Efficacy of transcutaneous electrical acupoint stimulation combined with epidural block for labor analgesia in parturients with preeclampsia

Abstract

Objective To evaluate the efficacy of transcutaneous electrical acupoint stimulation (TEAS) combined with epidural block for labor analgesia in parturients with preeclampsia. Methods One hundred and twenty parturients with preeclampsia who were at full term with a singleton fetus in vertex presentation, aged 24-37 yr, weighing 66-105 kg, with height between 157-171 cm, of American Society of Anesthesiologists physical status Ⅲ, were divided into 3 groups (n=40 each) using a random number table method: epidural labor analgesia in active phase of labor group (group A), epidural labor analgesia in latent phase of labor group (group B) and TEAS combined with epidural labor analgesia in active phase of labor group (group C). Epidural labor analgesia was performed in active phase of labor (cervical dilatation≥3 cm) in group A and in latent phase of labor (cervical dilatation≥1 cm) in group B. In group C, TEAS was carried out in latent phase of labor, bilateral Hegu and Sanyinjiao acupoints were selected as the main acupoints and Zusanli as the auxiliary acupoints, patients received TEAS with a frequency 2/100 HZ, disperse dense waves, intensity (starting at a voltage of 15 mA) increasing to the maximum current that could be tolerated until delivery of fetus, and epidural labor analgesia was performed when parturients were in active phase of labor.Epidural labor analgesia solution contained the mixture (100 ml) of 0.08% ropivacaine and sufentanil 0.4 μg/ml, and the analgesia pump was set up to deliver a 5 ml bolus dose with a 30-min lockout interval and background infusion at 8 ml/h and then turned off after delivery of fetus.Mean arterial pressure and visual analogue scale (VAS) scores were recorded when the cervical dilation was 1, 2, 3, 4 and 10 cm and immediately after delivery.The labor time, volume of postpartum hemorrhage, requirement for oxytocin, cesarean section, adverse reactions and Apgar score of the newborn were recorded.Maternal venous blood samples were collected when the cervical dilation was 1 and 10 cm for determination of the concentrations of dynorphin (DYN) and cortisol in serum and adrenocorticotropic hormone, norepinephrine and epinephrine in plasma (by enzyme-linked immunosorbent assay) and serum glucose concentration (by glucose oxidase method). Results Compared with group C, the VAS scores and mean arterial pressure were significantly increased when the cervical dilation was 2 and 3 cm, the concentrations of DYN, cortisol and blood sugar in serum and adrenocorticotropic hormone, norepinephrine and epinephrine in plasma were increased when the cervical dilation was 10 cm(P 0.05), and the duration of the first stage of labor was significantly prolonged, the requirement for oxytocin was increased, the serum concentration of DYN was decreased when the cervical dilation was 10 cm (P 0.05). Conclusion Compared with epidural labor analgesia performed in the latent and active phases of labor, TEAS combined with epidural block provides better efficacy for labor analgesia in parturients with preeclampsia. Key words: Electric stimulation therapy; Analgesia, epidural; Labor pain; Pre-eclampsia