Chronic pain is a common complication after cardiothoracic surgery. The prevalence of post-sternoyomy pain syndrome (PSPS) ranges from 33% to 91%. Exact pathogenetic mechanisms for developing chronic pain after sternotomy are unknown. Apart from intraoperative nerve damage and subsequent postoperative neuropathic pain, operation techniques, age, sex, pre-existing pain, genetic and psychosocial factors, severe postoperative pain, and analgesic management are suspected to have an impact on the development of PSPS .

Ultrasound-guided Pecto-intercostal Fascial Block (PIFB) has been advocated by some researchers for cardiac surgery. Pecto-intercostal fascial plane block (PIFB) is a novel, minimally invasive, regional fascial plane block technique. PIFB was first described by de la Torre in patients undergoing breast surgery . PIFB targets the anterior intercostal nerves as they run in the fascial plane between the pectoral and the intercostal muscles and emerge on either side of the sternum.

Also, lidocaine, a short-acting local anesthetic, has been proved to have analgesic and anti-inflammatory effects . The application of lidocaine by continuous infusion in the intraoperative period and immediately after the surgery appears to reduce the immediate postoperative pain, and may prevent the PSPS

Inclusion Criteria:

1. age between 18 and 75 years.
2. patient scheduled to undergo elective on-pump cardiac surgery with sternotomy.
3. American Society of Anesthesiologists classification of physical status < IV.

Exclusion Criteria:

1. emergency surgery.
2. off-pump surgery.
3. redo surgery.
4. ejection fraction less than 35%.
5. refusal of the patient.
6. known hypersensitivity to LA.
7. chronic opioid use or chronic pain patient.
8. psychiatric problems or communication difficulties.
9. liver insufficiency (defined as a serum bilirubin ≥ 34 μmol/l, albumin ≤ 35 g/dl, INR ≥ 1.7).
10. renal insufficiency (defined as a glomerular filtration rate < 44 ml/min).
11. obstructive sleep apnea syndrom.
12. coexisting hematologic disorders.
13. pregnancy or breastfeeding.