The Efficacy of Acu-TENS as an Adjunct Analgesic During USG-MVA

Objectives: To prospectively evaluate the potential of acu-TENS to reduce the pain experienced by women undergoing ultrasound-guided manual vacuum aspiration (USG-MVA) and evaluate its safety profile.

Hypothesis to be tested: Does the use of acu-TENS reduce pain in women undergoing USG-MVA?

Design and subjects: A prospective randomized control trial will be carried out at the Department of Obstetrics and Gynaecology of the Prince of Wales Hospital. Women undergoing USG-MVA for the treatment of early pregnancy loss before 12 weeks of gestation will be randomized to receive acu-TENS (intervention group) or sham acu-TENS (control group) for pain control during USG-MVA. We will recruit 54 participants in each of the two arms, so a total of 108 patients will be recruited.

Study instruments: USG-MVA will be performed using a 60ml charged syringe (MedGyn Aspiration Kit) with a flexible curette attached to it. Transabdominal ultrasound during the MVA procedure will be performed using Mindray DC-80A Diagnostic Ultrasound System. Acu-TENS will be performed using MTR+ Myolito Multifunctional Stimulator (MTRP-00003).

Main outcome measures: Primary outcome includes pain scores before, during and after USG-MVA. Secondary outcomes include (1) stress levels measured by heart rate, heart rate variability, blood pressure, State Trait Anxiety Inventory (STAI), and salivary cortisol; (2) anxiety level; (3) Surgeon's assessment on the patient co-operation score and patient intraoperative pain, (4) Client Satisfaction Questionnaire (CSQ8) and satisfaction score, and (5) any adverse events of acu-TENS.

Data analysis: Data analysis will be performed using the Statistical Packages of Social Sciences for Windows (SPSS, Inc).

Expected results: We expect that acu-TENS will result in at least a 35% reduction in pain experienced by women undergoing USG-MVA.