Central neurogenic
hyperventilation refers to progressive
tachypnea leading to hypocarbia and
respiratory alkalosis caused by cortical disorders, initially reported in
comatose patients with mainly pontine
infarction. Central neurogenic
hyperventilation in conscious patients is even rarer, numbering around 30 reported cases including seven children, mainly associated with infiltrative
gliomas and
lymphomas of the brainstem and pons. We report the evolution of central neurogenic
hyperventilation in a conscious child associated with an infiltrative
glioblastoma multiforme diagnosed 1 year before admission. He presented with progressive
tachypnea and
dyspnea of 1 week duration. On examination he was fully alert and aware of his respiratory disorder. Respiratory rate was 56 breaths per minute using accessory respiratory muscles.
Hyperventilation was unchanged during sleep. Arterial blood
gases disclosed marked hypocarbia: Pco(2) of 8 mm Hg resulting in severe
respiratory alkalosis at pH of 7.8. Central neurogenic
hyperventilation was therefore suggested after exclusion of other respiratory or
cardiac disorders. The exaggerated
tachypnea persisted along with
respiratory alkalosis. Over a period of 2 months his overall state markedly deteriorated; he lapsed into
coma, and finally succumbed after involvement of medullary cardiovascular centers. Although extremely rare in the pediatric age group, central neurogenic
hyperventilation should be suspected in any alert child presenting with unexplained increasing
tachypnea and hypocarbia leading to
respiratory alkalosis. The evolution of such a disorder may be an alarming sign of ensuing deterioration in patients with
tumors of the brainstem and medulla before cardiovascular derangement.