Impact of intrarectal diazepam on early postoperative pain following pelvic reconstructive surgery: a double-blind, randomized placebo-controlled trial

Abstract

To evaluate the effect of diazepam rectal suppositories on early postoperative pain following hysterectomy and vaginal reconstruction for pelvic organ prolapse. In this institutional review board approved, double-blind, randomized placebo-controlled trial, eligible patients were those scheduled to undergo a total vaginal hysterectomy with reconstructive surgery for prolapse. Consented patients were randomized to receive either a 10mg diazepam rectal suppository or an identical appearing placebo intraoperatively at the completion of surgery. Our primary outcome was vaginal pain 3.5-6 hours postoperatively utilizing the 100mm visual analog scale (VAS). Participants also completed surveys regarding pain at baseline, the morning of postoperative day (POD) one, and two-weeks postoperatively. Secondary outcomes included total morphine equivalents following surgery, patient satisfaction with pain control, and overall satisfaction. Chi-squared test, Fisher’s exact test, and Mann-Whitney test were utilized. Our sample size calculation demonstrated that 55 patients per arm were required to detect a difference in our primary outcome. From February 2020 to August 2021, 130 subjects were randomized. Seven patients withdrew, 113 have been analyzed to date; 57 in the diazepam group, 56 in placebo. The median age was 65 (IQR 27, 80), median BMI was 27.9 (IQR 18.70, 45.90), and 96.5% (n=109) of participants were white. There were no differences in baseline characteristics, prolapse stage, or types of procedures performed between groups. Ninety-nine percent (n=112) of participants had concurrent uterosacral ligament suspension, anterior and posterior repairs. Forty-one percent (n=46) had midurethral slings. Forty-five percent (n=51) had same-day discharge. There were no differences in the amount of intraoperative lidocaine injected (30.84 vs 30.16mL, p=0.679) or amount of rescue narcotics used in the immediate postoperative period (22.5 vs 16 morphine equivalents, p=0.286). There was also no difference in the primary outcome of VAS score for vaginal pain 3.5-6 hours postoperatively (24 vs 21mm, p=0.417). At their 2-week survey, patients in the placebo group reported higher satisfaction with pain control in the hospital (31 vs 41mm, p=0.012) and pain control at home (31 vs 40mm, p=0.043). No differences were noted among patients discharged on POD0 compared to those admitted overnight. In our population, placement of a 10mg Diazepam rectal suppository immediately following pelvic reconstructive surgery did not improve pain or narcotic usage in the early postoperative period. Although the placebo group reported slightly higher satisfaction with pain control two-weeks following surgery, overall pain levels were low. Therefore, we do not feel the addition of diazepam to the post-operative regimen is warranted.