Respiratory weaning failure worsens prognostic of patients following on-pump cardiac surgery. There are increasing evidences that pulmonary, diaphragmatic or cardiologic echographies are useful in order to improve this critical medical status.

Based both on a previous study conducted in the critical care unit of Purpan and on literature we hypothesize that a combined thoracic echography score could be of interest. We make the hypothesis that the use of a score based on thoracic combined echography (ETC = cardiac, pulmonary and diaphragmatic) allows to predict the failure of respiratory weaning in cardiac surgery and allows to improve the characterization of the causes of this failure

Inclusion Criteria:

• Adult (> 18 years old) beneficiating of mechanical ventilation following cardiac surgery
• Weaning test period
• Patient insured under the French social security system

Exclusion Criteria:

• Tracheostomy
• Neurological disorders
• Need for prophylactic non invasive ventilation.
• Global obstructive lung disease with a forced expiratory volume < 50%.
• Judicial protection
• Patient already included in a trial still running.
• Pregnancy

Patients will be recruited during the pre anesthetic visit