Age > 75 years; extra caution for patients between the age of 65 and 75 years. History of chronic lung disease; history of heart disease; history/current diabetes mellitus; immunocompromised state; abnormal ESR and/or CRP; lymphopenia or neutropenia; Charlson Score ≥ 2; ASA score > 2; preoperative hemoglobin < 12 g/dL; RAPT score ≤ 9; STOP-Bang score > 4. Here, CRP is linked to heart disorder.