Prediction of Weaning Outcome From Mechanical Ventilation Using Ultrasound

Inclusion Criteria: * Mechanically ventilated patients will be included in the study when the underlying disease that had required intubation is considered by the attending physician as reversed and after fulfilling the criteria of weaning (alertness, and Adequate gas exchange, normal pH levels, low and stable doses of vasoactive drugs, normal electrolyte levels, and a rapid shallow breathing index (RSBI) of 105 breaths per minute per liter or lower ) rendering the patient eligible to a first SBT. Exclusion Criteria: * Exclusion criteria include patients aged \< 21yrs , patients with tracheostomy, paraplegia with medullar level above T8, cardiac arrhythmias, severe ICU-acquired neuromyopathy, chronic obstructive pulmonary disease with forced expiratory volume \<50% of the theoretical predicted value, patients with planned prophylactic noninvasive ventilation after extubation, and patients who had previously failed a SBT