Serratus Posterior Superior Intercostal Plane Block, Versus Erector Spinae Facial Plane Blocks

patients were placed in the lateral decubitus position for SPSIPB. The blocks were performed under the guidance of ultrasonography (USG), a high-frequency linear probe (SonoSite HFL50x, 15-6 MHz, 55-mm broadband linear array, USA) transducer was placed at the level of the spine scapula in the transverse plane, and the upper medial border of the scapula, trapezius muscle, serratus posterior superior muscle (SPSM), 2nd and 3rd ribs were visualized. The ultrasound probe is rotated 90 degrees in a parasagittal orientation to identify the first rib. After its identification, the second and third ribs are confirmed. An 80 mm sono visible needle (type) was inserted in the caudocranial direction just medial to the scapula with the in-plane technique and driven between the 2nd and 3rd ribs targeting the inferior part of the SPSM. The target was confirmed by injecting the test dose with saline. Thirty ml of 0.25% bupivacaine was subsequently injected

US-guided ESPB, a commonly performed interfascial plane block, was first defined by Forero et al. (21). In this technique, LA is injected in the plane between the erector spinae muscles and the thoracic transverse processes. Thus, multiple thoracic levels are anesthetized by the LA spreading in a craniocaudal direction. The transducer was then placed approximately 3 cm lateral to the midline parasagittally. The T5 transverse process and the erector spinae, rhomboid major, trapezius muscles were viewed (i.e., from deep to superficial). The block needle was advanced in a craniocaudal direction using an in-plane approach through the trapezius, rhomboid major, and erector spinae muscles. After establishing contact with the hyperechoic transverse process, 30 mL of 0.25% bupivacaine was injected in small aliquots after hydrodissection (2-3 mL, 0.9% NaCl) and checking for negative blood aspiration after every 5 mL of injection.