A randomized double-blind controlled study comparing erector spinae plane block and thoracic paravertebral block for postoperative analgesia after breast surgery

BACKGROUND: Thoracic paravertebral block (PVB) is an effective regional block for pain control after breast surgery. However, accidentally puncturing adjacent vital structures may cause undesirable complications. Erector spinae plane block (ESPB) has been considered a safer proxy of PVB for beginners. This study aimed to evaluate the analgesic effects of ultrasound-guidance PVB and ESPB after breast surgery. METHODS: This randomized control trial was conducted in patients who underwent mastectomy. Forty-four females were randomly allocated into PVB group or ESPB group. All patients received a block with 20 ml of 0.5% levobupivacaine before general anesthesia. The primary outcome was the 24-h postoperative morphine requirements. The other outcomes of interest were postoperative pain scores, time to first analgesic request, dermatome of sensory blockade, block-related complications, and opioid adverse events. RESULTS: The 24-h morphine requirements were significantly lower in PVB compared to the ESPB group (3.5 ± 3.3 vs. 8.6 ± 3.8 mg, P < 0.001). The overall pain scores were also lower in the PVB group (P < 0.001). Only 14 patients in the PVB group requested additional morphine, whereas all patients in the ESPB group requested it (P = 0.004). The dermatome of sensory blockade was wider in the PVB group (7 vs. 4 levels, P = 0.019). No serious complications occurred in either group. CONCLUSIONS: Compared to ESPB, PVB provided lower postoperative opioid requirements, lower pain scores, and wider sensory blockade after mastectomy.