Serratus Posterior Superior Plane Block for Postoperative Pain in Cardiac Surgery

Bilateral ultrasound-guided Serratus Posterior Superior Plane Block (total of 60 ml, %0.25 bupivacaine) will be performed Multimodal analgesia : Intraoperatively, all patients will receive 0.05 mg/kg (IBW) iv morphine. Thirty minutes before the end of surgery, 1 gram of intravenous paracetamol will be administered. Postoperative analgesia: iv paracetamol 1gr every 8 hours and IV PCA of 0,5mg/ml morphine. In cases where rescue analgesia is required (NRS score ≥4),iv fentanyl 25-50 mcg and/or ibuprofen and/or ketamine 10 mg will be administered. Patients are routinely administered iv dexamethasone 4 mg and IV 8 mg ondansetron 20 minutes before end of surgery for postoperative nausea and vomiting prophylaxis.

IV PCA of 0,5mg/ml morphine (the bolus dose is 20 μg/kg, the lock-in time of 6-10 minutes, the 4-hour limit is adjusted to be 80% of the calculated total amount).

Bilateral ultrasound-guided needle placement will be performed in the same anatomical plane as in the SPSIP group, but instead of local anesthetic, an equivalent volume of normal saline (30 mL per side) will be injected. Multimodal analgesia : Intraoperatively, all patients will receive 0.05 mg/kg (IBW) iv morphine. Thirty minutes before the end of surgery, 1 gram of intravenous paracetamol will be administered. Postoperative analgesia: iv paracetamol 1gr every 8 hours and IV PCA of 0,5mg/ml morphine. In cases where rescue analgesia is required (NRS score ≥4),iv fentanyl 25-50 mcg and/or ibuprofen and/or ketamine 10 mg will be administered. Patients are routinely administered iv dexamethasone 4 mg and IV 8 mg ondansetron 20 minutes before end of surgery for postoperative nausea and vomiting prophylaxis.