Efficacy of pectoral nerve block versus thoracic paravertebral block for postoperative analgesia after radical mastectomy: a randomized controlled trial

Abstract

BackgroundPectoral nerve (PecS) block is a recently introduced technique for providing surgical anaesthesia and postoperative analgesia during breast surgery. The present study was planned to compare the efficacy and safety of ultrasound-guided PecS II block with thoracic paravertebral block (TPVB) for postoperative analgesia after modified radical mastectomy. MethodsForty adult female patients undergoing radical mastectomy were randomly allocated into two groups. Group 1 patients received a TPVB with ropivacaine 0.5%, 25 ml, whereas Group 2 patents received a PecS II block using same volume of ropivacaine 0.5% before induction of anaesthesia. Patient-controlled morphine analgesia was used for postoperative pain relief. ResultsThe duration of analgesia was significantly prolonged in patients receiving the PecS II block compared with TPVB [mean (sd), 294.5 (52.76) vs 197.5 (31.35) min in the PecS II and TPVB group, respectively; P<0.0001*. The 24 h morphine consumption was also less in the PecS II block group [mean (sd), 3.90 (0.79) vs 5.30 (0.98) mg in PecS II and TPVB group, respectively; P<0.0001]. Postoperative pain scores were lower in the PecS II group compared with the TVPB group in the initial 2 h after surgery [median (IQR), 2 (2–2.5) vs 4 (3–4) in the Pecs II and TPVB group, respectively; P<0.0001]. Seventeen patients in the PecS II block group had T2 dermatomal spread compared with four patients in the TPVB group (P<0.001). No block-related complication was recorded. ConclusionsWe found that the PecS II block provided superior postoperative analgesia than the TPVB in patients undergoing modified radical mastectomy without causing any adverse effect. Clinical trial registrationCTRI/2014/06/004692.