Common neurological indications of intubation and initiation of mechanical ventilation (MV) include ischemic and hemorrhagic stroke, neurotrauma, and intracranial hemorrhage. Mechanical ventilation is frequently applied to protect the airway from the risk of aspiration and to prevent both hypoxemia and hypercapnia, which are two major systemic factors of secondary brain insult.

Mechanical ventilation after endotracheal intubation predisposes these patients to an increased incidence of pulmonary complications such as ventilator-associated pneumonia (VAP), increased risk of deep vein thrombosis, bedsores, increased hospital stay, and poor clinical outcome.

The weaning process from MV involves the reduction of ventilator parameters and Extubation. Daily, careful evaluation of clinical and neurological conditions and completion of spontaneous breathing trial (SBT) should be considered in order to recognize and facilitate the process of withdrawal of the MV.

The diaphragm which is the principal respiratory muscle provides nearly 75% of the resting pulmonary ventilation. However, In ICU patients, the diaphragm is vulnerable to damage from hypotension, hypoxia, and sepsis. Diaphragmatic dysfunction and atrophy is the main precipitating factor for difficult and successful weaning.

Inclusion Criteria:

• patients attached to mechanical ventilation will be included in the study after the informed consent of the legal guardian.

Exclusion Criteria:

• Patients with severe acute lung injury, morbid obesity, chest wall deformity, direct diaphragmatic injury, cervical spine and patients who require neuromuscular infusion will be excluded from the study.