Effectiveness of P6 stimulation for reduction of nausea and vomiting during caesarean section under combined spinal-epidural anaesthesia: A randomised controlled trial

Objective: Obstetric patients who receive combined spinal-epidural (CSE) anaesthesia for elective caesarean section (CS) frequently experience intraoperative nausea and vomiting (N&V). Prophylactic therapy with antiemetic agents can have multiple adverse effects to the mother and baby. We designed a randomised clinical trial to evaluate the efficacy of electrical P6 stimulation for prophylactic N&V treatment for scheduled elective CS performed under CSE anaesthesia. Methods: Following the Institutional Review Board approval and informed consent, a total of 180 patients were randomly allocated into three groups: (1) P6 stimulation (via a peripheral nerve stimulator), (2) intravenous (IV) antiemetics (metoclopramide and ondansetron), and (3) control (no IV antiemetic medications and no P6 stimulation), with 60 parturients in each group. Results: Significantly fewer patients experienced intraoperative N&V in the P6 group (nausea 36.7% and vomiting 13.3%) and IV antiemetic group (nausea 23.3% and vomiting 16.7%) than those in the control group (nausea 73.3% and vomiting 45%; p<0.001). In addition, significantly fewer patients required rescue antiemetic medications in the P6 group (35%) and the IV antiemetic group (31.7%) than those in the control group (73.3%; p<0.001). There was no significant difference in the overall anaesthetic care satisfaction reported between the three study groups. Conclusion: Our data suggest that P6 stimulation is as simple and as effective as our routine prophylactic IV antiemetic treatment for preven­tion of N&V during CS performed under CSE anaesthesia that could be of great interest to patients and obstetric anaesthesiologists who prefer treatments with fewer potential side effects.