- Patients with severe comorbidities, such as liver diseases with asparate transaminase (AST) or alanine transaminase (ALT) greater than 3 times upper limit normal (ULN); alkaline phosphatase greater than 5 times the ULN; total bilirubin greater than 3.0 mg/dl; kidney diseases with serum creatinine greater than 2.0 mg/dl in men or 1.6 mg/dl in women; heart diseases; lung diseases; sepsis; and airway intubation.