Optimal Timing of Parasternal Intercostal Nerve Block Application for Acute Pain Management in Cardiac Surgery

Optimal Timing of Parasternal Intercostal Nerve Block Application (Pre-incisional Versus Post-incisional) for Acute Pain Management in Cardiac Surgery; a Randomized Double Blinded Clinical Trial

Patients experiencing pain after undergoing cardiac surgery may also experience prolonged immobilization, insufficient respiratory functions, and the inability to cough due to median sternotomy. Therefore, duration of mechanical ventilation, length of intensive care unit (ICU) stay, and length of hospital stay of these patients will increase significantly.

many facial plane blocks have been introduced as simple and safe intervention for thoracic wall anesthesia and analgesia. Parasternal intercostal nerve block (PSIB) is a "superficial block" which involves local anesthetic (LA) infiltration in the intercostal space around the sternum where the anterior branches of intercostal nerves exist.

Intraoperative LA administration under direct vision of the surgeon ensures adequate delivery of drugs and minimizes bleeding complication or inadvertent administration in blood vessels. Meanwhile, Preoperative administration of LA guided by ultrasound imaging has been used in variable surgical settings with noticeable success because of preemptive inhibition of noxious stimuli.

Inclusion Criteria:

• Age from 20-70 years,
• Scheduled to undergo elective cardiac surgeries through median sternotomy involving cardiopulmonary bypass (CPB).

Exclusion Criteria:

• Patients requiring preoperative inotropes, mechanical ventilation or intra-aortic balloon pump,
• patients who have previous cardiac surgery,
• prolonged CPB time (CPB>120 minutes),
• Intubation time more than 12hrs or planned for overnight ventilation.
• Allergy to any of used drugs,
• opioids addiction,
• Chronic liver disease, chronic renal disease, and cognitive impairment.