Emergence and influences of circadian rhythmicity in infants

Precision caffeine therapy for apnea of prematurity and circadian rhythms: New possibilities open up

Caffeine is the globally consumed psychoactive substance and the drug of choice for the treatment of apnea of prematurity (AOP), but its therapeutic effects are highly variable among preterm infants. Many of the molecular underpinnings of the marked individual response have remained elusive yet. Interestingly, the significant association between Clock gene polymorphisms and the response to caffeine therapy offers an opportunity to advance our understanding of potential mechanistic pathways. In this review, we delineate the functions and mechanisms of human circadian rhythms. An up-to-date advance of the formation and ontogeny of human circadian rhythms during the perinatal period are concisely discussed. Specially, we summarize and discuss the characteristics of circadian rhythms in preterm infants. Second, we discuss the role of caffeine consumption on the circadian rhythms in animal models and human, especially in neonates and preterm infants. Finally, we postulate how circadian-based therapeutic initiatives could open new possibilities to promote precision caffeine therapy for the AOP management in preterm infants.

Effect of a light-darkness cycle on the body weight gain of preterm infants admitted to the neonatal intensive care unit

The Continuous bright light conditions to which premature infants are subjected while hospitalized in Neonatal Intensive Care Units (NICU) can have deleterious effects in terms of growth and development. This study evaluates the benefits of a light/darkness cycle (LDC) in weight and early hospital discharge from the NICU. Subjects were recruited from three participating institutions in Mexico. Eligible patients (n = 294) were premature infants who were hospitalized in the low-risk and high-risk neonatal units classified as stable. The subjects randomized to the experimental group (n = 150) were allocated to LDC conditions are as follows: light from 07:00 to 19:00 and darkness (25 lx) from 19:00 to 07:00. The control group (n = 144) was kept under normal room light conditions (CBL) 24 h a day. Main outcome was weight gain and the effect of reducing the intensity of nocturnal light in development of premature infants. Infants to the LDC gained weight earlier, compared with those randomized to CBL, and had a significant reduction in length of hospital stay. These results highlight those premature infants subjected to a LDC exhibit improvements in physiological development, favoring earlier weight gain and consequently a decrease in hospital stays. ClinicalTrials.gov; 02/09/2020 ID: NCT05230706.

Development of the circadian system and relevance of periodic signals for neonatal development

Circadian rhythms are generated endogenously with a period of approximately 24h. Studies carried out during the last decade indicate that the circadian system develops before birth, and that the suprachiasmatic nucleus, a structure that is considered the mammalian circadian clock, is present in primates from the middle of pregnancy. Recent evidence shows that the infants' circadian system is sensitive to light from very early stages of development; it has also been proposed that low-intensity lighting can regulate the developing clock. After birth there is a progressive maturation of the outputs of the circadian system with marked rhythms in sleep-wake phenomena and hormone secretion. These facts express the importance of circadian photic regulation in infants. Thus, the exposure of premature babies to light/dark cycles results in a rapid establishment of activity/rest patterns, which are in the light-dark cycle. With the continuous study of the development of the circadian system and the influence on human physiology and disease, it is anticipated that the application of circadian biology will become an increasingly important component in the perinatal care.

Parents matter: barriers and solutions when implementing behavioural sleep interventions for infant sleep problems

Behavioural sleep interventions (eg, extinction-based methods) are among the most efficacious evidence-based techniques in the treatment of infant sleep problems. However, behavioural sleep interventions can be challenging for families to successfully implement. This review aims to summarise current research surrounding the potential barriers that arise when clinicians attempt to implement extinction-based methods with parents of infants. We provide a model that summarises 3 types of contextual-barriers; socio-cultural barriers, parent barriers, and infant barriers. Based on the current evidence, we propose that adopting a stepped care approach, planning ahead, increasing support, motivational interviewing, and/or emotional regulation may serve as useful tools for parents when implementing extinction-based methods. By considering these techniques, more families may receive the benefits of improved infant sleep.

Antituberculosis BCG vaccination: more reasons for varying innate and adaptive immune responses

Bacillus Calmette-Guérin (BCG) vaccination induces variable protection against pulmonary tuberculosis (TB), and a more effective TB vaccine is needed. The potential for BCG to provide protection against heterologous infections, by induction of innate immune memory, is increasingly recognized. These nonspecific responses may substantially benefit public health, but are also variable. In this issue of the JCI, Koeken and de Bree et al. report that BCG reduces circulating inflammatory markers in males but not in females, while de Bree and Mouritis et al. describe how diurnal rhythms affect the degree of BCG-induced innate memory. These studies further delineate factors that influence the magnitude of responses to BCG and may be crucial to harnessing its potential benefits.

Recommendations on neonatal light environment from the French Neonatal Society

AIM

Hospital light may affect neonatal neurosensory development and the well-being of parents and caregivers. We aimed to issue practical recommendations regarding the optimal light environment for neonatal units.

METHODS

A systematic evaluation was performed using PubMed to identify relevant papers published in English or French up to July 2018, and the different grades of evidence were evaluated.

RESULTS

We identified 89 studies and one meta-analysis and examined 31 eligible studies. The major results were that natural or artificial light should not exceed 1000 lux and that all changes in light level should be gradual. Light protection should be used for infants of <32 weeks of postmenstrual age and but must be individualised to each infant. Infants should not be exposed to continuous high light levels regardless of their term and postnatal age. Cycled light before discharge seemed to be safe and beneficial. For medical caregivers' well-being, higher light levels and access to natural light are recommended. Special attention should be given to protecting neonatal patients from high light levels that may be necessary when performing specific care procedures.

CONCLUSION

Consideration of general principles and practical applications can improve the neonatal light environment for newborn infants, parents and caregivers.

Sensory exposure of neonates in single-room environments (SENSE): an observational study of light

OBJECTIVES

To measure the internal and external light exposure of incubators and open cots in an Australian single-room configured neonatal unit and compare findings to current recommendations.

METHODS

Light meters were placed in the internal and external environment of incubators and open cots within occupied single rooms in a tertiary-level neonatal unit between 15 September and 28 October 2015. Data were recorded in one-second increments over a minimum of 48 hours per room.

RESULTS

Internal median light in incubators and open cots predominantly fell below 50 lux, with low amplitude diurnal cycling. Incubator covers substantially reduced external light exposure, contributing to very low light conditions (<10 lux). Periodically, light inside incubators peaked six times greater than the maximum recommendation of 600 lux. Overall, internal incubator and open cot lighting in the neonatal unit met American Academy of Pediatrics and American College of Obstetricians and Gynecologists recommendations for 65.1% of the time during the day and 25.6% overnight. Australasian Health Infrastructure Alliance recommendations were met for 6.7% of the time during the day and 2.4% overnight.

CONCLUSIONS

Overall, light levels fell predominantly below 50 lux with peak periods of extreme light exposure. Low amplitude cyclic light was evident, but it remains unknown if this is sufficient to produce an effect on circadian entrainment, especially in preterm neonates. Current guidelines do not stipulate optimal cyclic light levels in neonatal units to promote circadian rhythms in the newborn population. Further research to determine well-defined lighting parameters for neonates of different gestations is paramount.

The NICU Environment: Infusing Single-Family Room Benefits into the Open-Bay Setting

Two distinct architectural designs are found in today's NICUs-the open-bay (OPBY) and the single-family room (SFR) designs. When neonatology was recognized as a medical subspecialty in the 1970s, the OPBY design was the only platform offered to neonates and families. The OPBY design facilitated communication between staff, collegiality, and interprofessional collaboration among members of the neonatal team. Over time, pitfalls to the design were recognized, including increased transmission of sound and light. As a result, the SFR design emerged offering a family-centered, customizable environment. Through recognition and adoption of best practices, the neurodevelopmental benefits to SFRs can be infused within the OPBY unit. This article aims to identify best practices to infuse the benefits of SFR design (such as low light, low sound, and less overstimulation) into the OPBY NICU to reduce negative stimulation and optimize developmental outcomes for vulnerable neonates.

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

BACKGROUND

Potential benefits and harms of different lighting in neonatal units have not been quantified.

OBJECTIVES

• To determine effectiveness and safety of cycled light (CL) (approximately 12 hours of light on and 12 hours of light off) for growth in preterm infants at three and six months' corrected age (CA).• In separate analyses, to compare effects of CL with those of irregularly dimmed light (DL) or near darkness (ND), and effects of CL with those of continuous bright light (CBL), on growth in preterm infants at three and six months' CA.• To assess, in subgroup analyses, the effectiveness and safety of CL (vs control interventions (DL, ND and CBL)) introduced at different postmenstrual ages (PMAs) - before 32 weeks', at 32 weeks' and from 36 weeks' PMA - and to compare effectiveness and safety of CL for small for gestational age (GA) infants versus appropriately grown infants.

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Review Group to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 12), MEDLINE via PubMed (1966 to January 2016), Embase (1980 to January 2016) and the Cumulative Index to Nursing and Allied Health Literature (CINAHL; 1982 to January 2016). We searched clinical trials databases, conference proceedings and reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

Randomised or quasi-randomised trials of CL versus ND or CBL in preterm and low birth weight infants.

DATA COLLECTION AND ANALYSIS

We performed data collection and analyses according to the methods of the Cochrane Neonatal Review Group. We used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to assess the quality of evidence.

MAIN RESULTS

We identified one additional study enrolling 38 participants for inclusion in this update, for a total of nine studies reporting on 544 infants. In general, the quality of the studies was low, mainly owing to lack of blinding and small sample sizes.Six studies enrolling 424 infants compared CL versus ND. No study reported on weight at three or six months. One study (n = 40) found no statistically significant difference in weight at four months between CL and ND groups. In another study (n = 62), the ratio of day-night activity before discharge favoured the CL group (mean difference (MD) 0.18, 95% confidence interval (CI) 0.17 to 0.19), indicating 18% more activity during the day than during the night in the CL group compared with the ND group. Two studies (n = 189) reported on retinopathy of prematurity (stage ≥ 3) and reported no statistically significant differences between CL and ND groups (typical risk ratio (RR) 0.53, 95% CI 0.25 to 1.11, I(2) = 0%; typical risk difference (RD) -0.09, 95% CI -0.19 to 0.01, I(2) = 0%). Two studies (n = 77) reported length of hospital stay (days) and noted a significant reduction in length of stay between CL and ND groups favouring the CL group (weighted mean difference (WMD) -13 days, 95% CI -23 to -2, I(2) = 0%; no heterogeneity). The quality of the evidence according to GRADE was low for this outcome. One study (n = 37) reported less crying at 11 weeks' corrected age (CA) in the CL group compared with the ND group (MD -0.57 hours/24 h, 95% CI -1.09 to -0.05). Tests for heterogeneity were not applicable.Three studies enrolling 120 infants compared CL versus CBL. Two studies (n = 79) reported significantly shorter length of stay in the CL group compared with the CBL group (WMD -16.5 days, 95% CI -26.2 to -6.8, I(2) = 0%; no heterogeneity). The quality of the evidence according to GRADE was low for this outcome. One study (n = 41) reported higher mean weight at three months' CA among infants cared for in the CL nursery (P value < 0.02) and a lower mean number of hours spent awake in 24 hours at three months of age (P value < 0.005). Data could not be entered into RevMan or GRADE. One study (n = 41) reported shorter time on the ventilator in the CL compared with the CBL group (MD -18.2 days, 95% CI -31.40 to -5.0). One study (n = 41) reported a shorter time to first oral feeding in the CL group (MD -6.8 days, 95% CI -13.29 to -0.31). We identified no safety issues.

AUTHORS' CONCLUSIONS

Trials assessing the effects of CL have enrolled 544 infants. No study reported on our primary outcome of weight at three or six months. Results from one additional study strengthen our findings that CL versus CBL shortens length of stay, as does CL versus ND. The quality of the evidence on both comparisons for this outcome according to GRADE was low. Future research should focus on comparing CL versus ND.

Development of sleep/wake, activity and temperature rhythms in newborns maintained in a neonatal intensive care unit and the impact of feeding schedules

Biological rhythms in infants are described as evolving from an ultradian to a circadian pattern along the first months of life. Recently, the use of actigraphy and thermistors with memory has contributed to the understanding of temporal relations of different variables along development. The aim of this study was to describe and compare the development of the rhythmic pattern of wrist temperature, activity/rest cycle, sleep/wake and feeding behavior in term and preterm newborns maintained in a neonatal intensive care unit (NICU).

METHODS

Nineteen healthy preterm and seven fullterm newborns had the following variables monitored continuously while they were in the NICU: activity recorded by actigraphy, wrist temperature recorded with a thermistor and observed sleep and feeding behavior recorded by the NICU staff with diaries. Subjects were divided in 3 groups according to their gestational age at birth and rhythmic parameters were compared.

RESULTS

A dominant daily rhythm was observed for wrist temperature since the first two weeks of life and no age relation was demonstrated. Otherwise, a daily pattern in activity/rest cycle was observed for most preterm newborns since 35 weeks of postconceptional age and was more robust in term babies. Feeding and sleep/wake data showed an almost exclusive 3h rhythm, probably related to a masking effect of feeding schedules.

CONCLUSIONS

We found that wrist temperature develops a daily pattern as soon as previously reported for rectal temperature, and with acrophase profile similar to adults. Moreover, we were able to find a daily rhythm in activity/rest cycle earlier than previously reported in literature. We also suggest that sleep/wake rhythm and feeding behavior follow independent developmental courses, being more suitable to masking effects.

Very preterm infants show earlier emergence of 24-hour sleep-wake rhythms compared to term infants

BACKGROUND

Previous studies show contradictory results about the emergence of 24-h rhythms and the influence of external time cues on sleep-wake behavior in preterm compared to term infants.

AIMS

To examine whether very preterm infants (<32 weeks of gestational age) differ in their emergence of the 24-h sleep-wake rhythm at 5, 11 and 25 weeks corrected age compared to term infants and whether cycled light conditions during neonatal intermediate care affects postnatal 24-h sleep-wake rhythms in preterm infants.

STUDY DESIGN

Prospective cohort study with nested interventional trial.

SUBJECTS

34 preterm and 14 control term infants were studied. During neonatal hospitalization, preterm infants were randomly assigned to cycled light [7 am-7 pm lights on, 7 pm-7 am lights off, n=17] or dim light condition [lights off whenever the child is asleep, n=17].

OUTCOME MEASURES

Sleep and activity behavior recorded by parental diary and actigraphy at 5, 11 and 25 weeks corrected age.

RESULTS

Sleep at nighttime and the longest consolidated sleep period between 12 pm-6 am was longer (mixed model analysis, factor group: p=0.02, resp. p=0.01) and activity at nighttime was lower (p=0.005) at all ages in preterm compared to term infants. Cycled light exposed preterm infants showed the longest nighttime sleep duration. Dim light exposed preterm infants were the least active.

CONCLUSIONS

Preterm infants show an earlier emergence of the 24-h sleep-wake rhythm compared to term infants. Thus, the length of exposure to external time cues such as light may be important for the maturation of infant sleep-wake rhythms. Trial registry number: This trial has been registered at www.clinicaltrials.gov (identifier NCT01513226).

Mother-infant circadian rhythm: development of individual patterns and dyadic synchrony

BACKGROUND

Mutual circadian rhythm is an early and essential component in the development of maternal-infant physiological synchrony.

AIMS

The aim of this to examine the longitudinal pattern of maternal-infant circadian rhythm and rhythm synchrony as measured by rhythm parameters.

STUDY DESIGN

In-home dyadic actigraphy monitoring at infant age 4, 8, and 12 weeks.

SUBJECTS

Forty-three healthy mother-infant pairs.

OUTCOME MEASURES

Circadian parameters derived from cosinor and non-parametric analysis including mesor, magnitude, acrophase, L5 and M10 midpoints (midpoint of lowest 5 and highest 10h of activity), amplitude, interdaily stability (IS), and intradaily variability (IV).

RESULTS

Mothers experienced early disruption of circadian rhythm, with re-establishment of rhythm over time. Significant time effects were noted in increasing maternal magnitude, amplitude, and IS and decreasing IV (p<.001). Infants demonstrated a developmental trajectory of circadian pattern with significant time effects for increasing mesor, magnitude, amplitude, L5, IS, and IV (p<.001). By 12 weeks, infant phase advancement was evidenced by mean acrophase and M10 midpoint occurring 60 and 43 min (respectively) earlier than at 4 weeks. While maternal acrophase remained consistent over time, infants became increasingly phase advanced relative to mother and mean infant acrophase at 12 weeks occurred 60 min before mother. Mother-infant synchrony was evidenced in increasing correspondence of acrophase at 12 weeks (r=0.704), L5 (r=0.453) and M10 (r=0.479) midpoints.

CONCLUSIONS

Development of mother-infant synchrony reflects shared elements of circadian rhythm.

A comparison of the direct cost of care in an open-bay and single-family room NICU

OBJECTIVE

This research examined the proposition that the direct costs of care were no different in an open-bay (OPBY) as compared with a single-family room (SFR) neonatal intensive care (NICU) environment.

STUDY DESIGN

This was a sequential cohort study.

RESULT

General linear models were implemented using clinical and cost data for all neonates admitted to the two cohorts studied. Costs were adjusted to year 2007 U.S. dollars. Models were constructed for the unadjusted regression and subsequently by adding demographic variables, treatment variables, length of respiratory support and length of stay. With the exception of the last, none were found to achieve significance. The full model had R(2)=0.799 with P=0.0095 and predicted direct costs of care less in the SFR NICU.

CONCLUSION

For the time, location and administrative practices in place, this study demonstrates that care can be provided in the SFR NICU at no additional cost as compared with OPBY NICU.

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

BACKGROUND

The potential benefits and harms of different lighting in neonatal units have not been quantified.

OBJECTIVES

To compare the effectiveness of cycled lighting (CL) (approximately 12 hours of light on and 12 hours of light off) with irregularly dimmed light (DL) or near darkness (ND) and with continuous bright light (CBL) on growth in preterm infants at three and six months of age.

SEARCH METHODS

We conducted electronic searches of the literature (in January 2013) of the Cochrane Central Register of Controlled Trials, Issue 12, 2012 (CENTRAL), MEDLINE, EMBASE, CINAHL and abstracts from Pediatric Academic Societies' annual meetings. We searched Controlled-trials.com and Clinicaltrials.gov for ongoing trials and abstracts from the Pediatric Academic Societies (PAS) Annual Meetings (2000 to 2013) using the Abstracts2view website on 10 May 2013.

SELECTION CRITERIA

Randomized or quasi-randomised trials of CL versus ND or CBL in preterm and low birth weight infants.

DATA COLLECTION AND ANALYSIS

We performed data collection and analyses according to the methods of the Cochrane Neonatal Review Group.

MAIN RESULTS

Six studies enrolling 424 infants compared CL versus ND (including one additional trial identified in this update that enrolled 37 infants). No study reported on weight at three or six months. In one study (n = 40), there was no statistically significant difference in weight at four months between the CL and ND groups. In another study (n = 62), the ratio of day-night activity prior to discharge favoured the CL group (mean difference (MD) 0.18, 95% confidence interval (CI) 0.17 to 0.19) indicating 18% more activity during the day than during the night in the CL group compared with the ND group. Two studies (n = 189) reported on retinopathy of prematurity (stage ≥ 3). There was no statistically significant difference between the CL and ND groups (typical risk ratio (RR) 0.53, 95% CI 0.25 to 1.11, I(2) = 0%; typical risk difference (RD) -0.09, 95% CI -0.19 to 0.01, I(2) = 0%). Two studies (n = 77) reported on length of hospital stay (days). There was a significant reduction in the length of stay between the CL and the ND groups favouring the CL group (MD -13 days, 95% CI -2 to -23). One study (n = 37) reported on less crying at 11 weeks' corrected age (CA) in the CL group compared with the ND group (MD -0.57 hours/24 hours, 95% CI -1.09 to -0.05).There was no heterogeneity for this outcome (I(2) = 0%).Two studies enrolling 82 infants compared CL versus CBL. One study (n = 41) reported higher mean weight at three months' CA in infants cared for in the CL nursery (P value < 0.02) and lower mean number of hours spent awake in 24 hours at three months of age (P value < 0.005). One study (n = 41) reported shorter time on ventilator in the CL compared with the CBL group (MD -18.2 days, 95% CI -31.40 to -5.0). One study (n = 41) reported a shorter time to first oral feeding in the CL group (MD -6.8 days, 95% CI -13.29 to -0.31).For many outcomes, the trends favoured CL versus ND as well as CL versus CBL.We identified no safety issues.

AUTHORS' CONCLUSIONS

Trials assessing the effect of CL have enrolled 506 infants. Trends for many outcomes favoured CL compared with ND and CL compared with CBL. The studies may have lacked significance due to a lack of statistical power. Future research should focus on comparing CL to ND.

Recommended standards for newborn ICU design, eighth edition

This is the eighth edition of the Recommended Standards for Newborn ICU Design. It contains substantive changes in recommendations for patient room size and feeding preparation areas, and a number of refinements of previous Recommended Standards with respect to family space, hand hygiene, lighting and other aspects of the newborn intensive care unit (NICU) design.

The development of the circadian heart rate rhythm (CHR) in Asian infants

OBJECTIVE

To test the hypothesis that term-born Asian infants, at reduced risk to die of Sudden Infant Death Syndrome (SIDS) exhibit a circadian heart rate rhythm (CHR) at a later age than non-Asian term infants.

METHOD

Repeated overnight heart rate (HR) traces obtained with a battery-operated Polar S810i heart-rate monitor at home in 17 Asian Torajan infants in Indonesia, were compared with those of 52 non-Asian infants monitored as part of the Collaborative Home Infant Monitoring Evaluation (CHIME). HR was determined using a moving window averaging technique. A comparison of median HR during quiet sleep (QS) episodes (identified by minimum HR variability), established the presence of CHR.

RESULTS

Seventy three percent of non-Asian CHIME infants ≤7 weeks exhibited CHR compared to 45% of Asian Torajan infants. Between 8 and 12 weeks, 94% of non-Asian CHIME infants exhibited CHR, compared to 33% of Asian Torajan infants (p<0.001). Forty seven and 56% of Asian Torajan infants exhibited the CHR at the age intervals of 16-20 weeks and 21-25 weeks respectively. Active wakefulness percentages as a function of the entire recording and median QS HR were not significantly different in the two groups.

CONCLUSION

Despite the fact that Asian Torajan infants were on average a week older than non-Asian CHIME babies, between two and three months of age only one in three exhibited the CHR, compared to virtually all non-Asian CHIME infants. We speculate that the cause of this difference rests in the infants' environment rather than their genetic origin.

A Comprehensive Comparison of Open-Bay and Single-Family-Room Neonatal Intensive Care Units at Sanford Children's Hospital

Objective: This paper summarizes the results of a comprehensive comparison of open-bay (OPBY) and single-family-room (SFR) neonatal intensive care unit (NICU) designs.

Background: The NICU expanded from 7000 ft2 in two large rooms to 27,000 ft2 with 45 individual family spaces.

Results: Sound measurements indicated a significant reduction in the unoccupied SFR to less than half of the levels in the OPBY NICU. However, respiratory support equipment generated levels well above those of the ambient environment. Illumination was significantly reduced in the SFR. Ambient illumination in nursing work areas was less than recommended. In other comparisons with the OPBY NICU the SFR NICU was shown to have: a shorter interval until full enteric feedings were established; improved parent satisfaction; improved staff perceptions of the environment and care; a decrease in nurses State-Trait Anxiety scores; an increased need for total numbers of staff and nursing staff per shift; increased walking per shift by nurses and nurse practitioners; and improved sleep time in a very small sample of patients. Analysis of the cost of construction showed comparable cost per ft2; however, the cost per bed in the SFR NICU was much greater because of the increased area of this facility. Highly notable findings of this investigation included the same incidence of adverse outcomes of care and a reduction in the adjusted direct cost of care in the SFR NICU.

Conclusion: These data overwhelmingly support the SFR NICU in preference to the traditional OPBY facility. They substantiate that the SFR NICU should be the new standard for NICU care.

Clinical management of behavioral insomnia of childhood

Behavioral insomnia is highly prevalent, affecting approximately 25% of children. It involves difficulties initiating and maintaining sleep and frequently results in inadequate sleep, leading to an array of negative effects for both the child and the child's family. In this paper, we describe a variety of empirically supported behavioral interventions for insomnia from infancy through adolescence. We explore how biological, cognitive, and psychosocial developmental changes contribute to behavioral insomnia and how these changes may affect sleep and behavioral interventions. We also discuss barriers that prevent families from accessing interventions, including why many empirically-supported behavioral interventions are overlooked by health care providers.

Documenting the NICU design dilemma: comparative patient progress in open-ward and single family room units

OBJECTIVE

To test the efficacy of single family room (SFR) neonatal intensive care unit (NICU) designs, questions regarding patient medical progress and relative patient safety were explored. Addressing these questions would be of value to hospital staff, administrators and designers alike.

STUDY DESIGN

This prospective study documented, by means of Institution Review Board-approved protocols, the progress of patients in two contrasting NICU designs. Noise levels, illumination and air quality measurements were included to define the two NICU physical environments.

RESULT

Infants in the SFR unit had fewer apneic events, reduced nosocomial sepsis and mortality, as well as earlier transitions to enteral nutrition. More mothers sustained stage III lactation, and more infants were discharged breastfeeding in the SFR.

CONCLUSION

This study showed the SFR to be more conducive to family-centered care, and to enhance infant medical progress and breastfeeding success over that of an open ward.

A Comparison of Parent Satisfaction in an Open-Bay and Single-Family Room Neonatal Intensive Care Unit

Objective:

The purpose of this research was to test the hypothesis that parental satisfaction with neonatal intensive care is greater in a single-family room facility as compared with a conventional open-bay neonatal intensive care unit (NICU).

Methods:

This investigation was a prospective cohort study comparing satisfaction survey results for parents who responded to a commercially available parent NICU satisfaction survey following the provision of NICU care in open-bay and single-family room facilities. A subset of 16 items indicative of family-centered care was also computed and compared for these two NICU facilities.

Results:

Parents whose babies received care in the single-family room facility expressed significantly improved survey responses in regard to the NICU environment, overall assessment of care, and total survey score than did parents of neonates in the open-bay facility. With the exception of the section on nursing in which scores in both facilities were high, nonsignificant improvement in median scores for the sections on delivery, physicians, discharge planning, and personal issues were noted. The total median item score for family-centered care was significantly greater in the single-family room than the open-bay facility.

Conclusions:

Parental satisfaction with care in the single-family room NICU was improved in comparison with the traditional open-bay NICU. The single-family room environment appears more conducive to the provision of family-centered care. Improved parental satisfaction with care and the potential for enhanced family-centered care need to be considered in decisions made regarding the configuration of NICU facilities in the future.

The newborn intensive care unit environment of care: how we got here, where we're headed, and why

The newborn intensive care unit (NICU) is a life-defining place for many infants, families, and caregivers. The place in which such events occur is often remembered for its sights, sounds, and smells, but the physical environment of the NICU is far more than a memory tag; it can directly influence the quality of the experience for all of its inhabitants. A growing body of evidence demonstrates the profound impact of the physical environment on growth and development of the neonatal brain. The value of skin-to-skin care is now established. Psychology, sociology, and occupational health provide additional insight into the effect of the NICU setting on families and caregivers. Together, these lines of evidence point to the need for individualized environments. Single-family rooms are a growing trend in the NICU because they allow for individualized environments. Careful planning can avoid pitfalls and bring benefit to babies, families, and caregivers alike.

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

BACKGROUND

The potential benefits and harms of different lighting in neonatal units have not been quantified.

OBJECTIVES

To compare the effectiveness of cycled lighting (CL) (approximately 12 hours of light on and 12 hours of light off) with irregularly dimmed light or near darkness (ND) and with continuous bright light (CBL) on growth in preterm infants at three and six months of age.

SEARCH STRATEGY

Electronic searches of the literature were conducted (in May 2010) of the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE, EMBASE, CINAHL and abstracts from Pediatric Academic Societies' annual meetings.

SELECTION CRITERIA

Randomised or quasi-randomised trials of CL versus ND or CBL in preterm and low birth weight infants.

DATA COLLECTION AND ANALYSIS

Data collection and analyses were performed according to the methods of the Cochrane Neonatal Review Group.

MAIN RESULTS

Five studies enrolling 387 infants compared CL to ND. No study reported on weight at three or six months. In one study (n = 40) there was no statistically significant difference in weight at four months between the CL and the ND groups. In another study (n = 62) the ratio of day-night activity prior to discharge favoured the CL group (mean difference 0.18, 95% CI 0.17 to 0.19) indicating 18% more activity during day than night in the CL group compared to the ND group. Two studies (n = 189) reported on retinopathy of prematurity (stage ≥ 3). There was no statistically significant difference between the CL and ND groups (typical RR 0.53, 95% CI 0.25 to 1.11, I(2) = 0%; typical RD -0.09, 95% CI -0.19 to 0.01, I(2) = 0%).Two studies enrolling 82 infants compared CL to CBL. One study (n = 41) reported higher mean weight at three months corrected age in infants cared for in the CL nursery (P < 0.02) and lower mean number of hours spent awake in 24 hours at three months (P < 0.005). In one study (n = 41) days on a ventilator were reduced in the CL group (mean difference -18, 95% CI -31 to -5 days).For many outcomes the trends favoured CL versus ND as well as CL versus CBL.

AUTHORS' CONCLUSIONS

Trials assessing the effect of CL have enrolled 469 infants. Trends for many outcomes favoured cycled light (CL) compared to near darkness (ND) and CL compared to continuous bright light (CBL) The studies may have lacked significance due to a lack of statistical power. Future research should focus on comparing CL to ND.

Perinatal nutrient restriction induces long-lasting alterations in the circadian expression pattern of genes regulating food intake and energy metabolism

OBJECTIVE

Several lines of evidence indicate that nutrient restriction during perinatal development sensitizes the offspring to the development of obesity, insulin resistance and cardiovascular disease in adulthood via the programming of hyperphagia and reduced energy expenditure. Given the link between the circadian clock and energy metabolism, and the resetting action of food on the circadian clock, in this study, we have investigated whether perinatal undernutrition affects the circadian expression rhythms of genes regulating food intake in the hypothalamus and energy metabolism in the liver.

DESIGN

Pregnant Sprague-Dawley rats were fed ad libitum either a control (20% protein) or a low-protein (8% protein) diet throughout pregnancy and lactation. At weaning, pups received a standard diet and at 17 and 35 days of age, their daily patterns of gene expression were analyzed by real-time quantitative PCR experiments.

RESULTS

17-day-old pups exposed to perinatal undernutrition exhibited significant alterations in the circadian expression profile of the transcripts encoding diverse genes regulating food intake, the metabolic enzymes fatty acid synthase and glucokinase as well as the clock genes BMAL1 and Period1. These effects persisted after weaning, were associated with hyperphagia and mirrored the results of the behavioral analysis of feeding. Thus, perinatally undernourished rats exhibited an increased hypothalamic expression of the orexigenic peptides agouti-related protein and neuropeptide Y. Conversely, the mRNA levels of the anorexigenic peptides pro-opiomelanocortin and cocaine and amphetamine-related transcripts were decreased.

CONCLUSION

These observations indicate that the circadian clock undergoes nutritional programming. The programming of the circadian clock may contribute to the alterations in feeding and energy metabolism associated with malnutrition in early life, which might promote the development of metabolic disorders in adulthood.

Neonatal intensive care nursery staff perceive enhanced workplace quality with the single-family room design

OBJECTIVE

To compare perceived workplace quality in an open-bay neonatal intensive care unit (NICU) and a single-family room (SFR) NICU.

STUDY DESIGN

Prospective non-randomized, non-controlled cohort study.

RESULT

Staff workplace quality perceptions assessed included the following: the quality of being a Sanford Health System employee (NS-not significant), the quality of the NICU physical work environment, the quality of NICU patient care, the job quality in the NICU, the quality of health and safety in the NICU (NS), the quality of safety and security in the NICU, the quality of interaction with other members of the NICU health-care team (NS; in subanalysis nurse scores significantly declined), the quality of interaction with NICU technology and the off-job quality of life (NS). Scores for each category and the total scores were statistically greater in the SFR, except as noted (NS).

CONCLUSION

Staff perceptions of workplace quality were significantly greater in the SFR than the open-bay NICU.

Normal sleep in children and adolescents

This article reviews the normal development of sleep in infants, children, and adolescents, with specific focus on both the subjective and objective aspects of sleep. Notably, sleep duration decreases substantially from infancy through adolescence with increased consolidation of sleep to the nighttime period only. Sleep architecture exhibits developmental changes with decreases in slow-wave sleep and increases in stage 2 sleep from childhood through adolescence. Although the development of sleep is a dramatic and relatively rapid process during the first decades of life, changes in sleep continue across the life span.

Risk factors and consequences of early childhood dyssomnias: New perspectives

Dyssomnias are largely under-diagnosed in infants and toddlers. This literature review proposes an integrative model based on empirical data on determinants and consequences of sleep disturbances occurring in early life. This model proposes that parental behaviors that impede the child's autonomy toward sleep periods are primary grounds for the development of dyssomnias, e.g., parental presence until the child falls asleep, and putting an already sleeping child to bed. The model also indicates the serious potential consequences of a modest but chronic loss of sleep in childhood. At least three developmental domains could be directly affected: behavioral/social competence, cognitive performance, and physical condition. Thus, children with short nocturnal sleep duration before age 3.5 years show increased risk of high hyperactivity-impulsivity scores and low cognitive performance at 6 years compared to children who sleep 11 h per night, after controlling for potentially confounding variables. Moreover, persistent short sleep duration in early infancy increased the risk of suffering of obesity at 6 years of age, after controlling for potentially confounding variables. Finally, the importance of allowing the child to sleep at least 10 h per night in early childhood is stressed, as the National Sleep Foundation Poll suggests, for optimal child development.

Transition to an individual-room NICU design: process and outcome measures

Redesign of a neonatal intensive care unit is a major budget undertaking, demanding accountability for its equipment and feasibility of design. It must be philosophically based and driven by research supporting best practice. The NJCU at the Magee-Womens Hospital of the University of Pittsburgh Medical Center, a Level III, 74-bed unit, has made the change from a ward design to an individual-room design suitable for family-centered, developmentally supportive care. This article presents the design process as it occurred. Unique to this process are the involvement of NJCU-graduate families and the use of transition teams. Guidelines and recommendations are offered to others interested in designing and practicing in an individual-room NJCU. Outcome data demonstrate staff adjustment to the new design and practice model. A comparison of this NICU design is made with the Recommended Standards for Newborn ICU Design.

Iatrogenic environmental hazards in the neonatal intensive care unit

Premature infants in the neonatal intensive care unit (NICU) face many illnesses and complications. Another potential source of iatrogenic disease is the NICU environment. Research in this area, however, is limited.

Measurement of rest and activity in newborn lambs using actigraphy: studies in term and preterm lambs

The present study used actigraphy to monitor rest–activity cycles in lambs. We employed an Actiwatch Activity Monitor, which was secured on the lamb’s neck in 13 term lambs and six preterm lambs. Activity measurements began on the day of delivery and lasted for 7.3 ± 0.7 days. All lambs exhibited bouts of activity, lasting from ~2 to 60 min, separated by periods of inactivity of about equal duration. There was a progressive increase in the frequency and intensity of activity bouts with age, and a decrease in duration. In relation to postnatal age, preterm lambs had a significantly lower frequency and intensity of activity bouts compared with term lambs and significantly longer mean active bout duration. However, in relation to post-conceptual age, preterm animals were less active at birth, but thereafter the trajectory for activity development was steeper compared with the term lambs. These differences between term and preterm lambs may be due to several factors including differences in: (1) the lengths of time the two groups spent in utero and as neonates as a proportion of the perinatal period, which could influence the rate of muscle and bone growth; (2) prenatal and postnatal hormonal profiles; and (3) maternal care. We also found differences in postnatal motility in male and female lambs, with the trajectory of activity increasing in males at Days 4–5, which could be due, in part at least, to sex differences in both prenatal and postnatal hormonal profiles.

The effect of tobacco exposure on the fetal hypothalamic-pituitary-adrenal axis

OBJECTIVE

Our objective was to determine if maternal smoking is associated with programming of the fetal hypothalamic-pituitary-adrenal (HPA) axis. Cigarette smoking, which induces a state of hypoxia in the fetus, may promote in utero'programming' of the HPA axis. In utero, adaptations to the HPA axis, which become maladaptive later in life, have been hypothesised to contribute to the development of adult cardiovascular disease and metabolic disorders.

DESIGN

This was a prospective cohort study of term infants.

POPULATION AND SETTING

The study involved 104 infants born by elective caesarean section, 21 of whom were exposed to in utero tobacco and 83 were nonexposed.

METHODS

Healthy women with healthy pregnancies were recruited if they were undergoing elective caesarean section. Maternal blood was drawn for cortisol and cotinine in the morning, and the umbilical blood was drawn immediately after delivery of the baby.

MAIN OUTCOME MEASURES

Umbilical arterial cortisol and adrenocorticotropin hormone (ACTH) levels.

RESULTS

ACTH levels were significantly elevated in smoke-exposed infants [17 (4-22) pmol/l versus 4 (2-11) pmol/l, respectively, P= 0.005], while cortisol levels were similar [182 (130-240) nmol/l versus 192 (127-265) nmol/l, respectively, P= 0.541].

CONCLUSIONS

For the first time, it was shown that infants exposed to in utero tobacco smoke have significantly elevated ACTH levels compared with nonexposed infants. The results of this study warrant further exploration of the effect of smoking on the neonatal HPA axis as a potential set up for 'programming'.

Thermoregulatory control of feeding and sleep in premature infants

OBJECTIVE

The aim of the present study was to test the thermoregulatory feeding control hypothesis in sleeping, premature infants.

RESEARCH METHODS AND PROCEDURES

In premature infants, the energy supply from food intake is crucial for (in order of importance): organ operation, body homeothermia, and optimal growth. The Himms-Hagen model of thermoregulatory feeding control involving activation of heat production by brown adipose tissue (BAT) was formulated on the basis of work in (awake) rats. This hypothesis has also been put forward for the human neonate, which can also use BAT to produce metabolic heat. According to the model, feeding episodes occur during a transient increase in body temperature. Feeding is initiated by a dip in blood glucose concentration after sugar uptake by activated BAT.

RESULTS

In 14 neonates (bottle-fed on demand), food intake always took place during an increase in skin temperature (+0.19 +/- 0.21 degrees C). Awakening occurred 18 +/- 17 minutes after the minimum skin temperature level had been reached. When feeding time was imposed, feeding was not necessarily situated during an increase in skin temperature, and the sleep duration after food intake increased significantly (+43%). This could be considered as an adaptive response to the short-term sleep deprivation and/or stress elicited by an imposed feeding rhythm.

DISCUSSION

The validity of the model supports the use of on-demand feeding in neonatal care units, in accordance with the infant's physiological body temperature oscillations.

Frequency analysis of air and skin temperature in neonates in servo-controlled incubators

OBJECTIVE

To test a new system designed for digital recording of skin and air temperature, thereby allowing analysis of cyclic changes in temperature in neonates in servo-controlled incubators.

METHODS

Analysis of cyclic changes of serial skin and air temperature in asymptomatic infants in servo-controlled incubators adjusting heat output to the patient's temperature.

RESULTS

In nine asymptomatic neonates ranging from 25 to 40 weeks of gestational age, analysis showed peaks of coherence (squared correlation) between skin and air temperature measurements at periods ranging between 1.5 and 3 h.

CONCLUSION

We have established a new system to study cyclic changes in skin and air temperature in neonates in servo-controlled incubators. The analysis of this pilot study suggests that the most important changes in skin and air temperature in asymptomatic neonates occur at a periodicity of 1.5 to 3 h, which is similar to that previously described for neonatal temperature. Additional data are required to determine whether this new system may be useful in neonatal care.

Maternal fluoxetine infusion does not alter fetal endocrine and biophysical circadian rhythms in pregnant sheep

OBJECTIVE

Depression during pregnancy is frequently treated with the selective serotonin reuptake inhibitor (SSRI), fluoxetine (FX), commonly known as Prozac (Eli Lilly & Co, Indianapolis, IN). FX potentiates serotoninergic neurotransmission and serotonin has been implicated in the regulation of circadian rhythms. We have therefore investigated the effect of chronic administration of FX on maternal and fetal circadian rhythms in sheep.

METHODS

Following an initial bolus dose of 70 mg FX, an 8-day continuous infusion of FX (n = 11, 98.5 microg/kg x d) was performed. Controls (n = 13) were treated with sterile water vehicle only. Maternal and fetal plasma melatonin and prolactin concentrations were determined every 3 hours for 24 hours and then every 6 hours for 24 hours beginning on the fourth day of infusion.

RESULTS

FX treatment did not alter either the basal or circadian rhythms of either maternal or fetal plasma melatonin and prolactin concentrations. Fetal cardiovascular and behavioral state parameters were measured continuously. While the incidence of low-voltage (LV) electrocortical (ECOG) activity was significantly reduced in fetuses in the FX group, there was no effect of FX on the diurnal rhythms in fetal arterial pressure, heart rate, breathing movements, or behavioral state.

CONCLUSION

These results show that maternal FX treatment does not result in significant alterations in maternal and fetal hormonal and behavioral circadian rhythms.

Ontogenetic development of the mammalian circadian system

This review summarizes the current knowledge about the ontogenetic development of the circadian system in mammals. The developmental changes of overt rhythms are discussed, although the main focus of the review is the underlying neuronal and molecular mechanisms. In addition, the review describes ontogenetic development, not only as a process of morpho-functional maturation. The need of repeated adaptations and readaptations due to changing developmental stage and environmental conditions is also considered. The review analyzes mainly rodent data, obtained from the literature and from the author's own studies. Results from other species, including humans, are presented to demonstrate common features and species-dependent differences. The review first describes the development of the suprachiasmatic nuclei as the central pacemaker system and shows that intrinsic circadian rhythms are already generated in the mammalian fetus. As in adult organisms, the period length is different from 24 h and needs continuous correction by environmental periodicities, or zeitgebers. The investigation of the ontogenetic development of the mechanisms of entrainment reveals that, at prenatal and early postnatal stages, non-photic cues deriving from the mother are effective. Light-dark entrainment develops later. At a certain age, both photic and non-photic zeitgebers may act in parallel, even though the respective time information is 12 h out of phase. That leads to a temporary internal desynchronization. Because rhythmic information needs to be transferred to effector organs, the corresponding neural and humoral signalling pathways are also briefly described. Finally, to be able to transform a rhythmic signal into an overt rhythm, the corresponding effector organs must be functionally mature. As many of these organs are able to generate their own intrinsic rhythms, another aspect of the review is dedicated to the development of peripheral oscillators and mechanisms of their entrainment. The latter includes control by the central pacemaker as well as by distinct environmental signals. Ecological aspects of the described developmental changes in the circadian system and some practical consequences are also briefly discussed.