Abstract:Aim: To observe the effects of pre operative HANS on the dose of the patient controlled epidural analgesia (PCEA) and aversive side effects of PCEA, 40 ASA I patients undergoing Cesarean section were randomly divided into two groups: HANS group (20 cases) was given HANS preoperatively and PCEA postoperativly; control group (20 cases) was given PCEA only. For HANS stimulation, 2/100Hz wave was used for 30 minutes. The VAS score was recorded in eight time points (opening peritoneum; detaching peritoneum between uterus and bladder; fetal delivery; clearing cavity of uterus; exploring adnexa; 6 h, 12 h and 24 h after the operation), the doses of analgesics and complications were also observed. Results: HANS group had significantly less VAS scores than the control group. The dose of analgesics used in HANS group was not significantly less than the control group. The incidence of nausea and vomiting was significantly less in HANS group. Conclusion: preoperative use of HANS reduces pain during and after operation, and reduces the incidence of nausea and vomiting.