The aim of this clinical study is to demonstrate that pain following breast surgeries can be reduced through the application of serratus posterior superior intercostal plane block (SPSIPB). Seven patients scheduled for breast surgery were included in the study. The primary research question it seeks to address is as follows: • Can SPSIPB be applied to reduce pain following breast surgeries? Participants are expected to provide accurate responses to the researcher's questions for the assessment of postoperative pain.

Postoperative analgesia techniques for breast surgeries encompass options such as Paravertebral Block, Erector Spinae Plane Block, Serratus Anterior Plane Block, and Pectoral Nerve Blocks. Although the Paravertebral Block is considered the gold standard for postmastectomy pain relief, its limited usage is primarily attributed to complications. SPSIPB's potential in thoracic surgeries has been noted, offering a broad sensory block suitable for MRM and axillary lymph node dissection. In this study, the effectiveness of SPSIP block for post-mastectomy pain has been investigated.

Inclusion Criteria:

• Female patients who will undergo breast surgery

Exclusion Criteria:

• unstable patients
• patients with bleeding disorders
• Patients allergic to local anesthetic drugs
• Patients who did not agree to participate in the study
• Patients with infection at the application site

Since patients undergoing breast surgery were selected, the group consists of female patients.