Figure 44-29 A, Patient positioning and surface landmarks for a lumbar paravertebral nerve block (see Plate 10A in the color atlas of this volume). B, For a paravertebral nerve block, the needle is advanced perpendicularly until it contacts the transverse process. It is redirected to walk off the caudad edge of the transverse process and advanced 1 to 2 cm (see Plate 10B in the color atlas of this volume).