Evaluation of Quadratus Lumborum Blocks in Managing Postoperative Pain in Urogynecologic Surgery

INTRODUCTION:
Given the risks associated with opioid use, enhanced recovery after surgery (ERAS) protocols focus on a multimodal approach to managing postoperative pain, including non-opioid pain medications and regional blocks, such as quadratus lumborum (QL) blocks. While QL blocks have been studied in the general surgery literature for laparoscopic and open abdominal procedures, there is limited data evaluating their role in gynecologic surgery, particularly urogynecologic procedures. As patients undergoing urogynecologic surgery are typically older, minimizing opioid use in this population is essential.

OBJECTIVE:
The primary outcome was to compare in-hospital postoperative opioid requirements in patients who underwent a urogynecologic procedure and received a QL block versus those who did not. The secondary outcomes were to compare postoperative pain scores and time from out of operating room to hospital discharge between the two groups.

METHODS:
We performed a single-center retrospective cohort study of patients who underwent a laparoscopic or robotic apical suspension or total vaginal hysterectomy with/without concomitant prolapse repair between January 2022 to December 2024, in the setting of an established ERAS protocol. Beginning in 2022, pre-procedure QL blocks were performed at the surgeon’s discretion. Group differences were assessed using Wilcoxon rank sum tests for continuous variables and Fisher's exact tests and Pearson’s chi-squared test for categorical variables.

RESULTS:
A total of 428 patients were included in the analysis, of whom 102 (23.8%) received a QL block prior to their procedure, while 326 (76.2%) did not. A total of 319 (74.5%) patients had ambulatory surgery, while 109 (25.5%) were admitted postoperatively. The majority were White non-Hispanic (60%), obese (mean BMI 36) and had a mean age of 64 (Table 1). Of the patients who underwent a QL block, 85 patients (83.3%) underwent a laparoscopic or robotic surgery, while 17 patients (16.6%) underwent a vaginal hysterectomy with/without prolapse repairs. Patients who received a QL block had a lower first postoperative pain score (1.5 vs 2.0, p = 0.039) and two-hour postoperative pain score (2.3 vs 3.0, p = 0.017). There was no difference between the groups in time to the first opioid in the recovery room or from leaving the operating room to discharge. There was no difference in length of hospital stay for admitted patients, last pain score prior to discharge, or total morphine milligram equivalents (MME) required for ambulatory surgery or during hospital admission. Patients who received a QL block had longer surgeries (281 vs 252 minutes, p < 0.0001), although they did have an increased odds of same-day discharge (aOR 1.92, 95% CI 1.02–3.76).

CONCLUSIONS:
There was no difference in postoperative opioid requirements in patients who received a QL block prior to their urogynecologic procedure versus those who did not. While patients who received a QL block had statistically lower pain scores immediately following surgery, these scores were low overall in both groups, making the clinical significance of this finding unclear. The QL block group had increased odds of same-day discharge despite experiencing longer surgical times. A prospective study comparing QL versus no QL block is warranted to fully evaluate the potential benefits of this intervention.