This is a prospective, double-blinded, control trial. The Montreal Cognitive Assessment is used to screen preoperative mild cognitive impairment in 582 consecutive geriatric patients, scheduled for general, vascular or urological surgery under general and/or regional anesthesia.

At the preoperative visit, the co-researcher invites 322 general and vascular patients (male 190, female 132) and 260 urological patients (male 220, female 40) who meet the inclusion criteria to join the study. The process of the project is explained to the interested patients in details before an informed consent is obtained.

All participants are interviewed by using the Montreal Cognitive Assessment test. The history of drug used preoperatively (medication reconciliation) has also been recorded.

Inclusion Criteria:

• male or female aged 65 yr, ASA I-III scheduled for elective general, vascular or urological surgery under general and/or regional anesthesia.

Exclusion Criteria:

• unable to communicate in reading and writing
• psychosomatic patients
• insulin-dependant diabetes
• renal insufficiency (creatinine >1.5 mg/dL), renal dialysis
• uncontrolled congestive heart failure (American Heart Association Classification III or IV congestive heart failure), unstable angina, untreated cardiac arrhythmia
• active gastrointestinal bleeding.

The study enrolls 582 consecutive geriatric patients,322 general and vascular patients (male 190, female 132) and 260 urological patients (male 220, female 40) who undergoing general and/or regional anesthesia.