Lateral Femoral Cutaneous Nerve Block

Patient Position: Supine, with the thigh in a neutral position.

Indications:
In the diagnosis and treatment of meralgia paresthetica, a neuritic
type of pain in the lateral aspect of the thigh. Also can be used for
surgical anesthesia for tourniquet pain in lower limb surgery and for
skin graft harvest.

Needle Size: 50-mm insulated needle.

Medication/Volume: 0.25% bupivacaine 7 mL and 40 mg Depo-Medrol (Pharmacia Canada, Inc., Hamilton, Ontario, Canada) for a total of 8 mL.

Anatomic Landmarks: Anterior superior iliac spine, pubic tubercle, and the inguinal ligament.

Approach and Technique:
After sterile preparation of the region, the most medial part of the
anterior superior iliac spine is palpated, and a point 1 cm medial to
it is marked. Next, a vertical line is extended caudally just below the
inguinal ligament to determine the site of introduction of the needle (Fig. 71-1).
The site is prepared with Betadine (Purdue Pharma L.P., Stamford, CT).
Next, a 50-mm insulated needle connected to a nerve stimulator (1.5 mA,
2 Hz, 0.3 ms) is introduced perpendicular to the skin until paresthesia
on the lateral border of the thigh is elicited. The needle position is
adjusted to maintain the paresthesia with a current of 0.6 mA. After
negative blood aspiration, the local anesthetic mixture is slowly
injected. The needle is removed, and a Band-Aid (Johnson & Johnson,
Somerville, NJ) is applied.