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 con-trol 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 ultra-sound-guidance PVB and ESPB after breast surgery. Methods: This randomized control trial was conducted in patients who underwent mastec-tomy. 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 inter-est 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 mor-phine, 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 compli-cations occurred in either group. Conclusions: Compared to ESPB, PVB provided lower postoperative opioid requirements, lower pain scores, and wider sensory blockade after mastectomy.