Development of the Sleep and Wakefulness Rhythm in Preterm Infants Discharged from a Neonatal Care Unit

Shimada, Mieko; Segawa, Masaya; Higurashi, Makoto; Akamatsu, Hiroshi

doi:10.1203/00006450-199302000-00014

Cited by 53 publications

(33 citation statements)

References 5 publications

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“…Shimada et al (21,24), in a large study, also found no differences between term and preterm infants in the circadian rhythm of sleep, duration of day and night sleep, or the time of onset of the longest sustained sleep time. They showed entrainment to day-night rhythm by 48 wk PCA.…”

Section: Discussionmentioning

confidence: 97%

Circadian and Sleep Development in Preterm Infants Occurs Independently From the Influences of Environmental Lighting

2003

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This study investigated the effect of intermediate nursery illumination on circadian rhythm and sleep development of preterm infants. Preterm infants were randomly assigned to one of two intermediate nursery rooms: a dimly lighted room, the dim (control) group, or a day-night lighted room, the cycled (intervention) group. Continuous rectal temperature and sleep were recorded at 36 wk postconceptional age (before discharge) and at 1 and 3 mo corrected age at home. Preterm infants are exposed to continuous low or unpredictable high illumination for several weeks or months in the neonatal intensive care unit (NICU) and intermediate care nursery. These infants are deprived of several potentially important maternal entrainment factors (1-4). This lack of maternal input and exposure to random/unpredictable lighting in the nursery may hinder the development of sleep and circadian rhythms and may adversely influence clinical outcome (5). It is hypothesized that regular lighting in the nursery will improve circadian rhythm development and thereby enhance clinical outcome. Indeed, earlier studies have shown beneficial clinical effects of cycled light in the nursery (6 -8). However, the shortor long-term influences of light on development of circadian rhythm were not examined in these studies. A prospective randomized study was initiated to address the hypothesis that cycled light before discharge may improve circadian organization and sleep compared with continuous dim lighting. METHODSPreterm infants who were admitted to our nursery at Lucile Packard Children's Hospital at Stanford were eligible. Exclusion criteria were short stay (Ͻ10 d) and transfer to another hospital, major congenital malformations, intrauterine growth retardation, grade 3 or 4 intraventricular hemorrhage, parenchymal injury including periventricular leukomalacia, prenatal infection, or substance abuse. When the clinical condition of an infant in the NICU was stable, he or she was transferred to the intermediate nursery and was randomly assigned to one of two groups: a dimly lighted room, the dim (control) group, or a day-night lighted room, the cycled (intervention) group. We assigned one room of our two-room intermediate care nursery to a continuous dim condition (dim room) in which the lighting remained low (below 20 lux) around the clock. The infant's incubator/bassinet was also covered by a nearly opaque blanket except during feeding or other interventions by parents and caregivers. This is the recommendation of the Neonatal Individualized Developmental Care Program (9), and during the time of this study, dim lighting 24 h/d was used as the standard practice at Stanford for all preterm infants. Infants in the cycled room also had their incubator/bassinet covered with the same type of blanket from 1900 h to 0700 h; however, the blanket was removed from 0700 h to 1900 h, at which time the room lighting was also turned up to standard lighting levels (approximately 300 lux) to produce a regular light-dark cycled condi-

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Section: Discussionmentioning

confidence: 97%

Circadian and Sleep Development in Preterm Infants Occurs Independently From the Influences of Environmental Lighting

2003

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“…In addition, this in-formation is not available for premature infants. The ontogenetic maturation of the circadian sleep-wake rhythms in preterm and full-term infants has been widely accepted as the result of the length of exposure to environmental time cues, rather than neurologic maturity (7)(8)(9). These observations prompted us to compare the effects of prematurity on the temporal evolution of the circadian variation in salivary cortisol and on the daily rhythm of sleep and wakefulness in preterm infants.…”

Section: Introductionmentioning

confidence: 99%

Salivary cortisol as a tool for physiological studies and diagnostic strategies

Castro

Elias

Martinelli

et al. 2000

Braz J Med Biol Res

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Salivary cortisol is an index of plasma free cortisol and is obtained by a noninvasive procedure. We have been using salivary cortisol as a tool for physiological and diagnostic studies, among them the emergence of circadian rhythm in preterm and term infants. The salivary cortisol circadian rhythm in term and premature infants was established between 8 and 12 postnatal weeks. In the preterm infants the emergence of circadian rhythm was parallel to the onset of sleep rhythm. We also studied the use of salivary cortisol for screening for Cushings syndrome (CS) in control and obese outpatients based on circadian rhythm and the overnight 1 mg dexamethasone (DEX) suppression test. Salivary cortisol was suppressed to less than 100 ng/ dl after 1 mg DEX in control and obese patients. A single salivary cortisol measurement at 23:00 h and again after 1 mg DEX above the 90th percentile of the obese group values had sensitivity and specificity of 93 and 93% (23:00 h), and 91 and 94% (after DEX), respectively. The sensitivity improved to 100% when we combined both parameters. We also studied 11 CS children and 21 age-matched primary obese children for whom salivary cortisol sensitivity and specificity were 100/95% (23:00 h), and 100/95% (1 mg DEX), respectively. Similar to adults, sensitivity and specificity of 100% were obtained by combining 23:00 h and 1 mg DEX. The measurement of salivary cortisol is a useful tool for physiological studies and for the diagnosis of CS in children and adults on an outpatient basis. Correspondence

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“…420 Other studies have failed to demonstrate that weight gain is improved when babies are exposed to cycled lighting, 416,422 nor detected accelerated maturation in sleep-wake progression. 424 Although there is a progressive shift towards sleep-wake circadian rhythmicity with maturation, this may occur independently of the amount of ambient light exposure, suggesting circadian entrainment may occur based upon an endogenous, exposure-independent pacer mechanism. 423,424 Presently, it is clear that the newborn does not achieve an obvious circadian pattern until 3 to 4 months chronologic age, and that, prior to term birth, there is an in utero entrainment.…”

Section: To 32 Weeks Gestational Age and Beyondmentioning

confidence: 99%

The development of potentially better practices to support the neurodevelopment of infants in the NICU

et al. 2007

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Objective: To review the existing evidence used to identify potentially better care practices that support newborn brain development.Study Design: Literature review.Result: Sixteen potentially better practices are identified and grouped into two operational clinical bundles based upon timing for recommended implementation. Conclusion:Existing evidence supports the implementation of selected care practices that potentially may support newborn brain development.

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Development of the Sleep and Wakefulness Rhythm in Preterm Infants Discharged from a Neonatal Care Unit

Cited by 53 publications

References 5 publications

Circadian and Sleep Development in Preterm Infants Occurs Independently From the Influences of Environmental Lighting

Circadian and Sleep Development in Preterm Infants Occurs Independently From the Influences of Environmental Lighting

Salivary cortisol as a tool for physiological studies and diagnostic strategies

The development of potentially better practices to support the neurodevelopment of infants in the NICU

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