Hemodynamic Effects of the Combination of Dexmedetomidine-Fentanyl versus Midazolam-Fentanyl in Children Undergoing Cardiac Surgery with Cardiopulmonary Bypass

Abstract

To evaluate the efficacy of the combined infusion of dexmedetomidine and fentanyl on the hemodynamic response during cardiac surgery with cardiopulmonary bypass (CPB) in children. Thirty-two children, ages 1 month to 10 years, scheduled for cardiac surgery with cardiopulmonary bypass were randomly divided in two groups: the MDZ Group received midazolam 0.2 mg.kg(-1).h(-1), while the DEX group received dexmedetomidine 1 microg.kg(-1).h(-1) during one hour followed be a reduction by half in the rate of infusion in both groups. Both groups received fentanyl 10 microg.kg(-1), midazolam 0.2 mg.h(-1), and vecuronium 0.2 mg.kg(-1) for anesthesia induction. The same doses of fentanyl and vecuronium used during induction were infused during the first hour after induction, followed by a reduction to half. Infusions were initiated immediately after induction and maintained until the end of the surgery. Isoflurane was administered for a short time to control the hyperdynamic response to incision and sternotomy. In both groups, systolic blood pressure and heart rate reduced significantly after one hour of anesthetic infusion, but the increase in systolic and diastolic pressure and heart rate to skin incision were significantly lower in the DEX Group. A significantly lower number of patients demanded supplementation with isoflurane in the DEX Group. After CPB, patients in both groups had similar hemodynamic responses. Infusion of dexmedetomidine without bolus seems to be an effective adjuvant to fentanyl on the promotion of sedation and control of hemodynamic responses during surgery for congenital cardiopathies in children.