Erector Spinae Plane Block Versus PECS Block Type II for Breast Surgery: A Randomized Controlled Trial

Background: Regional anesthetic techniques are the primary analgesic techniques in breast cancer surgery. Novel techniques include the pectoralis (PECS) block and the erector spinae plane (ESP) block. Objectives: This study compared the analgesic efficacy of ultrasound-guided ESP and PECS-II blocks in patients undergoing unilateral modified radical mastectomy (MRM). Methods: The current prospective randomized controlled trial investigated 60 females scheduled for unilateral MRM under general anesthesia. The participants were randomized into two groups, namely a single-shot ESP block (n = 30) and a PECS-II block (n = 30). The ESP block was conducted at the level T4 using an in-plane approach. A volume of 20 ml of bupivacaine 0.25% was administered in both blocks. The outcome measures were total morphine consumption, analgesia duration, postoperative pain intensity, and nausea and vomiting. Results: More ESP participants required rescue morphine analgesia than those in the PECS group (P = 0.028). The ESP group showed significantly higher total morphine consumption (P = 0.005) and a shorter time to request analgesia (P = 0.003). Pain intensity was higher in the ESP group 1, 2, and 6 hours after the surgery. Conclusions: The PECS-II block is more effective in postoperative pain control after breast cancer surgery than the ESP block. It also prolongs the duration of analgesia and reduces the need for morphine 24 hours after the surgery.