Pediatric Regional Anesthesia for Orthopedic Surgery

Victor M. Zayas MD

Director, Pediatric Anesthesia

Introduction:

Anesthetic techniques should be tailored to address the special needs of children with orthopedic conditions such as club feet, cerebral palsy, scoliosis, deformities of the extremities, muscular dystrophy, spina bifida, and a variety of other orthopedic conditions.

One of the advantages of providing anesthesia for orthopedic procedures is that a variety of peripheral nerve blocks can be utilized to provide long-lasting pain relief after surgery. In many cases, the surgical procedure can be performed without general anesthesia after providing adequate sedation.

There is abundant literature regarding the use of caudal and lumber epidural anesthesia in children. In general, in children, the accepted standard of care is that these blocks are performed after induction of general anesthesia. Important points to remember when using spinal anesthesia in children is that pediatric patients require higher doses of local anesthetics, and the block regresses more quickly than in the adult. Peripheral nerve blocks, which are particularly useful for pediatric patients, include axillary, popliteal, femoral, and - in older patients - interscalene blocks.

Club Foot Repair:

A popliteal fossa nerve block provides up to 24 hours of analgesia for children undergoing club foot repair. This is usually combined with a block of the saphenous nerve just below the knee. A long-lasting local anesthetic, such as bupivacaine 0.25-0.5%, is used in a total dose of 2.5–3 mg/kg. Since the block is usually performed using a nerve stimulator after induction of general anesthesia, it is important to avoid muscle relaxants in order to facilitate endotracheal intubation. We have had children who have not required any pain medication for 24 hours after this usually painful procedure. In the future, this procedure may be performed as outpatient surgery, and a popliteal block may facilitate early discharge.

Cerebral Palsy:

Children with cerebral palsy sometimes require surgery of the extremities to relieve abnormalities of posture or gait. These children have special requirements related to patterns of breathing, seizures, sensitivity to pain medications, and other associated medical conditions. Anesthetic techniques should be tailored to minimize these risks. Postoperative pain relief is a major concern, because narcotics - particularly in combination with benzodiazepines for muscle spasms - may result in significant respiratory impairment in these children. For surgery of the lower extremities, we routinely use narcotic-free epidural infusions to treat pain postoperatively. These are very effective in treating pain and reducing muscle spasms.

We have safely performed hundreds of transarterial axillary blocks in pediatric patients using a short (5/8 inch) 25 gauge needle. In a patient with cerebral palsy, axillary blocks with long acting local anesthetics provide excellent operating conditions and prolonged relief of pain and muscle spasm following upper extremity surgery. In contrast to the adult, we routinely give a skin wheal at the needle entry site to minimize the amount of sedation required to perform the block.

Shoulder and Elbow Surgery:

Interscalene blocks provide excellent anesthesia and post operative analgesia for shoulder and elbow surgery. Interscalene blocks should be used with caution - if at all - in infants who are dependent on their diaphragm for breathing.

Knee, Femoral Fractures, and Osteotomies:

In addition to providing excellent postoperative analgesia for procedures for the knee, femoral blocks are quite useful for femoral fractures or osteotomies.

Conclusion:

In summary, regional anesthesia is a viable option for pediatric orthopedic surgery, resulting in improved pain control. It is important to communicate with the surgeon prior to placing a block. The surgeon may need to evaluate neurovascular status promptly after surgery, and a nerve block may prevent adequate evaluation. Examples include pinning of olecranon fractures (potential for ulnar nerve injury), and tibial osteotomies (compartment syndrome). Pediatric orthopedic surgeons will quickly appreciate the value of blocks and will soon begin to request them for their patients.