves CPR quality and motivation among rescuers-A randomized controlled simulation study

Interventions to optimize dispatcher-assisted CPR instructions: A scoping review

Aim

To review and summarize existing literature and knowledge gaps regarding interventions that have been tested to optimize dispatcher-assisted CPR (DA-CPR) instruction protocols for 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 ILCOR methodological framework and the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for scoping reviews (PRISMA-ScR). Studies were eligible for inclusion if they were published in peer-reviewed journals and evaluated interventions used to improve DA-CPR. The search was carried out in MEDLINE, EMBASE, Education Resources Information Center (ERIC), PsycINFO, the Cochrane Library, Evidence Based Medicine (EBM) Reviews, and the Campbell Library from 2000 to December 18, 2023.

Results

After full text review, 31 studies were included in the final review. The interventions reviewed were use of video at the scene (n = 9), changes in terminology about compressions (n = 6), implementation of novel DA-CPR protocols (n = 4), advanced dispatcher training (n = 3), centralization of the dispatch center (n = 2), use of metronome or varied metronome rates (n = 2), change in CPR sequence and compression ratio (n = 1), animated audio-visual recording (n = 1), pre-recorded instructions vs. conversational live instructions (n = 1), inclusion of "undress patient" instructions (n = 1), and specific verbal encouragement (n = 1). Studies ranged in methodology from registry studies to randomized clinical trials with the majority being observational studies of simulated EMS calls for OHCA. Outcomes were highly variable but included rates of bystander CPR, confidence & willingness to perform CPR, time to initiation of bystander CPR, bystander CPR quality (including CPR metrics: chest compression depth and rate; chest compression fraction; full chest recoil, ventilation rate, overall CPR competency), rates of automated external defibrillator (AED) use, return of spontaneous circulation (ROSC) and survival. Overall, all interventions seem to be associated with potential improvement in bystander CPR and CPR metrics.

Conclusion

There appears to be trends towards improvement on key outcomes however more research is needed. This scoping review highlights the lack of high-quality clinical research on any of the tested interventions to improve DA-CPR. There is insufficient evidence to explore the effectiveness of any of these interventions via systematic review.

Online training to improve BLS performance with dispatcher assistance? Results of a cluster-randomised controlled simulation trial

BACKGROUND

The prognosis for patients improves significantly with effective cardiopulmonary resuscitation (CPR) performed by bystanders. Current research indicates that individuals who receive CPR from trained bystanders have a greater likelihood of survival compared to those who receive dispatcher-assisted CPR from untrained laypersons. This cluster-randomised controlled trial assessed the impact of a 30-min online training session prior to a simulated cardiac arrest situation with dispatcher-assisted CPR (DA-CPR) on enhancing Basic Life Support (BLS) performance.

METHODS

This study was performed in 2018 in Hamburg, Germany. The primary outcome was the practical BLS skills of high school students in simulated out-of-hospital cardiac arrest scenarios with dispatcher assistance. The intervention group participants underwent a 30-min online BLS training session, while the control group did not receive an intervention. It was hypothesized that the average practical BLS scores of the intervention group would be 1.5 points higher than those of the control group.

RESULTS

BLS assessments of 286 students of 16 different classes were analysed. The estimated mean BLS score in the intervention group was 7.60 points (95% CI: 6.76 to 8.44) compared to 6.81 (95% CI: 5.97 to 7.65) in the control group adjusted for BLS training and class. Therefore, the estimated mean difference between the groups was 0.79 (95% CI: -0.40 to 1.97) and not significantly different (p-value: 0.176). Based on a logistic regression analysis the intervention had only a significant effect on the chance to pass the item "vertically above the chest" (OR = 4.99; 95% CI: 1.46 to 17.12) adjusted for BLS training and class.

CONCLUSION

Prior online training exhibits beneficial impacts on the BLS performance of bystanders during DA-CPR. To maximise the effect size, online training should be incorporated into a set of interventions that are mutually complementary and specifically designed for the target participants.

TRIAL REGISTRATION

DRKS00033531 . "Kann online Training Laien darauf vorbereiten Reanimationsmaßnahmen unter Anleitung der Leitstelle adäquat durchzuführen? " Registered on January 29, 2024.

Intentional interruptions during compression only CPR: A scoping review

Introduction

Out of hospital cardiac arrest (OHCA) remains one of the main causes of death among industrialized countries. The initiation of cardiopulmonary resuscitation (CPR) by laypeople before the arrival of emergency medical services improves survival. Mouth-to-mouth ventilation may constitute a hindering factor to start bystander CPR, while during continuous chest compressions (CCC) CPR quality decreases rapidly. The aim of this scoping review is to examine the existing literature on strategies that investigate the inclusion of intentional pauses during compression-only resuscitation (CO-CPR) to improve the performance in the context of single lay rescuer OHCA.

Methods

The protocol of this Scoping review was prospectively registered in Open Science Framework (https://osf.io/rvn8j). A systematic search of PubMed, Scopus, EMBASE, CINAHL was performed.

Results

Six articles were included. All studies were carried out on simulation manikins and involved a total of 1214 subjects. One study had a multicenter design. Three studies were randomized controlled simulation trials, the rest were prospective randomized crossover studies. The tested protocols were heterogeneous and compared CCC to CO-CPR with intentional interruptions of various length. The most common primary outcome was compressions depth. Compression rate, rescuers' perceived exertion and composite outcomes were also evaluated. Compressions depth and perceived exertion improved in most study groups while compression rate and chest compression fraction remained within guidelines indications.

Conclusions

In simulation studies, the inclusion of intentional interruptions during CO-CPR within the specific scenario of single rescuer bystander CPR during OHCA may improve the rate of compressions with correct depth and lower rate of perceived exertion. Further high-quality research and feasibility and safety of protocols incorporating intentional interruptions during CO-CPR may be justified.

The barriers and facilitators to initiation of telephone-assisted bystander cardiopulmonary resuscitation for patients experiencing out-of-hospital cardiac arrest in a private emergency dispatch centre in South Africa

Background

The incidence of cardiovascular diseases, and with it out-of-hospital cardiac arrest (OHCA), is on the increase in low- to middle-income countries (LMICs), like South Africa. Interventions such as mass public cardiopulmonary resuscitation (CPR) training campaigns and public access defibrillators are expensive and out of reach for many LMICs. Telephone-assisted CPR (tCPR) is a cost-effective, scalable alternative. This study explored the barriers and facilitators to tCPR uptake in OHCA in a private South African emergency dispatch centre.

Methods

This qualitative study applied inductive dominant content analysis to emergency call recordings of OHCA cases into a private emergency dispatch centre. Calls were analysed to the latent level to identify barriers and facilitators. Cases were sampled randomly, until data saturation.

Results

Saturation occurred after the analysis of 25 recordings. A further three recordings were analysed to confirm saturation of the facilitators; yielding a final sample size of 28 calls. Overall, t-CPR was offered in 23 (82.1%) cases, but only initiated in 8 (34.8%) of these calls. Five barriers ("Poor Communication"; "Lack of Support"; "Caller Hesitance or Uncertainty;" "Emotionality"; and "Practical Barriers") and three facilitators ("Caller Willingness"; "Support" and "CPR in Progress") were extracted.

Conclusion

Numerous barriers limit the initiation of tCPR in the South African private sector EMS. It is crucial to address these barriers and leverage the facilitators in order to improve tCPR uptake. This study highlights the importance of using specific language techniques and developing tailored tCPR algorithms to overcome these barriers, which is underpinned by standardised training of call-takers.

The understandability and quality of telephone-guided bystander cardiopulmonary resuscitation in the Western Cape province of South Africa: A manikin-based study

Background

The incidence of cardiovascular disease is on the increase in Africa and with it, an increase in the incidence of out-of-hospital cardiac arrest (OHCA). OHCA carries a high mortality, especially in low-resource settings. Interventions to treat OHCA, such as mass cardiopulmonary resuscitation (CPR) training campaigns are costly. One cost-effective and scalable intervention is telephone-guided bystander CPR (tCPR). Little data exists regarding the quality of tCPR. This study aimed to determine quality of tCPR in untrained members of the public. Participants were also asked to provide their views on the understandability of the tCPR instructions.

Methods

This study followed a prospective, simulation-based observational study design. Adult laypeople who have not had previous CPR training were recruited at public CPR training events and asked to perform CPR on a manikin. Quality was assessed in terms of hand placement, compression rate, compression depth, chest recoil, and chest exposure. tCPR instructions were provided by a trained medical provider, via loudspeaker. Participants were also asked to complete a short questionnaire afterwards, detailing the understandability of the tCPR instructions. Data were analysed descriptively and compared to recommended quality guidance.

Results

Fifty participants were enrolled. Hand placement was accurate in 74 % (n = 37) of participants, while compression depth and chest recoil only had compliance in 20 % (n = 10) and 24 % (n = 12) of participants, respectively. The mean compression rate was within guidelines in just under half (48 %, n = 24) of all participants. Only 20 (40 %) participants exposed the manikin's chest. Only 46 % (n = 23) of participants felt that the overall descriptions offered during the tCPR guidance were understandable, while 80 % (n = 40) and 36 % (n = 18) felt that the instructions on hand placement and compression rate were understandable, respectively. Lastly, 94 % (n = 47) of participants agreed that they would be more likely to perform bystander CPR if they were provided with tCPR.

Conclusion

The quality of CPR performed by laypersons is generally suboptimal and this may affect patient outcomes. There is an urgent need to develop more understandable tCPR algorithms that may encourage bystanders to start CPR and optimise its quality.

Documented Use of Emergency Medical Dispatch Protocols is Associated with Improved Survival in Out of Hospital Cardiac Arrest

OBJECTIVE

There are over 300,000 out-of-hospital cardiac arrests (OHCA) annually in the United States (US) and despite many scientific advances in the field, the survival rate remains low. We seek to determine if return of spontaneous circulation (ROSC) is higher when use of emergency medical dispatch (EMD) protocols is documented for OHCA calls compared to when no EMD protocol use is documented. We also seek identify care-related processes that differ in calls that use EMD protocols.

METHODS

This is a retrospective cohort study of U.S. adults with OHCA prior to emergency medical services (EMS) arrival using 2019 National EMS Information System data. The primary exposure was EMD usage during EMS call. The primary outcome was prehospital ROSC, and secondary outcomes included automated external defibrillator (AED) use before EMS arrival, bystander CPR, and end-of-event EMS survival (survival to the end of the EMS care at transport destination). Multivariable logistic regression adjusted for age, sex, race/ethnicity, primary insurance, rurality, initial rhythm, arrest etiology, and witnessed arrest.

RESULTS

Of the 96,269 OHCA cases included, EMD use was documented in 73%. Overall, 26% of subjects achieved ROSC in EMS care. EMD subjects were more likely to achieve ROSC (27.2% vs. 23.5%, uOR 1.22, 95%CI 1.18 - 1.26) even after adjusting for subject and arrest characteristics (aOR 1.13, 95%CI 1.08 - 1.17). EMD subjects also had higher end-of-event survival (19.1% vs. 16.4%, aOR 1.20, 95%CI 1.15 - 1.25). AED use before EMS arrival was more common in the EMD group (28.3% vs. 26.3% %diff 2.0, 95%CI 1.4 to 2.6), as was CPR before EMS arrival (63.8% vs. 55.1%, difference 8.6%, 95%CI 7.9 to 9.3%).

CONCLUSIONS

In this retrospective analysis, the rate of ROSC was higher in adult OHCA patients when EMD protocol use was reported compared to when it was not reported. The group with documented EMD use also experienced higher rates of bystander AED use, bystander CPR, and end-of-event survival.

Out-of-hospital cardiac arrest: Does rurality decrease chances of survival?

Background

Geographical setting is seldomly taken into account when investigating out-of-hospital cardiac arrest (OHCA). It is a common notion that living in rural areas means a lower chance of fast and effective helpwhen suffering a time-critical event. This retrospective cohort study investigates this hypothesis and compares across healthcare-divided administrative regions.

Methods

We included only witnessed OHCAs to minimize the risk that outcome was predetermined by time to caller arrival and/or recognition. Arrests were divided into public and residential. Residential arrests were categorized according to population density of the area in which they occurred. We investigated incidence, EMS response time and 30-day survival according to area type and subsidiarily by healthcare-divided administrative region.

Results

The majority (71%) of 8,579 OHCAs were residential, and 53.2% of all arrests occurred in the most densely populated cell group amongst residential arrests. This group had a median EMS response time of six minutes, whereas the most sparsely populated group had a median of 10 minutes. Public arrests also had a median response time of six minutes. 30-day survival was highest in public arrests (38.5%, [95% CI 36.9;40.1]), and varied only slightly with no statistical significance between OHCAs in densely and sparsely populated areas from 14.8% (95% CI 14.4;15.2) and 13.4% (95% CI 12.2;14.7).

Conclusion

Our study demonstrates that while EMS response times in Denmark are longer in the rural areas, there is no statistically significant decrease in survival compared to the most densely populated areas.

Different perceptions of thorax anatomy and hand placement for chest compressions among healthcare professionals and laypersons: Implications for cardiopulmonary resuscitation

Aim

The European Resuscitation Council guidelines recommend that the hand position for chest compressions is obtained by “placing the heel of your hand in the centre of the chest”. Importantly, guidelines are based on a study on healthcare professionals being extrapolated to laypersons. This study explored whether healthcare professionals and laypersons differ in anatomical knowledge necessary for obtaining the correct hand position for chest compressions and understanding of European Resuscitation Council guideline recommendations in the absence of a demonstration.

Methods

We asked laypersons and healthcare professionals to identify where to place the hands for chest compressions on digital pictures of the chest of a man and a woman. Both groups were asked to identify where to place the hands for chest compressions, the left nipple (positive control), the centre of the chest and to delineate the anterior area of the chest.

Results

In total, 50 laypersons and 50 healthcare professionals were included. Healthcare professionals were significantly better at identifying the correct hand position for chest compressions compared to laypersons (male chest: P = 0.03, female chest: P < 0.0001) and delineating the anterior area of the chest. We found no significant difference between groups when instructed to identify the left nipple nor the centre of the chest (male chest: P = 0.57, female chest: P = 0.50).

Conclusion

Laypersons and healthcare professionals have different perceptions of chest anatomy and where to perform chest compressions suggesting that caution should be taken when extrapolating results from healthcare professionals to laypersons. The ERC 2015 guideline recommendations on hand placement for chest compressions seems understandable by both laypersons and healthcare professionals.

Bystander performance using the 2010 vs 2015 ERC guidelines: A post-hoc analysis of two randomised simulation trials

BACKGROUND

The European Resuscitation Council (ERC) basic life support (BLS) 2015 guidelines were simplified compared to the 2010 guidelines. We aimed to compare BLS/automated external defibrillator (AED) skill performance and skill retention following training with the 2010 or 2015 BLS/AED guidelines.

METHODS

Post-hoc analysis of two randomised simulation trials including videorecordings of laypersons skill-tested after ERC BLS/AED training using either the 2010 (n = 70) or 2015 (n = 70) BLS guidelines. Outcomes: (a) correct sequence of the BLS/AED algorithm, (b) correct sequence of the BLS/AED algorithm with all skills performed correctly, and (c) time to EMS call, first chest compression and shock delivery immediately after training and three months later. Groups were compared using multivariate logistic regression.

RESULTS

Mean age (±standard deviation) was 40 (±11) vs. 44 (±11) years and 70% vs. 50% were females for the 2010 and 2015 groups, respectively. Correct sequence of the BLS/AED algorithm for the 2010 vs. 2015 group was 84% vs. 91%, P = 0.08 immediately after training and 16% vs. 41%, adjusted odds ratio (aOR): 5.6 (95% CI: 2.3-14.0, P < 0.001) after three months. Correct sequence with all skills performed correctly was 56% vs. 47%, P = 0.31 immediately after training and 5% vs. 16%, aOR: 4.8 (95% CI: 1.2-19.2), P = 0.03 after three months. Time to EMS call was shorter in the 2015 group immediately after training (P = 0.008) but all other time points did not differ.

CONCLUSION

The simplified 2015 BLS guidelines was associated with better adherence to the sequence of the BLS/AED algorithm when compared to the 2010 BLS guidelines three months after training in a simulated cardiac arrest scenario, without significantly improving skill performance immediately after training.

Quality of dispatcher-assisted vs. automated external defibrillator-guided cardiopulmonary resuscitation: a randomised simulation trial

BACKGROUND

Quality of hands-only cardiopulmonary resuscitation (CPR) is an important determinant of resuscitation outcome for cardiac arrest patients cared for by lay rescuers. We designed a simulation trial to assess and compare the quality of CPR among untrained lay people under two different scenarios: automated external defibrillator (AED)-guided and dispatcher-assisted CPR.

PATIENTS AND METHODS

A simulation study was performed involving 42 volunteers selected by non-probabilistic sampling. Participants were randomized into two CPR simulation scenarios with a manikin: (A) AED-guided CPR and (T) dispatcher-assisted CPR. The quality of CPR was evaluated by metric monitoring of the chest compressions and timing of actions. Content analysis of the telephone instructions was performed by two independent researchers using a checklist.

RESULTS

CPR was started in 20 of the 21 cases in scenario A and in all cases in scenario T. In total, 12 053 chest compressions were applied, 57.6% corresponding to scenario A. The proportion of compressions that were of an adequate depth was low in both cases, 15.3% in scenario A vs. 31.7% in scenario T (P < 0.001), while complete chest recoil was allowed in 66 and 72% (P < 0.001) of compressions, respectively. The AED advised to shock 91 times, and shocks were delivered in all cases.

CONCLUSIONS

Although guided CPR helps untrained people to initiate resuscitation manoeuvres, the quality of CPR was poor in both groups. Telephone guidance improved the proportion of compressions that achieved adequate chest compression and recoil but did not optimise the compression rate.

Strategies to improve communication in telementoring in acute care coordination: a scoping review

Background

Telementoring facilitates the coordination of advanced medical care in rural, remote or austere environments. Because the interpersonal element of telementoring has been relatively underexplored, we conducted a scoping review to identify strategies to improve communication in telementoring.

Methods

Two independent reviewers searched all English-language articles in MEDLINE and Scopus from 1964 to 2017, as well as reference lists of relevant articles to identify articles addressing telementored interactions between health care providers. Search results were gathered in June 2017 and updated in January 2018. Identified articles were categorized by theme.

Results

We identified 144 articles, of which 56 met our inclusion criteria. Forty-one articles focused on improving dispatcher-directed cardiopulmonary resuscitation (CPR). Major themes included the importance of language in identifying out-of-hospital cardiac arrest and how to provide instructions to enable administration of effective CPR. A standardized approach with scripted questions was associated with improved detection of out-of-hospital cardiac arrest, and a concise script was associated with improved CPR quality compared to no mentoring, unscripted mentoring or more complex instructions. Six articles focused on physician-physician consultation. Use of a handover tool that highlighted critical information outperformed an unstructured approach regarding transmission of vital information. Nine articles examined telementoring in trauma resuscitation. A common theme was the need to establish an understanding between mentor and provider regarding the limitations of the provider and his or her environment.

Conclusion

The available data suggest that standardization coupled with short, concise validated scripts could improve efficacy, safety and engagement. Improvements will require multidisciplinary input, practice and deliberate efforts to address barriers.

Major Differences in the Use of Protocols for Dispatcher-Assisted Cardiopulmonary Resuscitation Among ILCOR Member Countries

Introduction and Purpose

Dispatcher-assisted cardiopulmonary resuscitation (DA-CPR) increases the rate of bystander cardiopulmonary resuscitation (CPR). DA-CPR is recommended by resuscitation councils globally and it has been shown that the general public expects to receive pre-arrival instructions while waiting for help. A scientific advisory from the American Heart Association identifies standardized and structured DA-CPR protocols as important to increase bystander CPR rates. This study aims to investigate whether different International Liaison Committee on Resuscitation (ILCOR) member countries use DA-CPR protocols and to compare protocol contents between countries.

Methods

All resuscitation councils forming ILCOR were inquired by email to provide a copy of their DA-CPR protocol, and to state whether this protocol was used by all emergency dispatch centers in their country. The collected protocols were translated into English, and content was compared.

Results

A total of 60 countries were contacted (response rate: 83%). Of these, 46% stated to have a nationwide protocol, 30% reported to use local protocols, and 24% did not use a protocol. Overall, 54% provided a copy of their protocol. All translated protocols asked the rescuer to check for responsiveness and breathing, 35% to activate phone speaker function, half contained notes about agonal breathing and 59% included notes about integrating an automated external defibrillator.

Conclusion

Almost one quarter of ILCOR member countries did not use a protocol for DA-CPR. Half of the protocols included notes about agonal breathing. Activation of phone speaker function and protocolled encouragements during CPR were rarely included.

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.

The impact of resuscitation guideline terminology on quality of dispatcher-assisted cardiopulmonary resuscitation: A randomised controlled manikin study

BACKGROUND

Cardiopulmonary resuscitation (CPR) guidelines vary in the terminology used to describe target chest compression depth, which may impact CPR quality. We investigated the impact of using different chest compression depth instruction terminologies on CPR quality.

METHODS

We conducted a parallel group, three-arm, randomised controlled manikin trial in which individuals without recent CPR training were instructed to deliver compression-only CPR for 2-min based on a standardised dispatcher-assisted CPR script. Participants were randomised in a 1:1:1 ratio to receive CPR delivery instructions that instructed them to deliver chest compressions based on the following terminologies: 'press at least 5 cm', 'press approximately 5 cm' or 'press hard and fast.' The primary outcome was compression depth, measured in millimetres.

RESULTS

Between October 2017 and June 2018, 330 participants were randomised to 'at least 5 cm' (n = 109), 'approximately 5 cm' (n = 110) and 'hard and fast' (n = 111), in which mean chest compression depth was 40.9 mm (SD 13.8), 35.4 mm (SD 14.1), and 46.8 mm (SD 15.0) respectively. Mean difference in chest compression depth between 'at least 5 cm' and 'approximately 5 cm' was 5.45 (95% confidence interval (95% CI) 0.78-10.12), between 'hard and fast' and 'approximately 5 cm' was 11.32 (95% CI 6.65-15.99), and between 'hard and fast' and 'at least 5 cm' was 5.87 (95% CI 1.21-10.53). Chest compression rate and count were both highest in the 'hard and fast' group.

CONCLUSIONS

The use of 'hard and fast' terminology was superior to both 'at least 5 cm' and 'approximately 5 cm' terminologies.

TRIAL REGISTRATION

ISRCTN15128211.

Development of a novel cardiopulmonary resuscitation measurement tool using real-time feedback from wearable wireless instrumentation

AIM

The design and implementation of a wearable training device to improve cardiopulmonary resuscitation (CPR) is presented.

METHODS

The MYO contains both Electromyography (EMG) and Inertial Measurement Unit (IMU) sensors which are used to detect effective CPR, and the four common incorrect hand and arm positions viz. relaxed fingers; hands too low on the sternum; patient too close; or patient too far. The device determines the rate and depth of compressions calculated using a Fourier transform and dual-quaternions respectively. In addition, common positional mistakes are determined using classification algorithms (six machine learning algorithms are considered and tested). Feedback via Graphical User Interface (GUI) and audio is integrated.

RESULTS

The system is tested by performing CPR on a mannequin and comparing real-time results to theoretical values. Tests show that although the classification algorithm performed well in testing (98%), in real time, it had low accuracy for certain categories (60%), which are attributable to the MYO calibration, sampling rate and misclassification of similar hand positions. Combining these similar incorrect positions into more general categories significantly improves accuracy, and produces the same improved outcome of improved CPR. The rate and depth measures have a general accuracy of 97%.

CONCLUSION

The system allows for portable, real-time feedback for use in training and in the field, and shows promise toward classifying and improving the administration of CPR.

Interventions to improve the quality of bystander cardiopulmonary resuscitation: A systematic review

Background

Performing high-quality bystander cardiopulmonary resuscitation (CPR) improves the clinical outcomes of victims with sudden cardiac arrest. Thus far, no systematic review has been performed to identify interventions associated with improved bystander CPR quality.

Methods

We searched Ovid MEDLINE, Ovid EMBASE, EBSCO CINAHL, Ovid PsycInfo, Thomson Reuters SCI-EXPANDED, and the Cochrane Central Register of Controlled Trials to retrieve studies published from 1 January 1966 to 5 October 2018 associated with interventions that could improve the quality of bystander CPR. Data regarding participant characteristics, interventions, and design and outcomes of included studies were extracted.

Results

Of the initially identified 2,703 studies, 42 were included. Of these, 32 were randomized controlled trials. Participants included adults, high school students, and university students with non-medical professional majors. Interventions improving bystander CPR quality included telephone dispatcher-assisted CPR (DA-CPR) with simplified or more concrete instructions, compression-only CPR, and other on-scene interventions, such as four-hand CPR for elderly rescuers, kneel on opposite sides for two-person CPR, and CPR with heels for a tired rescuer. Devices providing real-time feedback and mobile devices containing CPR applications or software were also found to be beneficial in improving the quality of bystander CPR. However, using mobile devices for improving CPR quality or for assisting DA-CPR might cause rescuers to delay starting CPR.

Conclusions

To further improve the clinical outcomes of victims with cardiac arrest, these effective interventions may be included in the guidelines for bystander CPR.

'We're going to do CPR': A linguistic study of the words used to initiate dispatcher-assisted CPR and their association with caller agreement

BACKGROUND

In emergency ambulance calls for out-of-hospital cardiac arrest (OHCA), dispatcher-assisted cardiopulmonary resuscitation (CPR) plays a crucial role in patient survival. We examined whether the language used by dispatchers to initiate CPR had an impact on callers' agreement to perform CPR.

METHODS

We analysed 424 emergency calls relating to cases of paramedic-confirmed OHCA where OHCA was recognised by the dispatcher, the caller was with the patient, and resuscitation was attempted by paramedics. We investigated the linguistic choices used by dispatchers to initiate CPR, and the impact of those choices on caller agreement to perform CPR.

RESULTS

Overall, CPR occurred in 85% of calls. Caller agreement was low (43%) when dispatchers used terms of willingness ("do you want to do CPR?"). Caller agreement was high (97% and 84% respectively) when dispatchers talked about CPR in terms of futurity ("we are going to do CPR") or obligation ("we need to do CPR"). In 38% (25/66) of calls where the caller initially declined CPR, the dispatcher eventually secured their agreement by making several attempts at initiating CPR.

CONCLUSION

There is potential for increased agreement to perform CPR if dispatchers are trained to initiate CPR with words of futurity and/or obligation.

Association between the centralization of dispatch centers and dispatcher-assisted cardiopulmonary resuscitation programs: A natural experimental study

OBJECTIVES

We aimed to evaluate the associations between the centralization of dispatch centers and dispatcher-assisted bystander cardiopulmonary resuscitation (DA-BCPR) for out-of-hospital cardiac arrest (OHCA) patients.

METHODS

All emergency medical services (EMS)-treated adults in Gyeonggi province (34 fire departments covering 43 counties, with a population of 12.6 million) with OHCAs of cardiac etiology were enrolled between 2013 and 2016, excluding cases witnessed by EMS providers. In Gyeonggi province, 34 agency-based dispatch centers were sequentially integrated into two province-based central dispatch centers (north and south) between November 2013 and May 2016. Exposure was the centralization of the dispatch centers. Endpoint variables were BCPR and dispatcher-provided CPR instructions. Generalized linear mixed models for multilevel regression analyses were performed.

RESULTS

Overall, 11,616 patients (5060 before centralization and 6556 after centralization) were included in the final analysis. The OHCAs that occurred during the after-centralization period were more likely to receive BCPR (62.6%, 50.6% BCPR-with-DA and 12.0% BCPR-without-DA) than were those that occurred before-centralization period (44.6%, 16.6% BCPR-with-DA and 28.1% BCPR-without-DA) (p < 0.01, adjusted OR: 1.59 (1.38-1.83), adjusted rate difference: 9.1% (5.0-13.2)). For dispatcher-provided CPR instructions, OHCAs diagnosed at a higher rate during the after-centralization period than during the before-centralization period (67.4% vs. 23.1%, p < 0.01, adjusted OR: 4.57 (3.26-6.42), adjusted rate difference: 30.3% (26.4-34.2)). The EMS response time was not different between the groups (p=0.26).

CONCLUSIONS

The centralization of dispatch centers was associated with an improved bystander CPR rate and dispatcher-provided CPR instructions for OHCA patients.

Can a Software-Based Metronome Tool Enhance Compression Rate in a Realistic 911 Call Scenario Without Adversely Impacting Compression Depth for Dispatcher-Assisted CPR?

IntroductionImplementation of high-quality, dispatcher-assisted cardiopulmonary resuscitation (DA-CPR) is critical to improving survival from out-of-hospital cardiac arrest (OHCA). However, despite some studies demonstrating the use of a metronome in a stand-alone setting, no research has yet demonstrated the effectiveness of a metronome tool in improving DA-CPR in the context of a realistic 911 call or using instructions that have been tested in real-world emergency calls.HypothesisUse of the metronome tool will increase the proportion of callers able to perform CPR within the target rate without affecting depth.

METHODS

The prospective, randomized, controlled study involved simulated 911 cardiac arrest calls made by layperson-callers and handled by certified emergency medical dispatchers (EMDs) at four locations in Salt Lake City, Utah USA. Participants were randomized into two groups. In the experimental group, layperson-callers received CPR pre-arrival instructions with metronome assistance. In the control group, layperson-callers received only pre-arrival instructions. The primary outcome measures were correct compression rate (counts per minute [cpm]) and depth (mm).

RESULTS

A total of 148 layperson-callers (57.4% assigned to experimental group) participated in the study. There was a statistically significant association between the number of participants who achieved the target compression rate and experimental study group (P=.003), and the experimental group had a significantly higher median compression rate than the control group (100 cpm and 89 cpm, respectively; P=.013). Overall, there was no significant correlation between compression rate and depth.

CONCLUSION

An automated software metronome tool is effective in getting layperson-callers to achieve the target compression rate and compression depth in a realistic DA-CPR scenario.Scott G, Barron T, Gardett I, Broadbent M, Downs H, Devey L, Hinterman EJ, Clawson J, Olola C. Can a software-based metronome tool enhance compression rate in a realistic 911 call scenario without adversely impacting compression depth for dispatcher-assisted CPR? Prehosp Disaster Med. 2018;33(4):399-405.