title: Arousal and ventilatory responses to hypoxia in sleeping infants: effects of maternal smoking.
abstract: Our aim was to determine whether maternal cigarette smoking affects arousal and ventilatory responses to hypoxia in infants. Infants born to non-smoking (NS, n = 15) and smoking mothers (SM, n= 9) were studied at 2-5 weeks, 2-3 and 5-6 months. Ventilatory responses to 15% O(2) were determined preceding arousal. At each age and in both groups, infants aroused more frequently and earlier to hypoxia in active sleep (AS) than quiet sleep (QS). Arousal latency was longer in SM infants (in QS) at 5-6 months (P < 0.05). Baseline respiratory parameters were not different between groups, except that, at 2-3 months, SM infants had higher SP(O2) during AS than NS infants. Maternal smoking did not affect ventilatory responses preceding hypoxia-induced arousal in either sleep-state at any age. We conclude that mild hypoxia stimulates ventilation and arousal in infants up to 6 months and that arousability is depressed in SM infants at 5-6 months; however, ventilatory responses preceding arousal are not adversely affected by smoking.
authors.affiliation: Department of Paediatrics, Ritchie Centre for Baby Health Research, Monash University, Level 5, Monash Medical Centre, 246 Clayton Road, Clayton, Vic. 3168, Australia.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Parsiow
authors.forename: Peter M
authors.initials: PM
authors.lastname: Parslow
authors.forename: Susan M
authors.initials: SM
authors.lastname: Cranage
authors.forename: T Michael
authors.initials: TM
authors.lastname: Adamson
authors.forename: Richard
authors.initials: R
authors.lastname: Harding
authors.forename: Rosemary S C
authors.initials: RS
authors.lastname: Horne
mesh_terms: D001143:Arousal / Q000502:physiology*; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000503:physiopathology*; D007231:Infant, Newborn; D008137:Longitudinal Studies; D008297:Male; D016555:Matched-Pair Analysis; D018811:Maternal Exposure; D017286:Polysomnography; D011247:Pregnancy; D011248:Pregnancy Complications; D011297:Prenatal Exposure Delayed Effects; D012123:Pulmonary Ventilation / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D012119:Respiration; D015656:Respiratory Mechanics / Q000502:physiology*; D012890:Sleep / Q000502:physiology*; D012894:Sleep Stages / Q000502:physiology; D012907:Smoking / Q000009:adverse effects*