右美托咪定对室间隔缺损修补术婴儿心肌损伤的影响

Effect of dexmedetomidine on myocardial injury in infants undergping repair of ventricular septal defect

目的评价右美托咪定对室间隔缺损修补术婴儿心肌损伤的影响。方法择期拟行室间隔缺损修补术婴儿40例，3—6月龄，体重4—6kg，ASA分级Ⅱ或Ⅲ级，采用随机数字表法，将其分为2组（n=20）：对照组（C组）和右美托咪定组（D组）。人室后开放静脉通路，麻醉诱导后经鼻气管插管，行机械通气。D组在麻醉诱导后持续静脉输注右美托咪定0．5μg·kg^-1·h^-1至术毕，C组相同速率持续静脉输注生理盐水至术毕。于术前10min（T1）、切皮（T2）、胸骨劈开即刻（T3）、主动脉开放后10min（T4）和术毕（T5）时记录HR和BP。于T1、T5和术后24h（R）时采集右颈内静脉血样，测定血浆肌酸酶同工酶（CK．MB）活性和心肌肌钙蛋白T（cTnT）浓度。结果与L时比较，D组各时点HR和BP差异无统计学意义（P〉0．05），C组T3-5时HR和BP升高，2组T5-6时血浆CK-MB活性及cTnT浓度升高（P〈0．05）。与C组比较，D组T2-5时HR和BP、T5-6时血浆CK—MB活性及cTnT浓度降低（P〈0．05）。结论麻醉诱导后静脉输注右美托咪定0．5μg·kg^-1·h^-1可减轻室间隔缺损修补术婴儿的心肌损伤程度。

Objective To evaluate the effect of dexmedetomidine on myocardial injury in infants undergo- ing repair of ventrieular septal defect. Methods Forty ASA grade Ⅱ or Ⅲ infants, aged 3-6 months, weighing 4- 6 kg, scheduled for elective repair of ventricular septal defect, were randomly divided into 2 groups （ n = 20 each） ： control group （group C） and dexmedetomidine group （group D）. Anesthesia was induced with midazolam, etomidate, cisatracurium and sufenanil. The infants were mechanically ventilated after nasotracheal intubation. PET CO2 was maintained at 30-40 mm Hg, Anesthesia was maintained with cisatraeurium, sufenanil and sevoflurane. In group D, dexmedetomidine was infused at 0.5 μg·kg^-1·h^-1 until the end of operation. While in group C nor- mal saline was given at the same rate until the end of operation. BP and HR were recorded at 10 min before opera- tion （T1）, skin incision （T2）, chest opening （T3 ） , 10 min after aortic unclamping （T4） and the end of operation （T5 ） . Blood samples were taken from the right internal jugular vein for determination of plasma creatine kinase MB （CK-MB） activity and cardiac troponin T （cTnT） concentrations at Tl , T5 and 24 h after operation （T6） .Results Compared with the baseline value at T1 , no significant changes were found in HR and BP at different time points in group D, HR and BP were significantly increased at T2-T5 in group C, and the plasma CK-MB ctivity and cTnT concentration were significantly increased at T5 and Ts in the two groups （ P 〈 0.05）. HR and BP at T2_5 and plas- ma CK-MB activity and cTnT concentration at T5 and T6 were significarttly lower in group D than in group C （ P 〈 0.05）. Conclusion Dexmedetomidine infused at 0.5 μg·kg^-1·h^-1 after induction can reduce myocardial injuryin infants undergoing repair of ventricular septal defect.