Inclusion criteria | Exclusion criteria |
---|---|
1) Elder than 60 years old 2) Speak Chinese Mandarin 3) Scheduled to undergo hip or knee replacement surgery 4) The operation time is more than 2 h 5) Signed the inform consent 6) American Society of Anesthesiologists (ASA) classification I–II | 1) Existing cerebral disease, or have a history of neurological and psychiatric diseases including Alzheimer Disease, stroke, epilepsy and psychosis 2) Existing cognitive impairment as evidenced by Mini-Mental State Examination scores below 24 3) Several audition or vision disorder 4) Patients with tumours or infections 5) Unwillingness to comply with the protocol or procedures 6) Cannot communicate normally in Mandarin Chinese 7) Existing bradycardiac arrhythmia (Heart rate <60 bpm for any reasons) 8) Existing gastrointestinal ulcer 9) Existing urinary incontinence 10) Existing asthma or chronic obstructive pulmonary disease 11) Post-operative admission to ICU 12) Allergic to donepezil |