Pediatric emergency medicine trisk 1899 1899
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ADH), and rarely, encephalopathy with seizures. A palpable mass may occasionally be located
in the parathyroid region. Certain characteristic features have been associated with idiopathic
hypercalcemia in infancy, including hypertelorism, broad forehead, epicanthal folds,
prominent upper lip, an underdeveloped nasal bridge, and a small mandible. Not surprisingly,
these same features have been noted in infants with hyperparathyroidism. A family history
may be helpful because hyperparathyroidism has been associated with both multiple endocrine
neoplasia types I and II, which are inherited as autosomal-dominant conditions.
Hyperparathyroidism may also occur in infants of hypoparathyroid mothers.
Management/Diagnostic Testing
Radiologic findings consistent with hyperparathyroidism include evidence of demineralization
and bone resorption ( Figs. 89.2 and 89.3 ). Osteitis fibrosa cystica, although highly suggestive
of the diagnosis, is unusual in children. Hypercalcemia is usually present but may be subtle or
intermittent in mild cases. The serum inorganic phosphate level is usually low but may be
normal, especially in patients with decreased renal function. Mild hyperchloremic acidosis
may be present. Alkaline phosphatase level and urinary hydroxyproline excretion may be
elevated secondary to increased osteoclast activity. Because PTH causes a significant increase
in cAMP in the kidney tubule, the presence of excess cAMP in the urine is strongly suggestive
of excess PTH production. The determination of PTH levels is critical for diagnostic purposes,
and elevated levels of PTH, when the patient is hypercalcemic, are a definitive laboratory
finding. Acute management of hyperparathyroidism is essentially the same as management of
hypercalcemia (see Chapter 100 Renal and Electrolyte Emergencies ). The specific
management of hyperparathyroidism depends on the level of calcium and on the presence of
signs and symptoms.
Clinical Indications for Discharge or Admission
In the asymptomatic patient with serum calcium of less than 12 mg/dL, careful follow-up with
close attention to both bone mass and renal function is recommended. Young infants with
feeding difficulty or irritability may need low calcium formula and diuretic therapy. If the
child is persistently hypercalcemic, parathyroid surgery is the preferred treatment. In the case
of hyperplasia, the common reason for hyperparathyroidism in the infant, subtotal
parathyroidectomy is indicated. If an adenoma is present, as is usually the case in the older
child, simple removal of the involved parathyroid gland is adequate.
