Postoperative Analgesia Following Modified Radical Mastectomy with and without Intraoperative Pectoral Nerve Block: A Prospective Observational Study

Background: Acute pain after modified radical mastectomy (MRM) can be substantial. An intraoperative pectoral nerve (PECS) block performed under direct vision may provide analgesia without ultrasound guidance. This study compared postoperative pain, rescue analgesic use and haemodynamic variables between patients receiving general anaesthesia (GA) alone and those receiving GA plus an intraoperative PECS block. Material and Methods: In this prospective observational study, 60 women with American Society of Anesthesiologists physical status I–II undergoing unilateral MRM received GA alone (n = 30) or GA plus a PECS block (n = 30). After tumour resection, 0.2% ropivacaine was injected into the relevant fascial planes under direct vision. Pain was assessed using a 100-mm visual analogue scale (VAS) at 1, 6, 12 and 24 h. Secondary outcomes were rescue tramadol use and haemodynamic variables. Results: Median VAS scores were lower in the PECS group at 1 h (0 vs 30 mm), 6 h (0 vs 50 mm) and 12 h (20 vs 60 mm) (all P < 0.001), but not at 24 h (60 vs 60 mm; P = 0.678). All patients in the GA-alone group received three rescue tramadol doses. In the PECS group, 30% did not require rescue analgesia; among those who did, the median time to first request was 18 h. Time to first rescue analgesia differed between groups (log-rank P < 0.001). One hour after extubation, heart rate and mean arterial pressure were lower in the PECS group (both P < 0.001). Conclusion: An intraoperative PECS block administered under direct vision after resection was associated with effective analgesia for approximately 12 h after MRM and reduced rescue opioid requirements. The absence of a between-group difference in pain scores at 24 h supports planning multimodal analgesia before the block effect is expected to wane.

Keywords: Analgesia, mastectomy, pectoral nerves, postoperative pain, ropivacaine, tramadol.