11 Lumbar Plexus Block
Inguinal Perivascular Block (Three-in-One Block)
Perspective
The inguinal perivascular block is based on the concept of injecting local anesthetic near the femoral nerve in an amount sufficient to track proximally along fascial planes to anesthetize the lumbar plexus. The three principal nerves of the lumbar plexus pass from the pelvis anteriorly: the lateral femoral cutaneous, the femoral, and the obturator nerves. As illustrated in Figure 11-1, the theory behind this block presumes that the local anesthetic will track in the fascial plane between the iliacus and the psoas muscles to reach the region of the lumbar plexus roots.