Comparison of the Analgesic Efficacy of Erector Spinae Plane Block in Breast-Conserving Surgery Versus Serratus Anterior Block Combined With Additional Pecto-Intercostal II Block

This prospective randomized study will compare the effects of Erector Spinae Plane Block (ESPB) and Serratus Anterior Plane Block combined with Pectoral Nerve Block Type II (SAPB + PECS II) on intraoperative analgesia and postoperative opioid consumption in patients undergoing breast cancer surgery. Seventy patients (ASA I-III, aged 18-75 years) will be randomized into two groups using the sealed envelope method. Ultrasound-guided blocks will be performed preoperatively by the same anesthesiologist, with Group 1 receiving ESPB and Group 2 receiving a combined SAPB + PECS II technique performed through a single skin puncture (single needle entry site) with sequential injections into the two target fascial planes. All patients will undergo surgery under general anesthesia and receive postoperative analgesia via morphine patient-controlled analgesia. Pain scores and total opioid consumption will be statistically analyzed, with p \< 0.05 considered significant.