Describe the pre-anesthetic evaluation of the child with Down syndrome.
The pre-anesthetic evaluation of the child with Down syndrome should include a complete history and physical examination. The anesthetic assessment should focus par-ticularly on the organ systems most commonly involved in Down syndrome. A detailed systematic approach is neces-sary to prepare for potential intraoperative events. Further evaluation of these patients will depend on the extent of organ system involvement.
Atlantoaxial instability is present in 10–20% of children with Down syndrome and is a major source of concern in the perianesthetic period. Several neurologic deficits may be associated with atlantoaxial instability (Table 71.2).
Screening for atlantoaxial instability includes lateral cervical spine radiographs in the flexed, extended, and neutral positions. The atlas–dens interval is often used to quantify the movement of the atlantoaxial joint. This is measured from the posterior margin of the anterior arch of the first cervical spine to the anterior margin of the dens.
The normal atlas–dens interval for children is 4.5 mm or less.
The current recommendation is that screening for atlantoaxial instability should be done at 3–5 years of age. Follow-up cervical radiographs at 3 year intervals are no longer recommended. Obtaining a good history and neurologic assessment are key factors. When the child with Down syndrome presents for a general anesthetic, all precautions must be taken to maintain the cervical spine in a neutral position.