Procedures and Measurements
Neuromuscular blockade
NEUROMUSCULAR BLOCKADE
All patients were in the semirecumbent position (30° to 45° head-of-the-bed elevation) and sedated according to standard practice. Neuromuscular blockade was accomplished by cisatracurium continuous infusion at the dose of 35 mg · hStudy procedures are summarized in figure Flow chart of the study protocol. After assessment of eligibility, a single-breath derecruitment maneuver, followed by slow inflation, was performed to assess the presence of airway closure. Patients presenting with airway closure were excluded. After enrollment, each patient was ventilated at positive end-expiratory pressure (PEEP) 15 cm HAt the end of the PEEP trial (PEEP5FRC = EELVFor each derecruitment step (