Analgesic efficacy of ultrasound-guided retrolaminar block and erector spinae plane block in modified radical mastectomy: a randomized controlled study

Background & objective : Modified radical mastectomy (MRM) is the most commonly performed surgical procedure in breast cancer patients and is usually associated with severe postoperative pain. The peripheral nerve block techniques have been suggested in addition to the traditional opioid and non-opioid analgesics to manage acute post-mastectomy pain. We compared the analgesic efficacy of retrolaminar block (RLB) with erector spinae plane block (ESPB) in patients undergoing MRM, with an aim to establish the efficacy of one over the other. Methods: This randomized single -blind study included 60 female patients scheduled for MRM under general anesthesia and randomized into two equal groups. The RLB Group (n = 30) received a preoperative ultrasoundguided RLB with 20 ml levobupivacaine 0.25%. The ESPB Group (n = 30) received an ESPB with 20 ml levobupivacaine 0.25%. The primary outcome measure was the total postoperative morphine consumption. Secondary outcomes were total intraoperative fentanyl consumption, duration of analgesia, pain intensity (NPRS score), hemodynamic changes, and adverse effects. Results : The intraoperative fentanyl and postoperative morphine consumption were lower in the ESPB group than the RLB group, but the difference was near statistical significance (P = 0.066 and 0.058, respectively). Pain intensity at rest and on movement was comparable in both groups in the postoperative period, except that NPRS on movement was significantly lower in the ESPB group compared to RLB group (P = 0.039). Both techniques offered hemodynamic stability and there was no significant difference in the occurrence of PONV (P = 0.559). Conclusion: Ultrasound-guided single -point retrolaminar block and erector spinae plane block are safe and effective postoperative analgesic techniques for patients undergoing modified radical mastectomy with comparable effects in terms of opioid consumption, duration of analgesia, pain intensity, and occurrence of PONV. Abbreviations: BMI - body mass index; ESPB - erector spinae plane block; ESM - erector spinae muscle; MRMModified radical mastectomy; NPRS - Numerical pain rating scale; RLB - retrolaminar block;