持续性硬膜外阻滞对妊娠高血压综合征患者血管活性因子的影响

Effects of continual epidural block on vasomotory factors in patients with pregnancy induced hyperten-sion

目的探讨持续性硬膜外阻滞前后妊娠高血压综合征(简称“妊高征”)患者外周血血管活性因子一氧化氮(NO)、内皮素(ET)、前列环素(PGI2)、血栓素(TXA2) 水平的变化。方法选择剖宫产的妊高征孕妇(PIH组)和正常晚期妊娠孕妇(NLP组) 各30例,分别于硬膜外阻滞前及阻滞完善后测血压并抽取静脉血,测定外周血中NO、ET、 PGI2及TXA2的浓度变化。结果阻滞前PIH组NO和PGI2浓度显著低于NLP组 (P<0．01);而ET和TXA2浓度明显高于NLP组(P<0．01);阻滞后PIH组和NLP组NO、 PGI2浓度显著高于阻滞前(P<0．01);而ET和TXB2浓度麻醉前、后比较,差异无显著性 (P<0．05)。结论血浆中NO、PGI2浓度降低,ET、TXA2浓度升高是妊高征发病的重要原因之一;持续性硬膜外阻滞可使孕妇体内血管舒张因子(NO、PGI2)水平上升,而对血管收缩因子(ET,TXA2)影响不明显,可安全应用于妊高征孕妇剖宫产手术麻醉中。

Objctive To investigate the effects of continual epidural block on intravenous vasomotory factors including nitric oxide （NO）, endothelin （ET）, prostacyclin （PGI2） and thromboxane A2 （TXA2） concentrations in patients with pregnancy induced hypertension （PIH）. Methods Thirty gravidas with PIH, who underwent cesarean section, served as PIH group, and ten normal late stage gravidas as normal pregnancy group （NIP group）. Intravenous blood samples were taken immediately before and after epidural block to determine the concentrations of NO, ET, PGI2 and TX2. Results Before epidural block, the concentrations of NO and PGI2 were significantly lower in PIH group than those in NLP group （P〈0. 01）, while the concentrations of ET and TXA2 were significantly higher in PIH group than those in NLP group （P〈0. 01）. The concentrations of NO and PGI2 were increased significantly after epidural block in both groups （P〈 0. 01）. There were no significant statistical difference in concentrations of ET or TXA2 in both groups between before and after epidural block （P〉0. 05）. Conclnsion The results indicate that decreases in NO and PGI2 concentrations and increases in ET and TXA2 concentrations may have a role in the pathogenesis of pregnancy induced hypertension. Continual epidural block can improve the levels of vasodilative factors （NO and PGI2 ）, while it has not obvious effect on the levels of vasoconstrictive factors （ET and TXA2 ）.