Peripheral Nerve Blocks: A Color Atlas, 3rd Edition

45. Indications, Side Effects, and Complications of Peripheral Blocks Performed in Children

Giorgio Ivani

Valeria Mossetti

Indications

There is evidence that regional blocks are advantageous in pediatric surgical operations, but which blocks should one use and under what circumstances? In children safety is the absolute priority, therefore in choosing the best technique for a particular procedure in a child, the anesthetist should prefer the safest one. In 1996 Giaufré et al. reported the result of a prospective study on the practice of pediatric regional anesthesia by the Association des Anesthesistes Reanimateurs Pediatriques d'Expression Francaise. Data from 24,409 regional blocks were collected. Of 15,013 central blocks, 23 complications were reported, whereas of 9,396 peripheral blocks, no complications were reported. In cases in which it is possible to use either a central or a peripheral nerve block, we must remember the advantages of using a peripheral nerve block such as major safety, no urinary retention, longer duration, less need for postoperative analgesia, possible in patients with coagulation problems, and limitation of the area of analgesia to the surgical field. On the contrary the disadvantages are few: major technical demand, larger volume of anesthetic solution requested, longer onset time. Basically, whenever appropriate, a peripheral nerve block is preferable to an axial block. Many of the peripheral blocks are in fact safe, simple, easy to perform, and effective. The use of a nerve stimulator, when appropriate, greatly increases the success rate of some of these blocks.

All the variety of peripheral nerve blocks used in adults can be used in pediatrics. The commonly performed peripheral blocks in children are the brachial plexus block (parascalene or axillary) for forearm and hand surgery and for revascularization; the femoral nerve block for femoral fractures, femoral osteotomies, and quadriceps muscle biopsy; the fascia iliaca block with the same indications as for the femoral nerve block plus knee surgery; the sciatic nerve block with the lateral approach at the trochanter level for fibular osteotomy, club foot repair, and the remove of plantar foreign bodies; and the sciatic nerve block with the lateral approach at the popliteal level for tibial osteotomy or ankle fractures.

Contraindications

There are no particular contraindications to peripheral nerve blocks in children. Some include lesions of the skin at the point of injection, a severe generalized infection, an allergy to the local anesthetics (very rare), psychological disorders, or lack of consent from the parents. The presence of plastering is not a proper contraindication, but needs specific postoperative monitoring to identify any sign of compression. The management of patients with peripheral neuropathy is a controversial issue because there are no scientific data that suggest that a peripheral nerve block can worsen an illness, but there are always legal problems that could be raised.

Side Effects

Actually the disadvantages of this technique are very few if these blocks are performed by expert hands. One of the most frequent complications is the inadequate block. While proper side effects are very rare, nerve damage depends in part on the size and type of needle (only use pediatric set) but also on the pressure of injection of local anesthetic. If the needle is placed incorrectly intraneural, the injection of the local anesthetic with low pressure can lead to transitory damage of the nerve; if the pressure of injection is high, the nerve will be permanently damaged. Another complication is infection if the aseptic rules are not followed. This happens more frequently when a catheter is left in place for a long time. Another very rare side effect is haematoma, especially from the external jugular vein or axillary artery.

The most harmful side effect associated with the use of this technique is the systemic toxicity of local anesthetics. It may occur after inadvertent intravascular or intraosseous injection or following overdosage. The clinical symptoms and the treatment are the same as in adults. Since the little patient is sedate or under light general anesthesia it is impossible to recognize the minor initial symptoms of central nervous system toxicity (perioral and lingual paresthesia, dizziness, vertigo), while signs like convulsions and cardiovascular signs like electrocardiogram (ECG) anomalies can easily be seen.

Monitoring

To practice a safe peripheral nerve block it is necessary to have continuous monitoring, dedicated pediatric tools, and strictly observed drug guidelines. Blocks need to be executed by an expert anesthesiologist, in a surgery room, and with the same monitoring used for general anesthesia. As with any regional anesthetic technique, an I.V. line must be in place. Monitoring includes ECG, noninvasive blood pressure and pulse oximetry, and capnography if the child is sedated or anesthetized. All resuscitation drugs and all the equipment required for immediate handling of possible complications should be available.