Dexmetomedine for Post Operative Delirium in Elderly Patients Undergoing Elective Total Knee Replacement Under Spinal Anesthesia

Postoperative delirium is a geriatric syndrome occurring after anesthesia and surgery which manifests as acute alterations in mental status, involving changes in cognition, attention, and levels of consciousness that tend to fluctuate The use of dexmedetomidine with the intention to prevent postoperative delirium remains controversial. Where it has shown to be effective in older adult patients undergoing cardiovascular and non-cardiovascular surgeries

Inclusion Criteria:ASA physical status I- IIAge from 65to 75 years old,Elective total knee arthroplasty under spinal anaesthesia.Exclusion Criteria:Bleeding disordersAllergy to any of the drugs used in the studyRenal insufficiencyLiver failure-Neurological abnormalities -patients with hearing and visual impairment