Objective: To evaluate the influence of ambient temperature on infant's sle
ep and cardiorespiratory parameters during sleep.
Patients and method: 20 healthy infants with a median age of 11.5 weeks (ra
nge 7 to 18 weeks) were recorded polygraphically for one night, They were e
xposed to 3 different ambient temperatures (20 degrees C-25 degrees C-30 de
grees C). Ambient and core temperatures were measured throughout the proced
Results: influence of ambient temperature was seen in:
Respiratory parameters: The frequency of central apneas increased significa
ntly with increasing temperatures in REM sleep, but not in NREM sleep.
Heart rate (HR) parameters and HR spectral analysis: Elevation of temperatu
re was characterized by significantly higher basal HR, shorter RR intervals
, and lower parasympathetic activity in REM and NREM sleep.
Saturation in oxygen: During total sleep time, rise in temperature induced
a decrease in basal oxygen saturation. During REM sleep, a greater frequenc
y of oxygen saturation drops was associated with central apneas.
Core temperature: With increasing ambient temperature, the rise of rectal t
emperature was mild. Despite this lack of significant increase, similar res
ults were found when sleep and cardiorespiratory parameters were evaluated
according to rectal temperatures.
Conclusion: Changes in ambient temperatures associated with mild increases
in body temperature significantly modified cardiorespiratory parameters and
autonomic controls in healthy infants. The changes associated with increas
es in temperature were mainly seen during REM sleep.