Incidence of bradycardia at arrival to the operating room after oral or intravenous premedication with clonidine in children.

BACKGROUND: Clonidine has been advocated as a valid alternative for premedication in children but one of the few limitations is its association with reduced heart rate (HR), which thus raises the question of the safety of clonidine as premedication in children. The aim of this study was to investigate the incidence of bradycardia in children premedicated with oral or intravenous clonidine as compared to children not receiving pharmacologic premedication.

METHODS: An open, nonrandomized, observational study design was used. During the preoperative assessment visit the children were prescribed no premedication, intravenous or oral clonidine. On arrival to the operating room (OR) HR was recorded by connecting the patient to standard monitoring with pulseoximetry and/or Electrocardiogram. The primary outcome measure was the number of patients with a HR below 85% of the lower limit of the normal range (1st centile), which was defined as bradycardia that might need clinical intervention.

RESULTS: One thousand five hundred and seven patients were included in the analysis. 600 and 85 patients did not receive any premedication (Group 0), 305 patients received iv Clonidine (Group CIV), and 517 patients were given oral Clonidine (Group CPO). One patient in Group 0 (0.15%; 95% CI: 0-0.81%), none in Group CIV (0%; 95% CI: 0.00-0.98%), and 5 patients in Group CPO (0.97%; 95% CI: 0.31-2.24%) were observed to have a HR of <85% of the 1st centile.

CONCLUSION: The incidence of bradycardia following oral or intravenous premedication with clonidine in a pediatric population scheduled for anesthesia is low. Thus, it does not appear rational to refrain from using clonidine as premedication in children only due to fear of bradycardia.