Extubation is a crucial step when patients are being weaned from mechanical ventilator
support. Indeed, the patient has to face an increasing burden imposed to the ventilation
system. The ability to overcome this event will determine the patient survival. A warning
signal could be very useful is this situation. 2 recent studies have shown that measuring
diaphragmatic cupolas and muscular fibers thickening fraction could help to spot a population
with a high risk of "diaphragmatic weakness", characterized by a high failure extubation
rate. This study aims to verify that this kind of group of patients does exist.