Ultrasound-guided lateral versus posterior quadratus lumborum block for postoperative analgesia in robot-assisted partial nephrectomy: a retrospective study

Abstract

Objective To compare the postoperative 24-hour opioid consumption and pain relief between unilateral single-shot lateral and posterior quadratus lumborum block (QLB) in robot-assisted partial nephrectomy (RAPN). Design: A retrospective cohort study. Setting: A tertiary hospital. Interventions: Quadratus lumborum block. RAPN was performed under general anesthesia plus lateral QLB (n = 219) or posterior QLB (n = 201) for analgesia. Primary and secondary outcome measures: The primary outcome was postoperative cumulative sufentanil consumption at 24 and 48 hours. The secondary outcomes were visual analog scale (VAS) scores, time to first rescue analgesia, and intraoperative sufentanil consumption. Adverse effects and complications were also assessed. Results The postoperative 24-hour cumulative sufentanil consumption was significantly lower in the posterior QLB group 54.315[50.306–58.140](54.8 [51.7–59.5]) compared to the lateral QLB group (56.9 [49.1–65.8]) 55.913[48.675–62.595](P = 0.042). However, this difference was not noticed at for the 48-hour cumulative consumption. There were also no significant differences in postoperative VAS scores and time to first rescue analgesia between the two groups, although the postoperative BCS scores were significant higher in the lateral QLB group. Posterior QLB had a higher incidence of intraoperative ephedrine use, while lateral QLB was associated with a higher proportion of ipsilateral lower limb weakness. No significant differences were found in adverse effects or complications. Conclusions Posterior QLB was associated with modestly lower postoperative opioid consumption compared to lateral QLB in RAPN, although the difference was modest. Both techniques provided comparable pain relief.