POLYGRAPHIC EVALUATION OF NIGHT-TO-NIGHT VARIABILITY IN SLEEP CHARACTERISTICS AND APNEAS IN INFANTS

The study was designed to evaluate whether results of a single overnig ht recording session are sufficient for the study of sleep profiles an d detection of apneas in infants, or whether it would be beneficial to extend the recording period. Nineteen infants were recorded during su ccessive nights. Eight of the 19 infants were studied after an idiopat hic apparent life-threatening event, whereas the other 11 were healthy . There were 13 boys and six girls, with a median age of 11 weeks (ran ge 5-36 weeks). All infants were recorded polygraphically during 2 nig hts, and 11 were recorded during 3 successive nights. No significant d ifference was observed between any of the following variables, regardl ess of the number of nights for which the recording was performed: tot al recording time, total sleep time, delay in sleep onset, time awake, percent of rapid eye movement or nonrapid eye movement sleep, mean re spiratory rates, density and duration of central, obstructive or mixed apneas. The frequency of obstructed breathing events for each infant did not differ significantly from 1 night to the next. The present stu dy indicates that under adequate study conditions, recordings of a sin gle night can reliably describe the frequency of central and obstructi ve apneas in infants.