The obstructive sleep apnoea syndrome in adolescents.

BACKGROUND: The obstructive sleep apnoea syndrome (OSAS) results from a combination of structural and neuromotor factors; however, the relative contributions of these factors have not been studied during the important developmental phase of adolescence. We hypothesised that adenotonsillar volume (ATV), nasopharyngeal airway volume (NPAV), upper airway critical closing pressure (Pcrit) in the hypotonic and activated neuromotor states, upper airway electromyographic response to subatmospheric pressure and the ventilatory response to CO2 during sleep would be major predictors of OSAS risk. METHODS: 42 obese adolescents with OSAS and 37 weight-matched controls underwent upper airway MRI, measurements of Pcrit, genioglossal electromyography and ventilatory response to CO2 during wakefulness and sleep. RESULTS: ATV, NPAV, activated and hypotonic Pcrit, genioglossal electromyography and ventilatory response to CO2 during sleep were all associated with OSAS risk. Multivariate models adjusted for age, gender, body mass index and race indicated that ATV, NPAV and activated Pcrit each independently affected apnoea risk in adolescents; genioglossal electromyography was independently associated in a reduced sample. There was significant interaction between NPAV and activated Pcrit (p=0.021), with activated Pcrit more strongly associated with OSAS in adolescents with larger NPAVs and NPAV more strongly associated with OSAS in adolescents with more negative activated closing pressure. CONCLUSIONS: OSAS in adolescents is mediated by a combination of anatomic (ATV, NPAV) and neuromotor factors (activated Pcrit). This may have important implications for the management of OSAS in adolescents.

Understanding the anatomic basis for obstructive sleep apnea syndrome in adolescents.

RATIONALE: Structural risk factors for obstructive sleep apnea syndrome (OSAS) in adolescents have not been well characterized. Because many adolescents with OSAS are obese, we hypothesized that the anatomic OSAS risk factors would be more similar to those in adults than those in children. OBJECTIVES: To investigate the anatomic risk factors in adolescents with OSAS compared with obese and lean control subjects using magnetic resonance imaging (MRI). METHODS: Three groups of adolescents (age range: 12-16 yr) underwent MRI: obese individuals with OSAS (n = 49), obese control subjects (n = 38), and lean control subjects (n = 50). MEASUREMENTS AND MAIN RESULTS: We studied 137 subjects and found that (1) obese adolescents with OSAS had increased adenotonsillar tissue compared with obese and lean control subjects; (2) obese OSAS adolescents had a smaller nasopharyngeal airway than control subjects; (3) the size of other upper airway soft tissue structures (volume of the tongue, parapharyngeal fat pads, lateral walls, and soft palate) was similar between subjects with OSAS and obese control subjects; (4) although there were no major craniofacial abnormalities in most of the adolescents with OSAS, the ratio of soft tissue to craniofacial space surrounding the airway was increased; and (5) there were sex differences in the pattern of lymphoid proliferation. CONCLUSIONS: Increased size of the pharyngeal lymphoid tissue, rather than enlargement of the upper airway soft tissue structures, is the primary anatomic risk factor for OSAS in obese adolescents. These results are important for clinical decision making and suggest that adenotonsillectomy should be considered as the initial treatment for OSAS in obese adolescents, a group that has poor continuous positive airway pressure adherence and difficulty in achieving weight loss.

Long-term effects of caffeine therapy for apnea of prematurity on sleep at school age.

RATIONALE: Apnea of prematurity is a common condition that is usually treated with caffeine, an adenosine receptor blocker that has powerful influences on the central nervous system. However, little is known about the long-term effects of caffeine on sleep in the developing brain. OBJECTIVES: We hypothesized that neonatal caffeine use resulted in long-term abnormalities in sleep architecture and breathing during sleep. METHODS: A total of 201 ex-preterm children aged 5-12 years who participated as neonates in a double-blind, randomized, controlled clinical trial of caffeine versus placebo underwent actigraphy, polysomnography, and parental sleep questionnaires. Coprimary outcomes were total sleep time on actigraphy and apnea-hypopnea index on polysomnography. MEASUREMENTS AND MAIN RESULTS: There were no significant differences in primary outcomes between the caffeine group and the placebo (adjusted mean difference of -6.7 [95% confidence interval (CI) = -15.3 to 2.0 min]; P = 0.13 for actigraphic total sleep time; and adjusted rate ratio [caffeine/placebo] for apnea-hypopnea index of 0.89 [95% CI = 0.55-1.43]; P = 0.63). Polysomnographic total recording time and total sleep time were longer in the caffeine group, but there was no difference in sleep efficiency between groups. The percentage of children with obstructive sleep apnea (8.2% of caffeine group versus 11.0% of placebo; P = 0.22) or elevated periodic limb movements of sleep (17.5% in caffeine group versus 11% in placebo group) was high, but did not differ significantly between groups. CONCLUSIONS: Therapeutic neonatal caffeine administration has no long-term effects on sleep duration or sleep apnea during childhood. Ex-preterm infants, regardless of caffeine status, are at risk for obstructive sleep apnea and periodic limb movements in later childhood.

Effects of positive airway pressure therapy on neurobehavioral outcomes in children with obstructive sleep apnea.

RATIONALE: Positive airway pressure therapy is frequently used to treat obstructive sleep apnea in children. However, it is not known whether positive airway pressure therapy results in improvements in the neurobehavioral abnormalities associated with childhood sleep apnea. OBJECTIVES: We hypothesized that positive airway pressure therapy would be associated with improvements in attention, sleepiness, behavior, and quality of life, and that changes would be associated with therapy adherence. METHODS: Neurobehavioral assessments were performed at baseline and after 3 months of positive airway pressure therapy in a heterogeneous group of 52 children and adolescents. MEASUREMENTS AND MAIN RESULTS: Adherence varied widely (mean use, 170 ± 145 [SD] minutes per night). Positive airway pressure therapy was associated with significant improvements in attention deficits (P < 0.001); sleepiness on the Epworth Sleepiness Scale (P < 0.001); behavior (P < 0.001); and caregiver- (P = 0.005) and child- (P < 0.001) reported quality of life. There was a significant correlation between the decrease in Epworth Sleepiness Scale at 3 months and adherence (r = 0.411; P = 0.006), but not between other behavioral outcomes and adherence. Behavioral factors also improved in the subset of children with developmental delays. CONCLUSIONS: These results indicate that, despite suboptimal adherence use, there was significant improvement in neurobehavioral function in children after 3 months of positive airway pressure therapy, even in developmentally delayed children. The implications for improved family, social, and school function are substantial. Clinical trial registered with www.clinicaltrials.gov (NCT 00458406).

Nocturnal saturation and glucose tolerance in children with cystic fibrosis.

BACKGROUND: Glucose intolerance is common in cystic fibrosis (CF), and is associated with worsening pulmonary function and nutritional status, and increased mortality. As sleep-disordered breathing is associated with disorders of glucose metabolism, it was hypothesised that recurrent episodes of hypoxaemia during sleep, and sleep disruption, would be associated with inflammation and glucose intolerance in CF. METHODS: 25 children (aged 14±4 (mean±SD) years) with CF underwent polysomnography, actigraphy, measurement of serum inflammatory markers and oral glucose tolerance testing. Blood glucose area under the curve (AUC), as a cumulative measure of glucose response, was determined. Polysomnography data were compared with retrospective data from 25 healthy controls. RESULTS: Forced expiratory volume in 1 s was 92±14% predicted. 24 subjects underwent glucose tolerance testing, of whom 29% had impaired glucose tolerance and 4% had diabetes. The mean nocturnal oxygen saturation correlated negatively with glucose AUC at 120 min (r=-0.49, p=0.015). Partial correlations and regression models including age, body mass index, nocturnal saturation and pulmonary function indicated that nocturnal saturation accounted for the majority of the predictive power for glucose AUC (R(2)=0.24, p=0.001). There were no meaningful relationships between sleep quality, inflammation and glucose tolerance. CONCLUSIONS: Lower oxyhaemoglobin saturation is associated with worse glucose regulation in children with CF. Further studies are needed to determine whether lower saturation negatively impacts glucose regulation or, alternatively, whether abnormalities in glucose metabolism are an early sign of pulmonary dysfunction.

Upper airway sensory function in children with obstructive sleep apnea syndrome.

STUDY OBJECTIVES: Children with the obstructive sleep apnea syndrome (OSAS) have impaired responses to hypercapnia, subatmospheric pressure, and inspiratory resistive loading during sleep. This may be due, in part, to an impairment in the afferent limb of the upper airway sensory pathway. Therefore, we hypothesized that children with OSAS had diminished upper airway sensation compared to controls. DESIGN: Case-control. SETTING: Academic hospital. PARTICIPANTS: Subjects with OSAS aged 6-16 years, and age- and BMI-matched controls. INTERVENTIONS: Two-point discrimination (TPD) was measured during wakefulness with modified calipers in the anterior tongue, right interior cheek, and hard palate. RESULTS: Thirteen children with OSAS and 9 controls were tested. The age (mean +/- SD) for OSAS and controls was 11 +/- 4 vs. 13 +/- 2 years (NS); OSAS BMI Z score 2.4 +/- 0.5, controls 2.2 +/- 0.5 (NS); OSAS apnea hypopnea index 31 +/- 48, controls 0.4 +/- 0.5 events/hour (P < 0.001). Children with OSAS had impaired TPD in the anterior tongue (median [range]) = 9 [3-14] mm, controls 3 [1-7], P = 0.002) and hard palate (OSAS 6 [3-9] mm, controls 3 [1-4], P < 0.001). TPD in the cheek was similar between the groups (P = 0.12). CONCLUSION: TPD in the anterior tongue and hard palate was impaired in children with OSAS during wakefulness. We speculate that this impairment might be due to a primary sensory function abnormality or secondary to nerve damage and/or hypoxemia caused by OSAS. Further studies after treatment of OSAS are needed.

Differences in overnight polysomnography scores using the adult and pediatric criteria for respiratory events in adolescents.

STUDY OBJECTIVES: There was no consensus in the 2007 American Academy of Sleep Medicine scoring manual on whether pediatric or adult respiratory criteria should be used in adolescents due to lack of data. Our objective was to compare pediatric and adult criteria in adolescents referred for obstructive sleep apnea (OSA). We hypothesized that pediatric criteria would capture more respiratory events than adult criteria. DESIGN: Retrospective cross-sectional analysis. SETTING: Clinical sleep laboratory. PARTICIPANTS: 101 subjects aged 13-18 years clinically referred for OSA. INTERVENTIONS: Overnight polysomnogram. Data were scored using both adult and pediatric AASM criteria. For adult criteria, data were scored using both AASM hypopnea rule A, defined by > or = 4% desaturation, and B, defined by > or = 3% desaturation or arousal. RESULTS: Median (range) apnea hypopnea index (AHI) by pediatric criteria was 1.7 events/hour (0-42.9). AHI using rule A was 0.4 (0-35.6); rule B, 1.4 (0-38.4). A higher pediatric AHI was associated with greater differences between pediatric and adult AHI using either rule A or B. There was no significant discordance in OSA classification comparing pediatric and adult criteria rule B (P = 0.3), but there was a significant rate of discordance classification comparing pediatric and adult criteria rule A(P < 0.001). CONCLUSIONS: Either pediatric or adult criteria rule B can be used in adolescents as few subjects change diagnostic category between these 2 criteria. Use of adult rule A results in fewer children meeting criteria for OSA. Further research into the clinical relevance of the scoring metric in adolescents is warranted.

Rapid eye movement latency in children and adolescents.

Rapid eye movement sleep distribution changes during development, but little is known about rapid eye movement latency variation in childhood by age, sex, or pathologic sleep states. We hypothesized that: (1) rapid eye movement latency would differ in normal children by age, with a younger cohort (1-10 years) demonstrating shorter rapid eye movement latency than an older group (>10-18 years); (2) rapid eye movement latency in children would differ from typical adult rapid eye movement latency; and (3) intrinsic sleep disorders (narcolepsy, pediatric obstructive sleep apnea syndrome) would disrupt normal developmental patterns of rapid eye movement latency. A retrospective chart review included data from clinic visits and of rapid eye movement latency and other parameters measured by overnight polysomnography. Participants included 98 control children, 90 children with obstructive sleep apnea syndrome, and 13 children with narcolepsy. There were no statistically significant main effects of age category or sex on rapid eye movement latency. Rapid eye movement latency, however, exhibited a significant inverse correlation with age within the older control children. Healthy children exhibited rapid eye movement latencies significantly longer than adults. Normal control patients demonstrated significantly longer rapid eye movement latency than obstructive sleep apnea syndrome and narcolepsy patients.

Periodic limb movements and restless legs syndrome in children with a history of prematurity.

INTRODUCTION: Little is known about the pediatric population at an increased risk of restless legs syndrome (RLS) and periodic limb movement disorder (PLMD). Polysomnographic data from the Caffeine for Apnea of Prematurity-Sleep (CAPS) study showed a high prevalence of elevated periodic limb movement index (PLMI) in a cohort of ex-preterm children, but the clinical importance of this finding, such as association with RLS, is unknown. We hypothesized that ex-preterm children would have a high prevalence of RLS and PLMD. METHODS: Ex-preterm children enrolled in CAPS, now aged 5-12 years, completed home polysomnography (PSG) and standardized questionnaires. A diagnosis of RLS or PLMD was established by participants meeting the International Classification of Sleep Disorders, 3rd edition, criteria based on questionnaires and polysomnograms. The clinically available serum ferritin levels were assessed. RESULTS: In total, 167 participants underwent polysomnography and completed all questionnaires. The overall prevalence of RLS was 14/167 (8.4%). An additional 13 subjects (7.8%) were found to have PLMD. Of the 26 participants who had PLMI > 5/h, seven (26.9%) had RLS and 13 (50%) had PLMD. The serum ferritin levels were <50 mcg/L (range -38.4) for all eight participants referred for testing. CONCLUSIONS: Children with a history of prematurity have a high prevalence of RLS, particularly those with elevated periodic limb movements. Iron deficiency likely contributes to RLS and PLMD symptoms in this population. Clinicians evaluating ex-preterm children with sleep disturbances should evaluate for RLS and PLMD. Further studies including serum ferritin evaluation are required to confirm these findings.

Upper Airway Vibration Perception in School-Aged Children with Obstructive Sleep Apnea.

STUDY OBJECTIVES: Children with the obstructive sleep apnea (OSA) have impaired upper airway two-point discrimination compared to controls. In addition, blunted vibration threshold detection (VT) in the palate has been recognized in adults with OSA, but has not been studied in children. Both findings are indicative of a defect in the afferent limb of the upper airway dilator reflex that could prevent upper airway dilation secondary to airway loading, resulting in airway collapse. We hypothesized that children with OSA have impaired palate VT compared to controls, and that this improves after OSA treatment. METHODS: Case-control study. Children with OSA and healthy non-snoring controls underwent polysomnography and palate VT measurements. Children with OSA were retested after adenotonsillectomy. RESULTS: 29 children with OSA (median [interquartile range] age = 9.5 [7.5-12.6] years, obstructive apnea-hypopnea index [OAHI] = 11.3 [5.7-19.5] events/h, BMI z = 1.8 [1.3-2.1]) and 32 controls (age = 11.2 [9.3-13.5] years, P = 0.1; OAHI = 0.5 [0.1-0.7] events/h, P < 0.001; BMI z = 1 [0.3-1.7], P = 0.004) were tested. OSA palate VT (1.0 [0.8-1.5] vibration units) was similar to that of controls (1 [0.8-1.3], P = 0.37). 20 children with OSA were retested 4.4 (3.2-7.1) months after treatment. OAHI decreased from 13.1 (5.8-19) to 0.6 (0.2-2.5) events per hour (P < 0.001) postoperatively, but palate VT did not change (before = 1 [0.7-1.5], after = 1.2 [0.8-1.4], P = 0.37). CONCLUSIONS: Children with OSA and controls have similar palate VT. Unlike in adults, palate VT does not seem to be affected by childhood OSA.

Perinatal Risk Factors Associated with the Obstructive Sleep Apnea Syndrome in School-Aged Children Born Preterm.

STUDY OBJECTIVES: The obstructive sleep apnea syndrome (OSAS) is more prevalent in ex-preterm children compared to the general pediatric population. However, it is unknown whether OSAS in ex-preterm children is associated with specific perinatal risk factors. This multicenter cohort study aimed to determine perinatal factors associated with OSAS at school age. METHODS: 197 ex-preterm (500-1,250 g) children aged 5-12 y who participated as neonates in a double-blind, randomized clinical trial of caffeine versus placebo (Caffeine for Apnea of Prematurity) underwent comprehensive ambulatory polysomnography. A negative binomial regression model was used to identify perinatal risk factors associated with OSAS. RESULTS: 19 children had OSAS (9.6%). Chorioamnionitis and multiple gestation were positively associated with OSAS with P values of 0.014 and 0.03, respectively. Maternal white race (P = 0.047) and maternal age (P = 0.002) were negatively associated with OSAS. Other risk factors, such as birth weight, Apgar score at 5 min, antenatal corticosteroids, delivery route, and sex were not significant. CONCLUSIONS: OSAS is very frequent, and is associated with chorioamnionitis and multiple gestation in ex-preterm children. Those born to older white mothers appear to be protected. We speculate that the former may be due to systemic inflammation and the latter to a higher socio-economic status. COMMENTARY: A commentary on this article appears in this issue on page 721.

Validation of Actigraphy in Middle Childhood.

STUDY OBJECTIVES: Few studies have examined the validity of actigraphy in school-aged children. The objective of this study was to examine the validity of a commonly used actigraph compared to polysomnography (PSG) in a sample of children age 5 to 12 y born prematurely, sleeping in their natural home environment. METHODS: 148 children born preterm (85 boys and 63 girls), ages 5-12 y (mean = 9.3 y, standard deviation = 2.0) wore the Philips Respironics Actiwatch-2 for 1 night concurrently with comprehensive, ambulatory PSG in the child's home. Sleep outcome variables were sleep onset latency, total sleep time (TST), and sleep efficiency. Epoch-by-epoch comparisons were used to determine sensitivity, specificity, and accuracy. Secondary analyses examined differences between children with no sleep issues, obstructive sleep apnea syndrome, and periodic limb movements in sleep (PLMS). RESULTS: Actigraphy significantly underestimated TST (30 min) and sleep efficiency (5%). Actigraphy underestimated or overestimated sleep onset latency by at least 10 min for a third of the children. Sensitivity and accuracy were good at 0.88 and 0.84, respectively, whereas specificity was lower at 0.46. Differences between actigraphy and PSG for TST and sleep efficiency were greatest for children with PLMS. CONCLUSIONS: This study adds to the small existing literature demonstrating the validity of actigraphy in middle childhood. Although actigraphy shows good sensitivity (ability to detect sleep), specificity (ability to detect wake) is poor in this age group. Further, the results highlight the importance of considering whether a child has PLMS when interpreting actigraphic data, as well as the difficulties in accurately capturing sleep onset latency with actigraphy.

Sleep/Wake Patterns and Parental Perceptions of Sleep in Children Born Preterm.

STUDY OBJECTIVES: To compare sleep/wake patterns in children born preterm in Australia vs Canada and determine cultural differences in the relationship between parental perception of sleep and actual sleep behaviors. METHODS: Australian and Canadian children born preterm were recruited from the Caffeine for Apnea of Prematurity trial (n = 188, 5-12 y) and underwent 14 days actigraphy monitoring. Parents completed the National Sleep Foundation 2004 Sleep in America questionnaire. Cross-cultural differences in sleep characteristics assessed by actigraphy and parent-reported questionnaire were examined. Correlational analyses determined the associations between parental perceptions of child sleep need and sleep behavior. RESULTS: Actigraphy showed preterm children obtained, on average, 8 h sleep/night, one hour less than population recommendations for their age. There was no difference in total sleep time (TST) between Australian and Canadian cohorts; however, bed and wake times were earlier in Australian children. Bedtimes and TST varied by 60 minutes from night to night in both cohorts. Parent-reported child TST on the National Sleep Foundation questionnaire was 90 minutes longer than recorded by actigraphy. Both bedtime and TST on weekdays and weekends were related to parental perception of child sleep need in the Australian cohort. Only TST on weekdays was related to parental perception of child sleep need in the Canadian cohort. CONCLUSIONS: This study suggests that short sleep duration and irregular sleep schedules are common in children born preterm. Cultural differences in the association between parental perception of child sleep need and actual sleep behaviors provide important targets for future sleep health education.

Relationship between obstructive sleep apnea cardiac complications and sleepiness in children with Down syndrome.

OBJECTIVE/BACKGROUND: Children with Down syndrome (DS) have a high rate of pulmonary hypertension and sleepiness. They also have a high prevalence of obstructive sleep apnea syndrome (OSAS). We hypothesized that OSAS was associated with cardiovascular dysfunction and sleepiness in children with DS, and that this dysfunction was partly reversible. PATIENTS/METHODS: A total of 23 children with DS, aged 8-19 years, were evaluated with polysomnography, echocardiography, and measurement of brain natriuretic peptide (BNP). Children having OSAS were randomized to four months of actual or sham continuous positive airway pressure (CPAP) in a double-blinded fashion. RESULTS: Of the total participants, 20 (87%) had OSAS. On echocardiography, no participant was found to have pulmonary hypertension, and all participants had a BNP <10 pg/mL. The early/tissue Doppler (E/e') of the lateral mitral annulus, a measure of worse left ventricular (LV) diastolic function, correlated with the arousal index (r = 0.42, p = 0.043) and apnea hypopnea index (AHI; r = 0.61, p = 0.002) and inversely with the SpO2 nadir (r = -0.61, p = 0.002). Participants with OSAS had a high pediatric Epworth score [median interquartile range (IQR) = 8(4,9)],correlating with the arousal index (r = 0.49, p = 0.016). At four months, there were no changes in cardiovascular outcomes or sleepiness between those on actual versus sham CPAP. Hours of actual CPAP use was associated with improved E/e' mitral lateral (r = -0.48, p = 0.044), but surprisingly also correlated with LV mass z-score (r = 0.54, p = 0.018). CONCLUSIONS: In children with DS, LV diastolic function correlated with OSAS severity, with improvement with CPAP use. There was a tendency towards increased sleepiness in those with OSAS, which correlated with the arousal index. Larger studies are warranted to confirm these findings.

Prevalence of periodic limb movements during sleep in normal children.

STUDY OBJECTIVES: Although the American Academy of Sleep Medicine (AASM) mandates that periodic limb movements during sleep (PLMS) be scored on every polysomnogram, and considers a periodic limb movement index (PLMI) > 5/h abnormal in children, there is a lack of community-derived data regarding the prevalence of PLMS in children, and no data to support this cutoff value. Therefore, the aim of this study was to determine the prevalence of PLMS in a sample of normal children. DESIGN: Retrospective study. PARTICIPANTS: 195 healthy, non-snoring children aged 5-17 years, recruited from the community, who underwent polysomnography for research purposes. METHODS: PLMS were scored using the AASM 2007 criteria. MEASUREMENTS AND RESULTS: The group age (median [IQR]) was 12.9 [10-15] years, and 58% were male. Sleep architecture was normal, and the obstructive apnea hypopnea index was 0.1 [0-0.3]/h. The median PLMI was 0/h, ranging from 0 to 35.5/h. Fifteen (7.7%) subjects had a PLMI > 5/h, and only 3 (1.5%) met the adult pathologic criterion of more than 15/h. Use of the 95th percentile PLMI cutoff of 7.2/h produced little difference in categorization between groups. Children with a PLMI > 5/h had a higher arousal index than those with a lower PLMI (11.6 [8.8-14.6] vs 8.1 [6.1-9.9]/h, respectively, P = 0.003). CONCLUSIONS: This study provides normative data to the field and supports the clinical periodic limb movement index cutoff of > 5/h based on both prevalence and the correlate of increased sleep fragmentation. Periodic limb movements during sleep are infrequent in normal children recruited from the community. CITATION: Marcus CL, Traylor J, Gallagher PR, Brooks LJ, Huang J, Koren D, Katz L, Mason TB, Tapia IE. Prevalence of periodic limb movements during sleep in normal children.

Pilot study of nasal expiratory positive airway pressure devices for the treatment of childhood obstructive sleep apnea syndrome.

STUDY OBJECTIVES: Alternative therapies for childhood obstructive sleep apnea syndrome (OSAS) are needed as OSAS may persist despite adenotonsillectomy, and continuous positive airway pressure (CPAP) adherence is low. Nasal expiratory positive airway pressure (NEPAP) devices have not been studied in children. We hypothesized that NEPAP would result in polysomnographic improvement. Further, we aimed to determine NEPAP adherence, effects on sleepiness, behavior, and quality of life. METHODS: A randomized, double-blind, placebo-controlled, crossover pilot study was performed. CPAP candidates, 8-16 years old, underwent NEPAP and placebo polysomnograms. Subjects with ≥ 50% reduction in the apnea hypopnea index (AHI) from placebo to NEPAP night or AHI < 5/h on NEPAP night wore NEPAP at home for 30 days. Adherence was assessed by daily phone calls/emails and collecting used devices. RESULTS: Fourteen subjects (age 13.4 ± 1.9 years, BMI z-scores 2.2 ± 1 [mean ± SD]) were studied. There was significant improvement in the obstructive apnea index with NEPAP vs. placebo: 0.6 (0-21.1)/h vs. 4.2 (0-41.9)/h (median [range], p = 0.010) and trends for improvement in other polysomnographic parameters. However, responses were variable, with 3 subjects not improving and 2 worsening. Older children and those with less hypercapnia had a better response. Eight subjects were sent home with devices; one was lost to follow-up, and adherence in the remainder was 83% of nights; these subjects had a significant improvement in sleepiness and quality of life. CONCLUSIONS: NEPAP devices are a potential alternative therapy for OSAS in a small subset of children. Due to variability in individual responses, efficacy of NEPAP should be evaluated with polysomnography. CLINICAL TRIAL REGISTRATION: www.clinicaltrials.gov, identifier: NCT01768065.

Predictors of perioperative complications in higher risk children after adenotonsillectomy for obstructive sleep apnea: a prospective study.

OBJECTIVE: Retrospective studies have limitations in predicting perioperative risk following adenotonsillectomy in children with obstructive sleep apnea syndrome (OSAS). Few prospective studies exist. We hypothesized that demographic and polysomnographic (PSG) variables would predict respiratory and general perioperative complications. STUDY DESIGN: Prospective, observational cohort study. SETTING: Pediatric tertiary center. SUBJECTS AND METHODS: Consecutive children undergoing adenotonsillectomy for OSAS within 12 months of PSG were evaluated for complications occurring within 2 weeks of surgery. RESULTS: There were 329 subjects, with 27% <3 years old, 24% obese, 16% preterm, and 29% with comorbidities. In this higher risk population, 28% had respiratory complications (major and/or minor), and 33% had nonrespiratory complications. Significant associations were found between PSG parameters and respiratory complications as follows: apnea hypopnea index (rank-biserial correlation coefficient [r] = 0.174, P = .017), SpO2 nadir (r = -0.332, P < .0005), sleep time with SpO2 <90% (r = 0.298, P < .0005), peak end-tidal CO2 (r = 0.354, P < .0005), and sleep time with end-tidal CO2 >50 mm Hg (r = 0.199, P = .006). Associations were also found between respiratory complications and age <3 years (r = -0.174, P = .003) or black race (r = 0.123, P = .039). No significant associations existed between PSG parameters and nonrespiratory complications. A model using age <3 years, SpO2 nadir, and peak CO2 predicted respiratory complications better than the American Academy of Pediatrics or American Academy of Otolaryngology-Head and Neck Surgery Foundation guidelines but was imperfect (area under the curve = 0.72). CONCLUSION: Thus, PSG predicted perioperative respiratory, but not nonrespiratory, complications in children with OSAS. Age <3 years or black race are high-risk factors. Present guidelines have limitations in determining the need for postoperative admission.

Feasibility of comprehensive, unattended ambulatory polysomnography in school-aged children.

STUDY OBJECTIVES: Although unattended ambulatory polysomnography (PSG) is frequently performed in adults, few studies have been performed in children. The objective of this study was to evaluate the feasibility of comprehensive, ambulatory PSG, including electroencephalography, in school-aged children in the home environment. METHODS: A total of 201 children, born premature with birth weights of 500-1,250 grams, currently aged 5-12 years and living in Canada and Australia, underwent unattended ambulatory PSG. RESULTS: PSG was initially technically satisfactory in 183 (91%) cases. Fourteen studies were satisfactory when repeated, resulting in an overall satisfactory rate of 197 (98%). Artifact-free signals were obtained for ≥ 75% of recording time in more than 92% of subjects, with the exception of nasal pressure, which was satisfactory for ≥ 75% of recording time in only 67% of subjects. However, thermistry signals were satisfactory for ≥ 75% of recording time in 92% of subjects, and some measure of airflow was present for ≥ 75% of recording time in 96% of subjects. Children slept very well, with a long total sleep time (534 ± 73 [mean ± SD] minutes), high sleep efficiency (92% ± 5%), and low arousal index (9 ± 3/h). Parents and children reported a high rate of satisfaction with the study. CONCLUSIONS: This large, international study has shown that comprehensive, unattended, ambulatory PSG is feasible, technically adequate and well-tolerated in school-aged children when performed under research conditions. Further studies regarding the cost efficacy of this approach, and generalizability of the findings to a clinical population, are warranted.

Direct comparison of two new actigraphs and polysomnography in children and adolescents.

STUDY OBJECTIVES: To evaluate the validity and reliability of 2 new models of commercially available actigraphs compared to polysomnography for children and adolescents. DESIGN AND SETTING: Subjects concurrently wore the Ambulatory Monitoring Inc. Motionlogger Sleep Watch (AMI) and the Phillips Respironics Mini-Mitter Actiwatch-2 (PRMM) while undergoing overnight polysomnography (PSG) in a pediatric sleep laboratory housed in a tertiary care children's hospital. PARTICIPANTS: 115 youth (59 girls, 56 boys), ages 3-18 years (mean 8.8 years, SD 4.4 years). MEASUREMENTS: Outcome variables were total sleep time (TST), wake after sleep onset (WASO), and sleep efficiency (SE). Epoch-by-epoch comparisons were made between the 2 devices and PSG to determine sensitivity, specificity, and accuracy. Agreement between the 2 devices was determined with t-tests and the Bland-Altman concordance technique. Different algorithms/sensitivities, developmental age groups, and sleep disordered breathing (SDB) status were also examined. RESULTS: For both device brands, sensitivity (0.89-0.97), specificity (0.54-0.77), and accuracy (0.87-0.90) were similar to previous reports. Notably, compared to PSG, both device brands significantly overestimated WASO, while the AMI device also significantly underestimated TST. Inter-device comparison of the 2 brands found poor agreement for TST, WASO, and SE. Agreement with PSG differed depending on the scoring algorithm (AMI) or sensitivity setting (PRMM), as well as across developmental age group and sleep disordered breathing (SDB) status. CONCLUSIONS: Similar to previous reports, both new actigraph brands were found to have good sensitivity (to detect sleep), but poorer specificity (to detect wake). Study results also suggest that researchers should adjust the scoring algorithm/sensitivity depending on a study's design (e.g., young children vs. adolescents, healthy children vs. youth with SDB). Further, inter-device reliability was poor, suggesting the need for caution when comparing results across studies that use different brands of actigraphic devices.

Capturing PLMS and their variability in children with sickle cell disease: does ankle activity monitoring measure up to polysomnography?

OBJECTIVES: To test agreement and define differences in periodic limb movements in sleep (PLMS) measured by polysomnography and an ankle activity monitor, and to describe PLMS variability across nights, feasibility of home monitoring, and correlates of PLMS in children with sickle cell disease (SCD). METHODS: Twenty children with SCD and restless legs syndrome (RLS) symptoms or polysomnography-documented PLMS underwent concurrent attended polysomnography and ankle activity monitoring over one to two nights and home activity monitoring for three nights. Serum iron and ferritin were measured pre- and post-polysomnography. RESULTS: Adequate sensitivity (1.00), specificity (0.69), and mean bias (5.0±7.4 PLMS/h) for identifying elevated PLMS by activity monitor were obtained when scoring the period from sleep onset to offset rather than time in bed per manufacturer recommendation, and using a cut-point of 10 PLMS/h. Compared to activity monitor, only polysomnographic PLMS demonstrated periodicity, at inter-movement intervals (IMI) 20-35 s; the activity monitor overscored PLMS at the beginning and end of sleep and at shorter IMI (5-15s; p≤0.003), suggesting misclassification of nonperiodic leg movements as PLMS by activity monitor. PLMS varied across four nights by 16.1±13.4 PLMS/h. Post-polysomnography ferritin was associated (positively) with PLMS (p=0.034); RLS symptoms were not. CONCLUSIONS: Ankle activity monitoring is a valid screening measure for PLMS in children with SCD and can readily be performed at home. Interpretation should incorporate a threshold for elevated PLMS of 10/h and scoring from sleep onset to offset, which could be identified with concurrent wrist actigraphy, to better account for true PLMS.