Arousal and ventilatory responses to hypoxia in sleeping infants: effects of maternal smoking.
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.
Parsiow
Peter M
PM
Department of Paediatrics, Ritchie Centre for Baby Health Research, Monash University, Level 5, Monash Medical Centre, 246 Clayton Road, Clayton, Vic. 3168, Australia.
Parslow
Peter M
PM
Cranage
Susan M
SM
Adamson
T Michael
TM
Harding
Richard
R
Horne
Rosemary S C
RS
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*