Serratus vs ESP Block for Postoperative Pain in Unilateral Breast Surgery

This prospective, randomized, assessor-blinded, single-center clinical trial is designed to compare the effects of serratus posterior superior intercostal plane block (SPSIPB) and erector spinae plane block (ESPB) on postoperative analgesia in patients undergoing unilateral breast surgery. Eligible adult female patients will be randomly assigned in a 1:1 ratio to receive either SPSIPB or ESPB under ultrasound guidance prior to induction of general anesthesia.

All patients will receive standardized general anesthesia and postoperative multimodal analgesia. Postoperative pain will be assessed using the Numerical Rating Scale (NRS) at predefined time points within the first 24 hours, both at rest and during movement. The primary outcome is postoperative pain scores within 24 hours. The secondary outcome is total opioid consumption during the same period.

This study aims to determine whether SPSIPB provides comparable or superior analgesia compared to ESPB in unilateral breast surgery.

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