Serratus vs ESP Block for Postoperative Pain in Unilateral Breast Surgery

This prospective, randomized, assessor-blinded trial compares serratus posterior superior intercostal plane block (SPSIPB) and erector spinae plane block (ESPB) for postoperative analgesia in unilateral breast surgery. 54 patients will be randomized to receive either SPSIPB or ESPB before general anesthesia. The primary outcome is postoperative pain scores within the first 24 hours. The secondary outcome is opioid consumption.

Inclusion Criteria: * Female patients aged 18-65 years * ASA physical status I-III * Body mass index (BMI) between 18 and 35 kg/m² * Scheduled for elective unilateral breast surgery (mastectomy with or without sentinel lymph node biopsy) * Ability to understand and provide written informed consent Exclusion Criteria: * Infection at the site of block application * Known allergy to local anesthetics * Coagulopathy or anticoagulant therapy * Chronic opioid use * Pregnancy * Inability to communicate or cooperate * Refusal to participate * Failed block * Requirement of additional intraoperative analgesia outside the study protocol * Development of serious intraoperative complications