Table 1 The considered risk factors.

Patients comorbidity factors

1. Abnormal ECG (left bundle branch block, left ventricular hypertrophy, repolarization abnormalities, non-sinus rhythm)

2. Untreated hypertension or hypertension not controlled by medical therapy

3. Previous thromboembolism

4. Stable or controlled angina

5. Previous myocardial infarction with no clinical or diagnostic evidence of residual ischemia

6. Compensated heart failure or previous heart failure

7. Diabetes mellitus

8. Neoplastic disease

9. Transfusion in the preoperative period (> 4 units)

10. Smoking and/or drug addiction

11. BMI > 25 or < 17 weight loss>10% in the preoperative period, plasma proteins < 7 g/dl

12. Creatinine > 3.5 g/dl

13. Steroid use

14. Prevision of prolonged surgery (reoperation, anatomical abnormalities, etc.)

15. History of COPD/dyspnea

16. Decompensated heart failure

17. Valve disease

18. Severe arrhythmias: advanced AV block (second-degree block, Mobitz 2 > 2:1, block grade III)

Symptomatic ventricular arrhythmias, supraventricular arrhythmias with uncontrolled ventricular response

Surgical procedures factors

19. Breast surgery

20. Dental surgery

21. Endocrine surgery (no pheochromocytoma)

22. Eye surgery

23. Gynecological surgery

24. Reconstructive surgery

25. Minor orthopedic surgery (other than hip and spine)

26. Minor urological surgery

27. Abdominal surgery

28. Carotid surgery

29. Head and neck surgery

30. Neurologic/orthopedic (hip and spine) surgery

31. Lung/kidney transplant

32. Major urological surgery

33. Endocrine surgery (pheochromocytoma)

34. Peripheral vascular surgery

35. Aortic and major vascular surgery

36. Pancreas/liver surgery

37. Emergency abdominal surgery

Surgical technique factors

38. Open surgery

39. Laparoscopic surgery

40. Robotic surgery

41. Endoscopic surgery