Comparison of Analgesic Efficacy of Ultrasound Guided Rhomboid Intercostal Block versus Serratus Anterior Plane Block for Mastectomy Surgery: a randomized comparative study

Background: One of the most frequent malignant tumors in women is breast cancer. In this study, we investigated the analgesic effectiveness of rhomboid intercostal block (RIB) versus serratus anterior plane block (SAB) following modified radical mastectomy (MRM).
Methods: 60 patients who underwent MRM, were classified into two groups: RIB group and SAB group. Each group received 20ml of bupivacaine 0.25%. The outcomes were intraoperative fentanyl requirements, recovery time, time to the first request for fentanyl, number of patients requiring fentanyl, the total fentanyl consumption, dose of ketorolac, visual analog score (VAS) within 24 hours postoperative, level of patient's satisfaction and postoperative nausea and vomiting.
Results: Intraoperative fentanyl requirements were non-significantly lower in the RIB group versus in SAB group, and recovery time was shorter in RIB compared to SAB group (p=0.572). Time to the first request for fentanyl was longer in RIB compared to SAB group. Number of patients requiring fentanyl and their total fentanyl consumption were comparable in both group (p>0.05) while dose of ketorolac was significantly lower in RIB compared to SAB group (P=0.012). VAS score was insignificantly lower in RIB compared to SAB groups in all time intervals. Level of patient's satisfaction was significantly better in in RIB compared to SAB group (P=0.043).
Conclusion: US-guided RIB with 20ml of bupivacaine 0.25% in patients with mastectomy can effectively decrease the need for fentanyl with a longer time of first request. While comparing with SAB, the dose of ketorolac was lower, and the level of patient's satisfaction was better.