Effects of nasal CPAP therapy on respiratory and spontaneous arousals in infants with OSA.

Obstructive sleep apnea (OSA) in infants has been shown to resolve frequently without a cortical arousal. It is unknown whether infants do not require arousal to terminate apneas or whether this is a consequence of the OSA. We studied the apnea and arousal patterns of eight infants with OSA before and after treatment with nasal continuous positive airway pressure (CPAP). These infants were age matched to eight untreated infants with OSA and eight normal infants. Polysomnographic studies were performed on each infant. We found that the majority of central and obstructive apneas were terminated without arousal in all OSA infants. After several weeks of nasal CPAP treatment, the proportion of apneas terminating with an arousal during rapid-eye-movement sleep increased in treated infants compared with untreated infants. Spontaneous arousals during rapid-eye-movement sleep were reduced in all OSA infants; however, during CPAP treatment, the spontaneous arousals increased to the normal control level. We conclude that OSA in infants possibly depresses the arousal response and treatment of these infants with nasal CPAP partially reverses this depression.