Late onset congenital central hypoventilation syndrome after exposure to general anesthesia.

ABSTRACT

PURPOSE: Prolonged postoperative hypoventilation presents a challenge to anesthesiologists with regard to assessing etiology and related treatment. We present a case of recurrent episodes of postoperative hypoventilation in a previously asymptomatic child after uneventful general anesthesia. In this case, the child eventually required lifelong ventilatory support during sleep. CLINICAL FEATURES A case of postoperative hypoventilation in a previously asymptomatic six-year-old child was investigated to determine the possible etiology. After uneventful general anesthesia for dental surgery, the child experienced recurrent episodes of hypoventilation associated with sleep. The child's lungs were mechanically ventilated due to failure of all trials of weaning. Clinical examination was unremarkable and laboratory investigations excluded the possibility of thyroid, hepatic, renal, and neuromuscular diseases. Computerized tomography, magnetic resonance imaging, and electroencephalogram studies were within normal limits. A negative pyridostigmine trial ruled out myasthenia. The child was finally diagnosed as having "late onset congenital central hypoventilation syndrome". Genetic testing revealed a PHOX2B mutation consistent with this diagnosis. The child was discharged home on mechanical ventilatory support during sleep. CONCLUSION: Congenital central hypoventilation syndrome is a rare lifelong multisystem disorder which may occur during the neonatal period as a result of severe genetic mutation in the PHOX2B gene. In mild mutations, a triggering factor, such as sedation or anesthesia, may be required for the syndrome to manifest itself. These patients often require lifelong mechanical ventilatory support, particularly during sleep.