Effect of dexmedetomidine on hemodynamics in pediatric patients following cardiac surgery

BACKGROUND: Dexmedetomidine (DEX), a highly selective alpha2-adrenergic receptor agonist, has sedative and analgesic properties with minimal respiratory depression. We retrospectively evaluated the hemodynamic effects of dexmedetomidine in pediatric patients following cardiac surgery. METHODS: The subjects were twenty children aged 4 months to 15 years who had undergone cardiac surgery. After hemodynamics were stabilized in ICU, DEX was infused at a rate of 0.3-0.5 microg x kg(-1) min(-1), following initial loading (0.5 microg x kg(-1) over 10 min). Heart rate and blood pressure were analyzed just before starting infusion, following 1, 3, 6 hours during infusion, and at the end of the infusion. RESULTS: There was no change in blood pressure during measurement. HR was slightly decreased during DEX infusion but not significantly. After discontinuation of DEX, HR was significantly increased from 109 +/- 17 to 124 +/- 19 beats x min(-1) (mean +/- SD) (P < 0.05). Two patients were excluded from the study, because clinically significant bradycardia developed during DEX infusion. CONCLUSIONS: DEX had little effect on blood pressure in patients after cardiac surgery. DEX, however, had a tendency to decrease HR. Therefore, it shoud be used with caution in patients with low heart rate.