Effect of sleep disordered breathing severity in children with Down syndrome on parental wellbeing and social support.

INTRODUCTION: Sleep disorders, particularly sleep disordered breathing (SDB), are common in children with Down syndrome (DS). We investigated the relationship between SDB severity and parental psychological wellbeing and their perception of social support. METHODS: 44 children with DS (3-19 years) underwent overnight polysomnography and were categorised into three groups: primary snoring, Mild and Moderate/Severe obstructive sleep apnoea (OSA). Parents completed questionnaires about their child's behaviour (Child Behavior Checklist), sleep symptoms (Pediatric Sleep Survey Instrument) and SDB-related quality of life (OSA-18), together with the DUKE-UNC Functional Social Support (DUKE) and Psychological General Well-Being Index (PGWBI) questionnaires for themselves. 34 children completed a follow-up study after 2 years. RESULTS: There were no significant differences between SDB severity groups for parental perceived social support or psychological wellbeing. Total scores on the DUKE were below average and PGWBI scores were indicative of moderate psychological distress in all three groups. Reduced perceived levels of social support were significantly correlated with externalising child behaviour and sleep disturbance. Diminished parental psychological wellbeing was also significantly correlated with increased sleep disturbances and reduced quality of life in children. At follow-up there were no significant changes in any questionnaire outcome, however parents of children with improved SDB severity had improved PGWBI vitality scores. CONCLUSION: The degree of parent-reported sleep disturbance in children with DS was linked to suboptimal perceived parental social support and poor psychological wellbeing. Our results emphasise the need for enhanced awareness of the detrimental effects of sleep problems in children with DS on parental wellbeing.

Kangaroo mother care improves cardiorespiratory physiology in preterm infants: an observational study.

OBJECTIVES: To evaluate whether kangaroo mother care (KMC) in preterm infants on non-invasive respiratory support improves indices of cardiorespiratory wellbeing. STUDY DESIGN: Prospective quasi-experimental observational study. SETTING: Tertiary perinatal neonatal unit. PATIENTS: 50 very preterm infants being managed with nasal continuous positive airway pressure. INTERVENTIONS: Continuous high-resolution preductal pulse-oximetry recordings using Masimo Radical-7 oximeter for 1 hour (incubator care) followed by 1 hour during KMC performed on the same day. MAIN OUTCOME MEASURES: Measures of cardiorespiratory stability (dips in oxygen saturations (SpO2)) of ≥5% less than baseline, % time spent with oxygen saturations <90%, SpO2 variability and heart rate fluctuation and incidence of bradycardias. RESULTS: The gestational age and birth weight of the cohort were 28.4±2.1 weeks and 1137±301 g, respectively. Dips in SpO2 of ≥5% less than baseline were significantly fewer with KMC, median (IQR) 24 (12 to 42) vs 13 (3 to 25), p=0.001. SpO2 variability (Delta 12 s and 2 s), (1.24±0.6 vs 0.9±0.4, p=0.005 and 4.1±1.7 vs 2.8±1.2, p<0.0001) and rapid resaturation and desaturation indices were significantly lower during KMC, compared with incubator care. Percentage time spent in oxygen saturations <90% was less with KMC (7.5% vs 2.7%, p=0.04). Mean heart rate was comparable although fluctuations in heart rate (rise by >8 bpm) were lower with KMC (43±22 vs 33±20, p=0.03). Seven (14%) infants had bradycardias during incubator care and none during KMC, p=0.012. CONCLUSIONS: KMC improves cardiorespiratory stability in ventilated preterm infants. Regular KMC has the potential to improve clinical outcomes in this vulnerable cohort.

Improvement in quality of life with continuous positive airway pressure outweighs the treatment burden in children with obstructive sleep apnea.

INTRODUCTION: Continuous positive airway pressure (CPAP) for treatment of obstructive sleep apnea (OSA) may pose a significant burden on families. We assessed the impact of CPAP for children on quality of life (QOL) and caregiver treatment burden. METHODS: Prospective cohort study of children commencing outpatient CPAP in a specialist sleep centre 2020-2022. Questionnaires regarding sleep-related symptoms (PROMIS Pediatric Sleep Disturbance and Sleep-Related Impairment), QOL (OSA-18, QI-Disability), caregiver burden (Caregiver Strain Questionnaire) and overall health impact (Glasgow Children's Benefit Inventory) were completed by caregivers at CPAP commencement and 6 weeks later. RESULTS: Twenty-six patients completed follow-up (7 female; median age 11.4 year, baseline obstructive apnea hypopnea index 10.3/h; 77% overweight or obese, 73% comorbidity other than obesity). OSA-related QOL (OSA-18) significantly improved at follow-up (p < 0.01), as did child general QOL (p < 0.001), sleep disturbance (p < 0.01) and sleep-related impairment (p < 0.001). Caregivers mostly rated CPAP as beneficial to their child's health but 19% rated CPAP as harmful or having no effect. Caregiver strain reduced at follow-up (p < 0.001) and benefit outweighed inconvenience (p < 0.0001) in 81%. CPAP adherence was correlated with overall health impact (r = 0.67, p < 0.01) but not with caregiver rating of inconvenience. CONCLUSIONS: CPAP resulted in improvements in QOL and sleep-related symptoms, and reduced caregiver strain. Perceived benefits outweighed the burden of treatment for most but not all families. CPAP adherence was moderately correlated with family-reported measures of benefit but not related to perceived inconvenience. This study provides reassuring evidence regarding the benefits and impacts of CPAP for children, many of whom already have complex health care needs.

Is there a role for repeating the multiple sleep latency test across childhood when initially non-diagnostic?

BACKGROUND: The gold standard investigation for central disorders of hypersomnolence is the Multiple Sleep Latency Test (MSLT). As the clinical features of these disorders of hypersomnolence evolve with time in children, clinicians may consider repeating a previously non-diagnostic MSLT. Currently there are no guidelines available regards the utility and timing of repeating paediatric MSLTs. METHODS: Retrospective review of children aged 3-18years with ≥2MSLTs between 2005 and 2022. Narcolepsy was defined as mean sleep latency (MSL) <8min with ≥2 sleep onset REM (SOREM); idiopathic hypersomnia (IH) was defined as MSL <8min with <2 SOREM. MSLTs not meeting these criteria were labelled non-diagnostic. RESULTS: 19 children (9 female) with initial non-diagnostic MSLT underwent repeat MSLT, with 6 proceeding to a 3rd MSLT following 2 non-diagnostic MSLTs. The 2nd MSLT resulted in diagnosis in 6/19 (32 %) (3 narcolepsy, 3 IH); and 2/6 (33 %) 3rd MSLT were diagnostic (2 IH). Median age at initial MSLT was 7.5y (range 3.4-17.8y), with repeat performed after median of 2.9y (range 0.9-8.2y), and 3rd after a further 1.9 years (range 1.2-4.2y). Mean change in MSL on repeat testing was -2min (range -15.5min to +4.9min, p = 0.18). Of the 8 diagnostic repeat MSLTs, in addition to the MSL falling below 8 min, 2 children also developed ≥2 SOREM that had not been previously present. CONCLUSIONS: A third of repeat MSLTs became diagnostic, suggesting repeat MSLT should be considered in childhood if clinical suspicion persists. Further work needs to address the ideal interval between MSLTs and diagnostic cut-points specific to the paediatric population.

Sleepy Kids: are the current diagnostic criteria for multiple sleep latency tests enough?

Excessive daytime sleepiness (EDS) is common in childhood and is currently quantified using adult criteria on a multiple sleep latency test (MSLT). This study aimed to describe paediatric MSLT results, particularly focussing on a previously proposed alternative mean sleep latency (MSL) threshold for children of 12 min, and assess the impact of a 5th nap. We performed a retrospective analysis of MSLTs at a single paediatric centre from 2004 to 2021. Narcolepsy was defined as a mean sleep latency (MSL) ≤8min with ≥2 sleep onset REM (SOREM) periods. Idiopathic Hypersomnia (IH) was defined as a MSL ≤8min with <2 SOREMs. An ambiguous MSLT result was defined as a MSL 8-12min and/or ≥2 SOREM periods. Of 214 MSLTs [50 % female, median age 14.0y (range 3.3-20.1y)], narcolepsy was diagnosed in 48 (22 %), IH in 22 (10 %) and the result was ambiguous in 44 (21 %). Those with ambiguous MSLT results were older (15.6 vs 13.4y, p = 0.006) with a higher proportion of females (61 % vs 35 %, p = 0.01) in comparison to the narcolepsy group. A 5th nap was performed in 60 (28 %) of MSLTs and only changed the outcome in one case. In conclusion, MSLT results are borderline in 21 % of paediatric cases, suggesting that current adult diagnostic criteria may miss narcolepsy and IH in children. A 5th nap usually makes no difference or increases the MSL, suggesting that a four nap MSLT protocol could be used apart from rare cases where the result is borderline after the 4th nap.

Follow-up of children with Down syndrome and sleep disordered breathing and the effects of treatment on actigraphically recorded sleep, quality of life, behaviour, and daytime functioning.

Children with Down syndrome are at increased risk of obstructive sleep disordered breathing, which has deleterious effects on daytime functioning. We aimed to examine the effects of treatment of sleep disordered breathing on sleep quality and daytime functioning in children with Down syndrome, and hypothesised that these would be improved. Thirty-four children completed a baseline study and a follow-up 2 years later. Measures at both time points included 7 days of actigraphy and parents completed a number of questionnaires assessing sleep, behaviour, daytime functioning, and quality of life. All children had overnight polysomnography at baseline; 15 children (44%) were treated. At baseline the treated group had more severe sleep disordered breathing compared with the untreated group: obstructive apneoa-hypopnoea index 29.3 ± 38.2 events/h versus 3.3 ± 5.2 events/h (p < 0.01). Actigraphy showed no significant differences in total sleep time, sleep efficiency, sleep schedules from baseline to follow up in either group. The sleep disturbance (p < 0.01) and total problems (p < 0.05) scales on the OSA-18 and the sleep disordered breathing subscale on the Paediatric Sleep Problem Survey Instrument (p < 0.01) improved in the treated children. There were no changes in any measure in the untreated children. Treatment of sleep disordered breathing improves symptoms, sleep disturbance and quality of life in children with Down syndrome, but has no demonstrable impact on actigraphic sleep measures or daytime behaviour or function. In contrast, children who were not treated, despite having less severe disease at baseline, had increased sleep disruption and no change in quality of life.

Core outcomes and factors influencing the experience of care for children with severe acute exacerbations of asthma: a qualitative study.

OBJECTIVE: To identify the outcomes considered important, and factors influencing the patient experience, for parents and caregivers of children presenting to hospital with a severe acute exacerbation of asthma. This work contributes to the outcome-identification process in developing a core outcome set (COS) for future clinical trials in children with severe acute asthma. DESIGN: A qualitative study involving semistructured interviews with parents and caregivers of children who presented to hospital with a severe acute exacerbation of asthma. SETTING: Hospitals in 12 countries associated with the global Pediatric Emergency Research Networks, including high-income and middle-income countries. Interviews were conducted face-to-face, by teleconference/video-call, or by phone. FINDINGS: Overall, there were 54 interviews with parents and caregivers; 2 interviews also involved the child. Hospital length of stay, intensive care unit or high-dependency unit (HDU) admission, and treatment costs were highlighted as important outcomes influencing the patient and family experience. Other potential clinical trial outcomes included work of breathing, speed of recovery and side effects. In addition, the patient and family experience was impacted by decision-making leading up to seeking hospital care, transit to hospital, waiting times and the use of intravenous treatment. Satisfaction of care was related to communication with clinicians and frequent reassessment. CONCLUSIONS: This study provides insight into the outcomes that parents and caregivers believe to be the most important to be considered in the process of developing a COS for the treatment of acute severe exacerbations of asthma.

Sleep spindles are reduced in children with Down syndrome and sleep-disordered breathing.

BACKGROUND: Children with Down syndrome (DS) are at increased risk of sleep-disordered breathing (SDB). We investigated sleep spindle activity, as a marker of sleep quality, and its relationship with daytime functioning in children with DS compared to typically developing (TD) children. METHODS: Children with DS and SDB (n = 44) and TD children matched for age, sex and SDB severity underwent overnight polysomnography. Fast or Slow sleep spindles were identified manually during N2/N3 sleep. Spindle activity was characterized as spindle number, density (number of spindles/h) and intensity (density × average duration) on central (C) and frontal (F) electrodes. Parents completed the Child Behavior Check List and OSA-18 questionnaires. RESULTS: In children with DS, spindle activity was lower compared to TD children for F Slow and F Slow&Fast spindles combined (p < 0.001 for all). Furthermore, there were no correlations between spindle activity and CBCL subscales; however, spindle activity for C Fast and C Slow&Fast was negatively correlated with OSA-18 emotional symptoms and caregiver concerns and C Fast activity was also negatively correlated with daytime function and total problems. CONCLUSIONS: Reduced spindle activity in children with DS may underpin the increased sleep disruption and negative effects of SDB on quality of life and behavior. IMPACT: Children with Down syndrome (DS) are at increased risk of sleep-disordered breathing (SDB), which is associated with sleep disruption affecting daytime functioning. Sleep spindles are a sensitive marker of sleep quality. We identified for the first time that children with DS had reduced sleep spindle activity compared to typically developing children matched for SDB severity. The reduced spindle activity likely underpins the more disrupted sleep and may be associated with reduced daytime functioning and quality of life and may also be an early biomarker for an increased risk of developing dementia later in life in children with DS.

Cortical grey matter changes, behavior and cognition in children with sleep disordered breathing.

This paper investigated cortical thickness and volumetric changes in children to better understand the impact of obstructive sleep disordered breathing (SDB) on the neurodevelopment of specific regions of the brain. We also aimed to investigate how these changes were related to the behavioral and cognitive deficits observed in the condition. Neuroimaging, behavioral, and sleep data were obtained from 30 children (15 non-snoring controls, 15 referred for assessment of SDB) aged 7 to 17 years. Gyral-based regions of interest were identified using the Desikan-Killiany atlas. Student's t-tests were used to compare regions of interest between the controls and SDB groups. We found that the cortical thickness was significantly greater in the right caudal anterior cingulate and right cuneus regions and there were volumetric increases in the left caudal middle frontal, bilateral rostral anterior cingulate, left, right, and bilateral caudate brain regions in children with SDB compared with controls. Neither cortical thickness nor volumetric changes were associated with behavioral or cognitive measures. The findings of this study indicate disruptions to neural developmental processes occurring in structural regions of the brain; however, these changes appear unrelated to behavioural or cognitive outcomes.

Assessing sleep in children with Down syndrome: Comparison of parental sleep diaries, actigraphy and polysomnography.

BACKGROUND: This study compared measurements of sleep and wake assessed with actigraphy, sleep diary and polysomnography in children with Down syndrome (DS) and also compared measures of actigraphic sleep recording in children with DS and typically developing (TD) children. METHODS: Children with DS aged 3-19 years (N = 44) referred for assessment of sleep disordered breathing (SDB) underwent overnight polysomnography, together with 1 week of actigraphy with sleep diary. Actigraphy data from the children with DS were compared with data collected from TD children, matched for age and sex. RESULTS: 22 children (50%) with DS completed >3 consecutive nights of actigraphy with a matched sleep diary. There were no differences between bedtimes, wake times or time in bed on weeknights, weekends or over 7 nights between actigraphy and sleep diary. Total sleep time was over estimated by the sleep diary by almost 2 h and the number of night awakenings under-reported. Compared to matched TD children (N = 22), there was no difference in total sleep time, however children with DS fell asleep more quickly (p < 0.001), had more awakenings (p = 0.001) and more time awake after sleep onset (p = 0.007). Children with DS exhibited less variability in both bedtimes and wake times, and fewer had >1 h sleep schedule variability. CONCLUSIONS: Parental sleep diaries over-estimate total sleep time but accurately report bed and wake times compared to actigraphy in children with DS. Children with DS have more regular sleep patterns than TD children of the same age, which is important for optimising daytime functioning. The reasons behind this warrant further investigation.

Acute paediatric asthma treatment in the prehospital setting: a retrospective observational study.

OBJECTIVES: To describe the incidence of and patterns of 'escalated care' (care in addition to standard treatment with systemic corticosteroids and inhaled bronchodilators) for children receiving prehospital treatment for asthma. DESIGN: Retrospective observational study. SETTING: State-wide ambulance service data (Ambulance Victoria in Victoria, Australia, population 6.5 million) PARTICIPANTS: Children aged 1-17 years and given a final diagnosis of asthma by the treating paramedics and/or treated with inhaled bronchodilators from 1 July 2019 to 30 June 2020. PRIMARY AND SECONDARY OUTCOME MEASURES: We classified 'escalation of care' as parenteral administration of epinephrine, or provision of respiratory support. We compared clinical, demographic and treatments administered between those receiving and not receiving escalation of care. RESULTS: Paramedics attended 1572 children with acute exacerbations of asthma during the 1 year study period. Of these, 22 (1.4%) had escalated care, all receiving parenteral epinephrine. Patients with escalated care were more likely to be older, had previously required hospital admission for asthma and had severe respiratory distress at initial assessment.Of 1307 children with respiratory status data available, at arrival to hospital, the respiratory status of children had improved overall (normal/mild respiratory distress at initial assessment 847 (64.8%), normal/mild respiratory distress at hospital arrival 1142 (87.4%), p<0.0001). CONCLUSIONS: Most children with acute exacerbations of asthma did not receive escalated therapy during their pre-hospital treatment from ambulance paramedics. Most patients were treated with inhaled bronchodilators only and clinically improved by the time they arrived in hospital.

Sleep disordered breathing improvement prevents worsening of autonomic dysfunction in children with Down syndrome.

BACKGROUND: Resolution of sleep disordered breathing (SDB) in typically developing children normalises heart rate variability (HRV), a measure of autonomic control, to that of non-snoring controls. Children with Down Syndrome (DS) have dampened heart rate variability (HRV) but the effect of treatment is not known. To assess the effect of improvement of SDB on autonomic control we compared HRV in children with DS whose SDB improved over 2 y, to those whose SDB did not improve. METHODS: 24 children (3-19 y) had a baseline and follow-up polysomnographic study 2 y later. Improved SDB was defined as a reduction in obstructive apnea hypopnea index (OAHI) to ≤ 50% of baseline. Children were grouped into Improved (n = 12) and Unimproved (n = 12). Power spectral analysis of the ECG determined low frequency (LF), high frequency (HF) power and the LF/HF ratio. Seven children in the Improved and 2 in the Unimproved group were treated following the baseline study. RESULTS: In the Unimproved group at follow-up, LF power was lower compared to baseline during N3 and Total Sleep (p < 0.05 for both). HF power was lower during REM (p < 0.05). HRV remained unchanged between studies in the Improved group. CONCLUSION: Autonomic control worsened as indicated by lower LF and HF power in children whose SDB was not improved. In contrast, in those children with improved SDB, autonomic control remained the same, suggesting improvement in SDB severity prevents further worsening of autonomic control in children with DS.

Association of helminth infestation with childhood asthma: a nested case-control study.

OBJECTIVES: The association between helminthiasis and asthma remains inconclusive but can only be investigated in counties where helminthiasis is transitioning from a high to low burden. We investigated this association using data from a childhood respiratory cohort in Sri Lanka. METHODS: A case-control study was nested within a population-based cohort of children aged 6-14 years in Sri Lanka. The stool samples of 190 children with asthma and 190 children without asthma were analyzed to assess the burden of helminth infestation. Logistic regression models were fitted to investigate the association of gastrointestinal helminth species with asthma. RESULTS: Helminthiasis in children with and without asthma was 23.3% (n = 44) and 15.3% (n = 23), respectively. Those with asthma were more likely to have helminthiasis (odds ratio 3.7; 95% confidence interval 1.7, 7.7; P = 0.001), particularly with Trichiuris trichura (odds ratio 4.5; 95% confidence interval 1.6, 12.3; P = 0.004). Helminth eggs per gram of feces were not associated with asthma (P >0.05). CONCLUSION: Our findings demonstrate a positive association between T. trichura infestation and asthma and point to the need to fully characterize this association to understand the likely immunological mechanism that drives it. This association highlights an important public health intervention in countries where these infestations are still prevalent, affecting 24% of the population worldwide.

Periodic breathing in clinically stable very preterm infants.

OBJECTIVE: We aimed to investigate the frequency and severity of periodic breathing (PB) in clinically stable very preterm infants and identify infant and maternal factors associated with increased time spent and severity of PB in these infants. METHOD: Thirty-eight infants (28-32 weeks gestational age) who were ≥3 days off noninvasive respiratory support, were studied for 2-3 h with a daytime sleep study at 31-36 weeks postmenstrual age. Percent total sleep time spent in PB (%TSTPB) and time spent with SpO2 <90%, <80%, and cerebral oxygenation <55% during PB were calculated. Infant and maternal characteristics were correlated with %TSTPB and hypoxia during PB. RESULTS: The majority of infants (92%) had at least one episode of PB and infants spent a median 9.1 [interquartile range: 1.2, 15.5] %TSTPB. 80%, 37%, and 37% of infants experienced SpO2 <90%, <80% and cerebral oxygenation <55%, respectively, during PB. Shorter duration of respiratory support, multigravida, multiparity, and maternal vitamin D deficiency were associated with higher %TSTPB. Multigravida, shorter duration on respiratory support, apnea of prematurity, and resuscitation at birth were associated with hypoxia during PB. CONCLUSIONS: The majority of very preterm infants exhibited PB when they were off respiratory support and considered clinically stable. The time spent in PB was very variable between infants and was associated with significant hypoxia in some infants. Fewer days spent on respiratory support was associated with both increased frequency and severity of PB. However, the potential contribution of PB to neurocognitive outcomes remains uncertain and warrants further investigations.

The effects of sleep disordered breathing on sleep spindle activity in children and the relationship with sleep, behavior and neurocognition.

STUDY OBJECTIVES: Obstructive sleep disordered breathing (SDB), has adverse neurocognitive and behavioral sequelae in children, despite conventional measures of sleep disruption being unaffected. There is growing evidence that sleep spindles may serve as a more sensitive marker of sleep quality. We investigated the relationship between sleep spindles and sleep fragmentation and neurocognition across the spectrum of SDB severity in children. METHODS: Children 3-12 years old referred for clinical assessment of SDB and age matched control children from the community were recruited and underwent polysomnography. Sleep spindles were identified manually during N2 and N3 sleep. Spindle activity was characterised as spindle number, density (number of spindles/h) and intensity (spindle density x average spindle duration). Children completed a battery of tests assessing global intellectual ability, language, attention, visuospatial ability, sensorimotor skills, adaptive behaviors and skills and problem behaviors and emotional difficulties. RESULTS: Children were grouped into control, Primary Snoring, Mild OSA and Moderate/severe OSA, N = 10/group. All measures of spindle activity were lower in the SDB groups compared to the Control children and this reached statistical significance for Mild OSA (p < 0.05 for all). Higher spindle indices were associated with better performance on executive function and visual ability assessments but poorer performance on auditory attention and communication skills. Higher spindle indices were associated with better behavior. CONCLUSION: The reduced spindle activity observed in the children with SDB, particularly Mild OSA, indicates that sleep micro-architecture is disrupted and that this disruption may underpin the negative effects of SDB on attention, learning and memory.

Duration and Consequences of Periodic Breathing in Infants Born Preterm Before and After Hospital Discharge.

OBJECTIVE: To investigate the amount of time spent in periodic breathing and its consequences in infants born preterm before and after hospital discharge. METHODS: Infants born preterm between 28-32 weeks of gestational age were studied during daytime sleep in the supine position at 32-36 weeks of postmenstrual age (PMA), 36-40 weeks of PMA, and 3 months and 6 months of corrected age. The percentage of total sleep time spent in periodic breathing (% total sleep time periodic breathing) was calculated and infants were grouped into below and above the median (8.5% total sleep time periodic breathing) at 32-36 weeks and compared with 36-40 weeks, 3 and 6 months. RESULTS: Percent total sleep time periodic breathing was not different between 32-36 weeks of PMA (8.5%; 1.5, 15.0) (median, IQR) and 36-40 weeks of PMA (6.6%; 0.9, 15.1) but decreased at 3 (0.4%; 0.0, 2.0) and 6 months of corrected age 0% (0.0, 1.1). Infants who spent above the median % total sleep time periodic breathing at 32-36 weeks of PMA spent more % total sleep time periodic breathing at 36-40 weeks of PMA (18.1%; 7.7, 23.9 vs 2.1%; 0.6, 6.4) and 6 months of corrected age 0.9% (0.0, 3.3) vs 0.0% (0.0, 0.0). CONCLUSIONS: Percentage sleep time spent in periodic breathing did not decrease as infants born preterm approached term corrected age, when they were to be discharged home. High amounts of periodic breathing at 32-36 weeks of PMA was associated with high amounts of periodic breathing at term corrected age (36-40 weeks of PMA), and persistence of periodic breathing at 6 months of corrected age.

Heart rate surge at respiratory event termination in preterm and term born children with sleep disordered breathing.

BACKGROUND: Repetitive surges in heart rate (HR) at respiratory event termination underpin the altered autonomic HR control associated with sleep disordered breathing (SDB). As children born preterm are at greater risk of adverse cardiovascular outcomes, we aimed to determine whether the HR response to obstructive respiratory events was elevated compared to term-born children. METHODS: Fifty children (3-12 years) born preterm, were matched for SDB severity, age and gender with term born children. Multilevel modelling determined the effect of preterm birth and arousal on HR changes between a 10s baseline to the latter half of respiratory events and 15s post event during NREM and REM. RESULTS: 1203 events were analysed (NREM: term 380; preterm 383; REM: term 207; preterm 233). During NREM fewer events terminated in arousal in the preterm compared with term group (preterm 68%; term 84%; χ2 = 27.2, p < 0.001). There were no differences in REM. During NREM, HR was lower in the preterm group at all event phases, with and without associated arousals (P < 0.01 for all). % change in HR from baseline to post event was higher in the preterm compared with term group (preterm: median 23% IQR (12%,34%); term: 18% (10%,29%); p < 0.01) and late event to post event (preterm: 30% (21%, 32%); term 28% (20%,39%); p < 0.01) in events associated with arousals. CONCLUSION: The greater magnitude of surges in HR following respiratory events terminating with arousal in preterm born children, although small, occur repeatedly throughout the night and may contribute to adverse cardiovascular outcomes, although further studies are required.