RT Book, Section A1 Karmakar, Manoj K. A2 Hadzic, Admir SR Print(0) ID 1141735211 T1 Lumbar Paravertebral Sonography and Considerations for Ultrasound-Guided Lumbar Plexus Block T2 Hadzic's Textbook of Regional Anesthesia and Acute Pain Management, 2e YR 2017 FD 2017 PB McGraw-Hill Education PP New York, NY SN 9780071717595 LK accessanesthesiology.mhmedical.com/content.aspx?aid=1141735211 RD 2024/03/28 AB Lumbar plexus block (LPB) produces anesthesia of the major components of the ipsilateral lumbar plexus, the femoral nerve (FN), lateral femoral cutaneous nerve (LFCN), and the obturator nerve (OBN)1 LPB is used as a sole technique2,3,4 or in combination with a sciatic nerve5 block for anesthesia or analgesia in patients having hip2,3,4 or lower extremity surgery.2 It is also referred to as psoas compartment block (PCB)2,6,7 or posterior lumbar plexus block (PLB).3,7 The term PCB was originally coined by Chayen and colleagues.6 They believed that branches of the lumbar plexus and parts of the sacral plexus were located close to each other in a “compartment” between the psoas major and quadratus lumborum muscles at the level of the L4 vertebra6 and could be identified using “loss of resistance.”6 However, the lumbar plexus is located within the substance of the psoas muscle8,9,10,11 and local anesthetic is injected into a fascial plane within the posterior aspect of the psoas muscle during an LPB.9,10