Intraabdominal Hypertension and Occurrence of Microaspiration in Cirrhotics Under Mechanical Ventilation

Intra-abdominal pressure monitoring will be performed using intra-vesical pressure every 8 hour in the first 2 days of mechanical ventilation. Micro aspiration is defined by pepsin or amylase positivity in trachea suction. Two groups will be compared : one with IAH , one without IAH.