Postoperative pain following open-heart surgery is a significant challenge that may negatively affect recovery and overall clinical outcomes. Due to the risks and contraindications associated with neuraxial techniques, the use of fascial plane blocks has increased in recent years. In patients undergoing cardiac surgery, the location and intensity of postoperative pain may vary daily. However, during the first 24 hours, pain is typically most pronounced at the median sternotomy incision site and at the insertion sites of chest, mediastinal, and pleural drains.

Current postoperative analgesia practices in open-heart surgery commonly include multimodal regimens using simple analgesics such as paracetamol and nonsteroidal anti-inflammatory drugs, combined with a regional anesthesia technique such as the parasternal block. The Serratus Posterior Superior Intercostal Plane Block (SPSIPB) is an interfascial plane block that involves the injection of local anesthetic between the serratus posterior superior and intercostal muscles, providing wide dermatomal coverage from the upper cervical to lower thoracic regions. Although the technique has been used successfully in individual clinical cases, no randomized controlled studies have been conducted to evaluate its efficacy in open-heart surgery.

This study aims to compare the postoperative analgesic effectiveness of the SPSIPB with a combination of parasternal block and local anesthetic infiltration at drain insertion sites in patients undergoing open-heart surgery.

Postoperative pain following open-heart surgery is a significant challenge that may negatively affect recovery and overall clinical outcomes. Due to the risks and contraindications associated with neuraxial techniques, the use of fascial plane blocks has increased in recent years. In patients undergoing cardiac surgery, the location and intensity of postoperative pain may vary daily. However, during the first 24 hours, pain is typically most pronounced at the median sternotomy incision site and at the insertion sites of chest, mediastinal, and pleural drains.

Current postoperative analgesia practices in open-heart surgery commonly include multimodal regimens using simple analgesics such as paracetamol and nonsteroidal anti-inflammatory drugs, combined with a regional anesthesia technique such as the parasternal block. The Serratus Posterior Superior Intercostal Plane Block (SPSIPB) is an interfascial plane block that involves the injection of local anesthetic between the serratus posterior superior and intercostal muscles, providing wide dermatomal coverage from the upper cervical to lower thoracic regions. Although the technique has been used successfully in individual clinical cases, no randomized controlled studies have been conducted to evaluate its efficacy in open-heart surgery.

This study aims to compare the postoperative analgesic effectiveness of the SPSIPB with a combination of parasternal block and local anesthetic infiltration at drain insertion sites in patients undergoing open-heart surgery.

Inclusion Criteria:

• Patients aged 18-85 years with ASA physical status II-III undergoing elective open-heart surgery.

Exclusion Criteria:

Patients who do not consent to participate in the study

Patients with coagulopathy

History of allergy or toxicity to local anesthetics

Patients with hepatic or renal failure

Patients with uncontrolled diabetes mellitus

Patients with uncontrolled hypertension

Mentally disabled patients

Patients receiving chronic pain therapy (opioid use)

Use of antidepressant medication

Presence of neuropathic pain

Presence of infection at the injection site

Pregnant, suspected pregnant, or breastfeeding women

Individual participant data (IPD) will not be shared