Patient Position: The patient lies supine.

Indications: The simultaneous block of these two nerves provides anesthesia for surgery on the inguinal region: hernia repair, orchidopexy, hydrocele.

Needle Size: A short beveled needle (e.g., a caudal needle).

Volume: 0.2 to 0.3 ml/kg of ropivacaine 0.2% for children up to 7 years, levobupivacaine 0.5% for older children.

Anatomic Landmarks: Anterior superior iliac spine and the umbilicus (Fig. 52-1).

Approach and Technique: The line uniting the anterior superior iliac spine to the umbilicus is divided in four equal parts. A short beveled needle is then introduced vertically at the union of the most lateral part to the medial three-quarters of the line. The needle is introduced perpendicular to the skin until there is a loss of resistance, corresponding to the piercing of the superficial layer of the external oblique muscle.

Recently, Willschke, Marhofer, and Bosenberg demonstrated with the use of the ultrasound technique that the landmark is more lateral compared to the previous point of injection: less than 1 cm medial to the anterior superior iliac spine and in a double blind study they succeeded in reducing the amount of administered drug in the ultrasound group—only 1 to 2 mL—with an increase in duration of analgesia.