Patients are not expected to be alive for longer than 3 months.
Mini-mental State Examination (MMSE) [18] score = 23.
history of dementia, psychiatric illness or any diseases of central nervous system.
current use of sedatives or antidepressant.
alcoholism and drug dependence.
patients previously included in this study (for patients who have second intra-abdominal surgery during the study period).
difficult to follow up or patients with poor compliance.
uncontrolled hypertension (> 180/100 mmHg)

NCT01809041_exc_T1
Observation
expected to be alive
NCT01809041_exc_T2
Negation
not
NCT01809041_exc_T3
Value
longer than 3 months
NCT01809041_exc_T4
Measurement
Mini-mental State Examination (MMSE)
NCT01809041_exc_T5
Value
= 23
NCT01809041_exc_T6
Condition
dementia
NCT01809041_exc_T7
Condition
psychiatric illness
NCT01809041_exc_T8
Condition
diseases of central nervous system
NCT01809041_exc_T9
Drug
sedatives
NCT01809041_exc_T10
Temporal
current
NCT01809041_exc_T11
Drug
antidepressant
NCT01809041_exc_T12
Scope
sedatives or antidepressant
NCT01809041_exc_T13
Condition
alcoholism
NCT01809041_exc_T14
Condition
drug dependence
NCT01809041_exc_T17
Condition
uncontrolled hypertension
NCT01809041_exc_T18
Value
> 180/100 mmHg