Comparison of the Effects of Preoperative Electroacupuncture and Acupuncture on Postoperative Nausea and Vomiting in Patients Undergoing Hysterectomy: A Triple-Blind, Randomized Clinical Trial

The objective of this study is to evaluate and compare the effects of preoperative electroacupuncture and acupuncture on postoperative nausea and vomiting after hysterectomy

This will be a randomized, triple-blind, parallel-group clinical trial with 90 participants. Randomization will use variable block sizes generated by software.

The study will be conducted at Bahar Hospital, Shahroud

Women aged 18–60 years, ASA class I–II, BMI 20–30, non-smokers, and candidates for hysterectomy under general anesthesia will be included. Pregnancy, psychiatric disorders, chronic pain, recent antiemetic or steroid use, pacemaker, insertion-site infection, and surgery >3 hours will be exclusion criteria

Participants will be assigned to one of three groups: electroacupuncture, traditional acupuncture, or sham treatment administered preoperatively.

Incidence of postoperative nausea and vomiting at 4, 8, 12, and 24 hours; Nausea severity using a 100-mm VAS at the same time points; Use of antiemetic medications during 0–4, 4–8, 8–12, and 12–24 hours postoperatively

Randomization was performed using block randomization with variable block sizes to ensure balanced allocation across the three study groups. The random sequence was generated by an independent individual who was not involved in patient recruitment or intervention administration, using Random Allocation Software. Participant assignment was implemented through sequentially numbered, opaque, sealed envelopes (SNOSE). After confirming eligibility, the responsible researcher opened the next envelope in sequence to determine the participant’s group allocation. This method ensured proper randomization and allocation concealment.

In this study, participants, the principal investigator (except for the individual who will administer the intervention), clinical staff including physicians, anesthesiologists and nurses, as well as outcome assessors and data analysts will all be kept blinded to group allocation. The intervention will be administered in a separate room by an independent individual who will be the only person aware of the assignments and will have no role in data collection, clinical care or data analysis. The appearance of the device and the needle placement procedures will be standardized across all three groups to prevent participants from identifying their assigned intervention. Clinical staff will not be informed of group assignments at any stage of patient care. Outcome data will be collected by a trained nurse who will record information solely based on participant codes and will remain unaware of group allocation. The data analyst will receive anonymized coded data and will remain blinded until all analyses are completed. Group identities will only be revealed after the final analysis by the independent individual

A final decision regarding the sharing of individual participant data has not been made at this time. This matter requires further consideration of ethical issues, data confidentiality, and relevant regulations. The final decision will be made after consultation with the ethics committee and relevant stakeholders.