The influence of epidural labor analgesia on uterine contraction / 中华麻醉学杂志

ABSTRACT

Objective There is still a concern that epidural labor analgesia could affect uterinecontraction.The purpose of this study was to investigate the effect of epidural labor analgesia on uterinecontraction.Methods Forty ASA Ⅰ-Ⅱ primiparous women aged 20-30 yr at full term in normal uncomplicateddelivery were enrolled in this study.They were taller than 1.5 m and weighed less than 100 kg.The amnioticmembrane was artificially ruptured at 3 cm cervical dilation and a catheter was inserted into uterine cavity beyondthe head of the fetus and connected to a maternal-fetal monitor.The patients were randomly divided into 2 groupswith 20 patients in each groupⅠ control group received no analgesia and Ⅱ epidural group received continuousepidural analgesia(PCEA).An epidural catheter was placed at L_2-3.After a loading dose of 8-10 ml of the PCEAsolution(0.1% ropivacaine+1 ?g?ml~(-1) fentanyl)PCEA was started(bolus 3 ml,lockout interval 15 min andback ground infusion 6-8 ml?h~(-1)).The height of block was controlled below T_10.Blood samples were taken frommaternal vein at 3 cm cervical dilation(T_1),1h later(T_2)and at delivery(T_3)and from umbilical vein andamniotic fluid was aiso collected for determination of cortisol,PGE_2 and pitocin levels.VAS scores,intrauterinepressure,the frequency and duration of uterine contraction,the use of pitocin(%),incidence of cesareansection,the length of labor and neonatal Apgar scores were recorded.Results The maternal blood eortisolconcentration was significantly lower during PCEA(T_2,T_3)in group Ⅱ than in control group(P