Effect of increased environmental temperature on breathing patterns in preterm and term infants.
OBJECTIVE
This study was done to evaluate the effect of an increase in environmental temperature in healthy infants on breathing patterns during sleep.


METHODS
Ten preterm infants (mean gestational age 30.6 [SD 1.5] weeks) who reached maturity and 10 term comparison infants underwent polysomnographic studies before, during, and after exposure to raised environmental temperature. Core temperature and instances of central and obstructive apnea during active sleep and quiet sleep were recorded and compared between and within the two groups.


RESULTS
At environmental temperatures between 29 degrees and 30 degrees C, both groups of infants had longer and more frequent apneic episodes than at 24 degrees C. Compared with baseline findings, in preterm infants at a postconceptional age of 38 (SD 1) weeks, the apnea index increased during quiet sleep, whereas in term infants aged 36 to 72 hours (similar postconceptional age), an increased index was observed during active sleep.


CONCLUSIONS
A mild increase in environmental temperature has an effect on breathing patterns in both preterm (even when they have reached maturity) and term infants. However, a different response related to sleep state was observed in the two groups. We speculate that these effects may play a role in the association between a life-threatening event and elevated environmental temperature in both groups of infants.
Bader
D
D
Neonatal Department, Bnai-Zion Medical Center, Faculty of Medicine, Haifa, Israel.
Tirosh
E
E
Hodgins
H
H
Abend
M
M
Cohen
A
A
D001831:Body Temperature / Q000502:physiology; D004777:Environment; D006801:Humans; D007231:Infant, Newborn / Q000502:physiology*; D007234:Infant, Premature / Q000502:physiology*; D017286:Polysomnography; D012119:Respiration / Q000502:physiology*; D012891:Sleep Apnea Syndromes / Q000503:physiopathology; D012894:Sleep Stages / Q000502:physiology; D013696:Temperature