Cardiopulmonary Resuscitation Performance of Professional Rescuers With a New Defibrillation Algorithm

Study Overview
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Brief Summary
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In the Paris (France) Medical Emergency system, in the early phase of Out-of-hospital Cardiac Arrest (OHCA), the treatment of a Ventricular Fibrillation (VF) consists of delivering an External Electric Shock (EES) by a rescuer with the use of an Automated External Defibrillator (AED). This latter realizes a cardiac rhythm analysis every two minutes. This analysis requires that chest compressions (CC) be interrupted for a while. However, CC interruptions are potentially harmful due to the brain, and heart perfusions decrease. On the other hand, the recurrence of VF occurs mostly during the first minute after the shock, whereas the delay between 2 rhythm analysis is 2 minutes. The consequence is excessive time spent in VF, which is deleterious in terms of coronary and cerebral perfusion. The investigator implements a new AED algorithm whose operating principle is as follows. One minute after an EES administration, the AED realizes a cardiac rhythm analysis during which the rescuers do not need to interrupt the chest compressions (CC): this is called the rhythm analysis  in presence of CC The detection of a VF  in presence of CC  needs to be confirmed,  in absence of CC  The CC's are therefore interrupted for new rhythm analysis. Once the presence of VF is approved, the AED proposes a shock to be administred The aim of the study Study Design: This is a prospective observational study. The eligibility criteria are as follows: Patients in Out-Of-Hospital Cardiac Arrest. Basic Life support care with an AED. The primary endpoint is the  chest-compression fraction (CCF)  that represents the CPR-time performance during the ten first minutes of BLS care ( or < 10 min in case of Return Of Spontaneus Circulation (ROSC))

Detailed Description
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BACKGROUND For Out-Of-Hospital Cardiac Arrest (OHCA) patients suffering from ventricular fibrillation (VF) or ventricular tachycardia (VT), BLS care consists of administering external electric shocks (EES) and cardiopulmonary resuscitation (CPR). However, despite successful defibrillation, VF recurs in 50% of cases. Rescuers are forced to repeat EES as often as needed, without the recommendations specifying a maximum number. International guidelines recommend a 2-min CPR time between 2 rhythm analysis, that means one shock every 2 min. Since refibrillation occurs mostly during the first-minute post-shock, the patient will have to wait until the end of the 2 minutes before receiving the next EES. During that time, the chest compressions (CC) provide a reduced fraction of physiologic blood flow. The new AED algorithm provides the following changes : After a 60-second post-shock CPR-period, the AED performs an analysis in presence of CC i.e., without CC interruption is performed. Each time the AED detects a VF in presence of CC the algorithm requires the CC to be interrupted to perform an analysis in absence of CC  to confirm the rhythm shockability. Analyses in presence of CC are triggered every minute, possibly followed or not by an analysis  in absence of CC  at least, the algorithm performs an analysis  in absence of CC  systematically every 2 minutes. This new algorithm fits in between two historical CPR algorithms used in western medical systems - the one-minute and the two-minute CPR cycle- depending on the rhythm shockability detected  in presence of CC  OBJECTIVES The main objective is to measure the  CC fraction  during the ten first minutes of Fire Fighter BLS care in OHCA. The secondary objectives : Report on the available CPR quality parameters (CC frequency, hands-off maximum). Report on the AED's diagnostic performance when analyzing the rhythm in presence of CC  Report on the AED's diagnostic performance when analyzing the rhythm  in absence of CC  Report on the overall AED's diagnostic performance that results from the combination of two consecutive analyses  in presence of CC  and  in absence of CC Report on post-shock rhythms and their incidence Report on the number of EES per patient Report on the time distribution for the shocks administered per-patient to describe the rhythmic storm. Report on the incidence of Return Of Spontaneous Circulation (ROSC), survival at hospital admission, and survival at hospital discharge. Compare these reports to a historical cohort (2017). METHOD This is a prospective observational study. The observation window is limited to CPR cycles within the first 10 minutes of BLS care, or less if ROSC is presumed. The choice of 10 minutes is intended to observe the BLS team's action, without interfering with the ALS team that arrives later. The three following criteria define a presumptive ROSC: 1. presence of QRS complexes of broadly similar morphology 2. synchronous impedance curve variation with the QRS complexes (indicating intrathoracic movement, in that case, cardiac mechanical activity) 3. no on-going CC A CPR cycle is defined by the delay between two  in absence of CC  analyses. The study does not imply any change in current practice. There is no planned interim analysis. All consecutive participants with inclusion criteria and no exclusion criteria will be analyzed. STUDY SIZE A study size for a before-after comparison, with 2017 as the before period and 2020 as the after period has been calculated In our healthcare system, the average CC fraction was 65% in 2017, whereas the ERC guidelines recommend a minimum of 60%. With the use of the 2020 algorithm, for CA with shockable rhythm, the CC fraction is expected to decrease slightly, as the analyses become closer in time. It is assumed a CCfraction in 2020 being  equivalent  to 2017 (65%) and consider that a difference in CCfraction rate as large as 10% in favor of the 2017 period still allows the new algorithm to be non-inferior (delta = 0.1). The sample size calculation is based on an 80% power to confirm non-inferiority and a one-sided confidence level of 97.5%. As a result, the number of subjects to be included in each period is 285. Note that this same number of patients will be sufficient to detect an absolute 10% difference with an alpha risk of 5% and a power of 90%, between patients in the 2017 group and patients in the 2020 group with regard to the secondary endpoint Survival at hospital admission INTERRUPTION OR STOPPING OF THE STUDY The sponsor has the responsibility to report, to the national health authority, any serious and unexpected adverse events attributable to the new AED algorithm. RISKS A full report on the risks, the description of incidents, accidents and adverse events will be the subject of a chapter in the results section and also in the discussion. FINANCING Funding for the study is provided by the Paris Fire Brigade (promoter, following acceptance of the survey under French policy for clinical research projects) DISCUSSION The study will report on the CC fraction of an AED algorithm designed to analyze under CC.

Official Title
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Professional Rescuers Cardiopulmonary Resuscitation Performance After Implementation of a Defibrillation Algorithm for Early Treatment of Refibrillation, an Observational Study.

Conditions
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Cardiac Arrest, Sudden, Ventricular Tachycardia, Ventricular Fibrillation, Sudden Cardiac Death

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: -Non-traumatic OHCA in adults, treated by a BLS team and connected to an AED equipped either with the 2017 or with the 2020 algorithm. Exclusion Criteria: Use of AED in a pediatric mode CPR administered in 15:2 mode Patient already connected to another defibrillator at the arrival of the BLS Team No shock advised by defibrillator at first analysis Patient with a pacemaker Secondary Exclusion Criteria Surviving patients' opposition to the use of their data. Patients with unreadable electrocardiographic or impedance data.

Ages Eligible for Study
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Minimum Age: 12 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Report on Chest Compression Fraction (CCf) | CCf is the length of time the patient receives chest compression/management time (describe as a %) | 10 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Report on Cardiopulmonary Resuscitation (CPR) parameters : CPR ratio | CPR ratio (time during which the patient receives chest compression and bag ventilation / total management time; describe as a %) | 10 minutes | 
| Report on Cardiopulmonary Resuscitation (CPR) parameters :Prompt CPR fraction | Prompt CPR fraction (duration between the two AED announcements resume massage and interrupt massage/ total management time; describe as a %) | 10 minutes | 
| Report on Cardiopulmonary Resuscitation (CPR) parameters:Maximal Hands-Off time | Maximal Hands-Off time (longest time frame without any CC; describe in seconds) | 10 minutes | 
| Report on Cardiopulmonary Resuscitation (CPR) parameters:Chest Compression Frequency | Chest Compression Frequency (i.e., measurement of the mobile frequency over 3 to 5 compressions; describe as number of chest compressions by minute) | 10 minutes | 
| Report on the diagnostic performance of the AED algorithms during CC and  in absence of CC | Calculate Sensibility and Specificity | 10 minutes | 
| Report on the overall diagnostic performance resulting from the combination of the consecutive analyses  in presence of CC  and  in absence of CC | Calculate Sensibility and Specificity | 10 minutes | 
| Report on five-second-post-shock rhythms and their incidence | asystole, pulseless electrical activity, ventricular tachycardia, ventricular fibrillation for in absence of CC analysis, at 5 seconds | 10 minutes | 
| Report on 60-second-post-shock rhythms and their incidence | asystole, pulseless electrical activity, ventricular tachycardia, ventricular fibrillation for in absence of CC analysis, at 60 seconds | 10 minutes | 
| Report on 120 second-post-shock rhythms and their incidence | asystole, pulseless electrical activity, ventricular tachycardia, ventricular fibrillation for in absence of CC analysis, at 120 seconds | 10 minutes | 
| Report on 15-second-post-shock rhythms and their incidence | asystole, pulseless electrical activity, ventricular tachycardia, ventricular fibrillation for in absence of CC analysis, at 15 seconds | 10 minutes | 
| Report on 30-second-post-shock rhythms and their incidence | asystole, pulseless electrical activity, ventricular tachycardia, ventricular fibrillation for in absence of CC analysis, at 30 seconds | 10 minutes | 
| Report on the number of electrical shocks (EES) delivered and the duration of the rhythmic storm | Total number of EES delivered (describe as a number) | 1 hour | 
| Report on the number of electrical shocks (EES) intended and the duration of the rhythmic storm | Ratio number of EES intended / number of EES delivered (describe as a ratio %) | 1 hour | 
| Report on the temporal distribution of electrical shocks (EES) and the duration of the rhythmic storm | EES temporal distribution per patient | 1 hour | 
| Report on the delay from start to end of cumulative VF episodes | The time period from the start of the first occurence of VF to to the ending of the last episode of ventricular fibrillation (VF) ( seconds) | 1 hour | 
| The time period from the AED-switch-on and the first EES (describe in seconds) | The time period from the AED-switch-on and the first EES (describe in seconds) | 1 hour | 
| The distribution over time of EES. | The distribution over time of EES. | 1 hour | 
| Outcomes - ROSC | Return Of Spontaneous Circulation (ROSC) (describe as a ratio of patients with ROSC / patients included) | 2 hours | 
| Outcomes - admitted alive at hospital | Survival to hospital admission (describe as a ratio of patients admitted beating heart to hospital / patients included) | 2 hours | 
| Outcomes - discharged from hospital | Survival at hospital discharge (describe as a ratio of patients discharged alive from hospital / patients included) | 1 month | 
| Compare Chest Compression Fraction (CCf) to Paris Fire Brigade 2017 historical data | CCf is the length of time the patient receives chest compression/management time (describe as a %) | 10 minutes | 
| Prompt CPR fraction (duration between the two AED announcements resume massage and interrupt massage/ total management time; describe as a %) | Prompt CPR fraction (duration between the two AED announcements resume massage and interrupt massage/ total management time; describe as a %) | 10 minutes | 
| CPR ratio (time during which the patient receives chest compression and bag ventilation / total management time; describe as a %) | CPR ratio (time during which the patient receives chest compression and bag ventilation / total management time; describe as a %) | 10 minutes | 
| Maximal Hands-Off time (longest time frame without any CC; describe in seconds) | Maximal Hands-Off time (longest time frame without any CC; describe in seconds) | 10 minutes | 
| Chest Compression Frequency (i.e., measurement of the mobile frequency over 3 to 5 compressions; describe as number of chest compressions by minute) | Chest Compression Frequency (i.e., measurement of the mobile frequency over 3 to 5 compressions; describe as number of chest compressions by minute) | 10 minutes | 
| Compare Sensibility and Specificity of AED algorithm during CC and in absence of CC to 2017 algorithm Sensibility and Specificity | Compare Sensibility and Specificity of AED algorithm during CC and in absence of CC to 2017 algorithm Sensibility and Specificity | 10 minutes | 
| Compare the overall diagnostic performance resulting from the combination of the consecutive analyses  in presence of CC  and  in absence of CC to Paris Fire Brigade 2017 historical data | Compare the overall diagnostic performance resulting from the combination of the consecutive analyses  in presence of CC  and  in absence of CC to Paris Fire Brigade 2017 algorithm Sensibility and Specificity | 10 minutes | 
| Compare post-shock rhythms and their incidence to Paris Fire Brigade 2017 historical data | Compare asystole, pulseless electrical activity, ventricular tachycardia, ventricular fibrillation incidence for in presence of CC analysis, at 5 seconds to Paris Fire Brigade 2017 differents rhythms incidences. | 10 minutes | 
| Compare post-shock rhythms and their incidence to Paris Fire Brigade 2017 historical data | Compare asystole, pulseless electrical activity, ventricular tachycardia, ventricular fibrillation incidence for in absence of CC analysis, at 60 seconds to Paris Fire Brigade 2017 differents rhythms incidences. | 10 minutes | 
| Compare post-shock rhythms and their incidence to Paris Fire Brigade 2017 historical data | Compare asystole, pulseless electrical activity, ventricular tachycardia, ventricular fibrillation incidence for in absence of CC analysis, at 120 seconds to Paris Fire Brigade 2017 differents rhythms incidences. | 10 minutes | 
| Compare post-shock rhythms and their incidence to Paris Fire Brigade 2017 historical data | Compare asystole, pulseless electrical activity, ventricular tachycardia, ventricular fibrillation incidence for in absence of CC analysis, at 5 seconds to Paris Fire Brigade 2017 differents rhythms incidences. | 10 minutes | 
| Compare number of electrical shocks (EES) and the duration of the rhythmic storm to Paris Fire Brigade 2017 historical data | Total number of EES delivered (describe as a number) compare to Paris Fire Brigade 2017 historical data | 10 minutes | 
| Compare number of electrical shocks (EES) and the duration of the rhythmic storm to Paris Fire Brigade 2017 historical data | EES temporal distribution per patient compare to Paris Fire Brigade 2017 historical data | 10 minutes | 
| Compare number of electrical shocks (EES) and the duration of the rhythmic storm to Paris Fire Brigade 2017 historical data | The time period from the start of the first to the end of the last ventricular fibrillation (VF) episode (describe in seconds) compare to Paris Fire Brigade 2017 historical data | 10 minutes | 
| Compare number of electrical shocks (EES) and the duration of the rhythmic storm to Paris Fire Brigade 2017 historical data | The time period from the AED-switch-on and the first EES (describe in seconds) compare to Paris Fire Brigade 2017 historical data | 10 minutes | 
| Compare number of electrical shocks (EES) and the duration of the rhythmic storm to Paris Fire Brigade 2017 historical data | Compare the distribution over time of EES.to Paris Fire Brigade 2017 historical data | 10 minutes | 
| Outcomes - ROSC | Compare return Of Spontaneous Circulation (ROSC) to Paris Fire Brigade 2017 historical data (describe as a ratio of patients with ROSC / patients included) | 1 hour | 
| Outcomes - admitted alive at hospital | Compare survival to hospital admission to Paris Fire Brigade 2017 historical data (describe as a ratio of patients admitted beating heart to hospital / patients included) | 2 hours | 
| Outcomes - hospital discharge | Compare survival at hospital discharge to Paris Fire Brigade 2017 historical data (describe as a ratio of patients discharged alive from hospital / patients included) | 1 month | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Cardiac Arrest, Automatic External Defibrillator, Chest Compression Fraction, Electrical Cardiac Analysis under Chest Compressions