Analgesic Effect of TENS-WAA Combined With Tramadol Hydrochloride During Oocyte Retrieval Surgery

First Affiliated Hospital of the Chinese People's Liberation Army Naval Medical University

Status: Not yet enrolling

Conditions: Oocyte Retrieval for IVF; Pain

Treatments: Device: Transcutaneous Electrical Nerve Stimulation based on Wrist-Ankle Acupuncture theory（TENS-WAA)

Study type: Interventional

Funder types: Other

Identifiers

NCT07212127

CHEC2025-347

Details and patient eligibility

About

This study is a single-centre randomised controlled trial. It aimed to evaluate the efficacy and safety of transcutaneous electrical nerve stimulation based on wrist-ankle acupuncture theory(TENS-WAA) combined with tramadol hydrochloride for analgesia during transvaginal ultrasound-guided oocyte retrieval, by comparing the analgesic effects and the prevention of postoperative nausea and vomiting between the TENS-WAA combined with tramadol hydrochloride group (experimental group) and the sham TENS-WAA combined with tramadol hydrochloride group (control group). Participants were randomly assigned to the experimental or control group. The experimental group received percutaneous electrical nerve stimulation based on wrist-ankle acupuncture theory 30 minutes prior to the procedure, at a frequency of 2Hz with current intensity adjusted to the maximum tolerable level.Tramadol hydrochloride 100mg was administered intramuscularly 20 minutes before surgery. The control group received sham stimulation at the lowest intensity under identical conditions. The primary outcome measure was the Visual Analogue Scale (VAS). Secondary outcome measures included skin conductance response, postoperative nausea scale, and vomiting scale.

Enrollment: 60 estimated patients

Sex: Female

Ages: 21 to 42 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Females aged between 21 and 42 years.
• Patients diagnosed with infertility requiring oocyte retrieval for in vitro fertilisation-embryo transfer.
• Body Mass Index (BMI) 18.5 ≤ BMI ≤ 29.9 kg/m².
• Regular menstrual cycles with ultrasound monitoring demonstrating dominant follicle development and ovulation during the natural cycle; good ovarian reserve: follicle-stimulating hormone (FSH) < 10 IU/L, antral follicle count (AFC) > 6, anti-Müllerian hormone (AMH) > 1.5 ng/ml.
• Undergoing ovarian stimulation therapy using follicle-stimulating hormone (FSH) or gonadotropin protocols.
• Electing tramadol hydrochloride injection for analgesia during oocyte retrieval.
• Voluntary participation with signed written informed consent.

Exclusion criteria

• History of other chronic pain conditions, or prolonged use of opioid medications, history of anaesthetic drug addiction, or chronic alcohol abuse.
• Severe pelvic adhesions.
• Presence of pacemakers or other implanted medical electronic devices.
• Concurrent use of high-frequency surgical equipment, artificial heart-lung machines, medical shortwave therapy, or microwave therapy devices.
• Presence of scarring or skin lesions at electrode application sites.
• Severe anxiety, depression, or other psychiatric conditions impairing accurate description of sensations, or any other disorders potentially affecting pain perception.
• Conditions contraindicating or affecting oocyte retrieval, such as coagulation disorders, acute pelvic inflammation, vaginitis, trichomoniasis, endometriomas, ovarian cysts.
• Individuals with laparoscopically and/or ultrasonographically confirmed endometriosis.
• Patients with ovarian hyporesponsiveness following conventional ovarian stimulation medication.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

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60 participants in 2 patient groups, including a placebo group

Electrical Stimulation Group

Experimental group

Description:

According to the WAA theory, the selected Lower Zone 1 (LZ1) and Lower Zone 2 (LZ2) are defined as follows: LZ1 is located between the medial Achilles tendon and the medial malleolus, while LZ2 is positioned at the central inner edge of the ankle joint, near the posterior border of the tibia. Two electrode pads will be placed on each LZ1 and LZ2 of both legs, totaling eight electrode pads. The TENS-WAA device will be set to a frequency of 2 Hz, a pulse width of 500 μs, and a continuous waveform.The experimental group will receive transcutaneous electrical nerve stimulation based on wrist-ankle acupuncture theory 30 minutes prior to oocyte retrieval surgery, with current intensity adjusted to the maximum tolerable level. Tramadol hydrochloride 100mg will be administered intramuscularly 20 minutes before surgery.

Treatment:

Device: Transcutaneous Electrical Nerve Stimulation based on Wrist-Ankle Acupuncture theory（TENS-WAA)

Sham electrical stimulation group

Placebo Comparator group

Description:

Participants in the control group will have the electrodes placed in the same positions as those in the stimulation group,with identical electrical stimulation frequency and pulse width settings.However,the control group received sham stimulation at the lowest intensity under identical conditions.

Treatment:

Device: Transcutaneous Electrical Nerve Stimulation based on Wrist-Ankle Acupuncture theory（TENS-WAA)