Search

ObjectiveDiagnosis of obstructive sleep apnoea (OSA) is made on overnight polysomnography (PSG). Given the widespread availability of smartphone video technology, we aimed to develop and test a standardised scoring system for smartphone videos and compare these scores to PSG results.MethodsChildren aged 1–16 years undergoing PSG for suspected OSA were included. Parents were asked to take 1–2 min videos of the breathing they were concerned about. Videos were scored using a newly developed and tested tool on five components: inspiratory obstructive noises (1–4), presence of obstructive events (0–1), increased work of breathing (0–1), mouth breathing (0–1) and neck extension (0–1). Video scores and the Obstructive Apnoea Hypopnoea Index (OAHI) were compared using Spearman correlation. Sensitivity, specificity, positive predictive value and negative predictive value were calculated for different cut-off scores to achieve the best results.ResultsVideos from 43 children (28 men (65.1%), median age 5.7 years (range 2.6–14.0 years), median OAHI 3.8/hour (range 0–82 events/hour) were included. Nine children (20.9%) had a video score of 5 events/hour) .ConclusionWe have developed and validated a simple clinical tool (the Monash Obstructive Sleep Apnoea Video Score) to quantify abnormalities in breathing seen on short video recordings made on a smartphone. A low score rules out moderate–severe OSA and may be valuable in the triage of children with symptoms of OSA.

BACKGROUND Sleep disordered breathing (SDB) in typically developing (TD) children is associated with adverse cardiovascular effects. As children with Down syndrome (DS) are at increased risk for SDB, we aimed to compare the cardiovascular effects of SDB in children with DS to those of TD children with and without SDB. METHODS Forty-four children with DS (3-19 years) were age and sex matched with 44 TD children without SDB (TD-) and with 44 TD children with matched severity of SDB (TD+). Power spectral density was calculated from ECG recordings, for low frequency (LF), high frequency (HF), total power and the LF/HF ratio. RESULTS Children with DS had lower HF power, and higher LF/HF during sleep and when awake. There were no differences between groups for LF power. SpO2 nadir, average SpO2 drop and SpO2 > 4% drop were larger in the DS group compared to the TD+ group (p

Background Prone sleeping is used in preterm infants undergoing intensive care to improve respiratory function, but evidence suggests that this position may compromise autonomic cardiovascular control. To test this hypothesis, this study assessed the effects of the prone sleeping position on cardiovascular control in preterm infants undergoing intensive care treatment during early postnatal life. Methods Fifty-six preterm infants, divided into extremely preterm (gestational age (GA) 24-28 weeks, n = 23) and very preterm (GA 29-34 weeks, n = 33) groups, were studied weekly for 3 weeks in prone and supine positions, during quiet and active sleep. Heart rate (HR) and non-invasive blood pressure (BP) were recorded and autonomic measures of HR variability (HRV), BP variability (BPV), and baroreflex sensitivity (BRS) using frequency analysis in low (LF) and high (HF) bands were assessed. Results During the first 3 weeks, prone sleeping increased HR, reduced BRS, and increased HF BPV compared to supine. LF and HF HRV were also lower prone compared to supine in very preterm infants. Extremely preterm infants had the lowest HRV and BRS measures, and the highest HF BPV. Conclusions Prone sleeping dampens cardiovascular control in early postnatal life in preterm infants, having potential implications for BP regulation in infants undergoing intensive care.

The concept of personalised medicine is likely to revolutionise the treatment of adult obstructive sleep apnoea as a result of recent advances in the understanding of disease heterogeneity by identifying clinical phenotypes, pathophysiological endotypes, biomarkers and treatable traits. Children with the condition show a similar level of heterogeneity and paediatric obstructive sleep apnoea would also benefit from a more targeted approach to diagnosis and management. This review aims to summarise the adult literature on the phenotypes and endotypes of obstructive sleep apnoea and assess whether a similar approach may also be suitable to guide the development of new diagnostic and management approaches for paediatric obstructive sleep apnoea.

In adults there is a distinct gender difference in the prevalence and severity of sleep disordered breathing (SDB), however there have been limited studies examining the effects of gender in children with SDB. We aimed to compare the effects of gender on severity of SDB, blood pressure, sleep and respiratory characteristics, quality of life, behavior and executive function.We included 533 children aged 3-18 years, who underwent standard pediatric overnight polysomnography (PSG) between 2004 and 2016. Blood pressure was recorded prior to each study. Quality of life, behavior and executive function were assessed with parental questionnaires. Children were grouped by gender and SDB severity based on their obstructive apnea hypopnea index (OAHI) into non-snoring controls, Primary Snoring (PS) (OAHI≤1 event/h), Mild obstructive sleep apnea (OSA) (OAHI1-≤5 events/h) and moderate/severe (MS) OSA (OAHI5 events/h) and data compared with 2-way ANOVA.A total of 298 boys and 235 girls were studied. There were no differences in age, BMI z-score, SDB severity sleep characteristics or blood pressure between genders. Diastolic blood pressure was elevated in females with MS OSA compared to males (P 0.05). Quality of life, behavior and executive function scores were all elevated in the SDB groups compared to controls. Females with MS OSA exhibited more internalizing behavioral problems compared to males (59.2 ± 2.4 vs. 51.4 ± 2.3, P 0.05).In contrast to studies in adults, we identified no gender differences in the severity or consequences of SDB in children, other than females with moderate-severe OSA exhibiting more internalizing problems and higher diastolic blood pressure.

Geographic variation of paediatric tonsillectomy, with or without adenoidectomy, (A/T) has been described since the 1930s until today but no studies have investigated the factors associated with this variation. This study described the geographical distribution of paediatric A/T across the state of Victoria, Australia, and investigated area-level factors associated with this variation. We used linked administrative datasets capturing all paediatric A/T performed between 2010 and 2015 in Victoria. Surgery data were collapsed by patient residence to the level of Local Government Area. Regression models were used to investigate the association between likelihood of surgery and area-level factors. We found a 10.2-fold difference in A/T rates across the state, with areas of higher rates more in regional than metropolitan areas. Area-level factors associated with geographic variation of A/T were percentage of children aged 5–9 years (IRR 1.07, 95%CI 1.01–1.14, P = 0.03) and low English language proficiency (IRR 0.95, 95% CI 0.90–0.99, P = 0.03). In a sub-population analysis of surgeries in the public sector, these factors were low maternal educational attainment (IRR 1.09, 95% CI 1.02–1.16, P P = 0.048). Identifying areas of focus for improvement and factors associated with geographic variation will assist in improving equitable provision of paediatric A/T and decrease variability within regions.

OBJECTIVE To describe the contemporary epidemiology of paediatric adenotonsillectomy in an Australian setting, examine the incidence rate over 2010-2015 and investigate factors associated with inter-hospital transfer. DESIGN Retrospective population-based study. SETTING Multicentre study in the state of Victoria, Australia. PARTICIPANTS From the Victorian Admitted Episodes Dataset, which included all patients aged 0-19 years who underwent adenoidectomy and/or tonsillectomy in Victoria, Australia between 2010 and 2015. MAIN OUTCOME MEASURES Annual incidence rate, hospital volume, inter-hospital transfer. RESULTS Between 2010 and 2015, 59 008 patients underwent 61 281 procedures, with highest number performed in males (52.7%), children aged under 10 years (73.5%) and in the higher socioeconomic groups (24.6% in quintile 4 and 23.2% in quintile 5). Seventy-five cases (0.12%) resulted in inter-hospital transfer, which was significantly associated with young age (under 5 years). More than a third of hospitals (35.7%) performed an average rate of

Sleep-disordered breathing (SDB) in children has been associated with craniofacial characteristics. Facial photography provides a radiation-free means of estimating facial morphology through facial landmark analysis. Our objective was to determine whether facial analysis provides information about SDB severity. Specifically, we aimed to determine whether facial photographic measurements differ with SDB status, or were associated with SDB severity. Single-center cohort of children undergoing overnight polysomnography for assessment of SDB; non-snoring controls were recruited from the community to undergo polysomnography. Standardized front and lateral facial photographs were analyzed according to previously published protocols. Multivariate analysis of variance was used to determine if facial measurements differed between SDB groups and controls. Linear regression was performed to determine if facial measurements were associated with SDB severity. Seventy-eight children (9 controls, 17 primary snoring, 23 mild SDB, 27 moderate-severe SDB) were included. Facial angles and upper-to-lower face height ratio showed variation between SDB groups (p = 0.038). Facial measurements related to SDB severity, specifically an increased cervicomental angle (p = 0.001), and increased lower-to-upper face height (p = 0.006). Evaluation of craniofacial features using clinical photography is feasible. Preliminary investigation shows some relationship with SBD severity. Further work is needed to determine if craniofacial photography is useful for stratifying SDB risk in children.

BACKGROUND Both preterm birth and sleep disordered breathing (SDB) affect sleep in children. We compared the effects of SDB on sleep macro-architecture and micro-architecture in children born preterm (N = 50) and children born at term (N = 50). We hypothesized that sleep would be more disrupted in children born preterm. METHODS Polysomnographic studies matched for age (3-12 years) and SDB severity were analyzed. Sleep macro-architecture was assessed using standard criteria and micro-architecture was evaluated using spectral analysis of the electroencephalogram and slow wave activity (SWA) calculated for each sleep stage across the night. RESULTS Ex-preterm children (gestational age 29.3 ± 3.6 weeks, mean ± standard error of the mean) were not different from controls for demographic or respiratory parameters or sleep macro-architecture. Theta power in N2 tended to be higher for F4 (p

BACKGROUND AND OBJECTIVE Frequent central apnoeas are sometimes observed in healthy children; however; the pathophysiology of an elevated central apnoea index (CAI) is poorly understood. A raised CAI may indicate underlying ventilatory control instability (i.e. elevated loop gain, LG) or a depressed ventilatory drive. This pilot study aimed to compare LG in otherwise healthy children with an elevated CAI to healthy controls. METHODS Polysomnographic recordings from children (age > 6 months) without obstructive sleep apnoea and with a CAI > 5 events/h (n = 13) were compared with age and gender-matched controls with a CAI < 5 events/h (n = 13). Spontaneous sighs were identified during non-rapid eye movement (NREM) sleep, and breath-breath measurements of ventilation were derived from the nasal pressure signal. A standard model of ventilatory control (gain, time constant and delay) was used to calculate LG by transforming ventilatory fluctuations seen in response to a sigh into a ventilatory-drive signal that best matches observed ventilation. RESULTS The high CAI group had an elevated LG (median = 0.36 (interquartile range, IQR = 0.35-0.53) vs 0.28 (0.23-0.36); P ≤ 0.01). There was no difference in either the time constant (P = 0.63) or delay (P = 0.29) between groups. Elevated LG observed in the high CAI group remained after accounting for degree of hypoxia (average oxygen saturation (SpO2 ) during each analysable window) experienced (0.40 (0.30-0.53) vs 0.25 (0.23-0.37); P = 0.04). CONCLUSION An elevated CAI in otherwise healthy children is associated with a raised LG compared to matched controls with a low CAI, irrespective of level of hypoxia. This relative ventilatory instability helps explain the high CAI and may ultimately be able to help guide diagnosis and management in patients with high CAI.

Down syndrome (DS), the most common human chromosomal malformation, has an estimated annual incidence of one in 1000 live births worldwide. Sleep problems are common in children with DS, reported by parents in up to 65% of school-aged children, significantly higher rates than in typically developing (TD) children. Problems include difficulty in sleep initiation and maintenance together with obstructive sleep apnoea (OSA) which affects up to over 90%, of DS children compared with 1-5% in the general paediatric population. Any sleep problem has the potential to exert significant negative effects on daytime behaviour, learning and quality of life in TD children and there is now a growing body of evidence that children with DS are similarly affected. In addition to adverse effects on daytime functioning, OSA has adverse effects on the cardiovascular system and this is a particularly significant issue given the high rates of hypertension and premature cardiac disease in people with DS. This review discusses the effects of sleep problems and OSA on daytime functioning and cardiovascular function in children with DS and evidence of the effectiveness of treatment in improving outcomes and quality of life for these children.

Allergic rhinitis (AR) is a common risk factor for sleep disordered breathing (SDB) in children. Allergy to pollen is a trigger for allergic rhinitis, causing nasal inflammation, upper airway congestion and obstruction. We aimed to determine if the pollen count on the day of diagnostic polysomnography for SDB affected the result. Children (3–18 years; n = 90) who participated in research studies between 1 October and 31 December, when daily regional pollen counts were available, in the years 2005–2016 were eligible for inclusion. All children underwent overnight polysomnography for assessment of SDB severity. Pollen was categorised as grass or other pollen. Multiple stepwise linear regression was performed to determine whether the pollen count for that day, a diagnosis of asthma, age, and BMI-z-score were determinants of respiratory parameters measured on polysomnography, including the obstructive apnoea hypopnoea index (OAHI), SpO2 nadir, average SpO2 drop, SpO2 4% (ODI4), and average transcutaneous CO2 (TCM). Sixteen/90 children had AR. In children with AR, an increase in grass pollen of 1 grain/m3 predicted an increase in OAHI of 0.2 events/h, ODI4 of 0.18 times/h, SpO2

BACKGROUND Periodic breathing (PB) is common in preterm infants. We aimed to characterize the contribution of ventilatory control instability to the presence and persistence of PB longitudinally. METHODS Infants born between 28 and 32 weeks of gestation were studied using daytime polysomnography at: 32-36 weeks postmenstrual age (PMA) (N = 32), 36-40 weeks PMA (N = 20), 3 months corrected age (CA) (N = 18) and 6 months CA (N = 19). Loop gain, a measure of sensitivity of the ventilatory control system, was estimated by fitting a mathematical model to ventilatory patterns associated with spontaneous sighs. RESULTS The time spent in PB decreased from 32-36 weeks PMA to 6 months CA (P = 0.005). Across all studies, studies with PB (N = 62) were associated with higher loop gain compared to those without PB (N = 23) (estimated marginal mean ± SEM: 0.445 ± 0.01 vs 0.388 ± 0.02; P = 0.020). A threshold of loop gain >0.415 (measured at 32-36 weeks PMA) provided a sensitivity of 86% and a specificity of 75% to detect the presence of PB at 6 months CA. CONCLUSIONS The course of PB in preterm infants is related to changes in loop gain. Higher loop gain at 32-36 weeks PMA was associated with a greater risk of persistent PB at 6 months CA. IMPACT The developmental trajectory of periodic breathing and its relationship to ventilatory control instability is currently unclear. Unstable ventilatory control is a determinant of periodic breathing in preterm infants up to 6 months corrected age. Infants who display greater ventilatory control instability at 32-36 weeks postmenstrual age may be at increased risk of persistent periodic breathing at 6 months corrected age. Assessment of ventilatory control stability may assist in the early identification of infants at risk of persistent periodic breathing and its potential adverse effects.

Introduction Tonsillectomy and/or adenoidectomy (A/T) is first-line treatment for paediatric obstructive sleep apnoea. Provision of A/T is of critical interest to sleep medicine practitioners. Geographic variation of A/T has been described since the 1930s, but no studies have investigated the reasons behind it. This study aimed to describe the geographical distribution of paediatric A/T and investigate area-level factors associated with this variation. Methods Linked administrative datasets captured a complete state-wide population of paediatric A/T performed between 2010 and 2015. Surgery data were collapsed by patient residence to the level of Local Government Area. Regression models were used to investigate the association between likelihood of surgery and area-level factors. Results There was a 10.2-fold difference in A/T rates across the state, with higher rates more common in regional than metropolitan areas. Area-level factors associated with geographic variation that increased the likelihood of A/T were a higher proportion of children aged 5–9 years (IRR 1.07, 95%CI 1.01–1.14, P=0.03), while a higher proportion with low English-language proficiency (IRR 0.95, 95%CI 0.90–0.99, P=0.03) decreased the likelihood of A/T. In a sub-population of public sector surgeries, low maternal educational attainment increased the likelihood of A/T (IRR 1.09, 95%CI 1.02–1.16, P Discussion Significant variation in surgery rates exist by geographical area state-wide, with factors analysed having significant impacts. These findings suggest that improved surgical access and better community understanding of the indications for A/T could decrease geographic variation.

Background Children with Down syndrome (DS) are at increased risk for sleep disordered breathing (SDB), which can have adverse effects on the cardiovascular system. In adults with SDB, nocturnal dipping of heart rate (HR) and blood pressure (BP) is reduced, and this is associated with an increased risk of future cardiovascular events. We aimed to compare nocturnal dipping of HR and pulse transit time (PTT) (a surrogate inverse measure of BP change) in children with DS and SDB to those of typically developing (TD) children with and without SDB. Methods 19 children with DS (3–18 years) were age and sex matched with 19 TD children without SDB (TD-) and with 19 TD children with matched severity of SDB (TD+). Nocturnal dipping was assessed as the percentage change in HR and PTT from wake before sleep onset to total sleep, N2, N3 and REM sleep across the night and to the first cycle of sleep. Results Children with DS exhibited reduced nocturnal dipping of HR during total sleep, N2, N3 and REM sleep and increased PTT (reduced BP dipping) in N2 sleep. Fewer children with DS exhibited a greater than 10% fall in HR between wake and N2 or REM sleep compared to TD+ children. Conclusions Our findings demonstrate significantly reduced nocturnal dipping of HR in children with DS compared to TD children matched for SDB severity, suggesting SDB has a greater cardiovascular effect in these children. Further studies are required to fully understand the mechanisms involved and to assess if treatment of SDB improves nocturnal dipping.

Objectives Children with Down syndrome (DS) are recommended to undergo polysomnography (PSG) by the age of four years due to the high prevalence of obstructive sleep apnea (OSA) in this group, but compliance is incomplete. To further understand referral patterns for PSG in this condition, we aimed to compare demographics, PSG results, OSA severity, behavior, daytime functioning and quality of life (QOL) between children with DS referred for sleep testing and those recruited from the community. Study design Children 3–19 years with DS was included: 20 referred clinically for assessment of OSA and 24 volunteers from the community. Demographic and anthropometric data, PSG parameters, sleep-related symptoms and QOL, behavior and daytime functioning were compared between groups. Results OSA severity did not differ between groups: 50% of the clinical and 42% of the community group had moderate/severe OSA. The clinical group had a higher weight z-score, BMI z-score, waist and hip circumference and neck-to-waist ratio. Questionnaire scores for daytime functioning, behavior and QOL were not different between groups. Conclusions Despite not being referred for clinical sleep assessment, 42% of children with DS recruited from the community had moderate/severe OSA. There was no difference in the QOL, behavior, daytime functioning and sleep symptoms questionnaires although the clinical group had a higher BMI-Z score and overt signs of obesity. These findings underscore the importance of PSG screening of all children with DS.

Aims To review the contributions of Australian and New Zealand research on adenotonsillectomy for the treatment of symptoms of obstructed breathing during sleep (sleep disordered breathing, SDB) in children. Methods A search of the scientific literature was conducted using the MEDLINE (Ovid), PubMed and Scopus databases in August 2020. The following search string was used: (tonsillectomy OR adenoidectomy OR adenotonsillectomy) AND (paediatric OR child) AND (Australia OR New Zealand). A focused internet search was additionally conducted on Google to identify grey literature. Results Researchers from Australia and New Zealand have made important contributions to the understanding and improvement of adenotonsillectomy (AT), including its epidemiology, cost, surgical techniques and peri-operative safety. Rates of AT have fluctuated over the years, becoming the most common paediatric surgery today, with SDB becoming the most common indication. Research in Australia and New Zealand has also focussed on the impact of AT on quality of life, and behaviour, neurocognition and cardiovascular sequelae. Conclusions Australian and New Zealand researchers have played a significant role in understanding the epidemiology and improving the safety of AT. There are promising directions in research still to come, including better understanding of the reasons for geographical variation in surgery rates, developing more efficient pre-operative risk assessment tools and alternative treatment options for mild OSA.

* Abbreviations: NEC — : necrotizing enterocolitis NIRS — : near-infrared spectroscopy In this issue of Pediatrics, Howarth et al1 report on a completed longitudinal study of 46 preterm infants born at 15 million infants are born preterm (

Key points Sleep disordered breathing (SDB) affects 4-11% of children and is associated with adverse neurocognitive, behavioural and cardiovascular outcomes, including reduced autonomic control. The relationship between heart rate variability (HRV; a measure of autonomic control) and age found in non-snoring control children was absent during sleep in children with SDB. Age significantly predicted increasing cerebral oxygenation during wake in non-snoring control children, whereas during sleep, HRV significantly predicted decreasing cerebral oxygenation. Cerebral oxygenation was not associated with either age or HRV in children with SDB during both wake and sleep. SDB significantly disrupts the normal maturation of autonomic control and the positive association between autonomic control and cerebral oxygenation found in non-snoring children, and we speculate that the dampened autonomic control exhibited by children with SDB may have an attenuating effect on cerebral autoregulation via the moderating influence of HRV on cerebral blood flow. Abstract The repetitive episodes of hypoxia that are features of sleep disordered breathing (SDB) in children are associated with alterations in autonomic control of heart rate in an age-dependent manner. We aimed to relate heart rate variability (HRV) parameters to age and measures of cerebral oxygenation in children (3-12 years old) with SDB and non-snoring controls. Children (SDB, n = 117; controls, n = 42; 3-12 years) underwent overnight polysomnography. Total (TP), low- (LF) and high-frequency (HF) power, tissue oxygenation index (TOI) and fractional tissue oxygen extraction (FTOE) were analysed during wake and sleep. Pearson's correlations determined the association between age and HRV parameters, and multiple linear regressions between HRV, age and cerebral oxygenation parameters. During wake, age had a positive association with LF power, reflecting increased parasympathetic and sympathetic activity with increasing age for both control and SDB groups. This association was also evident during sleep in controls, but was absent in children with SDB. In controls, during wake TOI had a positive, and FTOE a negative association with age. During sleep, TP, LF and HF power were significant, negative determinants of TOI and positive determinants of FTOE. These associations were not seen in children with SDB during wake or sleep. SDB disrupts the normal maturation of the autonomic control of heart rate and the association between HRV and cerebral oxygenation exhibited by non-snoring control children of primary school age. These results highlight the impact SDB has on cardiovascular control and the potential impact on adverse cardiovascular outcomes.

Background We aimed to investigate the relationship between sleep quality, mood and health-related quality of life (HRQOL) in children with CF and controls. Methods Children (7–12years) and adolescents (13–18years) with CF and controls completed sleep evaluation: overnight oximetry and 14days of actigraphy. Age-appropriate questionnaires assessed mood (Children's Depression Inventory; CDI or Beck's Depression Inventory), HRQOL (CF Questionnaire-Revised; CFQ-R or PedsQL), and sleepiness (Pediatric Daytime Sleepiness Scale). Results 87 CF and 55 controls recruited. Children with CF had poorer sleep quality, more sleepiness and lower mood than controls, with a negative correlation between mood score and sleep efficiency. Sleepiness score was predictive of mood score and multiple CFQ-R domains. Adolescents with CF also demonstrated poorer sleep and more sleepiness than controls, but no difference in mood. Reduced sleep quality predicted lower CFQ-R scores. No correlation between sleep, mood or HRQOL in controls. Conclusions In children and adolescents with CF, impaired sleep quality is associated with lower mood and HRQOL in an age-specific manner. Future research will aid understanding of effective strategies for prevention and treatment of mood disorders and sleep disturbance in children with CF.

Good quality sleep of sufficient duration is vital for optimal physiological function and our health. Sleep deprivation is associated with impaired neurocognitive function and emotional control, and increases the risk for cardiometabolic diseases, obesity and cancer. Sleep develops during fetal life with the emergence of a recognisable pattern of sleep states in the preterm fetus associated with the development, maturation and connectivity within neural networks in the brain. Despite the physiological importance of sleep, surprisingly little is known about how sleep develops in individuals born preterm. Globally, an estimated 15 million babies are born preterm (

Childhood sleep-disordered breathing ranges in severity from primary snoring to obstructive sleep apnea and is associated with behavioral and neurocognitive deficits. It remains unknown why children with primary snoring, who do not experience peripheral oxygen desaturation or sleep fragmentation, experience similar daytime deficits as those with obstructive sleep apnea or why effects are age-dependent.To examine cerebral tissue oxygenation and oxygen extraction as an explanation for daytime deficits in children with primary snoring.Children referred for suspected sleep-disordered breathing and nonsnoring control subjects underwent overnight polysomnography with near-infrared spectroscopy. Children were categorized into 3- to 6-year (n = 87) and 7- to 12-year (n = 72) old groups, and according to the obstructive apnea-hypopnea index into primary snoring (≤1 event/h), mild (1-5 events/h), and moderate/severe obstructive sleep apnea (5 events/h). Cognitive and behavioral performance were assessed.In the 3- to 6-year group, there were no differences in cerebral oxygenation or oxygen extraction between severity groups. In the 7- to 12-year group, cerebral oxygenation was significantly lower, although these differences were small, in control subjects versus primary snoring during quiet wakefulness before sleep onset, N1, and REM. Oxygen extraction was significantly higher in control subjects versus primary snoring during N1 sleep, with no differences between primary snoring and obstructive sleep apnea groups. Cerebral oxygenation was not associated with cognitive performance in either age group or behavior in the 3- to 6-year group; however, it was associated with behavior in the school-aged children.Children with sleep-disordered breathing are able to maintain cerebral oxygenation, and the small changes observed are not related to cognitive deficits. However, in older children these differences were related to behavioral measures.

Advances in neonatal care have improved the survival rates of preterm infants, however, the likelihood of brain injury and neurodevelopmental disability remains a significant problem. Whilst the etiology of preterm brain injury is complex, impairments in the cardio- and cerebro-vascular function have been implicated. During infancy, sleep is vital for brain development. However, instabilities in cardio- and cerebro-vascular function are most marked during sleep. Sleeping position is an important part of a safe sleeping environment. Prone sleeping increases the risk of sudden infant death syndrome and is associated with reduced blood pressure, cerebral oxygenation and impaired autonomic cardiovascular control in infants born at term. Importantly, these effects are amplified by preterm birth. Hospitalized preterm infants are often slept in the prone position to improve respiratory function. However, there is little consensus regarding the sustained benefits of prone sleeping in this population. In light of the impaired cardio- and cerebro-vascular function during prone sleeping in term and preterm infants after hospital discharge, the likely adverse effects of prone sleeping in hospitalized preterm infants are concerning. This review examines the cardiovascular and cerebrovascular effects of prone sleeping in infants born at term, those born preterm after term equivalent age and whilst hospitalized.

Background Periodic breathing and short apnoeas are common in infants, particularly those born preterm, but are thought to be benign. The aim of our study was to assess the incidence and impact of periodic breathing and apnoea on heart rate, oxygen saturation and brain tissue oxygenation index (TOI) in infants born at term and preterm over the first 6 months after term equivalent age. Study design 19 infants born at (38–42 weeks gestational age) and 24 preterm infants (born at 27–36 weeks gestational age) were studied at 2–4 weeks, 2-3 months and 5-6 months post-term corrected age during sleep. Periodic breathing episodes were defined as ≥3 sequential apnoeas each lasting ≥3 s and apnoeas as ≥3 s in duration. Results Mean duration of periodic breathing episodes was longer in term infants than in preterm infants at 2–4 weeks (P

Background Preterm-born (PT) children have an increased risk for obstructive sleep apnoea (OSA) and adverse cardiovascular outcomes. Respiratory events elicit acute changes in heart rate (HR) in term-born (T) children. Whether this response is augmented in PT children with OSA remains unclear. We aimed to analyse the HR response during obstructive respiratory events in PT children with OSA. Methods Nine PT children (3–12 y), were matched for obstructive apnoea hypopnoea index (OAHI), age and gender with T children. Beat-to-beat HR was averaged 10s before, during and the peak after (post) each obstructive event, and peak HR was expressed as percentage change. Results 323 obstructive events in PT and 376 in T children were identified, consisting of 681 hypopnoeas (PT 320; T 361) and 18 apnoeas (PT 3; T 15). There were insufficient apnoeas in the PT group for analysis. For hypopnoeas during total sleep, the PT group had significantly lower HR compared to the T group before median 81bpm (IQR 74–87) vs 88 bpm (79–99); p Conclusion Although HR was lower during obstructive hypopnoeas in preterm compared with term-born children, the post event surge was significantly higher. This heightened HR response to respiratory events in children born preterm may underlie the worse cardiovascular outcomes in these children.

Introduction Immature cardio-respiratory control in preterm infants often manifests as periodic breathing (PB). A number of pre- and postnatal demographic and clinical factors, such as exposure to maternal smoking, respiratory support and medications may affect respiratory control. We aimed to identify specific factors affecting the frequency of PB in preterm infants before hospital discharge. Methods 32 healthy preterm infants (14M, 18F) born between 28–32 weeks of gestational age were studied for 2–3 hours with daytime polysomnography at 31–36 weeks (when they had been off respiratory support for ≥ 3 days). % sleep time spent in PB was calculated. Variables are reported as median (IQR) and were compared with Mann-Whitney U and Chi square tests, between infants who spent greater or less than the median time in PB. Results 29 infants (91%) exhibited at least one episode of PB. Median sleep time in PB was 9.6% (IQR 0.6, 15.6%). Infants with time in PB above the median spent fewer days on respiratory support (4.0 days (1.0, 7.5) vs 9.0 (6.5, 21.5) days, p=0.035), and were younger (post-menstrual age 33.8 (IQR 32.1, 34.5) vs 35.1 (IQR 32.4, 35.6) weeks, p= 0.039). Conclusions Of the large number of maternal and infant demographic and clinical variables examined, we found few associations with the time preterm infants spent in PB. Greater % time spent in PB was associated with earlier discontinuation of respiratory support, however larger studies are required to confirm these findings and to investigate if there are any long-term consequences.

Background Sleep disturbance is common in children with cystic fibrosis (CF) however there are limited studies investigating the causes for poor sleep quality. In a cross sectional observational study we aimed to evaluate the clinical correlates of sleep disturbance in this population. Methods Children with CF (7-18years) free from pulmonary exacerbation completed medical review, overnight oximetry, the OSA-18 and 14days of actigraphy recordings with a sleep diary. Results In addition to FEV1 Conclusions Reduced sleep quality in children with CF is related to lung health and co-morbidities. However, family characteristics and poor sleep hygiene in the child were also associated with sleep disturbance. Optimal management of CF would seem to be the primary intervention to alleviate children's sleep disturbance, however our data raises additional targets for attempts to improve sleep.

Background In both adults and children, obstructive sleep apnea (OSA) has significant adverse cardiovascular consequences. In adults, sleeping position has a marked effect on the severity of OSA; however, the limited number of studies conducted in children have reported conflicting findings. We aimed to evaluate the effect of sleeping position on OSA severity and the cardiovascular consequences in preschool-aged children. Methods This was a retrospective analysis of children (3–5 years of age) diagnosed with OSA (n = 75) and nonsnoring controls (n = 25). Sleeping position was classified as supine, semi-supine, left lateral, right lateral, prone, and semi-prone by using video recordings during one night of attended polysomnography. OSA severity and cardiovascular parameters were compared between the positions. Results All children spent significantly more sleep time in the supine position than in any other position. The obstructive apnea-hypopnea index was higher in the supine position than in the other sleeping positions during NREM (p Conclusions This study identified that preschool-aged children, whether nonsnoring controls or children with OSA, predominately sleep in the supine position, and OSA was more severe in the supine position. We suggest that to avoid the supine sleep position, positional therapy has the potential to ameliorate OSA severity, and the known cardiovascular consequences.

BackgroundFetal growth restriction (FGR) is associated with increased perinatal mortality and long-term cardiovascular and neurodevelopmental sequelae. We hypothesized that FGR impacts on the development of autonomic heart rate and blood pressure control, contributing to unfavorable short- and long-term outcomes following FGR.MethodsWe studied 25 preterm FGR and 22 preterm and 19 term appropriate for gestational age (AGA) infants. Preterm neonates were studied on postnatal day 1, and all infants were studied at 1 and 6 months post-term age. To investigate autonomic cardiovascular control, we examined heart rate variability (HRV) and baroreflex sensitivity using spectral power and transfer-function analyses.ResultsPreterm FGR neonates exhibited higher heart rates and reduced HRV compared with preterm AGA controls on postnatal day 1. No significant differences were found between the three groups at 1 or 6 months post-term age.ConclusionPreterm FGR neonates display compromised HRV on postnatal day 1, which may suggest increased vulnerability to circulatory instability. This may predispose these neonates to systemic and cerebral hypoperfusion and increase the risk of long-term neurodevelopmental sequelae. Differences were no longer found at 1 and 6 months post-term age, suggesting that the maturation of autonomic cardiovascular control may be preserved following FGR.

To measure sleep patterns and quality, objectively and subjectively, in clinically stable children with cystic fibrosis (CF) and healthy control children, and to examine the relationship between sleep quality and disease severity.Clinically stable children with CF and healthy control children (7-18 years of age) were recruited. Sleep patterns and quality were measured at home with actigraphy (14 days). Overnight peripheral capillary oxygen saturation was measured via the use of pulse oximetry. Daytime sleepiness was evaluated by the Pediatric Daytime Sleepiness Scale (PDSS) and subjective sleep quality by the Sleep Disturbance Scale for Children and Obstructive Sleep Apnea-18.A total of 87 children with CF and 55 control children were recruited with no differences in age or sex. Children with CF had significantly lower total sleep time and sleep efficiency than control children due to frequent awakenings and more wake after sleep onset. In children with CF, forced expiratory volume in 1 second and overnight peripheral capillary oxygen saturation nadir correlated positively with total sleep time and sleep efficiency and negatively with frequency of awakenings and wake after sleep onset. Patients with CF had significantly greater Sleep Disturbance Scale for Children (45 vs 35; P .001), Obstructive Sleep Apnea-18 (35 vs 24; P .001), and PDSS scores (14 vs 11; P .001). There was a negative correlation between PDSS and forced expiratory volume in 1 second (r = -0.23; P .05).Even in periods of clinical stability, children with CF get less sleep than their peers due to more time in wakefulness during the night rather than less time spent in bed. Objective measures of sleep disturbance and subjective daytime sleepiness were related to disease severity. In contrast, parents of children with CF report high levels of sleep disturbance unrelated to disease severity.

It is currently believed that babies die suddenly and unexpectedly during sleep when they fail to respond appropriately to a life-threatening challenge. The major risk factors, which include prone sleeping, head covering, exposure to cigarette smoke, and being born prematurely, all impair cardiorespiratory control and depress arousal responses from sleep. Conversely, those factors that reduce the risk, including breastfeeding, immunization, and sucking on a pacifier, increase these protective responses. Understanding the physiological mechanisms that likely underpin risk and protective factors is important so that parents and health professionals are aware that safe sleeping messages are supported by sound physiological evidence.

BACKGROUND AND OBJECTIVE The contribution of non-anatomical factors, such as ventilatory control instability (i.e. LG), to the pathogenesis of obstructive SDB in children is unclear. Therefore, we aimed to identify the relationship between LG and severity of SDB, demographic, anthropometric and anatomical characteristics in a clinically representative cohort of children. METHODS Children (aged 3-18 years) with various severities of SDB (n = 110) and non-snoring controls (n = 36) were studied. Children were grouped according to their OAHI. Anthropometric and upper airway anatomical characteristics were measured. Spontaneous sighs were identified on polysomnography and LG, a measure of the sensitivity of the negative feedback loop that controls ventilation, was estimated by fitting a mathematical model of ventilatory control to the post-sigh ventilatory pattern. RESULTS There was no difference in LG between controls and any of the SDB severity groups. However, LG was significantly lower in children with larger tonsils (tonsil grade 4) compared with children with smaller tonsils (tonsil grade 1) (median LG (range): 0.25 (0.20-0.42) vs 0.32 (0.25-0.44); P = 0.009) and in children with a modified Mallampati score of class III/IV compared with class I (0.28 (0.24-0.33) vs 0.37 (0.27-0.44); P = 0.009). CONCLUSION A direct relationship was not found between the severity of paediatric SDB and LG. However, an altered ventilatory control sensitivity may contribute to SDB in a subgroup of children depending on their degree of anatomical compromise of the airway.

Study ObjectivesPreterm infants undergoing intensive care are often placed prone to improve respiratory function. Current clinical guidelines recommend preterm infants are slept supine from 32 weeks’ postmenstrual age, regardless of gestational age at birth. However, respiratory function is also related to gestational and chronological ages and is affected by sleep state. We aimed to identify the optimal timing for adopting the supine sleeping position in preterm infants, using a longitudinal design assessing the effects of sleep position and state on cardiorespiratory stability.MethodsTwenty-three extremely (24–28 weeks’ gestation) and 33 very preterm (29–34 weeks’ gestation) infants were studied weekly from birth until discharge, in both prone and supine positions, in quiet and active sleep determined by behavioral scoring. Bradycardia (heart rate ≤100 bpm), desaturation (oxygen saturation ≤80%), and apnea (pause in respiratory rate ≥10 s) episodes were analyzed.ResultsProne positioning in extremely preterm infants reduced the frequency of bradycardias and desaturations and duration of desaturations. In very preterm infants, prone positioning only reduced the frequency of desaturations. The position-related effects were not related to postmenstrual age. Quiet sleep in both preterm groups was associated with fewer bradycardias and desaturations, and also reduced durations of bradycardia and desaturations in the very preterm group.ConclusionsCardiorespiratory stability is improved by the prone sleep position, predominantly in extremely preterm infants, and the improvements are not dependent on postmenstrual age. In very preterm infants, quiet sleep has a more marked effect than the prone position. This evidence should be considered in individualizing management of preterm infant positioning.

Study ObjectivesSleep disordered breathing (SDB) in children has significant effects on daytime functioning and cardiovascular control; attributed to sleep fragmentation and repetitive hypoxia. Associations between electroencephalograph (EEG) spectral power, autonomic cardiovascular control and cerebral oxygenation have been identified in adults with SDB. To date, there have been no studies in children. We aimed to assess associations between EEG spectral power and heart rate variability as a measure of autonomic control, with cerebral oxygenation in children with SDB.MethodsOne hundred sixteen children (3–12 years) with SDB and 42 controls underwent overnight polysomnography including measurement of cerebral oxygenation. Power spectral analysis of the EEG derived from C4-M1 and F4-M1, quantified delta, theta, alpha, and beta waveforms during sleep. Multiple regression tested whether age, SDB severity, heart rate (HR), HR variability (HRV), and cerebral oxygenation were determinants of EEG spectral power.ResultsThere were no differences in EEG spectral power derived from either central or frontal regions for any frequency between children with different severities of SDB so these were combined. Age, HR, and HRV low frequency power were significant determinants of EEG spectral power depending on brain region and sleep stage.ConclusionThe significant findings of this study were that age and autonomic control, rather than cerebral oxygenation and SDB severity, were predictive of EEG spectral power in children. Further research is needed to elucidate how the physiology that underlies the relationship between autonomic control and EEG impacts on the cardiovascular sequelae in children with SDB.

Study objectives Both central and obstructive respiratory events are features of sleep disordered breathing. The repetitive hypoxia associated with obstructive events is believed to underpin the adverse neurocognitive and cardiovascular sequelae of this disorder, however whether central events contribute to this has not been investigated. To compare changes in cerebral and peripheral oxygenation, blood pressure and heart rate, associated with central and obstructive events in children aged 3-6 and 7-12 years. Methods Sixty children referred for suspected sleep disordered breathing underwent overnight polysomnography. Beat-by-beat analysis determined changes from baseline in cerebral oxygenation, peripheral oxygen saturation, fractional tissue oxygen extraction, pulse transit time (a surrogate measure of blood pressure change), and heart rate, associated with central and obstructive respiratory events, during NREM and REM sleep. Results Eight hundred ninty-two events were analyzed: 493 central and 399 obstructive. Central events had a greater % change from baseline in cerebral oxygenation and heart rate nadir compared with obstructive events and these were greater in NREM compared with REM sleep. The 3- to 6-year-old children experienced a greater % change in TOI compared with the 7-12 year olds, while % change in heart rate was greater in 7-12 year olds. Conclusion Central respiratory events had similar falls in cerebral oxygenation and heart rate to obstructive events and should be considered when examining the sequelae of sleep disordered breathing, particularly as central events are common in children with sleep disordered breathing.

Frequency of dips below 90% on overnight oximetry can be used to estimate severity of obstructive sleep apnea (OSA) in children. Movement can result in artifact on oximetry recordings. Clinicians may therefore be tempted to remove periods of wakefulness from the recording to improve accuracy, but removal of such periods of potential artifact is time consuming. The aim of this study was to determine whether removing periods of wakefulness had a significant impact on analysis of overnight oximetry. Children aged 2-18 years (N = 108) with suspected OSA underwent overnight simultaneous oximetry and actigraphy at home on a single night. Actigraphy defined awake periods were "trimmed" from the oximetry data and oximetry variables compared between full and trimmed analysis. There was a statistically but not clinically significant difference between the full and trimmed data for mean SpO2 , minimum SpO2 , 4% desaturation index, and 3% desaturation index (all P

Aim This study aims to determine whether demographic or clinical factors predict obstructive sleep apnoea (OSA) severity in Australian children. Methods Demographic details and medical histories of 301 Australian children (3–17 years old) referred for assessment of OSA were examined retrospectively. Children underwent overnight polysomnography and were classified as having primary snoring (PS) (obstructive apnoea hypopnoea index (OAHI) ≤ 1 event per hour; n = 150), mild OSA (>1 OAHI ≤ 5 events per hour; n = 76) or moderate/severe (MS) OSA (OAHI > 5 events per hour; n = 75). Information obtained from parent-report questionnaire determined the predictive value of the following factors for determining OSA severity: gender, ethnicity, body mass index, asthma and/or allergic rhinitis, socio-economic status and parental smoking status (mother/father/both). Chi-squared analyses were used to compare the distribution of the demographic and clinical factors across the three groups. Statistically significant risk factors were subsequently entered into logistic regression analysis. Results Ethnicity and parental smoking were significant risk factors for MS OSA. Children with non-Caucasian ethnicity were 36% more likely than Caucasian children to be diagnosed with MS OSA than PS (P = 0.002). Children with fathers who smoked were 53% more likely to have MS OSA than PS compared with those with fathers who did not smoke (P = 0.008). Obesity was associated with OSA severity in primary school-aged children only. Gender, socio-economic status and history of asthma and/or allergic rhinitis were not risk factors. Conclusions Non-Caucasian ethnicity, paternal smoking and obesity in older children were associated with an increased risk of polysomnography-confirmed MS OSA in Australian children.

Intrauterine growth restriction (IUGR) refers to the situation where a fetus does not grow according to its genetic growth potential. One of the main causes of IUGR is uteroplacental vascular insufficiency. Under these circumstances of chronic oxygen and nutrient deprivation, the growth-restricted fetus often displays typical circulatory changes, which in part represent adaptations to the suboptimal intrauterine environment. These fetal adaptations aim to preserve oxygen and nutrient supply to vital organs such as the brain, the heart, and the adrenals. These prenatal circulatory adaptations are thought to lead to an altered development of the cardiovascular system and "program" the fetus for life long cardiovascular morbidities. In this review, we discuss the alterations to cardiovascular structure, function, and control that have been observed in growth-restricted fetuses, neonates, and infants following uteroplacental vascular insufficiency. We also discuss the current knowledge on early life surveillance and interventions to prevent progression into chronic disease.

Introduction Children with Down Syndrome (DS) are at increased risk for sleep disordered breathing (SDB). In typically developing (TD) children, SDB is associated with adverse cardiovascular effects including elevated heart rate and blood pressure and impaired autonomic control. The aim of this study was to compare the cardiovascular effects of SDB in children with DS to those of TD children with and without SDB. Methods 44 children with DS (3-18 y) were age and gender matched with 44 TD children without SDB (TD-) and with TD children with matched severity of SDB (TD+). Height, weight and blood pressure were measured and BMI, systolic and diastolic z-scores calculated. Heart rate variability (HRV) was calculated for 2 min artefact free epochs overnight. Power spectral density for the low frequency (LF), high frequency (HF), total power (TP) and the LF/HF ratio (sympathovagal balance) were calculated. Data were compared between groups with Kruskal-Wallis one-way ANOVA. Results Wake heart rate, systolic and diastolic z-scores were not different between groups. LF/HF was higher in the DS group compared to both TD+ (p Conclusion In children with DS and SDB, autonomic cardiovascular control is impaired compared to TD children matched for SDB severity and to non-snoring TD children. Our findings demonstrate significantly reduced parasympathetic activity (reduced HF power) and increased sympathovagal balance, that may contribute to increased risk of cardiovascular disease later in life. Support This study was funded by the Jack Brockhoff Foundation.

Sleep disordered breathing (SDB) is a common condition in infants and children. SDB encompasses a spectrum of respiratory disorders, which are defined as either obstructive or central in nature. Obstructive SDB ranges in severity from primary snoring (PS), to obstructive sleep apnea (OSA). There are a number of conditions characterized by central sleep apnea (CSA), including but not limited to periodic breathing in infants, Arnold Chiari malformations, and idiopathic CSA. SDB is associated with adverse cardiovascular and neurocognitive outcomes believed to be the consequence of the repeated cycles of hypoxia followed by reperfusion, hypercarbia, and sleep fragmentation. The peripheral hypoxia in individuals with SDB may not reflect cerebral oxygenation, and near infrared spectroscopy (NIRS) has been used to determine oxygen delivery and uptake in the brain. Neuroimaging in the form of structural and functional magnetic resonance imaging (MRI, fMRI), diffusion tensor imaging (DTI), and magnetic resonance spectroscopy (MRS) have become widely used to determine the structural, functional and chemical changes in the brain associated with SDB. This review will explore the relationship between central and obstructive SDB and changes in cerebral oxygenation together with changes in brain structure and function, in infants and children. It is important to identify any adverse effects so that they can be mitigated as early as possible to minimize any detrimental effects on the developing brain.

Over a third of children snore when they are asleep and until the last decade this has been considered benign by both parents and health professionals. Snoring was considered something that children would simply grow out of. Snoring is the hallmark symptom of sleep-disordered breathing (SDB), which ranges in severity from simple or primary snoring to obstructive sleep apnoea (OSA) which affects up to 6% of children.1 The incidence of SDB peaks in the preschool years when the size of the adenoids and tonsils—the primary cause of paediatric SDB—peaks in relation to the bony skeleton. In addition, childhood obesity increases the risk of OSA, particularly in older children. In adults, OSA is recognised as an independent risk factor for hypertension and reduced nocturnal dipping …

Despite significant reductions in incidence since the introduction of safe infant sleeping recommendations, sudden infant death syndrome is still the major cause of neonatal death in western countries. In the United States, over 2500 infants die suddenly and unexpectedly each year with nearly 100 deaths annually in Australia. Health professionals play a critical role in advising parents how to sleep their infants safely to minimise the risk of sudden infant death syndrome and sleeping accidents. Infants should be placed supine to sleep in a cot with a firm well-fitting mattress in the parental bedroom with no soft or loose bedding which could obstruct the airway. Exposure to smoking both before and after birth should be minimised. Breastfeeding should be encouraged, as should immunisation. Dummies can be recommended after breastfeeding has been established. This review outlines the evidence behind these recommendations.

Objective To determine the effect of prone sleeping on cerebral oxygenation in preterm infants in the neonatal intensive care unit. Study design Preterm infants, divided into extremely preterm (gestational age 24-28 weeks; n = 23) and very preterm (gestational age 29-34 weeks; n = 33) groups, were studied weekly until discharge in prone and supine positions during active and quiet sleep. Cerebral tissue oxygenation index (TOI) and arterial oxygen saturation (SaO2) were recorded. Cerebral fractional tissue extraction (CFOE) was calculated as CFOE = (SaO2 - TOI)/SaO2. Results In extremely preterm infants, CFOE increased modestly in the prone position in both sleep states at age 1 week, in no change in TOI despite higher SaO2. In contrast, the very preterm infants did not have position-related differences in CFOE until the fifth week of life. In the very preterm infants, TOI decreased and CFOE increased with active sleep compared with quiet sleep and with increasing postnatal age. Conclusion At 1 week of age, prone sleeping increased CFOE in extremely preterm infants, suggesting reduced cerebral blood flow. Our findings reveal important physiological insights in clinically stable preterm infants. Further studies are needed to verify our findings in unstable preterm infants regarding the potential risk of cerebral injury in the prone sleeping position in early postnatal life.