ALB and chronic obstructive pulmonary disease: Previous literatures found the several risk factors such as cardiac morbidity, male sex, age > 70 years, ASA > III, BMI (< 18.5 kg/m2 or > 30 kg/m2), diabetes mellitus, COPD, hypertension, renal disease, alcohol abuse, radiation therapy, anti-angiogenic therapy, preoperative malnutrition (serum albumin < 3.0 g/dL), and cervical anastomosis for anastomotic leakage [20–23].