Randomized, controlled, double-blind trial of topical lidocaine gel and intrauterine lidocaine infusion for pain relief during saline contrast sonohysterography

OBJECTIVES

To evaluate the efficacy of topical lidocaine gel and intrauterine lidocaine infusion administered prior to saline contrast sonohysterography (SCSH) in reducing pain level during the procedure.

METHODS

This was a randomized, double-blind, placebo controlled trial. We recruited 120 women scheduled to undergo SCSH and randomized them into one of three groups according to administration of gel and intrauterine infusion immediately prior to the procedure: (1) the 'lidocaine gel' group received 3 mL 2% lidocaine gel applied to the cervix and intrauterine infusion, using an infant feeding tube without balloon, of 5 mL normal saline; (2) the 'lidocaine infusion' group received 3 mL gel lubricant applied to the cervix and intrauterine infusion of 5 mL 2% lidocaine; (3) the placebo group received 3 mL gel lubricant applied to the cervix and intrauterine infusion of 5 mL normal saline. The tube was left in place for the SCSH procedure. The primary outcome measure was the overall pain level (on a scale of 0-100) reported by the women during the SCSH procedure. Women also rated their pain levels at various other time points and an observer assessed visible signs of the women's discomfort during the procedure, producing a distress score.

RESULTS

There were no significant differences among the three groups in baseline characteristics, volume of saline solution infused, tenaculum use and duration and difficulty level of the SCSH procedure. The median (range) pain scores during normal saline infusion for the SCSH procedure were 0 (0-65) in the placebo group, 2.5 (0-80) in the lidocaine gel group, and 0 (0-70) in the lidocaine infusion group. The pain scores at other time points, the overall pain score and the distress score were also comparable for the three groups. No significant adverse events were reported.

CONCLUSIONS

SCSH performed with an infant feeding tube without balloon is associated with very low pain levels. Topical lidocaine gel application and intrauterine lidocaine infusion do not further reduce pain levels during SCSH.