Diaphragmatic and Pulmonary US for Extubation Success Prediction

The ultrasound will be performed using the ultrasound system GE Logiq XP equipped with a linear probe of 10 MHz. The diaphragm is visualized as two parallel echogenic lines at the eighth intercostal space in the mid-axillary line. The images will be captured during the inspiratory and expiratory tidal volume to and during maximum inspiration and expiration. Each image will be frozen in B mode and the diaphragm thickness will be measured from the center line pleural half the peritoneal line. The fraction of diaphragmatic thickening it is calculated by the formula: diaphragmatic thickness at the end of inspiration - thickness to diaphragmatic at the end of exhalation / diaphragmatic thickness at the end of exhalation x 100. The number of areas with lines B also will be measured.