Modified Pectoral Nerve Block versus Serratus Block for Analgesia Following Modified Radical Mastectomy: A Randomized Controlled Trial

Background: Modified pectoral nerves (PECSII) and serratus blocks have been recently used for analgesia in breast surgery, but evidence comparing their analgesic benefits is limited. This prospective randomized, controlled study aims to examine the analgesic efficacy and safety profile of ultrasound-guided PECSII versus serratus blocks in patients undergoing modified radical mastectomy (MRM) for breast cancer. Patients and Methods: One-hundred and eighty adult females scheduled for MRM were randomly allocated to three groups. PECS group patients received a PECSII block with 30mL of bupivacaine 0.25%, whereas SAPB group received a serratus anterior plane block (SAPB) using the same volume of bupivacaine 0.25% before induction of anesthesia. The control group received general anesthesia alone. Outcomes included 24 hours morphine consumption, intraoperative fentanyl requirements, visual analogue scale (VAS) scores for pain at rest and during movement, time to first rescue analgesia, postoperative nausea and vomiting (PONV), and sedation scores. Results: Both PECSII and serratus blocks were associated with reduced postoperative morphine consumption compared to the control group (p<0.001). Both blocks were associated with reduced intraoperative fentanyl requirements, VAS scores, and PONV as compared with the control group. Also, they were associated with prolonged time to first rescue analgesia and better sedation scores in comparison with the control group. However, there were no differences between both blocks for all outcomes. Conclusion: PECSII and serratus blocks provide similarly adequate analgesia following modified radical mastectomy.