Comparison of postoperative analgesic efficacy between erector spinae plane block and rhomboid intercostal block in breast-conserving surgery and sentinel lymph node biopsy: a randomized non-inferiority clinical trial

Objectives: Breast-conserving surgery is a common breast operation type in the world. Patients may feel severe postoperative pain after the surgery. Several regional anesthesia methods are used for postoperative pain control as a part of multimodal analgesia management after breast surgery. Erector spinae plane block (ESPB) and rhomboid intercostal plane block (RIB) are commonly used techniques for this purpose. The studies that compare these methods are limited. Therefore, we aimed to compare the efficacy of ESPB and RIB. Methods: This prospective, randomized study included sixty female patients with ASA class I-II physical status in the study. All patients underwent general anesthesia. We performed the blocks at the end of the surgery before extubation. Participants were randomized into two groups between the operation: the Group ESPB (n=30) and the Group RIB (n=30). We performed 30 ml volume of 0.25% bupivacaine for the blocks. 400 mg ibuprofen 3x1 was ordered postoperatively, and a fentanyl PCA device (2 ml bolus, 0 ml infusion, 20 min lock time, 4 hour limit) was attached intravenously to the participants. If the pain score was ≥4, meperidine (0.5 mg/kg) was performed. Results: There were no differences in terms of demographical data. The postoperative opioid use, pain scores, adverse events, and the need for rescue analgesia were similar between groups. Conclusion: Both RIB and ESPB are effective regional anesthesia techniques following breast surgery. They are simple and safe methods. Anesthesiologists may prefer one or the other based on their clinical experience.