Indications and Contraindications

Lumbar Plexus Nerve Block

Femoral nerve blocks are the lower limb blocks most often used in pediatrics. Multiple effective techniques are recommended for children with a fractured shaft of the femur. When performed soon after the accident, they improve considerably the comfort of the child during transport; allow pain-free physical and radiologic examinations, wound dressings, and orthopedic procedures; and reduce bleeding. In elective surgery, they are recommended for pain relief during and after operations on the thigh (soft tissue and orthopedic procedures), provided the territory supplied by the lateral cutaneous nerve of the thigh is well anesthetized, which is usually obtained with a fascia iliaca compartment block. Conscious and slightly sedated pediatric patients tolerate quite well the performance of a muscle biopsy under femoral and lateral cutaneous nerve block.^[231] Placement of a catheter allows long-lasting pain relief after femoral fractures. ^{[232] [233]} This technique produces a high degree of patient's satisfaction in adults, especially with patient-controlled techniques,^[234] and the same should apply to children. However, attention must be paid to the bacterial precautions, because a prospective study of adults reported bacterial contamination of the catheter in 57% of patients after 48 hours (but no true infection).^[235] These block procedures have no specific contraindications.

Direct lumbar plexus blocks have limited indications in children. They are considered when a femoral block is contraindicated or unsuitable because of local lesions or because a sciatic nerve component is involved, as in hip surgery. They can also represent a valuable alternative to epidural anesthesia for unilateral operations on the hip and thigh and allow easy catheter placement for long-lasting pain relief.^[109]

Saphenous nerve blocks can complement a sciatic nerve block for operations on the leg or the foot. Because they require only a small volume of local anesthetic, these blocks do not increase the risks of systemic toxicity and allow complete analgesia of the leg and foot when combined with a sciatic block.

Other lumbar plexus nerve blocks have very limited indications in pediatrics. Lateral cutaneous nerve blocks can be used for muscle biopsy^[231] and surgery of the soft tissues in supplied areas, but most anesthesiologists prefer performing a single-shot procedure, blocking several nerves concomitantly, such as a fascia iliaca compartment block for these indications. Obturator nerve blocks have virtually no specific anesthetic indications. The technique is rather difficult and potentially dangerous, and only spastic children may benefit temporarily from such a specific block.

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Sacral Plexus Nerve Blocks

Sciatic nerve blocks are recommended for operations on the foot and the leg. Because the medial part of the leg is not anesthetized, it is usually necessary to perform a complementary block such as a femoral nerve block, a local infiltration, or preferably, a saphenous nerve block. Because of the simplicity of the technique and the low doses required, a popliteal approach should be considered first.^{[236] [237]} Proximal approaches are selected when the patient cannot be safely moved to perform a popliteal block, when surgery of the knee is planned (unusual in pediatric patients), or when the posterior femoral cutaneous nerve should be blocked at the same time. They have no specific contraindications.