U/s Guided Oblique Subcostal Transversus Abdominis Plane Block Versus Erector Spinae Plane Block as Preemptive Analgesia

Ultrasound-guided oblique subcostal transversus abdominis plane block will be performed in the supine position under strict aseptic precautions. placing a linear high-frequency ultrasound probe obliquely near the costal margin and xiphoid process On confirming the placement of the needle in the correct target space, 1 mL of 0.25% bupivacaine will be injected to hydro-dissect the fascia layer between the RA and TA. After confirming the separation of the transversus abdominis fascia plane, the remaining 19 mL of 0.25% bupivacaine will be administered, advancing the needle infero-laterally parallel to the subcostal margin. A similar procedure will be performed on the contralateral side of the abdomen with an injection of another 20 mL of 0.25% bupivacaine.

Ultrasound-guided erector spinae plane block will be performed in the sitting position. T7 spinous process will be located To perform the block. The tip of the T7 transverse process will be then identified using the ultrasound probe that is placed in a transverse orientation The ultrasound transducer will then be placed in a longitudinal orientation 2-3 cm lateral to the midline in a longitudinal orientation to identify the hyperechoic line of the transverse process with its associated acoustic shadow. After local anaesthetic infiltration, the block needle will be inserted in a craniocaudal direction until contact will be achieved with the T 7 transverse process where the tip will lay in the inter-fascial plane below the erector spinae muscle. A small bolus of local anaesthetic should be given through the block needle to confirm the proper needle position. A total of 20 mL bupivacaine 0.25% will be injected into the interfacial plane deep to the erector spinae muscle bilaterally.