Paravertebral Block Technique Unilateral right side nerve stimulator-guided PVB is performed while patients are in the left lateral decubitis position. The appropriate levels for the PVB are determined by palpation of the spinous processes. An intervertebral line is drawn at the appropriate levels and the injection site is marked 2.5 cm lateral to the midline. After aseptic preparation of the skin, 1 mL 1% lidocaine is infiltrated at the injection sites. A 21-G nerve stimulation needle (Stimuplex; B. Braun, Melsungen, Germany) is advanced 1-2 cm perpendicularly to the skin using a nerve stimulating current of 2.5-5.0 mA, while closely watching for contractions of the abdominal muscles. The tip of the needle is adjusted to maintain muscle contractions while reducing the stimulating current to approximately 0.5-0.6 mA.