Cardiac surgery, particularly procedures involving median sternotomy, is associated with significant postoperative pain. Acute postoperative pain is severe in cardiac patients undergoing sternotomy, and pain intensity is more severe than expected. Poorly controlled pain after surgery can lead to myocardial ischemia and pulmonary infections.Regional anesthesia techniques offer a promising alternative or adjunct to systemic opioids, providing targeted pain relief with fewer systemic side effects. The Serratus Posterior Superior Intercostal Plane Block (SPSIPB) is a novel regional anesthesia technique that involves injecting local anesthetic into the fascial plane between the serratus posterior superior muscle and the intercostal muscles