Inclusion Criteria:  Patient acceptance. Age ≥ 60 years old. American society of anesthesia (ASA) (II-III). Gender: males &females BMI < 35kg/m2. able to communicate verbally. Scheduled for exploration surgery for intestinal obstruction under general anesthesia of at least 60 min duration  Exclusion Criteria:  Patient refusal. Patients with delirium prior to surgery. Patients with drug misuse history or taking anti-psychotic drugs. Previous hospitalization within 3 months. Legal blindness, severe deafness. History of Acute cerebrovascular conditions; stroke or transient ischemic attack. Patients who could not be prepared with proper fluid resuscitation, electrolyte and acid-base correction prior to surgery. Patients who could be discharged from the intensive care unit (ICU) within two days. Patients with a known history of allergy to study drugs