Brachial Plexus Injury After Prone Positioning

Prone positioning will be performed according to the current guidelines. Particularly, face and limbs will be placed according to the "swimmer position", ensuring the face position in the direction of ventilator and limbs (one arm above head and opposite arm at side) positioned as to prevent abnormal extension or flexion against the shoulders and elbows. Patients will lie on low air loss pressure mattresses, thus avoiding the utilization of any thoraco-pelvic supports, which are not recommended. Electromyography (EMG) will be performed to evaluate the occurrence of brachial plexus injury (BPI).