Effectiveness of P6 Stimulation and Transdermal Scopolamine Patch for the Reduction of Nausea and Vomiting During Caesarean Section Under Combined Spinal-Epidural Anesthesia: A Randomized Clinical Trial

Background/Objectives: Obstetric patients undergoing elective cesarean section (CS) with combined spinal-epidural (CSE) anesthesia often experience intraoperative nausea and vomiting (N&V). While prophylactic treatment with antiemetic drugs can be effective, it may also carry potential adverse effects for both the mother and the baby. To address this, we designed a randomized clinical trial to assess the effectiveness of transdermal scopolamine patches and electrical P6 stimulation as preventive measures for N&V in patients scheduled for elective CS under CSE anesthesia. Methods: Following the Institutional Review Board approval and informed consent, a total of 240 patients were randomly allocated into three groups: (1) transdermal scopolamine, (2) P6 stimulation (via a peripheral nerve stimulator), and (3) combined transdermal scopolamine and P6 stimulation, with 80 parturients in each group. The primary outcome was defined as the presence or absence of intraoperative nausea and vomiting during the procedure. Results: The incidences of intraoperative nausea and vomiting were similar across all three treatment groups, with no significant differences observed at any point during the surgery. Additionally, there were no notable differences in overall satisfaction with anesthetic care among the three study groups. Conclusions: These findings indicate that while both transcutaneous P6 acupoint stimulation and transdermal scopolamine are straightforward, safe, and effective methods, combining these two antiemetic strategies does not offer additional benefits in reducing nausea and vomiting. Nevertheless, both approaches may be particularly appealing to patients and obstetric anesthesiologists who prioritize treatments with fewer potential side effects.