J. Declan Kennedy

Effects of birthweight and oxygen supplementation on lung function in late childhood in children of very low birth weight

Impaired respiratory function has been found frequently in ex‐premature children, but it is unclear which specific factors influence this impairment the most. The aim of this study was to determine the importance of the contributions of birth weight, gestational age, neonatal respiratory disease, and its treatment on subsequent childhood lung function at age 11 years in a cohort of children of very low birth weight (VLBW; ≤1,500 g). Detailed clinical histories were recorded, and lung function was measured in 60% (102 children) of surviving VLBW infants born 1981/1982, and compared with 82 matched control children (birth weight >2,000 g) of similar age.

Inconsistent sleep schedules and daytime behavioral difficulties in school-aged children

OBJECTIVES Current recommendations for healthy sleep in school-aged children are predominantly focused on optimal sleep duration (9-11h). However, given the importance of routine for circadian health, the stability of sleep/wake schedules may also be important, especially for daytime behavioral functioning. We examined the relationship between short sleep duration, sleep schedule instability and behavioral difficulties in a community sample of Australian children. METHODS Children, aged 5-10 years (N=1622), without chronic health or psychological conditions, were recruited from primary schools in Adelaide, South Australia. A parent-report questionnaire was used to assess sleep/wake behavior. Behavioral functioning was assessed using the Strengths and Difficulties Questionnaire. RESULTS Most children met sleep duration recommendations with approximately 5% reporting <9h and 3% >12h. Weekly variability of bed and rise times >1h were reported in up to 50% of children. Multinomial regression analysis revealed sleep duration <10h, bedtime latency >60 min, and bed and rise time variability >60 min significantly increased the risk of scoring in the 95th percentile for behavioral sub-scales. CONCLUSIONS Inconsistent sleep schedules were common and, similar to short sleep duration, were associated with behavioral difficulties. Considering the lack of study in this area, further research is needed for the development of new recommendations, education and sleep health messages.

Effect of antenatal tracheal occlusion on lung development in the sheep model of congenital diaphragmatic hernia: a morphometric analysis of pulmonary structure and maturity.

The incidence of congenital diaphragmatic hernia (CDH) is 1:1,207–5,000, and the condition is associated with high mortality and morbidity, attributed principally to associated pulmonary hypoplasia. Repairing the diaphragmatic defect by antenatal surgery has high mortality, mainly due to premature labor. Antenatal tracheal occlusion, which is achievable by less invasive methods, stimulates lung growth (weight and DNA). However, its effectiveness in reversing structural and maturational abnormalities and its optimal timing requires further investigation. We hypothesized that (1) antenatal tracheal occlusion performed in the lamb model of congenital diaphragmatic hernia will stimulate lung growth and structural development and restore lung structure and maturity toward normal levels by term gestation; (2) effects will be detectable by morphometric measurements of the following parameters: lung volume, ratio of parenchyma to nonparenchyma, volume density of connective tissue within nonparenchyma, ratio of gas exchange tissue to airspace in parenchyma, gas exchange surface area, capillary loading, alveolar/airspace density and alveolar perimeter; (3) effects will be seen in all lobes of the lung; and (4) a greater effect will be observed when tracheal occlusion is performed early rather than late in gestation.

Neurocognitive performance and behavior before and after treatment for sleep-disordered breathing in children

Neurocognitive and behavioral problems are increasingly reported in children with sleep-disordered breathing (SDB). The impact of treatment for SDB on neurocognition and behavior is, therefore, an issue of increasing importance. To date, there has been little consideration given to the quality of studies when reviewing associated neurocognitive and behavioral problems in children with SDB, and furthermore, there has been little systematic review of treatment outcomes. The aim of this review was to provide an up-to-date and critical review of the current literature. Findings indicate a specific pattern of neurocognitive problems in children with SDB; however, the pattern of behavioral problems is less clear. Very few studies were found to provide a rigorous investigation of posttreatment neurocognitive and behavior outcomes. Despite this, relatively consistent improvements in global intelligence, attention, and visual spatial ability are shown; however, persistent deficits in other domains are also evident. For behavior, problems of hyperactivity, aggression or conduct problems, and somatic complaints improve following treatment. In contrast, symptoms of anxiety and social problems less consistently improve. These findings should aid in the development of more targeted investigations and well-designed studies exploring both the causative mechanisms and the treatment response for neurocognitive and behavior problems in children with SDB.

Gender, socioeconomic, and ethnic differences in sleep patterns in school-aged children

OBJECTIVES Age-related changes in sleep behavior are well described in children, yet the effect of gender, socioeconomic status (SES), and ethnicity is less clear. These factors are important when developing culturally and socially appropriate guidelines for healthy sleep. The objective of our study was to examine the effects of age, gender, SES, and ethnicity on sleep patterns in school-aged children. METHODS A cross-sectional survey was conducted through primary schools in Adelaide, South Australia. Parents reported demographic information and sleep patterns for school and non-school days for 1845 children aged 5 to 10years. RESULTS 48% of the cohort were boys (mean age, 7.7±1.7y), 85% were Caucasian, and there was an equal distribution across defined SES bands. Sleep duration reduced with age and was shorter on non-school than school nights as a result of later bedtimes. Boys, children from low SES areas, and non-Caucasian children reported shorter sleep times than girls, children from high SES areas, and Caucasian children, respectively. Non-Caucasian children from low SES areas reported the shortest sleep opportunity. CONCLUSIONS The results from our study suggest that in addition to biological mechanisms, sleep behaviors are culturally and socially driven and should be considered when developing recommendations for healthy sleep in children.

Morphometric analysis of preterm fetal pulmonary development in the sheep model of congenital diaphragmatic hernia.

ABSTRACT Congenital diaphragmatic hernia (CDH) in humans carries high mortality/morbidity attributed to associated pulmonary hypoplasia. An understanding of the effects of CDH on fetal lung growth is important for development of successful treatments. This study aimed to quantitate structural differences between normal and CDH-affected preterm lamb lungs. We hypothesized that (a) pulmonary hypoplasia is present in preterm CDH-affected lungs; (b) the relative degree of pulmonary hypoplasia increases with gestation; and (c) the left upper lobe (LUL) is affected most. Fetal lambs were allocated to two groups. One group underwent surgery (72–74 days gestation) inducing CDH. Both groups (n = 7, n = 7) were delivered by cesarean section at 129 days (term: 145–149). Lungs were obtained at autopsy, were inflation-fixed, processed for histology, and morphometry was performed. Preterm lungs of CDH-affected lambs in comparison to those of normal lambs demonstrated a reduction in the following: lung weight (37.7 g vs. 116.3 g); lung weight:body weight (0.012 vs. 0.040); fixed lung volume (33.6 ml vs. 96.9 ml); gas-exchange surface area (4.56 m2 vs. 13.70 m2); parenchyma:nonparenchyma (59:41 vs. 72:28); and parenchymal airspace:tissue (16:84 vs. 35:65). Non-parenchyma connective tissue was increased (58%), airspaces were more numerous (1077/mm2) and smaller (perimeter 76.6 μm), gas-exchange surface density (2394 cm−1) was greater and capillary loading (0.04 ml/m2) was reduced compared to preterm normal lung (49%; 778/mm2; 108.7 μm; 2003 cm−1, 0.11 ml/m2, respectively). The LUL was affected most. These data quantitate pulmonary hypoplasia in preterm CDH-affected lambs. Comparisons with published data indicate increasing relative hypoplasia as gestation proceeds. Fetal interventions will affect lung development, depending on timing, with intervention still likely to be worthwhile during late gestation.

Sleep and neurocognitive functioning in children with eczema

Sleep disruption in childhood is associated with clearly defined deficits in neurocognition and behaviour. Childhood eczema is also a potent cause of sleep disruption though it is unknown whether it too results in neurocognitive deficits. To test this hypothesis, neurocognitive (WISC-IV), parental-reported sleep quality (Sleep Disturbance Scale of Children (SDSC)) and overnight polysomnographic (PSG) data were collected in 21 children with eczema and 20 healthy controls (age range 6-16 years). Children with eczema had worse sleep quality on both PSG (notably increased nocturnal wakefulness, a higher number of stage shifts and a longer latency to REM onset) and parental report. In addition, they demonstrated significant neurocognitive deficits (especially verbal comprehension, perceptual reasoning and to a lesser extent working memory) with a composite Full Scale IQ 16 points lower than controls. Parental reported sleep problems but not PSG parameters were correlated with reduced neurocognitive performance. However, hierarchical regression analyses revealed that eczema status was predictive while sleep fragmentation (parental or PSG) was not predictive of neurocognitive performance. As this is the first study to systematically examine neurocognitive functioning in children with eczema and given the finding of significant deficits it merits replication especially given the prevalence of the condition. The unanswered question is whether these cognitive deficits normalise with effective eczema treatment and if this is mediated by improvements in sleep architecture.

Chronic respiratory failure and neuromuscular disease.

The outlook for children with respiratory complications of neuromuscular disease has improved significantly in the past 15 years. This has been the result of many advances in clinical care, including improved monitoring of lung function and hypoventilation during sleep; coordinated respiratory care by experienced physicians with access to specialized respiratory services, especially physiotherapy; and, most importantly, the widespread introduction of noninvasive ventilation.

Sleep, executive functioning and behaviour in children and adolescents with type 1 diabetes

OBJECTIVE The aim of the study was to examine sleep, neurocognitive and behavioural functioning in children and adolescents with type 1 diabetes (T1D) compared to controls and to test whether sleep quality mediates the relationship between diabetes and neurocognitive and behavioural deficits. METHODS Participants include 49 children and adolescents with T1D (recruited from a hospital clinic) and 36 healthy controls (age range = 6-16 years). Parents completed a survey consisting of the Sleep Disturbances Scale for Children, the Behavior Rating Inventory of Executive Functions, and the Behavior Assessment System for Children-2. Diabetic and demographic parameters were collated from medical records. The survey was posted to participants. RESULTS Children with T1D compared to controls reported a higher frequency of sleep problems, and mild deficits in executive and behavioural functioning. Mediational analyses revealed that sleep quality fully mediated metacognitive functioning, externalised problematic behaviour, and internalised problematic behaviour, but not behavioural regulation. CONCLUSIONS Rather than the direct impact of T1D on daytime functioning, it is the consequent impact of T1D on sleep and the resulting sleep disruption which can explain much of the neurocognitive and behavioural deficits reported in children with T1D. Maintaining good nocturnal glycaemic control may play a much larger role than previously thought in regulating daytime functioning in children with T1D.

Differences in parental attitudes towards sleep and associations with sleep-wake patterns in Caucasian and Southeast Asian school-aged children in Australia.

Caucasian (N = 47) and Southeast (SE) Asian (N = 36) families completed a questionnaire on their attitudes toward sleep, as well as a 7-day sleep diary for their children aged 5 to 11 years. Cultural differences were found in the perceived importance of sleep, particularly compared to homework and belief of how much sleep a child needs. Differences were also found in sleep–wake behaviors and amount of time spent on homework, with SE Asian children reporting a shift in sleep timing and increased homework load compared to Caucasian counterparts. Parental attitudes toward sleep, perception of sleep need, and homework load were not associated with the regulation of actual sleep behaviors in children, regardless of cultural heritage.