Comparing Perioperative Analgesia After Ultrasound Guided Bilateral Erector Spinae Plane Block and Thoracic Paravertebral Block in Laparoscopic Sleeve Gastrectomy Patients

Erector spinae plane block will be performed using an ultrasound machine with a high frequency linear probe. The patients will be in sitting position to perform the block, the skin is sterilized and the transducer will be placed across the T7 spinous process then move laterally to identify transverse process of T7. Thereafter, the probe will be moved to a parasagittal plane to visualize skin and subcutaneous tissue layers, trapezius muscle, and lastly the erector spinae muscle just superficial to the transverse processes. The in-plane technique will be used, and the tip of the needle will be inserted in the fascial plane deep to the erector spinae muscle. After 2-3 mL of normal saline injection for hydro dissection to verify the correct needle tip placement, 30 mL of 0.25% bupivacaine will be injected deep to the erector spinae muscle. The same technique will be repeated on the contralateral side.

Thoracic paravertebral block will be performed using an ultrasound machine with a high frequency linear probe. The patients will be in sitting position to perform the block, the skin is sterilized and the transducer will be placed across the T7 spinous process then move laterally to identify transverse process of T7. Thereafter, the probe will be moved 3-5 cm laterally to identify the paravertebral space as the target injection site. After probe being rotated into transverse orientation, the needle will be inserted using the out-plane technique. Once the needle threads the internal intercostal membrane and arrives in the paravertebral space, 3 ml of normal saline will be injected firstly. If displacement sign of the pleura occurs, 25 ml of 0.25% bupivacaine will be then injected into the confirmed paravertebral space. The same technique will be repeated on the contralateral side.