Early Echographic Asystole as a Predictive Factor of Absence of Spontaneous Circulatory Activity Recovery (SCAR) in Prehospital Cardio Respiratory Arrests (CRA)

Study Overview
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Brief Summary
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Assessment of prognostic performances of CCU in CRA Recovery (CRAR) has already been explored but 1) Only in intra-hospital medicine, 2) in very variable timings. ACE Research focuses on the extra-hospital window and predictive value of Early CCU (within 12 minutes of rescucitation initiation) with ambitious endpoints : curable etiologies identification, early anticipation of ECMO procedures, early anticipation of organ donation process, and evaluation of intrinsic contribution criterion to resuscitation interruption. The primary objective of ACE study is to investigate the positive predictive value (PPV) of early ultrasound asystole on the absence of CRAR. The secondary objectives are multiple and innovative despite an observational design: impact on the morbi-mortality of the target population (frequency of curable etiologies, pre-therapeutic and therapeutic delays, morbidity...), delay of ECMO implementation of an ECMO (Extracorporeal Membrane Oxygenation), failure rate of organ donation due to overdelays, construction of a multifactorial score associated with CRAR.

Detailed Description
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Prehospital Cardio-Respiratory Arrests (CRA) represent a significant cause of mortality in France (between 30,000 and 50,000 cases per year) [1]. The prognosis is particularly pejorative, since only 5 to 6% of patients will leave the hospital alive with satisfying neurological condition [2,3]. Their management in France is part of a very singular Primary Care System, based on the medicalization of medical regulation (SAMU) and effectiveness (SMUR) and is based mainly on European recommendations (cardiac massage, ventilation and cardiac rhythm analysis) [4]). European 2015 recommendations advocate for the use of Cardiac Clinical Ultrasound (CCU) in Emergency Medicine, particularly to identify curable causes of CRA. Indeed, CCU is likely to reveal various curable etiologies as tamponade, massive pulmonary embolism, deep hypovolemia or suffocating pneumothorax[5]. Their identification allows the clinician to better adjust his therapeutic strategy and consequently improve patient prognosis. But its predictive value on the absence of Spontaneous Circulatory Activity Recovery (SCAR) focus clinicians' interest due to its impact on extracorporeal circulation procedures, organ donation or resuscitation interruption guideline. Several studies support the predictive value associated with the absence of mechanical cardiac activity and resuscitation failure [5-10]. However, proof level remains very shaky and transposition to prehospital medicine is clearly impossible (delays, management and environment differ largely). As a corollary, the European Resuscitation Council (ERC) ruled in 2015 that the prognostic performances of ultrasound asystole had not been sufficiently finely measured to consider it as a rigorous criterion for resuscitation interruption, appealing for pivotal studies [4]. ACE French National Trial fits precisely into this bibliographic gap. Our objectives are multiple: assess prognostic value of Early CCU (ECCU; ie. <M12), alone or combined with other clinical parameters (composite prognostic tool combining myocardial and/or electrical activity, capnography, No/Low Flow duration, and clinical profile -sex, age-) on the absence of SCAR ; describe frequency and typology of curable etiologies in the context of CRA, and estimate the possible prognostic impact of early CCU on morbidity and mortality; finally, in case of validation of its prognostic performances, estimate theoretical time savings on ECMO (Extracorporeal Membrane Oxygenation) and organ donation processes. Multicentric, based on rigorous methodology, high proof-level design and large sample (N=624), ACE wants to be resolutely pragmatic, by associating peripheric hospital and university hospital (Expertise), urban or rural environment (delays and intervention conditions), in order to answer definitely clinicians questioning of the emergency physicians. Continuing in the same vein, we aim a future validation study of a decision-making algorithm for pre-hospital management of CRAs to reduce morbidity and (Randomized Cluster Study in Stepped-Wedge integrating a medico-economic component).

Official Title
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Early Echographic Asystole as a Predictive Factor of Absence of Spontaneous Circulatory Activity Recovery (SCAR) in Prehospital Cardio Respiratory Arrests (CRA) - ACE Study

Conditions
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Prehospital Cardio-Respiratory Arrests, Spontaneous Circulatory Activity Recovery

Intervention / Treatment
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* Other: Non applicable - Non interventional study


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult (>18yo) presenting extra-hospital CRA. Exclusion Criteria: Resuscitation refusal.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Other: Non applicable - Non interventional study|Non interventional study|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Assess prognostic value of early echographic (ECCU) asystole (i.e. within the first 12 minutes of resuscitation) on resuscitation failure (absence of CRAR). | Patient in CRAR with extra-hospital care | 1 month | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Assess prognostic value of an early echographic (ECCU) asystole (i.e. within the first 12 minutes of resuscitation) on morbi-mortality evaluated at 30 days | Positive predictive value of ultrasound asystole within 12 minutes of the start of specialized CPR on the occurrence of death and/or sequelae at 30 days | 1 month | 
| Measure variations of the prognostic performances of the extra-hospital ECCU according to their timing of realization, on the absence of CRAR | Sensitive, specificity, negative predictive value, likelihood ratios of early ultrasound asystole to absence of CRAR | 1 month | 
| Study the link between ultrasound diagnosis and electrocardiogram electrical plots. | Recorded electrical activity patterns: | 1 month | 
| Creation of a multifactorial composite prognostic score associated with the absence of CRAR | composite score | 1 month |