Effect of Palatable Lidocaine Gel on Gag Reflex for Patients Undergoing Upper Gastrointestinal Endoscopy

patients will be sedated with 50 mg propofol(10 mg/ml) given slowly intravenously over 1 min

patients will received 0.5 mcg/ kg dexmedetomidine intravenously followed by syringe containing 50 mg propofol(10 mg/ml).

15 g of palatable lidocaine gel will be gradually applied 3-5 min before the endoscopy at three consecutive 30-s intervals to the base of the tongue, the palate and the peritonsillar areas and the patients will be informed to spread it within their mouth with their tongue and swallow it later to cover the oropharynx and esophagus. Patients will be asked to register the onset of numbness, then patient will receive syringe containing 50 mg propofol (10 mg/ml) intravenously as a sedation.