Postoperative pain following open-heart surgery is primarily caused by median sternotomy, although additional contributors include costovertebral joint stress related to sternal retraction and the presence of chest wall and mediastinal drains during the postoperative period. This pain is often severe, especially in the early postoperative hours, making effective management both challenging and essential. Insufficient pain control frequently necessitates high doses of opioids, which may lead to adverse effects such as nausea, vomiting, respiratory complications, and postoperative delirium. Excessive use of anesthetic agents or opioids can also delay extubation and prolong the process of weaning from mechanical ventilation.

The modified thoracoabdominal nerve block through the perichondrial approach (M-TAPA) is a regional anesthesia technique performed beneath the costal margin between the internal oblique and transversus abdominis muscles. It provides broad dermatomal coverage, extending approximately from the upper thoracic to the lower thoracic and upper lumbar segments. This study aims to evaluate the postoperative analgesic effectiveness of combining the M-TAPA block with a parasternal block in patients undergoing open-heart surgery.

Postoperative pain following open-heart surgery is primarily caused by median sternotomy, although additional contributors include costovertebral joint stress related to sternal retraction and the presence of chest wall and mediastinal drains during the postoperative period. This pain is often severe, especially in the early postoperative hours, making effective management both challenging and essential. Insufficient pain control frequently necessitates high doses of opioids, which may lead to adverse effects such as nausea, vomiting, respiratory complications, and postoperative delirium. Excessive use of anesthetic agents or opioids can also delay extubation and prolong the process of weaning from mechanical ventilation.

The modified thoracoabdominal nerve block through the perichondrial approach (M-TAPA) is a regional anesthesia technique performed beneath the costal margin between the internal oblique and transversus abdominis muscles. It provides broad dermatomal coverage, extending approximately from the upper thoracic to the lower thoracic and upper lumbar segments. This study aims to evaluate the postoperative analgesic effectiveness of combining the M-TAPA block with a parasternal block in patients undergoing open-heart surgery.

Inclusion Criteria:

• Patients aged 18 to 85 years with ASA physical status II-III who are scheduled to undergo elective open-heart surgery will be included.

Exclusion Criteria:

Patients who refuse to participate in the study

Patients with coagulopathy

Patients with a 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)

Patients using antidepressant medications

Patients with neuropathic pain

Patients with infection at the injection site

Pregnant, suspected pregnant, or breastfeeding women

Individual participant data (IPD) will not be shared