Erector Spinae Plane Block Versus Thoracic Paravertebral Block in Laparoscopic Cholecystectomy: A Randomized Controlled Trial on Opioid Consumption

All patients in the operating room receive the same anesthetic management under standard monitoring modalities. Both erector spinae plane block (ESPB) and thoracic paravertebral block (TPVB) are performed under ultrasound guidance at the T8 level using a linear probe and a longitudinal out-of-plane technique before induction of anesthesia. For ESPB, 10 mL of 0.375% bupivacaine is injected bilaterally between the deep fascia of the erector spinae muscle and the transverse process. For TPVB, 10 mL of 0.375% bupivacaine is injected bilaterally into the paravertebral space. After standard anesthesia induction, anesthesia is maintained with inhalation agents. Four milligrams of dexamethasone and 8 mg of ondansetron are administered for postoperative nausea and vomiting prophylaxis. As part of multimodal analgesia, all patients receive 1 g of paracetamol and 20 mg of tenoxicam.

All patients are followed according to a standardized postoperative analgesia protocol, which includes tramadol patient-controlled analgesia (10 mg bolus, 20-minute lockout). Postoperative static and dynamic pain scores are evaluated using the numeric rating scale (NRS) at 0, 1, 4, 6, 12, 18, and 24 hours. If the NRS score is greater than 3, 0.5 mg/kg meperidine is administered as rescue analgesia.