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

Introduction: The antihypertensive drug, clonidine, is a centrally acting alpha 2 agonist, useful as a premedication becauseof its sedative and analgesic properties. We examined the effect of clonidine given as an oral premedication in producing abloodless surgical field in patients undergoing endoscopic sinus surgery. We also evaluated the relation between bleeding volumeand consumption of fentanyl and hydralazine to control hypotension.Methods: This prospective double - blinded clinical trial was performed on 113 patients (ASA I, ASA II). Fifty-two patientsreceived oral clonidine (5 mo g/kg) while the other 61 patients received placebo. During general anesthesia, the hemodynamicendpoint of the anesthetic management was maintenance of hypotension (MAP) at 70 mmHg for producing a bloodless surgicalfield. The direct control of MAP was attained with inspired concentration increments of halothane up to maximum of 1.5vol % as needed. When it was unsuccessful, an intravenous fentanyl bolus of 2 mo g/kg was also added. When both drugs failed,hydralazine, was given intravenously as a bolus and intermittently, O.lmg/kg up to a maximum dose of 40 mg. Intraoperativebleeding 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.Results: There was less bleeding volume in the clonidine group (mean ±SD) than in the placebo group (144 ±75 Vs 225±72 ml, P 0.05). Frequency of bleeding severity scores 3 and 4 (troublesome with repeated suction) were lower in the clonidinegroup than in the placebo group (12% Vs 35%, P 0.05). Fentanyl requirement was significantly lower (112 ± 18 Vs142 ± 21 mo g, P 0.05) in the clonidine group. Hydralazine requirement was significantly lower (0.45 ± 1.68 Vs 2.67 ± 4.33 mg, P 0.05) as well.Conclusion: Premedication with oral clonidine reduces bleeding in endoscopic sinus surgery and also decreases fentanyl,and hydralazine consumption for controlling hypotension.