2.2. Participants
liver dysfunction, dementia
OBESE, SPINAL TUMORS
Patients who met the inclusion criteria underwent spinal surgery including laminoplasty, laminectomy, posterior spinal fusion, and resection of spinal tumors.The inclusion criteria were as follows: >75 years old, American Society of Anesthesiologists (ASA) physical status classification 1 to 3, and written informed consent. The exclusion criteria were as follows: liver dysfunction (Child-Pugh class B or C), renal replacement therapy, morbidly obese (BMI: body mass index ≥ 35), dementia, atypical surgery, and contraindications for use of anesthetics.