Dexmedetomidine is a highly selective α2adrenoceptor agonist recently introduced to anesthesia that produces dose dependent sedation, anxiolysis, and analgesia (involving spinal and supraspinal sites) without respiratory depression.

From a pharmacokinetic perspective,dexmedetomidine has a half life of nearly 2 hours, duration of action of nearly 4 hour, and thus, a side effect profile that is shorter in duration than clonidine.

Esmolol is a cardioselective beta₁ receptor blocker with rapid onset, a very short duration of action (elimination half-life is approximately 9 minutes) , and no significant intrinsic sympathomimetic or membrane stabilising activity at therapeutic dosages

The study will be a randomized double blinded study and will be carried by the Department of Anaesthesia at Beni-Suef University Hospital after obtaining approval from local research and ethical committee. Written informed consent will be obtained from each patient before operation. Aiming to assess of the early cognitive dysfunction after controlled hypotensive anesthesia with either dexmedetomidine or esmolol during middle ear surgeries

Inclusion Criteria:

Patients aging 20-50 years ASA physical status I-II . Males , females

Exclusion Criteria:

1. hypertensive patient
2. Patients receiving sedatives as midazolam.
3. Patients with ischemic heart diseases, heart block, congestive heart failure, valvular heart diseases.
4. Patients with cerebrovascular diseases.
5. Patients with impaired kidney function.
6. Patients with history of chronic liver diseases.
7. Patients with asthma, chronic obstructive lung diseases.
8. Patients with diabetes mellitus, coagulation disorders, pregnancy.
9. Patients with history of allergy to the drugs used in the study or patients with substance abuse .