Intranasal Versus Intravenous Dexmedetomidine for Hypotensive Anesthesia in FESS

• Intranasal dexmedetomidine (Drug), also known as Propofol 2 mg/kg, fentanyl 1 µg/kg, Cis-atracurium 0.15mg / kg, Isoflurane 1-1.5% in 50% oxygen: 45 -60 min before the operation, patients will receive dose of dexmedetomidine 1microgram/kg diluted in 10ml 0.9% saline administered to each naris as drops + infusion saline
• Intravenous dexmedetomidine (Drug), also known as Propofol 2 mg/kg,, fentanyl 1 µg/kg , Cis-atracurium 0.15mg / kg and Isoflurane 1-1.5% in 50% oxygen: patients will receive loading dose of dexmedetomidine 1 µg/kg diluted in 10ml 0.9% saline infused over 45- 60 min before induction of anesthesia, followed by continuous infusion of (0.4 µ g/kg/h) + intranasal saline.

Primary outcomes

• Improving quality of the operative field. [during surgery (intraoperatively) 2 hours]: Quality of intraoperative surgical field during functional endoscopic sinus surgery will be evaluated by the surgeons by rating the amount of bleeding according to a 6-point scale by Formmer's scores of surgical field quality (0= no bleeding; 1= bleeding, so mild it was not even a surgical nuisance; 2= moderate bleeding, a nuisance but without interference; 3= moderate bleeding that moderately compromised surgical; 4= bleeding, heavy but controllable, that significantly interfered; 5= massive uncontrollable bleeding.
• Amount of atropine consumption [First 24 hours postoperatively]: The total amount of atropine consumed will be recorded

Secondary outcomes

• Hemodynamics(Heart rate (bpm)) [2 hours]: Heart rate (bpm), at base line, 5minute, 10 minute , 30 minute, 45 minute, 60 minute after patient received intranasal and after infusion of loading dose of dexmedetomidine , 5, 15, 30, 45, 60 minutes after induction of anesthesia, at end of surgery and 30 minute after recovery.
• Hemodynamics(Mean arterial blood pressure mm Hg)) [2 hours]: Mean arterial blood pressure mm Hg) at base line, 5minute, 10 minute , 30 minute, 45 minute, 60 minute after patient received intranasal and after infusion of loading dose of dexmedetomidine , 5, 15, 30, 45, 60 minutes after induction of anesthesia, at end of surgery and 30 minute after recovery.
• Pain score [First 24 hours postoperatively]: Pain measured with VAS: (visual analogue scale) will be assessed in post anesthesia care unit, 1, 2, 4, 6, 8, 12, 18, and 24hours postoperative. The Visual Analogue Scale (VAS) measures pain intensity. The VAS consists of a 10cm line, with two end points representing 0 ('no pain') and 10 ('pain as bad as it could possibly be'). patients are asked to rate their current level of pain by placing a mark on the line.
• Adverse events [24 postoperatively]: Adverse events will be recorded such as nausea, vomiting, hypotension and bradycardia.
• hemostatic stuffing [24 hours postoperatively]: The degree of adverse reactions of hemostatic stuffing after functional endoscopic sinus surgery will be also evaluated (1=no swelling, can tolerate; 2= swelling, can barely tolerate; 3= swelling, cannot tolerate).

Sex: All, ages: 21 Years to 70 Years

Inclusion Criteria:

* Patients older than 21 years of age.
* Both genders.
* American Society of Anesthesiologists (ASA) physical status classification I - III who underwent functional endoscopic sinus surgery.

Exclusion Criteria:

* Patients with a body mass index > 30 kg/m2
* Existing or recent significant disease.
* Contraindications to the use of dexmedetomidine.
* History or presence of a significant disease.
* Significant cardiovascular disease risk factors.
* Significant coronary artery disease.
* Any known genetic predisposition.
* History of any kind of drug allergy.
* Drug abuse.
* Psychological or other emotional problems.
* Special diet or lifestyle.
* Clinically significant abnormal findings in physical examination, electrocardiographic (ECG) or laboratory screening.
* Known systemic disease requiring the use of anticoagulants.
* Any nasal disorders that may hinder nasal administration of the drugs as repeated nasal bleeding or nasal tumors.
* Patients with a history of previous functional endoscopic sinus surgery.