This study aims to evaluate the effect of continuous erector spinae plane block (CESPB) using ropivacaine on postoperative pain in patients undergoing elective mastectomy. In addition to pain control, this study investigates the impact of CESPB on systemic inflammatory response as measured by nuclear factor kappa B (NF-κB) levels, opioid consumption, and quality of recovery. Patients will be randomly assigned to receive CESPB or standard analgesia without block. Outcomes will be assessed within the first 24 hours after surgery. The findings are expected to provide evidence on the clinical and biological benefits of CESPB as part of multimodal analgesia in breast surgery.