ABSTRACT
Autonomic system changes during ERCP lead to increased blood pressure [BP] and heart rate [HR] and decrease in arterial O2 saturation [SPO2]. This study was carried out with the objective of evaluating the clonidine pre-medication effects on systolic BP, HR and SPO2 during ERCP. This randomized clinical trial study was conducted on 40 ERCP candidates. Patients were classified into two groups. The first group didn't receive any premediacation. The patients of second group were given 0.2 mg clonidine 2 hours before ERCP. BP, HR and SPO2 of all patients were recorded before, during and after ERCP. The collected data were analyzed using chi-square, t-test and repeated measures ANOVA [P<0.05]. Age, sex, systolic BP, HR and SPO2 values were identical in both groups before induction [P>0.05]. Analysis of variance of systolic BP, HR and SPO2 showed that SBP and HR changes were significantly lower in the clonidine group at different times [during and after endoscopy] [in the order P<0.004, P<0.017], but no significant difference was observed in SPO2_changes in either groups. The amount of administered sodium thiopental had no significant difference in either group. On the basis of this study, clonidine as an alpha-2 agonist can inhibit BP and HR increase during ERCP by decreasing sympathic discharge but does not decrease the need for sedative drugs