Clonidine and dexmedetomidine for controlled hypotension during functional endoscopic sinus surgery: a comparative study.

Background: Functional endoscopic sinus surgery (FESS) is minimally invasive, ambulatory endoscopic surgical procedure usually performed in most paranasal sinus diseases. Controlled hypotension during anaesthesia (hypotensive anesthesia) improves surgical field visibility and reduces risk of injuring surrounding structures. Clonidine (C) and dexmedetomidine (D) are both used to reduce blood pressure and heart rate while maintaining tissue perfusion.