Hollmén A I, Jouppila R, Jouppila P
Ann Chir Gynaecol. 1984;73(3):149-52.
Sufficient placental blood flow is mandatory for the well-being of the fetus. The delicate balance between uterine perfusion pressure and uterine vascular resistance can be critically disturbed during epidural anaesthesia. Maternal hypotension is common when extensive block for Caesarean Section is used. If hypotension as well as aortocaval compression is avoided and sufficient preload (Ringer's lactate) is used intervillous blood flow (IBF) will not significantly change. Ephedrine given to prevent or treat maternal hypotension will not adversely effect IBF. Lumbar epidural analgesia used for pain relief during labor (10 ml dose of local anaesthetic (1.a.] will significantly (p less than 0.05) improve IBF in healthy parturients. Epinephrine (less than or equal to 50 micrograms), added to the local anaesthetic, will not decrease IBF. IBF can be severely reduced in pregnancy-induced hypertension (PIH) since the fetus is chronically asphyxiated it is crucial to avoid any further decrease in IBF. Extensive sympathetic blockade (T8) using epidural analgesia (10 ml dose of 1.a.) has been shown to significantly (p less than 0.01) improve IBF in parturients with PIH by decreasing uteroplacental vascular resistance.
充足的胎盘血流对胎儿的健康至关重要。硬膜外麻醉期间，子宫灌注压与子宫血管阻力之间的微妙平衡可能会受到严重干扰。剖宫产采用广泛阻滞时，产妇低血压很常见。如果避免低血压以及主动脉腔静脉受压，并使用足够的预负荷（乳酸林格液），绒毛间隙血流（IBF）不会有显著变化。用于预防或治疗产妇低血压的麻黄碱不会对IBF产生不利影响。分娩期间用于缓解疼痛的腰段硬膜外镇痛（10毫升局部麻醉剂剂量）将显著（p<0.05）改善健康产妇的IBF。添加到局部麻醉剂中的肾上腺素（≤50微克）不会降低IBF。妊娠高血压（PIH）时IBF可能会严重降低，由于胎儿长期窒息，避免IBF进一步降低至关重要。已证明，采用硬膜外镇痛（10毫升局部麻醉剂剂量）进行广泛交感神经阻滞（T8）可通过降低子宫胎盘血管阻力，显著（p<0.01）改善PIH产妇的IBF。
