Uniform reporting of measured quality of cardiopulmonary resuscitation (CPR)

Patient's airway monitoring during cardiopulmonary resuscitation using deep networks

Cardiopulmonary resuscitation (CPR) is a crucial life-saving technique commonly administered to individuals experiencing cardiac arrest. Among the important aspects of CPR is ensuring the correct airway position of the patient, which is typically monitored by human tutors or supervisors. This study aims to utilize deep transfer learning for the detection of the patient's correct and incorrect airway position during cardiopulmonary resuscitation. To address the challenge of identifying the airway position, we curated a dataset consisting of 198 recorded video sequences, each lasting 6-8 s, showcasing both correct and incorrect airway positions during mouth-to-mouth breathing and breathing with an Ambu Bag. We employed six cutting-edge deep networks, namely DarkNet19, EfficientNetB0, GoogleNet, MobileNet-v2, ResNet50, and NasnetMobile. These networks were initially pre-trained on computer vision data and subsequently fine-tuned using the CPR dataset. The validation of the fine-tuned networks in detecting the patient's correct airway position during mouth-to-mouth breathing achieved impressive results, with the best sensitivity (98.8 %), specificity (100 %), and F-measure (97.2 %). Similarly, the detection of the patient's correct airway position during breathing with an Ambu Bag exhibited excellent performance, with the best sensitivity (100 %), specificity (99.8 %), and F-measure (99.7 %).

The association of recent simulation training and clinical experience of team leaders with cardiopulmonary resuscitation quality during in-hospital cardiac arrest

OBJECTIVE

We aimed to investigate the association of recent team leader simulation training (<6 months) and years of clinical experience (≥4 years) with chest compression quality during in-hospital cardiac arrest (IHCA).

METHODS

This cohort study of IHCA in four Danish hospitals included cases with data on chest compression quality and team leader characteristics. We assessed the impact of recent simulation training and experienced team leaders on longest chest compression pause duration (primary outcome), chest compression fraction (CCF), and chest compression rates within guideline recommendations using mixed effects models.

RESULTS

Of 157 included resuscitation attempts, 45% had a team leader who recently participated in simulation training and 66% had an experienced team leader. The median team leader experience was 7 years [Q1; Q3: 4; 11]. The median duration of the longest chest compression pause was 16 s [10; 30]. Having a team leader with recent simulation training was associated with significantly shorter longest pause durations (difference: -7.11 s (95%-CI: -12.0; -2.2), p = 0.004), a higher CCF (difference: 3% (95%-CI: 2.0; 4.0%), p < 0.001) and with less guideline compliant chest compression rates (odds ratio: 0.4 (95%-CI: 0.19; 0.84), p = 0.02). Having an experienced team leader was not associated with longest pause duration (difference: -1.57 s (95%-CI: -5.34; 2.21), p = 0.42), CCF (difference: 0.7% (95%-CI: -0.3; 1.7), p = 0.17) or chest compression rates within guideline recommendations (odds ratio: 1.55 (95%-CI: 0.91; 2.66), p = 0.11).

CONCLUSION

Recent simulation training of team leaders, but not years of team leader experience, was associated with shorter chest compression pauses during IHCA.

Top 5 barriers in cardiac arrest research as perceived by international early career researchers - A consensus study

Aim of the study

Cardiac arrest research has not received as much scientific attention as research on other topics. Here, we aimed to identify cardiac arrest research barriers from the perspective of an international group of early career researchers.

Methods

Attendees of the 2022 international masterclass on cardiac arrest registry research accompanied the Global Out-of-Hospital Cardiac Arrest Registry collaborative meeting in Utstein, Norway, and used an adapted hybrid nominal group technique to obtain a diverse and comprehensive perspective. Barriers were identified using a web-based questionnaire and discussed and ranked during an in-person follow-up meeting. After each response was discussed and clarified, barriers were categorized and ranked over two rounds. Each participant scored these from 1 (least significant) to 5 (most significant).

Results

Nine participants generated 36 responses, forming seven overall categories of cardiac arrest research barriers. "Allocated research time" was ranked first in both rounds. "Scientific environment", including appropriate mentorship and support systems, ranked second in the final ranking. "Resources", including funding and infrastructure, ranked third. "Access to and availability of cardiac arrest research data" was the fourth-ranked barrier. This included data from the cardiac arrest registries, medical devices, and clinical studies. Finally, "uniqueness" was the fifth-ranked barrier. This included ethical issues, patient recruitment challenges, and unique characteristics of cardiac arrest.

Conclusion

By identifying cardiac arrest research barriers and suggesting solutions, this study may act as a tool for stakeholders to focus on helping early career researchers overcome these barriers, thus paving the road for future research.

Extracting physiologic and clinical data from defibrillators for research purposes to improve treatment for patients in cardiac arrest

Background

A defibrillator should be connected to all patients receiving cardiopulmonary resuscitation (CPR) to allow early defibrillation. The defibrillator will collect signal data such as the electrocardiogram (ECG), thoracic impedance and end-tidal CO2, which allows for research on how patients demonstrate different responses to CPR. The aim of this review is to give an overview of methodological challenges and opportunities in using defibrillator data for research.

Methods

The successful collection of defibrillator files has several challenges. There is no scientific standard on how to store such data, which have resulted in several proprietary industrial solutions. The data needs to be exported to a software environment where signal filtering and classifications of ECG rhythms can be performed. This may be automated using different algorithms and artificial intelligence (AI). The patient can be classified being in ventricular fibrillation or -tachycardia, asystole, pulseless electrical activity or having obtained return of spontaneous circulation. How this dynamic response is time-dependent and related to covariates can be handled in several ways. These include Aalen's linear model, Weibull regression and joint models.

Conclusions

The vast amount of signal data from defibrillator represents promising opportunities for the use of AI and statistical analysis to assess patient response to CPR. This may provide an epidemiologic basis to improve resuscitation guidelines and give more individualized care. We suggest that an international working party is initiated to facilitate a discussion on how open formats for defibrillator data can be accomplished, that obligates industrial partners to further develop their current technological solutions.

Compliance with CPR quality guidelines and survival after 30 days following out-of-hospital cardiac arrest. A retrospective study

BACKGROUND

Our study assessed the quality of cardiopulmonary resuscitation (CPR) given by emergency medical services in Southern Ostrobothnia Finland, as is advised in the international guidelines. The goal was to evaluate the current quality of CPR given to patients who suffered an out-of-hospital cardiac arrest and to examine possible measures for improving emergency medical services.

METHODS

A retrospective study was conducted on out-of-hospital cardiac arrest patients in Southern Ostrobothnia, Finland, during a three-year period. Confounding caused by each patient's individual medical history was addressed by calculating Charlson Comorbidity Index (CCI), a score describing individual's risk for death in 10 years. The Utstein analysis and the CPR metrics were acquired from the medical records hospital district in question and analysed in an orderly manner using SPSS. Descriptive statistics are presented as mean (SD) and median [IQR].

RESULTS

We found that of the 349 patients, 144 (41%) received ROSC, 96 (28%) survived to the hospital and 51 (15%) survived for at least 30 days. CPR metrics data were available for 181 patients. CCIs were 3.0 versus 5.0 (p = .157) for the ones who did and those who did not survive at least 30 days. Correspondingly, following metrics were as follows: Mean compression depth was 5.1 (1.3) versus 5.6 (0.8) cm (p = .088), median 28 [18;40] versus 40 [26;54]% of the compressions were in target depth (p = .015) and median compression rate was 113 [109;119] versus 112 [108;120] min-1 (p = .757). The median no-flow fraction was 5.1 [2.8;7.1] versus 3.7 [2.5;5.5] s (p = .073). Ventricular fibrillation (OR 8.74, 95% CI 2.89-26.43, p < .001), public location (OR 3.163, 95% CI 1.03-9.69, p = .044) and compression rate of 100-110/min (OR 7.923, 95% CI 2.11-29.82, p = .002) were related to survival.

CONCLUSION

Patients who suffered out-of-hospital cardiac arrest in Southern Ostrobothnia received CPR that met the international CPR quality target values. The proportion of unintentional pauses during CPR was low and the 30-day survival rate exceeded the international average.

Impedance-Based Ventilation Detection and Signal Quality Control During Out-of-Hospital Cardiopulmonary Resuscitation

Feedback on ventilation could help improve cardiopulmonary resuscitation quality and survival from out-of-hospital cardiac arrest (OHCA). However, current technology that monitors ventilation during OHCA is very limited. Thoracic impedance (TI) is sensitive to air volume changes in the lungs, allowing ventilations to be identified, but is affected by artifacts due to chest compressions and electrode motion. This study introduces a novel algorithm to identify ventilations in TI during continuous chest compressions in OHCA. Data from 367 OHCA patients were included, and 2551 one-minute TI segments were extracted. Concurrent capnography data were used to annotate 20724 ground truth ventilations for training and evaluation. A three-step procedure was applied to each TI segment: First, bidirectional static and adaptive filters were applied to remove compression artifacts. Then, fluctuations potentially due to ventilations were located and characterized. Finally, a recurrent neural network was used to discriminate ventilations from other spurious fluctuations. A quality control stage was also developed to anticipate segments where ventilation detection could be compromised. The algorithm was trained and tested using 5-fold cross-validation, and outperformed previous solutions in the literature on the study dataset. The median (interquartile range, IQR) per-segment and per-patient F 1-scores were 89.1 (70.8-99.6) and 84.1 (69.0-93.9), respectively. The quality control stage identified most low performance segments. For the 50% of segments with highest quality scores, the median per-segment and per-patient F 1-scores were 100.0 (90.9-100.0) and 94.3 (86.5-97.8). The proposed algorithm could allow reliable, quality-conditioned feedback on ventilation in the challenging scenario of continuous manual CPR in OHCA.

Temporal analysis of continuous chest compression rate and depth performed by firefighters during out of hospital cardiac arrest

BACKGROUND

Quality of chest compressions (CC) during cardiopulmonary resuscitation (CPR) often do not meet guideline recommendations for rate and depth. This may be due to the fatiguing nature of physically compressing a patient's chest, meaning that CPR quality reduces over time.

OBJECTIVE

This analysis investigates the effect of CPR duration on the performance of continuous CCs delivered by firefighters equipped with CPR feedback devices.

METHODS

Data were collected from a first responder group which used CPR feedback and automatic external defibrillator devices when attending out-of-hospital cardiac arrest events. Depth and rate of CC were analysed for 134 patients. Mean CC depth and rate were calculated every 5 s during two-minute episodes of CPR. Regression models were created to evaluate the relationship between applied CC depth and rate as a function of time.

RESULTS

Mean (SD) CC depth during the investigation was 48 (9) mm. An inverse relationship was observed between CC depth and CPR duration, where CC depth decreased by 3.39 mm, over two-minutes of CPR (p < 0.001). Mean (SD) CC rate was 112.06 (5.87) compressions per minute. No significant relationship was observed between CC rate and CPR duration (p = 0.077). Mean depth was within guideline range for 33.58% of patient events, while guideline rate was observed in 92.54% of cases.

CONCLUSIONS

A reduction in CC depth was observed during two-minutes of continuous CCs while CC rate was not affected. One third of patients received a mean CC depth within guideline range (50 to 60 mm).

The impact of alcohol use on the quality of cardiopulmonary resuscitation among festival attendees: A prespecified analysis of a randomised trial

BACKGROUND

Cardiac arrests often occur in public places, but despite the undisputed impact of bystander CPR, it is debated whether one should act as a rescuer after alcohol consumption due to the perceived adverse effects. We provide the first objective data on the impact of alcohol levels on CPR-skills.

METHODS

Pre-specified analysis of a randomised study at the Lowlands music festival (August 2019, the Netherlands) on virtual reality vs face-to-face CPR-training. Participants with an alcohol level ≥ 0.5‰ (WHO-endorsed cut-off for traffic participation) were eligible provided they successfully completed a tandem gait test. We studied alcohol levels (AL, ‰) in relation to CPR-quality (compression depth and rate) and CPR-scenario performance.

RESULTS

Median age of the 352 participants was 26 (22-31) years, 56% were female, with n = 214 in Group 1 (AL = 0‰), n = 85 in Group 2 (AL = 0-0.5‰) and n = 53 in Group 3 (AL ≥ 0.5‰). There were no significant differences in CPR-quality (depth: 57 [49-59] vs 57 [51-60] vs 55 mm [47-59], p = 0.16; rate: 115 [104-121] vs 114 [106-122] vs 111 min^-1 [95-120], p = 0.19). There were no significant correlations between alcohol level and compression depth (Spearman's rho -0.113, p = 0.19) or rate (Spearman's rho -0.073, p = 0.39). CPR-scenario performance scores (maximum 13) were not different between groups (12 (9-13) vs 12 (9-13) vs 11 (9-13), p = 0.80).

CONCLUSION

In this study on festival attendees, we found no association between alcohol levels and CPR-quality or scenario performance shortly after training.

TRIAL REGISTRATION

Lowlands Saves Lives is registered on https://www.

CLINICALTRIALS

gov (NCT04013633).

Quality of chest compressions during prehospital resuscitation phase from scene arrival to ambulance transport in out-of-hospital cardiac arrest

AIM

Prehospital cardiopulmonary resuscitation is performed from scene arrival to hospital arrival. The diverse prehospital resuscitation phases can affect the quality of chest compressions. This study aimed to evaluate the dynamic changes in chest compression quality during prehospital resuscitation.

METHODS

Adult out-of-hospital cardiac arrest patients treated without prehospital return of spontaneous circulation were included in Seoul between July 2020 and September 2021. The chest compressions quality was assessed using a real-time chest compression feedback device. The prehospital phase was divided by key events during the prehospital resuscitation timeline (phase 1: first 2 min after initiation of chest compression, phase 2: from the end of phase 1 to 1 min prior to ambulance departure; phase 3: from 1 min before to 1 min after ambulance departure; phase 4: from the end of phase 3 to hospital arrival). The main outcome was no-flow fraction. The no-flow fraction between prehospital phases was compared using repeated-measure analysis of variance.

RESULTS

In total, 788 patients were included. Mean no-flow fraction was the highest in phase 3 (phase 1: 11.3% ± 13.8, phase 2: 19.3% ± 12.3, phase 3: 33.0% ± 34.9, phase 4: 18.7% ± 23.7, p < 0.001). The mean number of total no-flow events per minute was also the highest in phase 3. The minute-by-minute analysis showed that the no-flow fraction rapidly increased before ambulance departure and decreased during ambulance transport.

CONCLUSION

Dynamic changes in chest compression quality were observed during prehospital resuscitation phase. The no-flow fraction was the highest from 1 min before to 1 min after ambulance departure.

Manual and Mechanical Induced Peri-Resuscitation Injuries-Post-Mortem and Clinical Findings

(1) Background: Injuries related to resuscitation are not usually systematically recorded and documented. By evaluating this data, conclusions could be drawn about the quality of the resuscitation, with the aim of improving patient care and safety. (2) Methods: We are planning to conduct a multicentric, retrospective 3-phased study consisting of (1) a worldwide literature review (scoping review), (2) an analysis of anatomical pathological findings from local institutions in North Rhine-Westphalia, Germany to assess the transferability of the review data to the German healthcare system, and (3) depending on the results, possibly establishing potential prospective indicators for resuscitation-related injuries as part of quality assurance measures. (3) Conclusions: From the comparison of literature and local data, the picture of resuscitation-related injuries will be focused on and quality indicators will be derived.

Healthcare Provider Characteristics and Cardiopulmonary Resuscitation Quality During Infant Resuscitation: A Simulation Study

INTRODUCTION

Healthcare providers' anthropometric characteristics can adversely affect adult cardiopulmonary resuscitation (CPR) performance quality. However, their effects on infant CPR are unknown. We aimed to determine any relationships between healthcare provider characteristics (anthropomorphic, demographics, training, occupational data) and simulated infant CPR performance at multiple international sites. Our secondary aim was to examine provider's CPR performance degradation.

METHODS

Providers from 4 international hospitals performed 2 minutes of single-rescuer simulated infant CPR using 2015 American Heart Association Basic Life Support criteria with guidance from a real-time visual performance feedback device. Providers' characteristics were collected, and the simulator collected compression and ventilation data. Multivariate analyses examined the entire 2 minutes and performance degradation.

RESULTS

Data from 127 participants were analyzed. Although median values for all compression variables (depth, rate, lean) and ventilation volume were within guideline target ranges, when looking at individuals, only 52% chest compressions and 20% ventilations adhered to the American Heart Association guidelines. Age was found to be independently associated with ventilation volume (direct-relationship), and height was associated with chest compression lean (shorter participant-deeper lean). No significant differences were noted based on sex or body mass index. Neonatal intensive care unit participants were noted to perform shallower chest compressions (P < 0.001). Overall, there was minimal evidence of performance degradation over 2 minutes.

CONCLUSIONS

Isolated provider characteristics were noted among a diverse cohort of healthcare providers that may affect the CPR quality on a simulated infant. Understanding the relationships between provider characteristics and CPR quality could inform future infant CPR guidelines customized for the provider and not just the patient.

A sliding-window based algorithm to determine the presence of chest compressions from acceleration data

This publication presents in detail five exemplary cases and the algorithm used in the article (Orlob et al. 2022). Defibrillator records for the five exemplary cases were obtained from the German Resuscitation Registry. They consist of accelerometry, electrocardiogram and capnography time series as well as defibrillation times, energies and impedance when recorded. For these cases, experienced physicians annotated time points of cardiac arrest and return of spontaneous circulation or termination of resuscitation attempts, as well as the beginning and ending of every single chest compression period in consensus, as described in Orlob et al. (2022). Furthermore, an algorithm was developed which reliably detects chest compression periods automatically without the time-consuming process of manual annotation. This algorithm allows for an usage in automatic resuscitation quality assessment, machine learning approaches, and handling of big amounts of data (Orlob et al. 2022).

Chest compression fraction calculation: A new, automated, robust method to identify periods of chest compressions from defibrillator data - Tested in Zoll X Series

AIM

To introduce and evaluate a new, open-source algorithm to detect chest compression periods automatically by the rhythmic, high amplitude signals from an accelerometer, without processing single chest compression events, and to consecutively calculate the chest compression fraction (CCF).

METHODS

A consecutive sample of defibrillator records from the German Resuscitation Registry was obtained and manually annotated in consensus as ground truth. Chest compression periods were determined by different automatic approaches, including the new algorithm. The diagnostic performance of these approaches was assessed. Further, using the different approaches in conjunction with different granularities of manual annotation, several CCF versions were calculated and compared by intraclass correlation coefficient (ICC).

RESULTS

131 defibrillator recordings with a total duration of 5755 minutes were analysed. The new algorithm had a sensitivity of 99.39 (95% CI 99.38, 99.41)% and specificity of 99.17 (95% CI 99.15; 99.18)% to detect chest compressions at any given timepoint. The ICC compared to ground truth was 0.998 for the new algorithm and 0.999 for manual annotation, while the ICC of the proposed algorithm compared to the proprietary software was 0.978. The time required for manual annotation to calculate CCF was reduced by 70.48 (22.55, [94.35, 14.45])%.

CONCLUSION

The proposed algorithm reliably detects chest compressions in defibrillator recordings. It can markedly reduce the workload for manual annotation, which may facilitate uniform reporting of measured quality of cardiopulmonary resuscitation. The algorithm is made freely available and may be used in big data analysis and machine learning approaches.

Quality of Cardiopulmonary Resuscitation and 5-Year Survival Following in-Hospital Cardiac Arrest

PURPOSE

To improve cardiac arrest survival, international resuscitation guidelines emphasize measuring the quality of cardiopulmonary resuscitation (CPR). We aimed to investigate CPR quality during in-hospital cardiac arrest (IHCA) and study long-term survival outcomes.

PATIENTS AND METHODS

This was a cohort study of IHCA from December 2011 until November 2014. Data were collected from the hospital switch board, patient records, and from defibrillators. Impedance data from defibrillators were analyzed manually at the level of single compressions. Long-term survival at 1-, 3-, and 5 years is reported.

RESULTS

The study included 189 IHCAs; median (interquartile range (IQR)) time to first rhythm analysis was 116 (70-201) seconds and median (IQR) time to first defibrillation was 133 (82-264) seconds. Median (IQR) chest compression rate was 126 (119-131) per minute and chest compression fraction (CCF) was 78% (69-86). Thirty-day survival was 25%, while 1-year-, 3-year-, and 5-year survival were 21%, 14%, and 13%, respectively. There was no significant association between any survival outcomes and CCF, whereas chest compression rate was associated with survival to 30 days and 3 years. Overall, 5-year survival was associated with younger age (median 68 vs 74 years, p=0.003), less comorbidity (Charlson comorbidity index median 3 vs 5, p<0.001), and witnessed cardiac arrest (96% vs 77%, p=0.03).

CONCLUSION

We established a systematic collection of IHCA CPR quality data to measure and improve CPR quality and long-term survival outcomes. Median time to first rhythm check/defibrillation was <3 minutes, but median chest compression rate was too fast and median CCF slightly below 80%. More than half of 30-day survivors were still alive at 5 years.

Pre-charging the defibrillator before rhythm analysis reduces hands-off time in patients with out-of-hospital cardiac arrest with shockable rhythm

AIM

To evaluate the effect of pre-charging the defibrillator before rhythm analysis on hands-off time in patients suffering from out-of-hospital cardiac arrest with shockable rhythm.

METHODS

Pre-charging was implemented in the Emergency Medical Service in the Central Denmark Region in June 2018. Training consisted of hands-on simulation scenarios, e-learning material, and written instructions. Data were extracted from the Danish Cardiac Arrest Registry for a 14-month period spanning the implementation of pre-charging. Patients having received at least one shock were included. Transthoracic impedance data were analysed. We recorded hands-off time and peri-shock pauses for all defibrillation procedures and the total hands-off fraction for all cardiac arrests.

RESULTS

Impedance and outcome data were available for 178 patients. 523 defibrillation procedures were analysed. The pre-charge method was associated with shorter median hands-off time per defibrillation procedure (7.6 (IQR 5.8-9.9) vs. 12.6 (IQR 10-16.4) seconds, p < 0.001) but longer pre-shock pause (4 (IQR 2.7-6.1) vs 1.7 (IQR 1.2-3) seconds, p < 0.001) when compared to the current guideline-recommended defibrillation method. The total hands-off fraction per cardiac arrest was reduced after implementation of the pre-charge method (16.5% vs. 20.4%, p = 0.003). No increase in shocks to non-shockable rhythms or personnel was registered. Patients who received only pre-charge defibrillations had an increased odds ratio of return of spontaneous circulation (aOR 2.91; 95%CI 1.09-7.8, p = 0.03).

CONCLUSION

Pre-charging the defibrillator reduced hands-off time during defibrillation procedures, reduces the total hands-off fraction and may be associated with increased return of spontaneous circulation in out-of-hospital cardiac arrest with shockable rhythm.

Methodology and framework for the analysis of cardiopulmonary resuscitation quality in large and heterogeneous cardiac arrest datasets

BACKGROUND

Out-of-hospital cardiac arrest (OHCA) data debriefing and clinical research often require the retrospective analysis of large datasets containing defibrillator files from different vendors and clinical annotations by the emergency medical services.

AIM

To introduce and evaluate a methodology to automatically extract cardiopulmonary resuscitation (CPR) quality data in a uniform and systematic way from OHCA datasets from multiple heterogeneous sources.

METHODS

A dataset of 2236 OHCA cases from multiple defibrillator models and manufacturers was analyzed. Chest compressions were automatically identified using the thoracic impedance and compression depth signals. Device event time-stamps and clinical annotations were used to set the start and end of the analysis interval, and to identify periods with spontaneous circulation. A manual audit of the automatic annotations was conducted and used as gold standard. Chest compression fraction (CCF), rate (CCR) and interruption ratio were computed as CPR quality variables. The unsigned error between the automated procedure and the gold standard was calculated.

RESULTS

Full-episode median errors below 2% in CCF, 1 min^-1 in CCR, and 1.5% in interruption ratio, were measured for all signals and devices. The proportion of cases with large errors (>10% in CCF and interruption ratio, and >10 min^-1 in CCR) was below 10%. Errors were lower for shorter sub-intervals of interest, like the airway insertion interval.

CONCLUSIONS

An automated methodology was validated to accurately compute CPR metrics in large and heterogeneous OHCA datasets. Automated processing of defibrillator files and the associated clinical annotations enables the aggregation and analysis of CPR data from multiple sources.

Resuscitation Team Roles and Responsibilities: In-Hospital Cardiopulmonary Arrest Teams

Patients who experience an in-hospital cardiopulmonary arrest event often have poor outcomes. Those outcomes are influenced by institutional factors, including the effectiveness of the responding team. Two main types of response teams may exist for in-hospital settings: basic life support trained staff providing initial interventions, and advanced cardiac life support teams. The interface between these two responses, and differences in discipline, experience, and skill mix, adds complexity to team dynamics. In-hospital cardiopulmonary arrest teams benefit from addressing these and other factors, which may lead to lack of clarity in role and responsibility identification and ultimately team performance.

The effective group size for teaching cardiopulmonary resuscitation skills - A randomized controlled simulation trial

AIM OF THE STUDY

The ideal group size for effective teaching of cardiopulmonary resuscitation is currently under debate. The upper limit is reached when instructors are unable to correct participants' errors during skills practice. This simulation study aimed to define this limit during cardiopulmonary resuscitation teaching.

METHODS

Medical students acting as simulated Basic Life Support course participants were instructed to make three different pre-defined Basic Life Support quality errors (e.g., chest compression too fast) in 7 min. Basic Life Support instructors were randomized to groups of 3-10 participants. Instructors were asked to observe the Basic Life Support skills and to correct performance errors. Primary outcome was the maximum group size at which the percentage of correctly identified participants' errors drops below 80%.

RESULTS

Sixty-four instructors participated, eight for each group size. Their average age was 41 ± 9 years and 33% were female, with a median [25th percentile; 75th percentile] teaching experience of 6 [2;11] years. Instructors had taught 3 [1;5] cardiopulmonary resuscitation courses in the year before the study. A logistic binominal regression model showed that the predicted mean percentage of correctly identified participants' errors dropped below 80% for group sizes larger than six.

CONCLUSION

This randomized controlled simulation trial reveals decreased ability of instructors to detect Basic Life Support performance errors with increased group size. The maximum group size enabling Basic Life Support instructors to correct more than 80% of errors is six. We therefore recommend a maximum instructor-to-participant ratio of 1:6 for cardiopulmonary resuscitation courses.

Efficacy of a new dispatcher-assisted cardiopulmonary resuscitation protocol with audio call-to-video call transition

BACKGROUND

Video call based dispatcher-assisted cardiopulmonary resuscitation (V-DACPR) has been suggested to improve the quality of bystander cardiopulmonary resuscitation. In the current system, dispatchers must convert the audio calls to video calls to provide V-DACPR. We aimed to develop new audio call-to-video call transition protocols and test its efficacy and safety compared to conventional DACPR(C-DACPR).

METHODS

This was a randomized controlled simulation trial that compared the quality of bystander chest compression that was performed under three different DACPR protocols: C-DACPR, V-DACPR with rapid transition, and V-DACPR with delayed transition. Adult volunteers excluding healthcare providers were recruited for the trial. The primary outcome of the study was the mean proportion of adequate hand positioning during chest compression.

RESULTS

Simulation results of 131 volunteers were analyzed. The mean proportion of adequate hand positioning was highest in V-DACPR with rapid transition (V-DACPR with rapid transition vs. C-DACPR: 92.7% vs. 82.4%, p = 0.03). The mean chest compression depth was deeper in both V-DACPR groups than in the C-DACPR group (V-DACPR with rapid transition vs. C-DACPR: 40.7 mm vs. 35.9 mm, p = 0.01, V-DACPR with delayed transition vs. C- DACPR: 40.9 mm vs. 35.9 mm, p = 0.01). Improvement in the proportion of adequate hand positioning was observed in the V-DACPR groups (r = 0.25, p < 0.01 for rapid transition and r = 0.19, p < 0.01 for delayed transition).

CONCLUSION

Participants in the V-DACPR groups performed higher quality chest compression with higher appropriate hand positioning and deeper compression depth compared to the C-DACPR group.

Airway strategy and chest compression quality in the Pragmatic Airway Resuscitation Trial

BACKGROUND

Chest compression (CC) quality is associated with improved out-of-hospital cardiopulmonary arrest (OHCA) outcomes. Airway management efforts may adversely influence CC quality. We sought to compare the effects of initial laryngeal tube (LT) and initial endotracheal intubation (ETI) airway management strategies upon chest compression fraction (CCF), rate and interruptions in the Pragmatic Airway Resuscitation Trial (PART).

METHODS

We analyzed CPR process files collected from adult OHCA enrolled in PART. We used automated signal processing techniques and a graphical user interface to calculate CC quality measures and defined interruptions as pauses in chest compressions longer than 3 s. We determined CC fraction, rate and interruptions (number and total duration) for the entire resuscitation and compared differences between LT and ETI using t-tests. We repeated the analysis stratified by time before, during and after airway insertion as well as by successive 3-min time segments. We also compared CC quality between single vs. multiple airway insertion attempts, as well as between bag-valve-mask (BVM-only) vs. ETI or LT.

RESULTS

Of 3004 patients enrolled in PART, CPR process data were available for 1996 (1001 LT, 995 ETI). Mean CPR analysis duration were: LT 22.6 ± 10.8 min vs. ETI 25.3 ± 11.3 min (p < 0.001). Mean CC fraction (LT 88% vs. ETI 87%, p = 0.05) and rate (LT 114 vs. ETI 114 compressions per minute (cpm), p = 0.59) were similar between LT and ETI. Median number of CC interruptions were: LT 11 vs. ETI 12 (p = 0.001). Total CC interruption duration was lower for LT than ETI (LT 160 vs. ETI 181 s, p = 0.002); this difference was larger before airway insertion (LT 56 vs. ETI 78 s, p < 0.001). There were no differences in CC quality when stratified by 3-min time epochs.

CONCLUSION

In the PART trial, compared with ETI, LT was associated with shorter total CC interruption duration but not other CC quality measures. CC quality may be associated with OHCA airway management.

Virtual reality as a teaching method for resuscitation training in undergraduate first year medical students: a randomized controlled trial

Background

Virtual reality is an innovative technology for medical education associated with high empirical realism.

Therefore, this study compares a conventional cardiopulmonary resuscitation (CPR) training with a Virtual Reality (VR) training aiming to demonstrate: (a) non-inferiority of the VR intervention in respect of no flow time and (b) superiority in respect of subjective learning gain.

Methods

In this controlled randomized study first year, undergraduate students were allocated in the intervention group and the control group. Fifty-six participants were randomized to the intervention group and 104 participants to the control group. The intervention group received an individual 35-min VR Basic Life Support (BLS) course and a basic skill training. The control group took part in a “classic” BLS-course with a seminar and a basic skill training.

The groups were compared in respect of no flow time in a final 3-min BLS examination (primary outcome) and their learning gain (secondary outcome) assessed with a comparative self-assessment (CSA) using a questionnaire at the beginning and the end of the course. Data analysis was performed with a general linear fixed effects model.

Results

The no flow time was significantly shorter in the control group (Mean values: control group 82 s vs. intervention group 93 s; p = 0.000). In the CSA participants of the intervention group had a higher learning gain in 6 out of 11 items of the questionnaire (p < 0.05).

Conclusion

A “classic” BLS-course with a seminar and training seems superior to VR in teaching technical skills. However, overall learning gain was higher with VR. Future BLS course-formats should consider the integration of VR technique into the classic CPR training or vice versa, to use the advantage of both teaching techniques.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13049-021-00836-y.

Effect of Face-to-Face vs Virtual Reality Training on Cardiopulmonary Resuscitation Quality: A Randomized Clinical Trial

Importance

Bystander cardiopulmonary resuscitation (CPR) is crucial for survival after cardiac arrest but not performed in most cases. New, low-cost, and easily accessible training methods, such as virtual reality (VR), may reach broader target populations, but data on achieved CPR skills are lacking.

Objective

To compare CPR quality between VR and face-to-face CPR training.

Design, Setting, and Participants

Randomized noninferiority trial with a prospective randomized open blinded end point design. Participants were adult attendees from the science section of the Lowlands Music Festival (August 16 to 18, 2019) in the Netherlands. Analysis began September 2019.

Interventions

Two standardized 20-minute protocols on CPR and automated external defibrillator use: instructor-led face-to-face training or VR training using a smartphone app endorsed by the Resuscitation Council (United Kingdom).

Main Outcomes and Measures

During a standardized CPR scenario following the training, we assessed the primary outcome CPR quality, measured as chest compression depth and rate using CPR manikins. Overall CPR performance was assessed by examiners, blinded for study groups, using a European Resuscitation Council-endorsed checklist (maximum score, 13). Additional secondary outcomes were chest compression fraction, proportions of participants with mean depth (50 mm-60 mm) or rate (100 min-1-120 min-1) within guideline ranges, and proportions compressions with full release.

Results

A total of 381 participants were randomized: 216 women (57%); median (interquartile range [IQR]) age, 26 (22-31) years. The VR app (n = 190 [49.9%]) was inferior to face-to-face training (n = 191 [50.1%]) for chest compression depth (mean [SD], VR: 49 [10] mm vs face to face: 57 [5] mm; mean [95% CI] difference, -8 [-9 to -6] mm), and noninferior for chest compression rate (mean [SD]: VR: 114 [12] min-1 vs face to face: 109 [12] min-1; mean [95% CI] difference, 6 [3 to 8] min-1). The VR group had lower overall CPR performance scores (median [IQR], 10 [8-12] vs 12 [12-13]; P < .001). Chest compression fraction (median [IQR], 61% [52%-66%] vs 67% [62%-71%]; P < .001) and proportions of participants fulfilling depth (51% [n = 89] vs 75% [n = 133], P < .001) and rate (50% [n = 87] vs 63% [n = 111], P = .01) requirements were also lower in the VR group. The proportion of compressions with full release was higher in the VR group (median [IQR], 98% [59%-100%] vs 88% [55%-99%]; P = .002).

Conclusions and Relevance

In this randomized noninferiority trial, VR training resulted in comparable chest compression rate but inferior compression depth compared with face-to-face training. Given the potential of VR training to reach a larger target population, further development is needed to achieve the compression depth and overall CPR skills acquired by face-to-face training.

Trial Registration

ClinicalTrials.gov identifier: NCT04013633.

Automatic identification of compressions and ventilations during CPR based on the fuzzy c-means clustering and deep belief network

Background

A transthoracic impedance (TTI) signal is an important indicator of the quality of chest compressions (CCs) during cardiopulmonary resuscitation (CPR). We proposed an automatic detection algorithm including the wavelet decomposition, fuzzy c-means (FCM) clustering, and deep belief network (DBN) to identify the compression and ventilation waveforms for evaluating the quality of CPR.

Methods

TTI signals were collected from a cardiac arrest model that electrically induced cardiac arrest in pigs. All signals were denoised using the wavelet and morphology method. The potential compression and ventilation waveforms were marked using an algorithm with a multi-resolution window. The compressions and ventilations in these waveforms were identified and classified using the FCM clustering and DBN methods.

Results

Using the FCM clustering method, the positive predictive values (PPVs) for compressions and ventilations were 99.7% and 95.7%, respectively. The sensitivities of recognition were 99.8% for compressions and 95.1% for ventilations. The DBN approach exhibited similar PPV and sensitivity results to the FCM clustering method. The time cost was satisfactory using either of these techniques.

Conclusions

Our findings suggest that FCM clustering and DBN can be utilized to effectively and accurately evaluate CPR quality, and provide information for improving the success rate of CPR. Our real-time algorithms using FCM clustering and DBN eliminated most distortions and noises effectively, and correctly identified the compression and ventilation waveforms with a low time cost.

Systematic review and meta-analysis appraising efficacy and safety of adrenaline for adult cardiopulmonary resuscitation

BACKGROUND

There is a beneficial effect of adrenaline during adult cardiopulmonary resuscitation (CPR) from cardiac arrest but there is also uncertainty about its safety and effectiveness. The aim of this study was to evaluate the use of adrenaline versus non-adrenaline CPR.

METHODS

PubMed, ScienceDirect, Embase, CENTRAL (Cochrane Central Register of Controlled Trials) and Google Scholar databases were searched from their inception up to 1st July 2020. Two reviewers independently assessed eligibility and risk of bias, with conflicts resolved by a third reviewer. Risk ratio (RR) or mean difference of groups were calculated using fixed or random-effect models.

RESULTS

Nineteen trials were identified. The use of adrenaline during CPR was associated with a significantly higher percentage of return of spontaneous circulation (ROSC) compared to non-adrenaline treatment (20.9% vs. 5.9%; RR = 1.87; 95% confidence interval [CI] 1.37-2.55; p < 0.001). The use of adrenaline in CPR was associated with ROSC at 19.4% and for non-adrenaline treatment - 4.3% (RR = 3.23; 95% CI 1.89-5.53; p < 0.001). Survival to discharge (or 30-day survival) when using adrenaline was 6.8% compared to non-adrenaline treatment (5.5%; RR = 0.99; 95% CI 0.76-1.30; p = 0.97). However, the use of adrenaline was associated with a worse neurological outcome (1.6% vs. 2.2%; RR = 0.57; 95% CI 0.42-0.78; p < 0.001).

CONCLUSIONS

This review suggests that resuscitation with adrenaline is associated with the ROSC and survival to hospital discharge, but no higher effectiveness was observed at discharge with favorable neurological outcome. The analysis showed higher effectiveness of ROSC and survival to hospital discharge in non-shockable rhythms. But more multicenter randomized controlled trials are needed in the future.

Monitoring chest compression rate in automated external defibrillators using the autocorrelation of the transthoracic impedance

Aim

High-quality chest compressions is challenging for bystanders and first responders to out-of-hospital cardiac arrest (OHCA). Long compression pauses and compression rates higher than recommended are common and detrimental to survival. Our aim was to design a simple and low computational cost algorithm for feedback on compression rate using the transthoracic impedance (TI) acquired by automated external defibrillators (AEDs).

Methods

ECG and TI signals from AED recordings of 242 OHCA patients treated by basic life support (BLS) ambulances were retrospectively analyzed. Beginning and end of chest compression series and each individual compression were annotated. The algorithm computed a biased estimate of the autocorrelation of the TI signal in consecutive non-overlapping 2-s analysis windows to detect the presence of chest compressions and estimate compression rate.

Results

A total of 237 episodes were included in the study, with a median (IQR) duration of 10 (6–16) min. The algorithm performed with a global sensitivity in the detection of chest compressions of 98.7%, positive predictive value of 98.7%, specificity of 97.1%, and negative predictive value of 97.1% (validation subset including 207 episodes). The unsigned error in the estimation of compression rate was 1.7 (1.3–2.9) compressions per minute.

Conclusion

Our algorithm is accurate and robust for real-time guidance on chest compression rate using AEDs. The algorithm is simple and easy to implement with minimal software modifications. Deployment of AEDs with this capability could potentially contribute to enhancing the quality of chest compressions in the first minutes from collapse.

Real-time feedback improves chest compression quality in out-of-hospital cardiac arrest: A prospective cohort study

Background

Current guidelines underline the importance of high-quality chest compression during cardiopulmonary resuscitation (CPR), to improve outcomes. Contrary to this many studies show that chest compression is often carried out poorly in clinical practice, and long interruptions in compression are observed. This prospective cohort study aimed to analyse whether chest compression quality changes when a real-time feedback system is used to provide simultaneous audiovisual feedback on chest compression quality. For this purpose, pauses in compression, compression frequency and compression depth were compared.

Methods

The study included 292 out-of-hospital cardiac arrests in three consecutive study groups: first group, conventional resuscitation (no-sensor CPR); second group, using a feedback sensor to collect compression depth data without real-time feedback (sensor-only CPR); and third group, with real-time feedback on compression quality (sensor-feedback CPR). Pauses and frequency were analysed using compression artefacts on electrocardiography, and compression depth was measured using the feedback sensor. With this data, various parameters were determined in order to be able to compare the chest compression quality between the three consecutive groups.

Results

The compression fraction increased with sensor-only CPR (group 2) in comparison with no-sensor CPR (group 1) (80.1% vs. 87.49%; P < 0.001), but there were no further differences belonging compression fraction after activation of sensor-feedback CPR (group 3) (P = 1.00). Compression frequency declined over the three study groups, reaching the guideline recommendations (127.81 comp/min vs. 122.96 comp/min, P = 0.02 vs. 119.15 comp/min, P = 0.008) after activation of sensor-feedback CPR (group 3). Mean compression depth only changed minimally with sensor-feedback (52.49 mm vs. 54.66 mm; P = 0.16), but the fraction of compressions with sufficient depth (at least 5 cm) and compressions within the recommended 5–6 cm increased significantly with sensor-feedback CPR (56.90% vs. 71.03%; P = 0.003 and 28.74% vs. 43.97%; P < 0.001).

Conclusions

The real-time feedback system improved chest compression quality regarding pauses in compression and compression frequency and facilitated compliance with the guideline recommendations. Compression depth did not change significantly after activation of the real-time feedback. Even the sole use of a CPR-feedback-sensor (“sensor-only CPR”) improved performance regarding pauses in compression and compression frequency, a phenomenon known as the ‘Hawthorne effect’. Based on this data real-time feedback systems can be expected to raise the quality level in some parts of chest compression quality.

Trial registration

International Clinical Trials Registry Platform of the World Health Organisation and German Register of Clinical Trials (DRKS00009903), Registered 09 February 2016 (retrospectively registered).

Variability in chest compression rate calculations during pediatric cardiopulmonary resuscitation

AIM

The mathematical method used to calculate chest compression (CC) rate during cardiopulmonary resuscitation varies in the literature and across device manufacturers. The objective of this study was to determine the variability in calculated CC rates by applying four published methods to the same dataset.

METHODS

This study was a secondary investigation of the first 200 pediatric cardiac arrest events with invasive arterial line waveform data in the ICU-RESUScitation Project (NCT02837497). Instantaneous CC rates were calculated during periods of uninterrupted CCs. The defined minimum interruption length affects rate calculation (e.g., if an interruption is defined as a break in CCs ≥ 2 s, the lowest possible calculated rate is 30 CCs/min). Average rates were calculated by four methods: 1) rate with an interruption defined as ≥ 1 s; 2) interruption ≥ 2 s; 3) interruption ≥ 3 s; 4) method #3 excluding top and bottom quartiles of calculated rates. American Heart Association Guideline-compliant rate was defined as 100-120 CCs/min. A clinically important change was defined as ±5 CCs/min. The percentage of events and epochs (30 s periods) that changed Guideline-compliant status was calculated.

RESULTS

Across calculation methods, mean CC rates (118.7-119.5/min) were similar. Comparing all methods, 14 events (7%) and 114 epochs (6%) changed Guideline-compliant status.

CONCLUSION

Using four published methods for calculating CC rate, average rates were similar, but 7% of events changed Guideline-compliant status. These data suggest that a uniform calculation method (interruption ≥ 1 s) should be adopted to decrease variability in resuscitation science.

Automatic Detection of Ventilations During Mechanical Cardiopulmonary Resuscitation

Feedback on chest compressions and ventilations during cardiopulmonary resuscitation (CPR) is important to improve survival from out-of-hospital cardiac arrest (OHCA). The thoracic impedance signal acquired by monitor-defibrillators during treatment can be used to provide feedback on ventilations, but chest compression components prevent accurate detection of ventilations. This study introduces the first method for accurate ventilation detection using the impedance while chest compressions are concurrently delivered by a mechanical CPR device. A total of 423 OHCA patients treated with mechanical CPR were included, 761 analysis intervals were selected which in total comprised 5 884 minutes and contained 34 864 ventilations. Ground truth ventilations were determined using the expired CO ₂ channel. The method uses adaptive signal processing to obtain the impedance ventilation waveform. Then, 14 features were calculated from the ventilation waveform and fed to a random forest (RF) classifier to discriminate false positive detections from actual ventilations. The RF feature importance was used to determine the best feature subset for the classifier. The method was trained and tested using stratified 10-fold cross validation (CV) partitions. The training/test process was repeated 20 times to statistically characterize the results. The best ventilation detector had a median (interdecile range, IDR) F ₁-score of 96.32 (96.26-96.37). When used to provide feedback in 1-min intervals, the median (IDR) error and relative error in ventilation rate were 0.002 (-0.334-0.572) min^-1 and 0.05 (-3.71-9.08)%, respectively. An accurate ventilation detector during mechanical CPR was demonstrated. The algorithm could be introduced in current equipment for feedback on ventilation rate and quality, and it could contribute to improve OHCA survival rates.

Rationale and design of the Lowlands Saves Lives trial: a randomised trial to compare CPR quality and long-term attitude towards CPR performance between face-to-face and virtual reality training with the Lifesaver VR app

INTRODUCTION

Layperson cardiopulmonary resuscitation (CPR) is a key aspect in the chain of survival after cardiac arrest. New, low-cost, easily accessible training methods such as virtual reality (VR) training with a smartphone application may reach broader populations, but data on CPR performance are scarce.

METHODS AND ANALYSIS

The Lowlands Saves Lives trial is a prospective randomised open-blinded end-point evaluation study, comparing two 20 min CPR training protocols: standardised, certified instructor-led face-to-face training complying with current education guidelines (using Laerdal Little Anne manikins), and VR training, using the UK Resuscitation Council endorsed Lifesaver VR app. In the latter, chest compressions are practiced on a pillow.During VR training, participants learn to resuscitate by completing a filmed CPR scenario while wearing VR goggles and headphones. Eligible for inclusion are adult attendees of Lowlands Science, a specific section of the 3-day Lowlands music festival (50 000 attendees), dedicated exclusively to science. Following the training, all participants will perform a CPR test on a Laerdal Resusci Anne QCPR manikin. Primary outcome measures are depth and rate of chest compressions, measured using CPR manikins. The key secondary outcome is overall CPR performance, with real-time examination (blinded for study group) of all items of a European Resuscitation Council endorsed checklist, and evaluation of a sample of videotaped CPR tests by a blinded event committee.Given the unique setting of a festival, the primary additional analysis will address the impact of alcohol levels on CPR quality parameters and overall performance. Follow-up questionnaires will evaluate the attitude towards performing CPR. This unique study may provide important insights into innovative CPR training methods, factors that impact CPR performance and the impact on long-term attitude towards resuscitation.

ETHICS AND DISSEMINATION

This study received approval from the research ethics committee of the Radboudumc. All participants will provide written informed consent. The results of this study will be published in peer-reviewed journals and presented at (inter)national conferences.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov registry (NCT04013633).

Impact of 'synchronous' and 'asynchronous' CPR modality on quality bundles and outcome in out-of-hospital cardiac arrest patients

During cardiopulmonary resuscitation (CPR), the need to interrupt chest compressions to provide synchronous ventilations prevents blood flow continuity, reducing the possibility to ensure high-quality CPR bundles of care and, thus, having a potentially negative impact on perfusion and patient outcome. Contemporaneous asynchronous chest compressions and ventilations may avoid these potentially negative effects. Only a few studies measured the CPR quality metrics during synchronous and asynchronous CPR modality and its relation to patient outcome. A prospective observational study was conducted on 285 consecutive adult patients with out-of-hospital cardiac arrest treated by EMS teams over a 30-month period. Ventilation rate, chest compression fraction (i.e. cardiac arrest time spent delivering uninterrupted chest compressions compared to total cardiac arrest time) and chest compression rate per minute were collected in real time by defibrillators and analysed through a dedicated software (electrical cardiac activity through the ECG, chest compression and ventilations through the transthoracic impedance) during synchronous and asynchronous CPR modalities. During asynchronous CPR modality, higher ventilation rate and chest compression fraction (p  < 0.001), and lower chest compression rate per minute (p < 0.001) were ensured, being all cited metrics more adherent to the high-quality CPR bundles. Ventilation rate provided during the whole CPR was an independent predictor for a good neurological outcome (OR 3.795, p = 0.005). Asynchronous chest compression and ventilation ensured the most adequate chest compression fraction, uninterrupted chest compression rate and ventilation rate.

Can real-time feedback improve the simulated infant cardiopulmonary resuscitation performance of basic life support and lay rescuers?

BACKGROUND

Performing high-quality chest compressions during cardiopulmonary resuscitation (CPR) requires achieving of a target depth, release force, rate and duty cycle.

OBJECTIVE

This study evaluates whether 'real time' feedback could improve infant CPR performance in basic life support-trained (BLS) and lay rescuers. It also investigates whether delivering rescue breaths hinders performing high-quality chest compressions. Also, this study reports raw data from the two methods used to calculate duty cycle performance.

METHODOLOGY

BLS (n=28) and lay (n=38) rescuers were randomly allocated to respective 'feedback' or 'no-feedback' groups, to perform two-thumb chest compressions on an instrumented infant manikin. Chest compression performance was then investigated across three compression algorithms (compression only; five rescue breaths then compression only; five rescue breaths then 15:2 compressions). Two different routes to calculate duty cycle were also investigated, due to conflicting instruction in the literature.

RESULTS

No-feedback BLS and lay groups demonstrated <3% compliance against each performance target. The feedback rescuers produced 20-fold and 10-fold increases in BLS and lay cohorts, respectively, achieving all targets concurrently in >60% and >25% of all chest compressions, across all three algorithms. Performing rescue breaths did not impede chest compression quality.

CONCLUSIONS

A feedback system has great potential to improve infant CPR performance, especially in cohorts that have an underlying understanding of the technique. The addition of rescue breaths-a potential distraction-did not negatively influence chest compression quality. Duty cycle performance depended on the calculation method, meaning there is an urgent requirement to agree a single measure.

Circumstances, outcome and quality of cardiopulmonary resuscitation by lifeboat crews

BACKGROUND

Little is known regarding circumstances, outcomes and quality of cardiopulmonary resuscitation (CPR) and the use of automated external defibrillators (AEDs) performed by operational lifeboat crews. Our aim is to evaluate circumstances, outcomes and quality of CPR performed by the Royal Dutch Lifeboat Institution (KNRM) in out-of-hospital cardiac arrest (OHCA).

METHODS

The internal KNRM database has been used to identify and analyse all OHCA cases between July 2011 and December 2017. A limited set of AED data was available to study the quality of CPR.

RESULTS

In 37 patients the lifeboat crew members have performed CPR, of which 29 (78.4%) occurred under hostile conditions. The median response time to arrive at the location was 15min. In 11 (29.7%) patients return of spontaneous circulation was achieved at any moment during CPR and 3 (8.1%) patients were still alive after one month. The lifeboat AED was used in 12 patients. Their recordings show a high median compression frequency (120, IQR 111-131) and prolonged median interruption periods (pre-analysis pause 11s (IQR 10-13), post-analysis pause 4s (IQR 3-8), pre-shock pause 24s (IQR 19-26), post-shock pause 6s (IQR 6-11), ventilation pause 6s (IQR 4-8) and other pauses 9s (IQR 4-17)).

CONCLUSIONS

Compared to most out-of-hospital resuscitations, resuscitations by lifeboat crews have a low incidence, occur under difficult circumstances and in a younger population. AED's on lifeboats have not contributed to any of the survivals. Analysis of AED information can be used to study the quality of CPR and provide input for improving future training of lifeboat crews.

Impact of Transitory ROSC Events on Neurological Outcome in Patients with Out-of-Hospital Cardiac Arrest

In out-of-hospital cardiac arrest (OHCA), the occurrence of temporary periods of return to spontaneous circulation (t-ROSC) has been found to be predictive of survival to hospital discharge. The relationship between the duration of t-ROSCs and OHCA outcome has not been explored yet. The aim of this prospective observational study was to analyze the duration of t-ROSCs during OHCA and its impact on outcome. Defibrillator-recorded OHCA events were analyzed via dedicated software. The number of t-ROSC episodes and their overall durations were recorded. The study endpoint was the good neurologic outcome at hospital discharge. Among 285 patients included in the study, 45 (15.8%) had one or more t-ROSCs. The likelihood of t-ROSC occurrence was higher in patients with a shockable rhythm (p = 0.009). The cumulative length of t-ROSC episodes was significantly higher for patients who achieved sustained ROSC (p < 0.001). The adjusted cumulative t-ROSC length was an independent predictor for good neurological outcome at hospital discharge (OR 1.588, 95% CI 1.017 to 2.481; p = 0.042). According to our findings and data from previous studies, t-ROSC episodes during OHCA should be considered as a favorable prognostic factor, encouraging continuing resuscitative efforts.

Effects of Chest Compression Fraction on Return of Spontaneous Circulation in Patients with Cardiac Arrest; a Brief Report

Introduction:

The association between chest compression fraction (CCF) and return of spontaneous circulation (ROSC)has been a controversial issue in literature; and both positive and negative correlations have been reported between CCF and survival rate.

Objective:

The present study was conducted to determine the relationship between the rate and outcomes of chest compression and between CCF and ROSC in patients with cardiac arrest.

Method:

The present prospective observational study was conducted during 2018 on patients with cardiac arrest aged 18–80 years. Participants with end-stage renal diseases, malignancies and grade IV heart failure were excluded. A stop watch was set upon the occurrence of a code blue in the emergency department, and time was recorded by the observer upon the arrival of the code blue team leader (a maximum permissible duration of 10 minutes). The interruptions in chest compressions were recorded using a stopwatch, and CCF was calculated by dividing the duration of chest compression by the total duration of cardiac arrest observed.

Results:

Totally, 45 participants were enrolled. Most of the patients had non-shockable rhythms and underwent CPR based on related algorithm. Hypoxia and hypovolemia were the two probable etiology of cardiac arrest; and coronary artery disease was the most prevalent underlying disease. All patients with ROSC had CCF more than 70%. A CCF below 70% was observed in 21 cases (46.7%), and a fraction of at least 70% in 24 cases. All patients with ROSC had CCF more than 70%. A CCF below 70% was observed in 21 cases (46.7%), and a fraction of at least 70% in 24. A significantly higher duration and fraction of chest compression was observed in the participants who attained ROSC (P<0.001).

Conclusion:

Based on the findings of current study, it seems that significantly higher chest compression durations and fractions were found to be associated with ROSC, which was achieved in the majority of the participants with a CCF of at least 80%.

Comparison of Cardiopulmonary Resuscitation Quality Between Standard Versus Telephone-Basic Life Support Training Program in Middle-Aged and Elderly Housewives: A Randomized Simulation Study

INTRODUCTION

For cardiac arrests witnessed at home, the witness is usually a middle-aged or older housewife. We compared the quality of cardiopulmonary resuscitation (CPR) performance of bystanders trained with the newly developed telephone-basic life support (T-BLS) program and those trained with standard BLS (S-BLS) training programs.

METHODS

Twenty-four middle-aged and older housewives without previous CPR education were enrolled and randomized into two groups of BLS training programs. The T-BLS training program included concepts and current instruction protocols for telephone-assisted CPR, whereas the S-BLS training program provided training for BLS. After each training course, the participants simulated CPR and were assisted by a dispatcher via telephone. Cardiopulmonary resuscitation quality was measured and recorded using a mannequin simulator. The primary outcome was total no-flow time (>1.5 seconds without chest compression) during simulation.

RESULTS

Among 24 participants, two (8.3%) who experienced mechanical failure of simulation mannequin and one (4.2%) who violated simulation protocols were excluded at initial simulation, and two (8.3%) refused follow-up after 6 months. The median (interquartile range) total no-flow time during initial simulation was 79.6 (66.4-96.9) seconds for the T-BLS training group and 147.6 (122.5-184.0) seconds for the S-BLS training group (P < 0.01). Median cumulative interruption time and median number of interruption events during BLS at initial simulation and 6-month follow-up simulation were significantly shorter in the T-BLS than in the S-BLS group (1.0 vs. 9.5, P < 0.01, and 1.0 vs. 10.5, P = 0.02, respectively).

CONCLUSIONS

Participants trained with the T-BLS training program showed shorter no-flow time and fewer interruptions during bystander CPR simulation assisted by a dispatcher.

Metrics save lives: value and hurdles faced

PURPOSE OF REVIEW

Affirmation of the importance of precision in fundamentals of resuscitation practices with improving neurologically intact survival from sudden cardiac arrest, correlated with both measurements of resuscitation metrics generically and recently further refined metric parameters specifically.

RECENT FINDINGS

Quality of baseline cardiopulmonary resuscitation (CPR) in historic intervention trials may not be 'high quality' as once assumed. Optimal chest compression rates are within the narrow spectrum of 106-108/min for adults. Optimal ventilation rates remain within the 8-10/min range.

SUMMARY

Although traditional CPR teaching of 'hard and fast' chest compressions has promoted a relatively easy to remember directive, the reality is that laypersons and medical professionals alike may unwittingly provide markedly suboptimal chest compression depths and rates. Prior resuscitation studies that focused upon airway adjuncts, defibrillation strategies, and/or pharmaceutical interventions that did not simultaneously gauge the underlying CPR chest compression rates, chest compression fraction of time, and ventilation rates should be cautiously interpreted in light of discovery that assumption of 'high-quality CPR' without measurement of the metrics of such is likely a faulty assumption.

Analysis of bystander CPR quality during out-of-hospital cardiac arrest using data derived from automated external defibrillators

BACKGROUND

Little is known regarding the quality of cardiopulmonary resuscitation (CPR) performed by bystanders in out-of-hospital cardiac arrest (OHCA). We sought to determine quality of bystander CPR provided during OHCA using CPR quality data stored by Automated External Defibrillators (AEDs).

METHODS

We used the Resuscitation Outcomes Consortium database to identify OHCA cases of presumed cardiac etiology where an AED was utilized. We then matched AED data to each case identified. AED data was analyzed using manufacturer software in order to determine overall measures of bystander CPR quality, changes in bystander CPR quality over time, and adherence to existing 2010 Resuscitation Quality Guidelines.

RESULTS

100 cases of OHCA of presumed cardiac etiology involving bystander CPR and with corresponding AED data. Mean age was 62.3 years, and 75% were male. Bystanders demonstrated high-quality CPR over all minutes of resuscitation, with a chest compression fraction of 76%, a compression depth of 5.3 cm, and a compression rate of 111.2 compressions/min. Mean perishock pause was 26.8 s. Adherence rates to 2010 Resuscitation Guidelines for compression rate and depth were found to be 66% and 55%, respectively. CPR quality was lowest in the first minute, resulting from increased delay to rhythm analysis (mean 40.7 s). In cases involving shock delivery, latency from initiation of AED to shock delivery was 59.2 s.

CONCLUSIONS

We found that bystanders perform high-quality CPR, with strong adherence rates to existing Resuscitation Guidelines. High-quality CPR is maintained over the first five minutes of resuscitation, but was lowest in the first minute.

COSCA (Core Outcome Set for Cardiac Arrest) in Adults: An Advisory Statement From the International Liaison Committee on Resuscitation

Cardiac arrest effectiveness trials have traditionally reported outcomes that focus on survival. A lack of consistency in outcome reporting between trials limits the opportunities to pool results for meta-analysis. The COSCA initiative (Core Outcome Set for Cardiac Arrest), a partnership between patients, their partners, clinicians, research scientists, and the International Liaison Committee on Resuscitation, sought to develop a consensus core outcome set for cardiac arrest for effectiveness trials. Core outcome sets are primarily intended for large, randomized clinical effectiveness trials (sometimes referred to as pragmatic trials or phase III/IV trials) rather than for pilot or efficacy studies. A systematic review of the literature combined with qualitative interviews among cardiac arrest survivors was used to generate a list of potential outcome domains. This list was prioritized through a Delphi process, which involved clinicians, patients, and their relatives/partners. An international advisory panel narrowed these down to 3 core domains by debate that led to consensus. The writing group refined recommendations for when these outcomes should be measured and further characterized relevant measurement tools. Consensus emerged that a core outcome set for reporting on effectiveness studies of cardiac arrest (COSCA) in adults should include survival, neurological function, and health-related quality of life. This should be reported as survival status and modified Rankin scale score at hospital discharge, at 30 days, or both. Health-related quality of life should be measured with ≥1 tools from Health Utilities Index version 3, Short-Form 36-Item Health Survey, and EuroQol 5D-5L at 90 days and at periodic intervals up to 1 year after cardiac arrest, if resources allow.

Neonatal Resuscitation Program Rolling Refresher: Maintaining Chest Compression Proficiency Through the Use of Simulation-Based Education

BACKGROUND

Structured training courses have shown to improve patient outcomes; however, guidelines are inconsistently applied in up to 50% of all neonatal resuscitations. This is partly due to the fact that psychomotor skills needed for resuscitation decay within 6 months to a year from the completion of a certification course. Currently, there are no recommendations on how often refresher training should occur to prevent skill decay.

PURPOSE

Improve provider proficiency and confidence in the performance of neonatal resuscitation with a focus on chest compression effectiveness.

METHODS

The study recruited neonatal intensive care unit providers (n = 25). A simulation-based Neonatal Resuscitation Program (NRP) curriculum was developed and executed. Training sessions were delivered utilizing in situ simulations at varying time intervals. Pre- and postconfidence surveys and practicum skill scores were collected and evaluated by a content expert. Categorical data were summarized by frequency and percentage and tested for distributional equality via Pearson chi-square tests or Fisher exact tests depending on cell sample size distribution. All statistical tests were 2-sided with P < .05 considered statistically significant.

RESULTS

Provider overall confidence and rate of chest compressions improved; however, there was no statistically significant difference between groups. Rolling refresher training at varied time intervals did not demonstrate statistically significant differences in chest compression quality among NRP providers.

IMPLICATIONS FOR PRACTICE

Rolling refresher training more frequently than every 6 months may not provide added benefit to NRP providers.

IMPLICATIONS FOR RESEARCH

Additional research is needed to determine optimal refresher training frequency to prevent skill decay.

Quality of bystander cardiopulmonary resuscitation during real-life out-of-hospital cardiac arrest

BACKGROUND

Cardiopulmonary resuscitation (CPR) can increase survival in out-of-hospital cardiac arrest (OHCA). However, little is known about bystander CPR quality in real-life OHCA.

AIM

To describe bystander CPR quality based on automated external defibrillator (AED) CPR process data during OHCA and compare it with the European Resuscitation Council 2010 and 2015 Guidelines.

METHODS

We included OHCA cases from the Capital Region, Denmark, (2012-2016) where a Zoll AED was used before ambulance arrival. For cases with at least one minute of continuous data, the initial 10min of CPR data were analysed for compression rate, depth, fraction and compressions delivered for each minute of CPR. Data are presented as median [25th;75th percentile].

RESULTS

We included 136 cases. Bystander median compression rate was 101min^-1 [94;113], compression depth was 4.8cm [3.9;5.8] and compressions per minute were 62 [48;73]. Of all cases, the median compression rate was 100-120min^-1 in 42%, compression depth was 5-6cm in 26%, compression fraction≥60% in 51% and compressions delivered per minute exceeded 60 in 54%. In a minute-to-minute analysis, we found no evidence of deterioration in CPR quality over time. The median peri-shock pause was 27s [23;31] and the pre-shock pause was 19s [17;22].

CONCLUSIONS

The median CPR performed by bystanders using AEDs with audio-feedback in OHCA was within guideline recommendations without deterioration over time. Compression depth had poorer quality compared with other parameters. To improve bystander CPR quality, focus should be on proper compression depth and minimizing pauses.

Improving quality in measuring time to initiation of CPR during in-hospital resuscitation

OBJECTIVE

Time from the onset of "low or no flow" indicators of cardiac failure to initiation of cardiopulmonary resuscitation is an important quality metric thought to improve the likelihood of survival and preservation of end organ function. We hypothesized that delays in initiation of chest compressions were under recognized during in-hospital resuscitation and aimed to develop a system which identifies the actual time of deterioration during cardiac events.

METHODS

Retrospective review on prospectively identified resuscitation records and monitor data were compared. Return of spontaneous circulation, survival, and changes in functional status of patients pre- and post-events with chest compressions were collected as outcome measures.

RESULTS

Between October 2012 and April 2015, 59 events which met eligibility criteria occurred in either our pediatric cardiac or general pediatric intensive care units. The median time from event onset to initiation of chest compressions was 47s(s) (interquartile range (IQR) 28-80s) as assessed using monitor data, while the resuscitation record reported a median time of 0s (IQR 0-60s), reflecting the time from recognition to initiation of chest compressions. According to the resuscitation record, 81% vs. 63% of events achieved the quality standard of less than one minute depending on which review method was used (p=0.04).

CONCLUSIONS

There is a significant difference between time of deterioration to initiation of chest compressions and the time of recognition to initiation of chest compressions. Resuscitation records should be modified to include more information about the actual timing of patient deterioration.

Evaluation of a newly developed infant chest compression technique: A randomized crossover manikin trial

BACKGROUND

Providing adequate chest compression is essential during infant cardio-pulmonary-resuscitation (CPR) but was reported to be performed poor. The "new 2-thumb technique" (nTTT), which consists in using 2 thumbs directed at the angle of 90° to the chest while closing the fingers of both hands in a fist, was recently introduced. Therefore, the aim of this study was to compare 3 chest compression techniques, namely, the 2-finger-technique (TFT), the 2-thumb-technique (TTHT), and the nTTT in an randomized infant-CPR manikin setting.

METHODS

A total of 73 paramedics with at least 1 year of clinical experience performed 3 CPR settings with a chest compression:ventilation ratio of 15:2, according to current guidelines. Chest compression was performed with 1 out of the 3 chest compression techniques in a randomized sequence. Chest compression rate and depth, chest decompression, and adequate ventilation after chest compression served as outcome parameters.

RESULTS

The chest compression depth was 29 (IQR, 28-29) mm in the TFT group, 42 (40-43) mm in the TTHT group, and 40 (39-40) mm in the nTTT group (TFT vs TTHT, P < 0.001; TFT vs nTTT, P < 0.001; TTHT vs nTTT, P < 0.01). The median compression rate with TFT, TTHT, and nTTT varied and amounted to 136 (IQR, 133-144) min versus 117 (115-121) min versus 111 (109-113) min. There was a statistically significant difference in the compression rate between TFT and TTHT (P < 0.001), TFT and nTTT (P < 0.001), as well as TTHT and nTTT (P < 0.001). Incorrect decompressions after CC were significantly increased in the TTHT group compared with the TFT (P < 0.001) and the nTTT (P < 0.001) group.

CONCLUSIONS

The nTTT provides adequate chest compression depth and rate and was associated with adequate chest decompression and possibility to adequately ventilate the infant manikin. Further clinical studies are necessary to confirm these initial findings.

A comparison between the two methods of chest compression in infant and neonatal resuscitation. A review according to 2010 CPR guidelines

AIM

The quality of chest compression (CC) delivered during neonatal and infant cardiopulmonary resuscitation (CPR) is identified as the most important factor to achieve the increase of survival rate without major neurological deficit to the patients. The objective of the study was to systematically review all the available studies that have compared the two different techniques of hand placement on infants and neonatal resuscitation, from 2010 to 2015 and to highlight which method is more effective.

METHODS

A review of the literature using a variety of medical databases, including Cochrane, MEDLINE, and SCOPUS electronic databases. The following MeSH terms were used in the search: infant, neonatal, CPR, CC, two-thumb (TT) technique/method, two-finger (TF) technique/method, rescuer fatigue, thumb/finger position/placement, as well as combinations of these.

RESULTS

Ten studies met the inclusion criteria; nine observational studies and a randomized controlled trial. All providers performed either continuous TF or TT technique CCs and the majority of CPR performance was taken place in infant trainer manikin.

CONCLUSIONS

The majority of the studies suggest the TT method as the more useful for infants and neonatal resuscitation than the TF.

Simulation-based Randomized Comparative Assessment of Out-of-Hospital Cardiac Arrest Resuscitation Bundle Completion by Emergency Medical Service Teams Using Standard Life Support or an Experimental Automation-assisted Approach

INTRODUCTION

Effective resuscitation of out-of-hospital cardiac arrest (OHCA) patients is challenging. Alternative resuscitative approaches using electromechanical adjuncts may improve provider performance. Investigators applied simulation to study the effect of an experimental automation-assisted, goal-directed OHCA management protocol on EMS providers' resuscitation performance relative to standard protocols and equipment.

METHODS

Two-provider (emergency medical technicians (EMT)-B and EMT-I/C/P) teams were randomized to control or experimental group. Each team engaged in 3 simulations: baseline simulation (standard roles); repeat simulation (standard roles); and abbreviated repeat simulation (reversed roles, i.e., basic life support provider performing ALS tasks). Control teams used standard OHCA protocols and equipment (with high-performance cardiopulmonary resuscitation training intervention); for second and third simulations, experimental teams performed chest compression, defibrillation, airway, pulmonary ventilation, vascular access, medication, and transport tasks with goal-directed protocol and resuscitation-automating devices. Videorecorders and simulator logs collected resuscitation data.

RESULTS

Ten control and 10 experimental teams comprised 20 EMT-B's; 1 EMT-I, 8 EMT-C's, and 11 EMT-P's; study groups were not fully matched. Both groups suboptimally performed chest compressions and ventilations at baseline. For their second simulations, control teams performed similarly except for reduced on-scene time, and experimental teams improved their chest compressions (P=0.03), pulmonary ventilations (P<0.01), and medication administration (P=0.02); changes in their performance of chest compression, defibrillation, airway, and transport tasks did not attain significance against control teams' changes. Experimental teams maintained performance improvements during reversed-role simulations.

CONCLUSION

Simulation-based investigation into OHCA resuscitation revealed considerable variability and improvable deficiencies in small EMS teams. Goal-directed, automation-assisted OHCA management augmented select resuscitation bundle element performance without comprehensive improvement.