An intrathecal injection of morphine 300μg will be administered at the L3-L4 or L4-L5 level.

In the intraoperative period, intravenous meperidine 0.5 mg/kg will be given 30min before the end of surgery.

After the linear ultrasound (US) probe will be placed 2-3 cm lateral to the T8 spinous process, 10 ml of 0.25% bupivacaine hydrochloride will be injected cauda-cranially into the interfacial space below the erector spinae muscle, above the transverse process. Next, the needle will be withdrawn till subcutaneously and the linear US probe will be placed 2-3 cm lateral to the T10 spinous process. Finally, 10 ml of 0.25% bupivacaine hydrochloride will be injected cranio-caudally into the interfacial space below the erector spinae muscle, above the transverse process.

This procedure will be performed bilaterally. A total of 40 ml of 0.25% bupivacaine will be injected for bilateral and bi-level ESPB application.

In the intraoperative period, intravenous meperidine 0.5 mg/kg will be given 30min before the end of surgery.

An intrathecal injection of morphine 300μg will be administered at the L3-L4 or L4-L5 level.

Additionally, in the postoperative period a dexketoprofen dose of 50 mg twice daily were administered iv for multimodal analgesia.

Pain will be assessed at rest and while coughing using the visual analog scale on a scale from 0 (no pain) to 10 (worst pain). Pain assessment will be done at 0st, 1st, 2nd,4th, 12th, and 24th hours after surgery.

Remifentanil consumption for intraoperative period will be recorded

Opioid consumption for 24 hours will be recorded