Transversus Abdominis Plane Lock Versus Quadratus Lumborum Block in Children

The operator applied a linear ultrasound probe transversally to the mid-axillary line between the costal margin and iliac crest. Landmarks were then identified as three muscles layers beneath the subcutaneous tissue; from external to internal lay respectively the external oblique muscle (EO), the internal oblique muscle (IO) and the transversus abdominis (TA). The needle was inserted in plane from the iliac crest level on the midaxillary line advancing towards the midline to the fascia laying between the IO and the TA muscles until pop detection. A clear aspiration ruled out vascular effraction. Finally, the space between the two muscle planes was hydrodissected with the bupivacaine.The end goal was visualizing the IO moving upward leaving room to a hypoechoic lens-shaped local anesthetic distribution.

The patient was laid in a lateral decubitus position. The operator applied the probe transversally on the iliac crest directing the indicator to display the back muscles encompassed by the thoracolumbar fascia (TLF).The intended image was spotted by the emergence of the transverse process L4, delimiting the stem of a shamrock-like shape. Quadratus lumborum (QL) muscle represented the upper leaf of the shamrock, and psoas major (PM) and erector spinae (ES) stood respectively for the anterior and posterior leaves. The needle was inserted in plane from the postero-median lumbar wall directed antero-laterally with tip aiming at the posterior border of the QL muscle adjacent to the ES muscles. Pop detection indicated the middle TLF where the local anesthetic would spread, homogenous and resistance-free