Risk Factors for Postoperative Complications in Major Non-cardiac Surgery: Post-hoc Analysis of the OPHIQUE Multicentre Study

Inclusion Criteria: * Abdominal, orthopaedic or vascular surgery under general anaesthesia and with an estimated duration of surgery \> 2 hours * Adult patients (age ≥ 18 years) * ASA score ≥ II * Patient with at least two of the following comorbidities: age \> 50 years, high blood pressure (HTA), heart failure, ECG abnormality, smoking, stroke, transient ischemic attack (TIA), peripheral arterial disease (PAD), insulin-dependent or non-insulin-dependent diabetes mellitus (NIDDM), ascites, chronic renal failure (CRF) * Signature of the consent form * Affiliation to a social security scheme Exclusion Criteria: * Severe untreated or unbalanced hypertension * Preoperative renal failure on dialysis * Acute heart failure * Acute coronary insufficiency * Vascular surgery with renal plasty * Cardiac surgery * Permanent laparoscopy * Chronic respiratory failure with home oxygen therapy * Acute respiratory distress syndrome with FiO2\>60%. * Preoperative shock * Surgery under spinal anaesthesia and epidural only * Refusal to participate by the patient * Pregnant, parturient or breastfeeding women * Patients under guardianship or curators, under court protection or deprived of public rights * The patient already included in another therapeutic trial with an experimental molecule * Emergency surgery * Patients who do not want their personal data to be used in the framework of the research