Ultrasound standard for lumbar plexus block

Abstract

Editor-The lumbar plexus block (LPB) has been traditionally performed with the needle puncture guided by landmark and the injection point confirmed by nerve stimulator. Various ultrasound approaches could help improve the safety, but each has its own problems. Not until the advent of the 'Shamrock method' 1 did I routinely, perhaps more easily, apply ultrasound for real-time guidance during LPB. Personally, I recommend the 'Shamrock method' to be the standard of ultrasound monitoring for LPB in combination with pressure and stimulator monitoring, the so-called triple monitoring. Several advantages could be found while applying the 'Shamrock method' compared with others.Firstly, the 'Shamrock method' is the real needle in-plane one without changing the practice of traditional landmarkguided LPB, all the same besides additional information of needle trajectory. The lumbar plexus is almost always located ventral to the medial half of the transverse process on shamrock view. Although absolute posterior-anterior approach could also be accomplished and assisted by the famous 'trident sign', 2 most clinicians consider it an out-of-plane technique and hard to prevent inadvertent needle puncture during LPB, at least possible for the kidney 3 and intestines. Using the 'Shamrock method', the needle shaft usually could be found after slightly tilting the transducer. Personal experience revealed

Ultrasound-Guided Lumbar Sympathetic Ganglion Blockade Using Shamrock Method: A Prospective Case Series

“…The lumbar paravertebral region was successfully imaged in all patients ( Figure 2). Overall ultrasound visibility of the lumbar paravertebral structures was judged as good with a median UVS of 15 (range, [8][9][10][11][12][13][14][15][16][17][18] (Table). Real-time USG needle insertion to the anterolateral aspect of L2 vertebrae was performed in each patient studied.…”

“…Recently, it was recognized as a Shamrock method and an ultrasound standard for lumbar plexus block (9). To obtain the complete Shamrock view, the curve transducer should be placed at Volume 3 May, 2016 Number 3 the flank just above the transverse process of the vertebrae.…”

“…Patients were positioned in the lateral position, with the side to be blocked uppermost and with the hip and knees flexed ( Figure 1A) (9,10). All LSGBs were performed using a Sonosite Turbo (Philips Healthcare, Andover, Massachusetts, USA) ultrasound system and a curved array transducer (C5-2, 5-2 MHz) under strict aseptic precautions.…”

Comparison of lumbar plexus block using the short axis in-plane method at the plane of the transverse process and at the articular process: a randomized controlled trial

“…The shamrock method, which was first described by Sauter AR, is a useful technique, and our method is similar except for the site of needle insertion [ 22 ]; however, the ultrasound signal of the needle is often blocked by the transverse processes in the shamrock method because of its posterior puncture direction, which causes the puncture needle to skew out of the ultrasonic plane (Puncture needle deflected and is not in the ultrasonic plane). Although the shamrock method, which was improved by Lin [ 23 ], adopted a new puncture approach through the inter-transverse process, its main puncture site is located in the lateral intervertebral foramen, which may lead to intraspinal drug infiltration.…”

Transversus Abdominis Plane Block: An Updated Review of Anatomy and Techniques

“…In other words, the probe is placed in the gravity-dependent part as a general rule below the needle insertion site for single-shot peripheral nerve blocks [ 65 , 66 ]. Jelly introduction into the central part of the body should be avoided whenever possible, even if it is aseptic [ 67 ], and ultrasound gel itself near peripheral nerves may cause inflammation [ 68 ]. Performing the dual TAP block in this sequence keeps the needle away from gravity-dependent gel contamination.…”