Anterior Quadratus Lumborum Block Versus Erector Spinae Plane Block After Elective Cesarean Section

quadratus lumborum block, anterior approach using a curvilinear (5-8MHz) transducer. The transducer will be positioned transverse above the iliac crest at the posterior axillary line and slided posteriorly till the Shamrock sign is identified (the transvers process represent the stem and the attached erector spinae, QL and Psoas major muscles represent the three leaves). A 22 G, 100 mm needle will be advanced in-plane from lateral to medial through the QL muscle to reach the inter-fascial plane between the QL and psoas major muscles, posterior to the transversalis fascia. After ensuring negative aspiration, the local anesthetic solution (20 ml of 0.25% isobaric bupivacaine) will be injected anterior to the QL muscle. The procedure will be repeated on the opposite side of the back

the block will be given at the level of the 9th thoracic transverse process using a linear 6-13 MHz ultrasound transducer. The transducer will be positioned vertically 3 cm to the side of the midline to visualize the muscles of the back, the transverse process, and the pleura between the two transverse processes. Then, a 22G 10-mm needle will be introduced in the cranial-caudal direction toward the transverse process (T9) using the in-plane method till the needle tip crosses all the muscles. The tip of needle should be in the plane between the transverse process and the erector spinae muscle. After ensuring negative aspiration, the local anesthetic solution (20 ml of 0.25% isobaric bupivacaine) will be injected below the muscle. The procedure will be repeated on the opposite side of the back