Cycled light in the intensive care unit for preterm and low birth weight infants

Neonatal Unit, Mayanei HaYeshua Medical Centre, Bnei Brak, Israel.
Cochrane database of systematic reviews (Online) (Impact Factor: 6.03). 01/2011; 8(1):CD006982. DOI: 10.1002/14651858.CD006982.pub2
Source: PubMed


The pregnant woman is exposed to variable intensities of lighting and sound and, in general, lower levels at night. Some of the lighting and sound reaches the fetus in the womb and induces circadian rhythms. Circadian is a term used to describe biological processes that recur naturally on a 24-hour basis. After birth, preterm infants are cared for in an environment that has no planned light-dark cycles or any other circadian entraining signals. Infants are exposed to either continuous bright light, continuous near darkness or an unstructured combination of the two. Our primary objective was to determine the effectiveness of cycled light (approximately 12 hours of light on and 12 hours of light off) on growth in preterm infants at three and six months of corrected gestational age. To May 2013, 506 infants have been enrolled in trials assessing the effect of cycled light. One study reported improved growth at three months of age in infants exposed to cycled lighting compared with continuous bright light. One study found no difference in weight at four months of age. Only a few outcomes reached statistical significance, which is likely to be due to the small number of infants enrolled in the studies, but trends for most outcomes (weight gain, length of stay, incidence of retinopathy of prematurity, time spent crying) favoured cycled light compared with near darkness and cycled light compared with continuous bright light.

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    • "Several studies in the last few years have highlighted the fact that postnatal environment, and in particular light, exerts a major long-lasting influence on the individual's circadian system later in life [2]. This may also occur in preterm babies exposed to abnormal light environments in Neonatal Intensive Care Units, as this experience can affect their short-term recovery and growth [3], together with their long-term sleep patterns and neurodevelopment [4], [5]. Therefore, it is critical to determine the mechanisms behind early programming of the circadian system by light, as a first step towards uncovering the consequences of abnormal light exposure during development. "
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    ABSTRACT: Early life programming has important consequences for future health and wellbeing. A key new aspect is the impact of perinatal light on the circadian system. Postnatal light environment will program circadian behavior, together with cell morphology and clock gene function within the suprachiasmatic nucleus (SCN) of the hypothalamus, the principal circadian clock in mammals. Nevertheless, it is still not clear whether the observed changes reflect a processing of an altered photic input from the retina, rather than an imprinting of the intrinsic molecular clock mechanisms. Here, we addressed the issue by systematically probing the mouse circadian system at various levels. Firstly, we used electroretinography, pupillometry and histology protocols to show that gross retinal function and morphology in the adult are largely independent of postnatal light experiences that modulate circadian photosensitivity. Secondly, we used circadian activity protocols to show that only the animal's behavioral responses to chronic light exposure, but not to constant darkness or the acute responses to a light stimulus depend on postnatal light experience. Thirdly, we used real-time PER2::LUC rhythm recording to show long-term changes in clock gene expression in the SCN, but also heart, lung and spleen. The data showed that perinatal light mainly targets the long-term adaptive responses of the circadian clock to environmental light, rather than the retina or intrinsic clock mechanisms. Finally, we found long-term effects on circadian peripheral clocks, suggesting far-reaching consequences for the animal's overall physiology.
    PLoS ONE 05/2014; 9(5):e97160. DOI:10.1371/journal.pone.0097160 · 3.23 Impact Factor
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    • "Higher physical demands and workloads placed on nurses could negatively affect the level of care provided. Additional key physical characteristics include internal and external noise [50,51], temperature control, exposure to light [52,53], practice of developmentally supportive care [54], provision and extent of family-centered care, provision and extent of breastfeeding support, potential for continuous parental involvement, as well as training and preparation for discharge home. "
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    ABSTRACT: The International Network for Evaluating Outcomes in Neonates (iNeo) is a collaboration of population-based national neonatal networks including Australia and New Zealand, Canada, Israel, Japan, Spain, Sweden, Switzerland, and the UK. The aim of iNeo is to provide a platform for comparative evaluation of outcomes of very preterm and very low birth weight neonates at the national, site, and individual level to generate evidence for improvement of outcomes in these infants.Methods/design: Individual-level data from each iNeo network will be used for comparative analysis of neonatal outcomes between networks. Variations in outcomes will be identified and disseminated to generate hypotheses regarding factors impacting outcome variation. Detailed information on physical and environmental factors, human and resource factors, and processes of care will be collected from network sites, and tested for association with neonatal outcomes. Subsequently, changes in identified practices that may influence the variations in outcomes will be implemented and evaluated using quality improvement methods. The evidence obtained using the iNeo platform will enable clinical teams from member networks to identify, implement, and evaluate practice and service provision changes aimed at improving the care and outcomes of very low birth weight and very preterm infants within their respective countries. The knowledge generated will be available worldwide with a likely global impact.
    BMC Pediatrics 04/2014; 14(1):110. DOI:10.1186/1471-2431-14-110 · 1.93 Impact Factor
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    • "The results of our experiments could also inform the recent debate as to whether lighting conditions affect outcomes in the care of human preterm infants in neonatal intensive care units [15], [16]. In this brightly illuminated environment, preterm infants can display what appear to be escape responses, including squinting of the eyes, turning of the head away from light, saluting, and finger splaying [17]. "
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