The objective of this study is to determine whether the use of post-incisional surgeon-delivered parasternal block is at least non-inferior in relieving postoperative pain in adult patients scheduled for cardiac surgery involving sternotomy compared with ultrasound-guided post-incisional PIFB.

Patients will be randomly allocated (using a sequence of computer-generated random numbers) into one of two groups (44 patients in each); group P (ultrasound guided parasternal; PIFP block) and group S (surgeon delivered parasternal block).

1. group P (ultrasound guided parasternal; PIFP block): Bupivacaine 0.25 % will be injected into the fascial plane between the pectoralis major muscle and external intercostal muscle or costal cartilages on each side of sternum after skin closure under ultrasound guidance
2. Group S (surgeon delivered parasternal block). Just before wiring the sternum, the surgeon will inject bupivacaine 0.25 % in 4 mL aliquots into the anterior (2nd-6th) intercostal spaces on each side about 2 cm lateral to the sternal edge with a total volume of 40 mL under direct vision.

Inclusion Criteria:

• Age: from 18 to 75 years.
• Rheumatic heart disease needing elective valve replacement (mitral, aortic, or double valve replacement) via median sternotomy and under CPB (cardiopulmonary bypass)
• Hemodynamic stability (no evidence of heart failure, not on vasoactive drugs, and not on mechanical ventilation).

Exclusion Criteria:

• • Previous, urgent, or emergent cardiac surgery.

  • Patients undergoing coronary artery bypass grafting (CABG)
  • local infection of the skin at the site of needle puncture,
  • Allergy to bupivacaine,
  • Coagulation disorders,
  • Clinically significant liver or kidney disease,
  • Heart failure or severe pulmonary hypertension.
  • severe renal, pulmonary, liver, or endocrine systemic disease,