Analgesic Efficacy of Intrauterine Lidocaine Flushing in Hysterosalpingo-foam Sonography: A Double-blind Randomized Controlled Trial

Study Objective: To evaluate the efficacy of flushing the uterine cavity with lidocaine before hysterosalpingo-foam sonography (HyFoSy) to reduce procedure-related pain. Design: A double-blind randomized controlled trial was conducted at the Department of Obstetrics and Gynecology, Shamir Medical Center, Israel between June 2020 and September 2020 involving 80 women undergoing a HyFoSy procedure. Setting: University-affiliated medical center. Patients: A total of 40 women were assigned randomly to the lidocaine group and 40 to the saline (placebo) group using a predetermined randomization code. Intrauterine instillation before the procedure consisting of either lidocaine 2% or normal saline alone was conducted, respectively. Interventions: The primary outcome measure was the visual analog scale (VAS) pain score during the phase of intrauterine foam instillation reported by the women after the procedure. The VAS consisted of a 10-cm line ranging from 0 to 10 (anchored by 0 = no pain and 10 = very severe pain). On the basis of the VAS scores, the pain level ratings were classified as mild (rated 1–3), moderate (4–6), or severe (7–10). Measurements and Main Results: The patient characteristics and obstetric data were found to be similar in both groups. Comparison of the VAS pain scores experienced during the procedure showed that women in the lidocaine flushing group rated the procedure less painful than the women in the saline group (3.0 ± 1.3 vs 6.3 ± 1.5, respectively; p = .001). The incidence of severe pain was significantly lower in the lidocaine group than the saline group (2.5% and 45.0%, respectively, p = .001). Conclusion: Lidocaine flushing of the uterine cavity before HyFoSy significantly decreased the pain known to be caused by this procedure and had the advantage of no side effects. It is easily applied, relatively inexpensive, and may affect compliance with this procedure.