高胸段硬膜外阻滞对非停跳冠状动脉搭桥术患者围术期血浆内皮素及心钠素水平的影响

Effects of high thoracic epidural block on plasma endothelin and artrial natriuretic polypeptide in patients undergoing off-pump coronary artery bypass grafting

目的评价高胸段硬膜外阻滞对冠心病行非停跳冠状动脉搭桥术患者血浆内皮素(ET)及心钠素(ANP)水平的影响。方法20例拟行非停跳冠状动脉搭桥术患者随机分为2组(n= 10):A组为全麻组;B组为高胸段硬膜外阻滞复合全麻组。采用放免法测定术前、术后1 h、24h及48 h血浆ET及ANP浓度;记录血液动力学参数及所用血管活性药剂量。结果与A组比较,B组术后各时点血浆ET及ANP浓度降低,血管活性药物用量减少(P<0．05)。两组血液动力学指标尽管均在正常范围,但A组波动明显。结论高胸段硬膜外阻滞可抑制ET、ANP的释放,有助于冠状动脉搭桥术患者围术期血液动力学的稳定。

Objective To investigate the effects of high thoracic epidural blockade （TEB） on the plasma concentrations of endothelin （ET） and artrial natriuretic polypeptide （ANP） in patients undergoing off-pump coronary artery bypass grafting （CABG）.Methods Twenty NYHA class Ⅰ -Ⅲ patients aged 38-61 yrs weighing 51-80 kg undergoing off-pump CABG were randomly divided into 2 groups of 10 patients each： group A general anesthesia and group B general anesthesia ＋ TEB. Epidural catheter was placed through T4.5 interspace one day before operation, The sensory block extended from T1 to T7 segmental levels. TEB was started before induction of general anesthesia with 0.8 % lidocaine 5-8 ml followed by infusion at 5-6 ml·h^-1 and was maintained until 48 h after operation. General anesthesia was induced with midazolam, fentanyl, propofol and pancuronium and maintained with continuous IV infusion of propofol and isoflurane inhalation and intermittent IV boluses of fentanyl and pancuronium. ECG, direct BP, HR, CVP, SpO2, PET CO2, body temperature, ACT, blood gases and electrolytes were monitored during operation. The amount of nitroglycerin, dopamine and phenylephrine used were recorded. Blood samples were taken from artery immediately after induction of general anesthesia and at 1, 24 and 48 h after operation for determination of plasma ET and ANP concentrations. Results Plasma ET and ANP concentrations were significantly lower in group B than in group A at 1, 24 and 48 h after operation （ P 〈 0.05）. The hemodynamics was more stable and less amount of vasoactive drugs were used in group B than in group A （ P 〈 0.05）. Conclusion TEB can effectively inhibit the release of ET and ANP and is helpful in maintaining stable hemodynamics in patients undergoing off-pump CABG.