Objective: To investigate the effect of electroacupuncture (EA) analgesia at the latent stage of labor on epidural analgesia, labor outcome and neonatal score so as to provide the reference to the clinical labor analgesia.
Methods: According to the random number table, 104 primipara of vaginal delivery were divided into three groups, named an EA group (37 cases), a sham-EA group (36 cases) and an epidural block group (31 cases). In the EA group, when the cervix opened up by 1 cm, Han's acupoint nerve stimulation apparatus was attached to bilateral Hegu (LI4) and bilateral Sanyinjiao (SP6) to achieve EA analgesia till the active stage (the cervix up 3 cm). In the sham-EA group, the procedure was same as the EA group, but with the sham-stimulation. In the epidural block, EA was not used in intervention. When the cervix opened up 3 cm, the epidural block and the patient-controlled epidural analgesia were all adopted in each group. The score of visual analogue scale (VAS) and the dosage of Sufentanil and Ropivacaine in patient-controlled analgesia pump at the different time points were compared among the groups. Respectively, in 1 h of EA stimulation (T1), 2 h of EA stimulation (T2), at the moment of epidural block (T3) and the complete open of the cervix (T6), the venous blood sample was collected to determine the concentration of beta-endorphin (beta-EP), and the use time of oxytocin, the bleeding amount and the state of newborn were recorded.
Results: There was no statistical difference in immediate of EA stimulation (T0) among the groups in VAS score (P>0.05). But, in T1 to T6, VAS score in the EA group was reduced obviously as compared with the sham-EA group and the epidural block group separately (P<0.05). There was no statistical difference in the use time of oxytocin among the three groups (P>0.05). In the sham-EA group and the epidural block group, bleeding amount during labor and in 24 h after labor was all higher than that of the EA group (P<0.05). In each group, the concentration of beta-EP in T3 and T6 was increased obviously as compared with that in T1 and T2 respectively (P<0.05). In the EA group, the concentration of beta-EP in T1 to T3 and in T6 was higher than that in sham-EA group and the epidural block group respectively (P<0.05). The dosage of Ropivacaine and Sufentanil in the EA group was less than that in either the sham-EA group or the epidural block group (P<0.05). There was no significant difference in amniotic fluid turbidity rate and Apgar score among the three groups (P>0.05).
Conclusion: Electroacupuncture analgesia at the latent stage of labor effectively relieves labor pain of primipara, increases the concentration of beta-EP, enhances the effect of epidural block analgesia, reduces labor bleeding and has no side effect on newborn. The combination of electroacupuncture analgesia and the epidural anesthesia in the latent stage is applicable in the whole process of labor.
Keywords: Electroacupuncture; Endorphin; Epidural labor analgesia; Labor outcome; Latency period.