Clonidine premedication effects on inhaled induction with sevoflurane in adults: a prospective, double‐blind, randomized study

Background:  The purpose of this study was to evaluate whether oral clonidine premedication becomes an alternative to N 2 O in terms of shortening the induction time and attenuation of the adrenergic response to tracheal intubation during inhalation induction with sevoflurane, and to evaluate the quality of anesthetic induction according to the patient's satisfaction. Methods:  We studied 84 female patients who were randomly allocated into four study groups: Groups I and II received a placebo orally, and Groups III and IV received clonidine at 150 and 300 µg, respectively, 90 min before induction of anaesthesia. Patients were anesthetized using a triple‐deep‐breath technique with 5% sevoflurane in Groups I, III and IV, and with 60% N 2 O−5% sevoflurane in group II. Results:  Induction time was significantly longer ( P <  0.05) in Group I. Increases in mean blood pressure and heart rate after tracheal intubation were significantly suppressed in Groups III and IV but not in Group II compared with Group I. Comfort and impression of anesthesia was better in Groups III and IV than in Groups I and II. Conclusion:  In volatile anesthetic induction, pre‐anesthetic clonidine may become an alternative to N 2 O and may provide more comfort than with N 2 O.