Transcutaneous Electrical Nerve Stimulation for Pain Control During First-trimester Abortion

Abortion is common: one in four individuals will seek this care during their reproductive lifetime. Most abortions occur in the first trimester and nearly all - greater than 95% - occur in the outpatient clinic setting. Uterine aspiration is painful; most patients desire additional analgesia beyond local anesthesia. However, not every patient is a candidate for office sedation since multiple medical conditions are a contraindication and patients must have a ride home. The prolonged motor delay from some anesthetic agents makes driving after sedation unsafe. Without a known escort to monitor for surgical and anesthetic complications as recommended by the American Society of Anesthesia, most clinics do not allow patients to use public transportation, taxis, or rideshare services. Arranging a ride may be harder for those seeking abortion care than other surgical procedures given privacy concerns and the need to travel far distances. As abortion restrictions increase and more people need to travel far distances to access care, it is important to investigate non-pharmacologic pain control options. Transcutaneous electrical nerve stimulation (TENS) delivers an electrical current through the skin to activate the descending inhibitory systems in the central nervous system, effectively reducing sensitivity to pain. A previous trial comparing TENS to IV sedation found similar postoperative pain scores with a significantly shorter recovery time in the TENS group; however, this study did not evaluate or report intraoperative pain scores. It was found in a randomized controlled trial comparing TENS to IV sedation (in conjunction with local anesthesia) for first-trimester surgical abortion and that TENS had non-inferior pain scores to IV sedation and was considered an acceptable modality for pain control among participants. Through this proposed double blinded randomized controlled trial, it is hoped to demonstrate that TENS is a superior, non-invasive alternative pain control option for people undergoing surgical abortion in the first trimester who otherwise are not eligible for or decline IV sedation. Ultimately, the hope is to identify an inexpensive, alternative, non-pharmacologic pain control strategy for those with a medical or social contraindication to IV sedation in an effort to decrease barriers to accessing abortion care.

Inclusion criteria

• 18 years old or older
• English- or Spanish-fluency
• <12 weeks gestation
• Presenting for aspiration abortion

Exclusion criteria

• Planned use of oral or IV sedation
• Contraindications to office-based procedure as determined by attending physician
• Fetal demise
• Requiring pre-procedure use of misoprostol
• Contraindication to TENS units use (pacemaker or epilepsy)