不同剂量右美托咪啶对非体外循环下冠状动脉旁路移植手术中熵指数和血流动力学的影响

Effects of dexmedetomidine at different dosages on entropy index and hemodynamics during off-pump coronary artery bypass grafting

目的探讨不同剂量右美托咪啶(DEX)在非体外循环下冠状动脉旁路移植术(OPCAB)中对熵指数和血流动力学的影响。方法选择2016年6月至2017年12月岳阳市第一人民医院心胸外科接受OPCAB的患者80例,根据随机数表法分为A、B、C及D 4组,每组20例。麻醉诱导前B、C及D 3组患者分别静注DEX负荷量0.5、0.7和1.0μg/kg(均为50 ml,10 min输注完毕),A组静注50 ml生理盐水。随后B、C及D 3组分别以0.5、0.7、1.0μg/(kg·h)维持剂量持续输注至关胸,A组不作处理。4组患者经麻醉诱导插管进行机械通气,并行右颈内静脉穿刺技术。比较4组患者给药前(T_0)、给药后插管时(T_1)、开胸后(T_2)、吻合血管后心脏位置复原后(T_3)反应熵(RE)、状态熵(SE)及血流动力学[中心静脉压(CVP)、心脏指数(CI)、胸腔内血容量指数(ITBI)和全身外周血管阻力指数(SVRI)]变化。采用SPSS 19.0统计软件对数据进行分析。根据数据类型,组间比较采用单因素方差分析、LSD-t检验或χ~2检验。结果与T_0比较,4组患者在T_(1～3)时RE、SE显著下降;与T_1比较,4组患者在T_(2～3)的RE、SE显著下降,差异有统计学意义(P<0.05)。与A组比较,B、C、D组在T_(1～3)的RE、SE均显著下降;与B组比较,C、D组在T_(1～3)的RE、SE亦显著下降,差异有统计学意义(P<0.05)。与T_0时比较,T_1时A、C、D组患者的CVP显著升高,4组患者的CI、ITBI、SVRI显著下降;T_(2～3)时A、C、D组患者CVP显著上升,C、D组患者CI、ITBI、SVRI显著下降,差异有统计学意义(P<0.05)。与T_1时比较,T_(2～3)时A、C、D组患者的CVP显著下降;C、D组患者的CI、ITBI、SVRI显著升高,差异有统计学意义(P<0.05)。与A组或B组比较,T_(2～3)时C和D组患者的CVP均显著升高,CI显著降低,差异均有统计学意义(P<0.05)。T_(0～3)期间C、D组之间上述指标差异均无统计学意义。结论 DEX可以提高OPCAB手术麻醉效果,改善熵指数,其中应用0.7μg/kg剂量组对该手术血流动力学稳定效果最佳。

Objective To investigate the effect of dexmedetomidine (DEX) at different dosages on entropy index and hemodynamics during off-pump coronary artery bypass grafting (OPCAB). Methods From June 2016 to December 2017, 80 patients undergoing OPCAB in the Department of Cardiothoracic Surgery of the First People′s Hospital of Yueyang were selected and randomized into groups A, B, C and D, with 20 in each group. Before anesthesia induction, groups B, C and D were given DEX at 0.5, 0.7 and 1.0 μg/kg (50 ml, 10 min) respectively, and group A was given 50 ml saline. Subsequently, DEX was infused at 0.5, 0.7, and 1.0 μg/(kg·h) respectively in groups B, C and D until chest closure, while group A was not treated. Mechanical ventilation was performed by anesthesia induction and followed by the right internal jugular vein puncture in 4 groups. The 4 groups were compared in the respects of response entropy (RE), state entropy (SE) and hemodynamics [central venous pressure (CVP), cardiac index (CI), intrathoracic blood volume index (ITBI) and systemic vascular resistance index (SVRI)]before administration (T0), after intubation (T1), after thoracotomy (T2), after cardiac reposition (T3). SPSS statistics 19.0 was used to analyze the data. According to the data type, single factor variance analysis, LSD- t test or χ^2 test was used for comparison among groups. Results Compared with T 0, RE and SE decreased significantly at T1-3 in all 4 groups, and compared with T1, RE and SE decreased significantly at T2-3 in all 4 groups ( P <0.05). RE and SE in group B, C and D were significantly lower than group A at T1-3 , and RE and SE in group C and D were significantly lower than group B at T1-3 ( P <0.05). Compared with T 0, CVP in group A, C and D increased significantly, and CI, ITBI and SVRI in 4 groups decreased significantly at T1;CVP in group A, C and D increased significantly, and CI, ITBI and SVRI in group C and D decreased significantly at T 2-3 ( P <0.05). Compared with T1, CVP in group A, C and D decreased significantly at T2-3 , and CI, ITBI and SVRI in group C and D increased significantly, with significant difference( P <0.05). Compared with group A or B, CVP in group C and D increased significantly and CI decreased significantly at T2-3 ( P <0.05). There was no difference between C and D in terms of those indices above all. Conclusion DEX is able to enhance anesthesia and entropy index of OPCAB, and a dosage at 0.7 μg/kg offers the best effect for hemodynamic stability.