This study evaluate the effect of adding dexmedetomidine intravenous infusion to propofol intravenous infusion during sedation for drug induced sleep endoscopy. Twenty five patients will receive propofol only while the other twenty five will receive propofol and dexmedetomidine.

Propofol is a commonly used intravenous anesthetic drug used for procedural sedation. Dexmedetomidine is an alpha 2 adrenergic receptor agonist which has a sedative and analgesic effects.In the current study the success of the sedation during drug induced sleep endoscopy will be assessed.

Inclusion Criteria:

• age more than 18 years
• patients with obstructive sleep apnea
• ASA 1and2

Exclusion Criteria:

• patient refusal
• age less than 18 years
• morbid obesity
• known or suspected allergy to the studied drugs