Abnormalities of the chemical control of breathing: Clinical correlates in infants and children.

Abnormalities of the chemical control of breathing may go unrecognized and lead to life-threatening events, especially during sleep. Tests to assess chemical control in vivo have not yet been standardized, and their results may be difficult to interpret. Non-invasive monitoring of gas exchange and polysomnography are essential to assess the severity of hypoventilation and the extent to which it is dependent on the state of alertness. One has to be aware that some patients may have increased vulnerability to stress, and that mild infections may trigger acute hypoventilation. To date, no pharmacological approaches have proved effective in the long-term. Therefore, the management of infants and children with abnormal chemical control of breathing includes ventilatory support during sleep and diaphragmatic pacing during wakefulness, if necessary. Further research is needed to improve our understanding of the mechanisms controlling chemosensitivity and of the developmental plasticity of chemosensitivity during infancy and childhood. Genetic influences, as well as environmental factors in utero or during early infancy, may contribute to abnormal chemical control of breathing during infancy and childhood.