This study evaluated the effects of parasternal block and wound site infiltration on postoperative pain in patients undergoing median sternotomy. Patients were allocated to receive parasternal block, wound site infiltration, or standard systemic analgesia. Salivary opiorphin levels and postoperative pain scores were assessed to compare analgesic effectiveness between the groups.

This randomized prospective study included patients undergoing surgery through median sternotomy. The study compared three perioperative analgesic approaches: parasternal block, wound site infiltration, and standard systemic analgesia without local intervention at the surgical site.

Salivary samples were collected before surgery, after sternotomy, and during the postoperative period to measure opiorphin levels. Postoperative pain was assessed using visual analogue scale scores, and additional analgesic requirement, opioid consumption, extubation time, intensive care unit stay, and adverse effects such as nausea and vomiting were recorded.

Inclusion Criteria:

• Patients scheduled for surgery through median sternotomy
• Patients who provided informed consent

Exclusion Criteria:

• Age under 30 years
• Presence of ischemic, inflammatory, or systemic disease, except cardiovascular disease
• Use of analgesic medication within the last 24 hours
• Diagnosis of psychiatric disorder
• Presence of any oral pathology, including active dental caries, aphthous lesions, or salivary gland inflammation
• Prolonged intubation or inability to be separated from mechanical ventilation for more than 8 hours

Individual participant data will not be shared due to participant privacy and confidentiality considerations.

Participants and postoperative outcome assessors were blinded to group assignment. In addition, laboratory personnel performing salivary opiorphin measurements were blinded to treatment allocation.