Effects of remifentanil infusion on hemodynamics before CPB in children undergoing cardiac surgery

Objective To evaluate the effects of remifentanil infusion on hemodynamics before CPB in children undergoing cardiac surgery.Methods Seventy-five children(1-12 years old) undergoing selective cardiac surgery were randomly allocated into 5 groups with 15 cases each.The patients in group F were injected fentanyl 10 μg/kg before skin incision after fentanyl 10 μg/kg injected for anesthesia induction.The patients in 4 remifentanil groups were given remifentanil infusion in the dose of 0.5(group R0.5),1.0(group R1.0),1.5(group R1.5)or 2.0(group R2.0)μg·kg-1·min-1 for the maintenance of anesthesia after a bolus injectionof 2 μg/kg for induction.Heart rate and mean artery pressure were recorded before induction(T0),at 2 min after intubation(T1),2 min after incision(T2),and 2 min after thoractomy(T3).At the same time,the frequency of metaraminol use was recorded before CPB.Results The hemodynamic parameters were generally stable at T0-T3 in all groups.Heart rate was higher in groups of R0.5 and R1.0 than that in group F(P0.05).The frequency of metaraminol use in group R2.0 significantly increased as high as 60%.Conclusion The hemodynamics can be kept stable by infusion of remifentanil 0.5-1.5 μg·kg-1·min-1 in children undergoing cardiac surgery.