[Sleep evolution from fetal life to adulthood: respiratory and neurologic aspects]

OBJECTIVE: This article has the purpose of presenting some basic concepts about sleep, besides offering a brief review of the main ventilatory and neurologic changes during sleep, from fetal life up to adulthood. METHODS: Bibliographic review of international literature including original articles and textbook chapters.RESULTS: The sleep-wake cycle undergoes changes from fetal life to adolescence, both in duration (the fetus sleeps most of the time in utero, and the adult sleeps about 8 hours a day), and in its distribution throughout the day (the newborńs sleep is fragmented and occur during the day as much as during the night; the adultacute;s sleep is a single stage that happens at night). The sleep has two basic stages: Non-REM and REM sleep. From the respiratory standpoint, physiologic changes can be appreciated along the time, being infants more susceptible to respiratory events during sleep than adults. CONCLUSIONS: The recognition of the value of sleep and its effects on human organisms has been growing, specially in the last two decades, with the establishment of the first sleep disorders centers. The expressive scientific work developed in this area has provided us with a better understanding of this neurologic state in wich we spend about half of our lives.