Oral Clonidine Premedication Decreases Intraoperative Bleeding in Patients Undergoing Endoscopic Sinus Surgery

The antihypertensive drug, clonidine, is a centrally acting alpha 2 agonist, useful as a premedication because of its sedative and analgesic properties. We examined the effect of clonidine given as an oral premedication in producing a bloodless surgical field in patients undergoing endoscopic sinus surgery. We also evaluated the relation between bleeding volume and consumption of fentanyl and hydralazine to control hypotension. This prospective double - blinded clinical trial was performed on 113 patients (ASA I, ASA II). Fifty-two patientsreceived oral clonidine (5 µg/kg) while the other 61 patients received placebo. During general anesthesia, the hemodynamic endpoint of the anesthetic management was maintenance of hypotension (MAP) at 70 mmHg for producing a bloodless surgical field. The direct control of MAP was attained with inspired concentration increments of halothane up to maximum of 1.5 vol % as needed. When it was unsuccessful, an intravenous fentanyl bolus of 2 µg/kg was also added. When both drugs failed, hydralazine, was given intravenously as a bolus and intermittently, 0.1mg/kg up to a maximum dose of 40 mg. Intraoperative bleeding was assessed on a six – point scale from 0 (= no bleeding) to 5 (= severe bleeding). Data were compared with chisquaretest, fisher''s exact test and Student t-test. There was less bleeding volume in the clonidine group (mean ± SD) than in the placebo group (144 ± 75 Vs 225 ± 72 ml, P