To Study the Effect of Sevoflurane and Propofol V Sevoflurane and Dexmedetomidine on Postoperative Cognitive Dysfunction

Postoperative Cognitive Dysfunction (POCD), is a subtle decline in cognitive function characterized by impairment of memory and reduced ability to concentrate in elderly patients exposed to general anaesthesia. This prospective study aims to compare incidence and severity of POCD in two groups of patients. Group P receiving Intravenous Propofol and Inhalational anesthetic Sevoflurane. Group D receiving Intravenous Dexmedetomidine and Inhalational anesthetic Sevoflurane, Neuropsychological Test will be performed 24 hours before surgery and on postoperative day 3 and day 7.