Influence of Oxygen on Perioperative Outcome in Patients Undergoing General Anaesthesia for Elective Non-cardiac Surgery

Inclusion Criteria: * Written informed consent * Patients eligible for the study should be scheduled for elective or non-emergent non-cardiac vascular surgery under general anaesthesia with endotracheal intubation, and have either * proven CAD and will undergo high- or intermediate surgical risk procedure according to European (European Society of Cardiology, ESC / European Society of Anaesthesiology and Intensive Care, ESAIC) guidelines on non-cardiac surgery. or * two or more risk factors for CAD and will undergo high- or intermediate surgical risk procedures according to European ESC/ESAIC guidelines on non-cardiac surgery. Exclusion Criteria: * Acute coronary event 30 days before surgery * Acute congestive heart failure * Hemodynamic instability before induction of aneasthesia (vasopressor or inotrope infusion since hospitalization for index surgery) * Atrial fibrillation or other severe arrhythmia * Severe pulmonary disease (dependent on oxygen therapy or the Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage 4 or severe carbon monoxide diffusion impairment or severe pulmonary hypertension) * Preoperative oxygen saturation (SpO2) below 90% on room air * Increased risk of oxygen toxicity (e.g., chemotherapy for malignancy within 3 months, bleomycin treatment, airway laser surgery) * Scheduled surgery in the thoracic cavity * ICU admission for respirator weaning and delayed extubation * Pre-existing surgical site infection (SSI) * Current active signs…