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

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.

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.

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.

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.