A randomised controlled trial of the pectoral nerves‐2 (PECS‐2) block for radical mastectomy

Summary We randomly allocated 50 women scheduled for radical mastectomy to pectoral nerves‐2 (PECS‐2) block (n = 25) or no block (n = 25), 20 and 22 of whom we analysed for the primary outcome of a cumulative 24‐h postoperative morphine dose. We gave intra‐operative sufentanil, magnesium, dexamethasone and droperidol. Participants received regular postoperative paracetamol, ibuprofen and patient‐controlled intravenous morphine. Pectoral nerves‐2 block reduced mean (SD) cumulative 24 h postoperative morphine dose from 9.7 (8.9) mg to 5.0 (5.4) mg and 48 h morphine dose from 12.8 (12.5) mg to 6.0 (6.5) mg, p = 0.04 for both. The mean (SD) pain scores 24 h and 48 h after surgery were similar with or without block: 0.8 (1.4) vs. 1.2 (1.9), p = 0.39; and 0.2 (0.4) vs. 0.9 (1.8), p = 0.09, respectively. Rates of postoperative nausea, vomiting and pruritus were unaffected. Rates of chronic pain at six postoperative months were 2/19 and 2/18 after block and no block, respectively, p = 0.95.