title: Changes in the temporal structure of periodic breathing with postnatal development in preterm infants.
abstract: The progressive decrease in the periodic cycle duration (PCD) of periodic breathing with postnatal age in term infants has been previously reported by a number of authors and is thought to be associated with peripheral chemoreceptor maturation. We hypothesized that a similar decrease should be observed in preterm infants. Therefore, in this study we measured the changes in PCD with postnatal age in a small group of preterm (n = 4) infants followed longitudinally (36 afternoon nap studies) over the first 6 mo postnatally. PCD declined in these infants from 17.1 +/- 3.3 s (mean +/- 2 SD) at 9 d to 9.8 +/- 3.2 s (mean +/- 2 SD) at 105 d. The regression slope was -0.072 s/d. Beyond 105 d there was no change in PCD up to 6 mo postnatally. We found no significant difference between active and quiet sleep. These results are similar to results previously published in term infants but apparently contradict recent data on a group of preterm infants. Possible reasons for this discrepancy are discussed. By examining long epochs of periodic breathing in these infants we also identified characteristic changes in PCD and V/A ratio, defined as the duration of the ventilatory period divided by the duration of the apneic interval. V/A ratio fell from the start of an epoch from 1.21 +/- 0.08 (mean +/- SEM) to a minimum of 0.62 +/- 0.03 and then increased again to 0.8 +/- 0.05 at the end of the epoch.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Institute of Reproduction and Development, Monash Medical Centre, Clayton, Victoria, Australia.
authors.forename: M H
authors.initials: MH
authors.lastname: Wilkinson
authors.forename: S
authors.initials: S
authors.lastname: Cranage
authors.forename: P J
authors.initials: PJ
authors.lastname: Berger
authors.forename: N
authors.initials: N
authors.lastname: Blanch
authors.forename: T M
authors.initials: TM
authors.lastname: Adamson
mesh_terms: D000367:Age Factors; D002628:Chemoreceptor Cells / Q000254:growth & development / Q000502:physiology; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature / Q000254:growth & development / Q000502:physiology*; D008297:Male; D008954:Models, Biological; D010507:Periodicity; D012119:Respiration / Q000502:physiology*; D015656:Respiratory Mechanics / Q000502:physiology; D012143:Respiratory Physiological Phenomena; D012137:Respiratory System / Q000254:growth & development / Q000294:innervation; D012890:Sleep / Q000502:physiology