Effect of Optimal Positive End-Expiratory Pressure on Oxygenation and Intrapulmonary Shunt During One-lung Ventilation

The study groups received an alveolar recruitment maneuver(increase inspiratory pressure to 30cmH2O for 10s) at the 10min after one-lung ventilation. After the alveolar recruitment maneuver,the study group titrate PEEP from 4cmH2O,increased in 2cmH2O steps and hold at each step for 1min,and the static pulmonary compliance(Cst) would be record.Optimal PEEP was determined until the maximal static pulmonary compliance was obtained.

In the control group at PEEP level of 5 cmH2O was established and maintained during the study period