Effect of Individualized Positive End-expiratory Pressure (PEEP) in Patients Who Have an Intrinsic PEEP During One-lung Ventilation

This study investigates the effects of three extrinsic PEEP settings-5 cmH2O, 0 cmH2O, and an individualized PEEP (70% of the measured intrinsic PEEP)-on intrinsic PEEP and hemodynamic stability in patients with intrinsic PEEP undergoing lung resection surgery, using a randomized, crossover design.

Inclusion Criteria: * American Society of Anesthesiologists Physical Status I - III * The Eastern Cooperative Oncology Group Performance Status Grade 0 - 2 * Lung resection surgery requiring one-lung ventilation for over 60 minutes * Indication of double-lumen endobronchial tube (female 35 Fr, male 37 Fr) * Patient who is diagnosed with intrinsic PEEP during one-lung ventilation Exclusion Criteria: * Large bullae * Emergency surgery * Mechanical ventilation before surgery * Hemodynamic instability before surgery * Surgery requiring cardiopulmonary bypass * Pregnancy, breastfeeding patient * Patient's refusal to participate * No intrinsic PEEP during one-lung ventilation