右美托咪定对体外循环下小儿心脏手术时应激反应的影响

Effects of dexmedetomidine on stress response in pediatric cardiac surgery with cardiopulmonary bypass

目的 探讨右美托咪定（DEX）对体外循环（CBP）下小儿心脏手术时应激反应的影响. 方法择期行开放性心脏手术的小儿患者40例,随机分为2组（n=20）：右美托咪定组（DEX组）先给予起始负荷量右美托咪定（0.5 μg/kg,10 min内泵注完毕）,继而以0.5 μg·kg-1·h-1的速率泵注维持;对照组（C组）给予等量生理盐水.分别于药物干预前（T0）、药物干预后5 min （T1）、10 min （T2）、15 min （T3）、切皮后10 min （T4）、开胸后10 min （T5）及CBP后10 min （T6）时记录两组患者平均动脉压（MAP）、心率（HR）及中心静脉压（CVP）并检测血浆中皮质醇、肾上腺素、去甲肾上腺素及血糖水平. 结果与T0比较,DEX组MAP和HR均下降（P〈0.05）,而C组于T4～T6均升高（P〈0.05）.与T0比较,两组在T5～T6时血浆皮质醇、肾上腺素、去甲肾上腺素及血糖水平均上升（P〈0.05）;与C组比较,DEX组上述应激反应相关指标于相应各时点均降低（P〈0.05）. 结论在行开放性心脏手术的小儿患者中,术中静脉输注DEX可改善血流动力学和由手术创伤及CBP所引发的应激反应.

Objective To study the effects of dexmedetomidine on the stress response in pediatric cardiac surgery with cardiopulmonary bypass. Methods Forty pediatric patients undergoing open heart surgery were randomly assigned to two groups （n=20）. The patients of control group （C group） received equal saline and the patients of treatment group （DEX group） received an initial bolus dose of dexmedetomidine （0.5 μg/kg）over 10 min, followed immediately by a continuous infusion of 0.5 Ixg＇kg-l＂h-1. Mean blood pressure （MAP）, heart rate （HR）, central venous pressure （CVP） of the two groups were recorded before treatment （TO）, at 5 rain （TI）, 10 min （T2）, 15 min after treatment （T3）, 10 rain after skin incision （T4）, 10 rain after sternotomy （%） and 10 rain after CBP （T6）. The sequential concentrations of plasma cortisol, epinephrine, norepinephrine, and blood glucose of the two groups were measured respectively at the above time points. Results Compared to TO, MAP and HR of DEX group were both decreased significantly （P〈O.05）. In C group, MAP and HR of patients were increased during T4-T6 （P〈0.05）. Compared to TO, plasma eortisol, epinephrine, norepinephrine, and blood glucose of the two groups were increased significantly during T5-T6 （P〈 0.05）. Compared with C group, the above values associated with stress response of DEX group were significantly lower（P〈0.05）. Conclusion Dexmedetomidine attenuated the hemodynamie and stress response to surgical injury and CBP in pediatric patients undergoing corrective surgery for congenital heart disease.