Parasternal Intercostal Nerve Block and Chronic Pain After Cardiac Surgery

Chronic post-sternotomy pain is a common but under-recognised complication of cardiac surgery, reported in roughly 11 to 56 percent of patients and capable of persisting for years after the operation. Effective control of pain in the early postoperative period is thought to reduce the central sensitisation that drives the transition from acute to chronic pain. This single-centre, prospective, randomised, patient- and assessor-blinded controlled trial investigates whether an ultrasound-guided bilateral parasternal intercostal nerve block, performed preemptively after induction of general anaesthesia and before surgical incision, reduces the incidence of chronic pain three months after cardiac surgery performed through a median sternotomy. A total of 174 adults scheduled for elective cardiac surgery will be randomised in a 1:1 ratio to receive either the block plus the institution's standard multimodal analgesia protocol, or the standard protocol alone. The primary endpoint is the incidence of chronic post-sternotomy pain at three months, assessed with the Turkish version of the Brief Pain Inventory - Short Form. Secondary endpoints cover acute pain scores, opioid consumption, postoperative nausea and vomiting, and complications.

Inclusion Criteria: * Age between 18 and 75 years * Scheduled for elective cardiac surgery via median sternotomy * Able to understand and use the Numeric Rating Scale for pain * Willing to participate and able to provide written informed consent Exclusion Criteria: * Surgery planned by a minimally invasive or thoracoscopic approach * Refusal to participate * Known allergy to the local anaesthetics or analgesics to be used * Chronic opioid use * Coagulopathy * Infection at the planned block site * Pregnancy or lactation * Inability to communicate or to score pain reliably * Psychiatric or neurological condition preventing reliable completion of the BPI-SF and NRS assessments