In this study, we aimed to compare the effects of this block, which is routinely applied in our hospital but has not been studied in our hospital or in the literature before, on the pain in the first 24 hours after the operation, between the single-level and the two-level block.

Inclusion Criteria:

• Adult patients aged 18 years and older
• American Society of Anesthesiologists physical status of II-III
• Undergoing elective coronary artery bypass grafting (CABG), valve repair/replacement, or combined CABG/valve procedure via median sternotomy

Exclusion Criteria:

• Patients who are unable to communicate
• Patients who have had emergency surgery, reoperation, thoracotomy or mastectomy
• Patients with a history of chronic pain
• Patients who are using chronic opioids or sedatives
• Patients who have had a re-sternotomy within 24 hours of surgery
• Patients with liver or kidney failure
• Patients who are using narcotics

Patients over the age of 18 who will undergo sternotomy