Effects of warm and cool thermal conditions on ventilatory responses to hyperoxic test in neonates.
Body temperature interacts with respiratory control, but it is unclear what sites or mechanisms mediate those interactions. We hypothesized that warm and cool thermal conditions affect the decrease in ventilation (VE) seen during the hyperoxic test (HT), a breathing response believed to reflect the strength of the peripheral chemoreceptor drive. A breath-by-breath analysis during a 30 s HT was performed in eight premature neonates (postconceptional age: 36 +/- 1 weeks) under neutral, warm, and cool thermal conditions. Quiet sleep (QS) and active sleep (AS) were scored by neurophysiological criteria. The VE fall was higher in AS than in QS, and warm and cool conditions significantly enhanced the response only in AS (-24.2 +/- 6.0, -39.1 +/- 9.1, and -37.5 +/- 14.1% in neutral, warm, and cool conditions, respectively). Central control mechanisms of the respiratory chemoreflex may explain the increase in peripheral chemoreceptor drive during AS in response to thermal challenges, which may produce increased breathing instability leading to apnea in early life.
Chardon
Karen
K
Environnement Toxique Périnatal et Adaptations Physiologiques et Comportementales (EA2088), School of Medicine, 3 rue des Louvels, Amiens 80036, France. karen.chardon@u-picardie.fr
Telliez
Frédéric
F
Bach
Véronique
V
Leke
André
A
Delanaud
Stéphane
S
Bouferrache
Belkacem
B
Libert
Jean-Pierre
JP
Gaultier
Claude
C
D001831:Body Temperature; D001833:Body Temperature Regulation / Q000502:physiology*; D003080:Cold Temperature; D005260:Female; D006358:Hot Temperature; D006801:Humans; D018496:Hyperoxia; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology*; D008297:Male; D010100:Oxygen / Q000378:metabolism*; D017286:Polysomnography; D012119:Respiration; D012129:Respiratory Function Tests; D012890:Sleep; D013696:Temperature
D010100:Oxygen