Analgesia of Erector Spinae Plane Block Versus Quadratus Lumborum Block

For each side, the eighth thoracic transverse process will be identified by a linear US transducer (HFL38\_10-5 MHz), puncture will be performed in the plane in the craniocaudal direction until the needle contacts the transverse process, and 20 ml of bupivacaine 0.25% and 4 mg dexamethasone will be injected visualizing the hydrodissection. After 30 minutes, the degree of sensory block in the trunk will be assessed by the pinprick test and any undesirable motor weakness will be recorded as a side effect.

For each side, shamrock sign with three leaves (psoas major muscle anteriorly, the erector spinae muscle posteriorly and the quadratus lumborum muscle adherent to the apex of the transverse process of the L4 vertebral body) will be identified by a curved array US transducer (6-2MHz), puncture will be performed in-plane, the needle will be advanced through the quadratus lumborum muscle penetrating the ventral proper fascia of the quadratus lumborum muscle, and 20 mL of bupivacaine 0.25% and 4 mg dexamethasone will be injected in that space visualizing the hydrodissection. After 30 minutes, the degree of sensory block in the trunk will be assessed by the pinprick test and any undesired motor weakness will be recorded as a side effect

Propofol (2 mg/kg)

Fentanyl (1µg/Kg)

atracurium (0.5mg/kg)

endotracheal intubation

Inhalational isoflurane in oxygen/air mixture

atracurium boluses (0.2 mg/Kg/20 minutes) will be used for maintenance of general anesthesia