Comparison of Ultrasound-Guided Quadratus Lumborum Plane Block and External Oblique Intercostal Plane Block for Postoperative Analgesia After Laparoscopic Cholecystectomy: a Two-Center Randomized Controlled Trial

After endotracheal intubation, patients in the supine position will be given a lateral tilt and the areas to be treated will be cleaned with surgical antiseptic solution. The convex USG probe will be covered in a sterile manner. Then, the sterile probe will be placed transversely on the crista iliaca. The probe will be directed cranially until the external oblique muscle, internal oblique muscle and transverse abdominis muscle are clearly visualized. The psoas major muscle and the transverse process of the vertebra will be visualized. The QL muscle will be visualized between the aponeuros of the transverse abdominis muscle and the psoas major muscle. A 20 G 100 mm block needle will be advanced from posterolateral to anteromedial using the "in-plane" technique. The needle will be directed between the QL muscle and the psoas major muscles. 20 ml of 0.25% bupivacaine (Buvasin®, Vem İlaç, Turkey) will be injected on each side between the fasciae of these two muscles and the LA distribution

After endotracheal intubation, a 20-gauge 100 mm long block needle will be inserted at the T6-T7 level under USG guidance and bilateral EOIB will be applied with 20 cc of 0.25% Bupivacaine on each side under the external oblique intercostal muscle (total 40ml bilaterally).