Individualized Lung Recruitment Maneuver Guide by Pulse-oximetry in Anesthetized Patients

General anesthesia and mechanical ventilation promotes atelectasis and airway closure. The open-lung approach (OLA) strategy restores the functional residual capacity. Pulse oximetry hemoglobin saturation (SpO2) using room air can diagnose shunt induced by lung collapse during general anesthesia and the SpO2 breathing air was useful to detect the lung´s opening and closing pressure during a recruitment maneuver (RM) in morbidly obese anesthetized patients. Investigators hypothesized that the SpO2 breathing air can personalize the open-lung approach.