腰麻剖宫产低血压两种防治措施下胎盘的体视学研究

Stereological study on placentae of the cases with hypotension during spinal anesthesia for cesarean section under two kinds of preventive and therapeutic measures

目的:探讨一种有效防治剖宫产低血压且对母婴最有利的方法。方法:选择单胎足月择期行腰麻下剖宫产的初产妇40例随机分为两组,分别给予静脉泵入麻黄素和去氧肾上腺素防治腰麻后低血压。记录术中心率(HR)、收缩压(SBP)、舒张压(DBP)、1 min及5 min的Apgar评分、产妇恶心呕吐发生率;抽取脐动脉血进行血气分析,分别监测脐动脉血PaO2、PaCO2、pH、乳酸等;同时取胎盘组织进行常规免疫组织化学染色,通过抗CD34标记血管内皮细胞显示血管的方法进行胎盘绒毛间质内微血管体视学研究。结果:两组SBP、DBP、PaO2、PaCO2和产妇恶心呕吐发生率差异无统计学意义(P>0.05);麻黄素组心率和脐动脉血乳酸值明显高于去氧肾上腺素组,差异有统计学意义(P<0.05);麻黄素组脐动脉血pH值明显低于去氧肾上腺组,差异有统计学意义(P<0.05);两组微血管长度密度差异无统计学意义(P>0.05),麻黄素组微血管体积密度明显小于去氧肾上腺组,差异有统计学意义(P<0.05)。结论:剖宫产腰麻应用去氧肾上腺素防治低血压有利于增加子宫胎盘血量,改善胎儿血供和氧供,从而降低胎儿缺血缺氧。

Objective：To explore an effective method to prevent and treat hypotension and be beneficial for the parturient women and infants.Methods：Forty primiparous women of single pregnancy and full-term who were treated with selective cesarean section under spinal anesthesia were randomly divided into two groups,then the women in the two groups were treated with intravenous pump of ephedrine and norepinephrine to prevent and treat hypotension,respectively.The intraoperative heart rate（HR）,systolic blood pressure（SBP）,diastolic blood pressure（DBP）,one minute Apgar score,five minutes Apgar score,the incidence of maternal nausea and vomiting were recorded;umbilical artery blood samples were obtained for blood gas analysis,PaO2,PaCO2,pH,and lactic acid in umbilical artery blood were monitored,respectively;placental tissue samples were obtained for routine immunohistochemical assay,stereological study of microvessels in stromal tissue of placental villous were performed by labeling vascular endothelial cells with anti-CD34.Results：There was no significant difference in SBP,DBP,PaO2,PaCO2,and the incidence of maternal nausea and vomiting between the two groups（P0.05）.HR and blood lactic acid value in ephedrine group were significantly higher than those in norepinephrine group（P0.05）.The umbilical artery blood pH value in ephedrine group was significantly lower than that in norepinephrine group（P0.05）.There was no significant difference in microvessel length density between the two groups（P0.05）,the microvessel volume density in ephedrine group was significantly lower than that in norepinephrine group（P0.05）.Conclusion：Norepinephrine used in spinal anesthesia for cesarean section to prevent hypotension is helpful to increase uterine and placental blood flow volume,improve blood supply and oxygen supply,and relieve fetal hypoxia and ischemia.