Effects of Oral Clonidine on Cardiovascular Response to Tracheal Intubation

Hwang, Jai Hyun; Choi, Jong Moo; Cho, Seong Kang

Abstract

Induction of general anesthesia with tracheal intubation is routine proeedure but causes varying degrees of sympathetic stimulation such as increases in blood pressure and heart rate. Many approaches have been tried to attenuate these hemodynamic responses To evaluate the effects of clonidine, a-2 adrenergic receptor agonist, on the hemodynamic changes induced by intubation, we administered clonidine(5 ug/kg, P.O.) 90 minutes before induction of anesthesia. We measured systolic pressure, diastolic pressure and heart rate before premedication, before induction, after intubation and 5, 10 minutes after intubation and compared with control group. The results were as follows: 1) After intubation systolic and diastolic blood pressures increased significantly in both group(P<0.05) but the increasing rate was significantly less than in clonidine group. (P<0.05) 2) After intubation the increaae in heart rate in clonidine group was significantly less than in control group (p<0.05). 3) The trend of increase in heart rate in clonidine group was more stabilized than control group. 4) Systolic blood pressure and heart rate in clonidine group were significantly decreased in preinduction period after premedication.