Ultrasound Study of the Diaphragm Evolution Under ECMO

Diaphragmatic atrophy and diaphragmatic dysfunction are described in human resuscitation under mechanical ventilation, but this diaphragmatic function has not been studied in patients with cardiogenic shock and also under cardiac assistance by extracorporeal circulation called ECLS (Extra -corporeal Life support). Diaphragmatic dysfunction in intensive care has been described during prolonged stay in intensive care and early sepsis. It is associated with dyspnea and delayed weaning from mechanical ventilation. The atrophy of the diaphragm muscle is related to both loss of function and also loss of muscle performance.

Decreases in heart muscle and diaphragm performance may require both cardiac and respiratory assistance. Cardiac and respiratory dysfunctions can complicate the weaning of the respiratory assistance and also extracorporeal circulatory support supports. These two supports, respiratory and circulatory assistance, allow the purification of CO2 and respiratory assistance is known to influence the diaphragmatic function. The role of the muscular pump function in the withdrawal process of the ECLS, remains largely unknown. The aim of our study is to give a description of the physiology of the diaphragm in case of cardiogenic shock: we want to evaluate the force of the diaphragm according to the ventilation under ECLS. No studies have yet evaluated the influence of ECLS as a CO2 purification system on the performance of the diaphragm muscle.

Ultrasound is used in the patient's bed in daily practice to measure cardiac function, vessel study and diaphragm muscle. This method is reproducible and non-invasive. It can be hypothesized that there is a muscular involvement of the diaphragm under extracorporeal membrane oxygenation (ECMO) measurable by ultrasound method. Our main hypothesis is that the diaphragm force evolves according to the cleaning of the CO2 by the ECLS during the weaning of this one.

This is a Monocentric Prospective Observational Descriptive study. The objective of this study is to evaluate prospectively and consecutively the evolution of diaphragmatic muscle stress in cardiogenic shock with ultrasounds during the first ECMO weaning in intensive care patients.

When cardiogenic shock occurs, during the first ECLS weaning, we also will evaluate prospectively :

• The evolution of diaphragm muscle thickness
• The evolution of the function of the diaphragm muscle We will evaluate the impact of different risk factors on the diaphragmatic function: respiratory variables, parameters and duration of mechanical ventilation, ECLS parameters and duration, number and type of associated organ failure, gasometric variables, hemodynamic variables, presence of a cardiotomy.

And we also will evaluate the impact of the diaphragmatic function on the patient's future:

• Failure to wean from mechanical ventilation
• ECLS weaning failure
• Death in intensive care
• Length of stay in intensive care Patients will be informed and consents will be collected during hospitalization in intensive care.

Inclusion criteria

• Patient hospitalized in intensive care for cardiogenic shock under ECMO (extracorporeal membrane oxygenator)
• Veno-arterial ECMO
• ECMO withdrawal decision
• Patient or family agreeing to participate in research

Exclusion criteria

• Patient under guardianship or curatorship
• Contraindication to spontaneous ventilation
• Pregnant woman
• Anechoic patient for diaphragmatic ultrasound