diaphragm ultrasounds during weaning and Pimax measures

For each patient intubated and ventilated in our ICU we will performed diaphragm ultrasound during the weaning process.

We will performed the measurement of diaphragmatic maximum excursion during a maximal inspiration using an abdominal standard preset with M-mode, with the so called anatomical M-mode.

We will put the probe in the right subcostal window to use the hepatic window to assess the movement of the diaphragm. We will performed the measure of the diaphragm excursion with patient in semi-recumbent position and through a transhepatic transverse oblique scan while the patient is on mechanical ventilation and undergo a Pimax maneuver, that consists in a temporary occlusion of the airway with an expiratory pause.

We will performed the measure three times, and we will take into account the best one made by the patient.

To assess the correlation between maximum inspiratory pressure (Pi max) and the diaphragm maximum inspiratory excursion measured with ultrasound.

To assess the predicting value of the diaphragm maximum inspiratory excursion measured with ultrasound for the weaning success.