Our study is designed to evaluate the effect of intranasal insulin on postoperative cognitive dysfunction.

Primary outcome:

1. The occurrence of cognitive dysfunction at approximately 7 days after surgery.

Secondary outcome:

1. Incidence of any side effect.

Inclusion Criteria:

1. Age 40 - 60 years.
2. Both gender.
3. Patients will be scheduled for elective major abdominal, thoracic, orthopedic, open gynecological, open urological, spine, otolaryngological surgeries under general anesthesia with expected hospital stay >4 days.

Exclusion Criteria:

• 1. Drug allergy. 2. Patients with major psychiatric disease. 3. Patients receive major tranquillizers and antidepressant. 4. Those undergoing neurosurgery or cardiac surgery. 5. Those unable or unwilling to abide by the study procedure 6. Those who could not follow procedure or who had poor comprehension of dutch language. 7. Those with sever visual and auditory disorder / handicaps.

1. Age 40 - 60 years.
2. Both gender.
3. Patients will be scheduled for elective major abdominal, thoracic, orthopedic, open gynecological, open urological, spine, otolaryngological surgeries under general anesthesia with expected hospital stay >4 days.