Protective Ventilation With Higher Versus Lower PEEP During General Anesthesia for Surgery in Obese Patients

Inclusion Criteria: * Patient scheduled for open or laparoscopic surgery under general anesthesia * Intermediate-to-high risk for PPCs following surgery, according to the ARISCAT risk score (≥ 26) * BMI ≥ 35 kg/m2 * Expected duration of surgery ≥ 2 h Exclusion Criteria: * Age \< 18 years * Previous lung surgery (any) * Persistent hemodynamic instability, intractable shock (considered hemodynamically unsuitable for the study by the patient's managing physician) * History of previous severe chronic obstructive pulmonary disease (COPD) (non-invasive ventilation and/or oxygen therapy at home, repeated systemic corticosteroid therapy for acute exacerbations of COPD) * Recent immunosuppressive medication (patients receiving chemotherapy or radiation therapy up to two months prior to surgery) * Severe cardiac disease (New York Heart Association class III or IV, acute coronary syndrome or persistent ventricular tachyarrhythmias) * Invasive mechanical ventilation longer than 30 minutes (e.g., general anesthesia for surgery) within last 30 days * Pregnancy (excluded by anamneses and/or laboratory analysis) * Prevalent acute respiratory distress syndrome expected to require prolonged postoperative mechanical ventilation * Severe pulmonary arterial hypertension, defined as systolic pulmonary artery pressure \> 40 mmHg * Intracranial injury or tumor * Neuromuscular disease (any) * Need for intraoperative prone or lateral decubitus position * Need for one-lung ventilation * Cardiac surgery * Neurosurgery * Planned reintubation following surgery * Enrolled in other interventional study or refusal of informed consent