Upper airway dynamic responses in children with the obstructive sleep apnea syndrome

Parental experiences in navigating health services for paediatric residual obstructive sleep apnoea: An exploratory qualitative descriptive study

OBJECTIVES

To explore parents' experiences and perceptions regarding engagement in health services for managing residual paediatric obstructive sleep apnoea (OSA) across levels of care.

METHODS

Qualitative description guided study design. Data were collected through semi-structured interviews with parents of children diagnosed with residual OSA at a university-based sleep clinic. The relevant literature informed the interview guide and was piloted before data collection. Inductive, manifest content analysis was used to describe parents' perceptions and experiences using data-driven categories and sub-categories. Several strategies were employed to ensure rigour in this study.

RESULTS

Eight interviews were conducted. Parents' views were organized into five categories: awareness of the sleep issue, interaction with non-sleep specialists, interaction with sleep specialists, interaction with dental professionals, and further actions and support. Parents reported several engagement issues due to their interactions with different care providers. These issues included having to personally identify and raise the sleep problem, feeling that care providers did not take this problem seriously, waiting for an extended period to be referred for sleep services, and receiving conflicting or insufficient treatment recommendations. Overall, parents perceived that their actions and the services received across levels of care were not effective enough to address paediatric OSA.

CONCLUSION

Based on this exploratory qualitative descriptive research, along with developing evidence-based clinical guidelines for paediatric OSA screening and management tailored to different levels of care, strategies intended to improve the engagement of patients and care providers in addressing paediatric OSA should be developed and empirically tested.

Does REM AHI Predict Persistent OSA After Pediatric Adenotonsillectomy?

OBJECTIVE

The utility of REM AHI in managing pediatric obstructive sleep apnea (OSA) is not fully understood. This study aimed to evaluate the relationship of preoperative REM AHI to postoperative persistence of OSA in children who underwent adenotonsillectomy.

METHODS

This retrospective chart review identified children under the age of 18 years that received an adenotonsillectomy for OSA and a preoperative and postoperative polysomnogram. Children with craniofacial or neuromuscular disorders or a tracheostomy were excluded. The primary outcome was the postoperative persistence of OSA, defined as a postoperative obstructive apnea-hypopnea index (oAHI) ≥ 1.5 events/hour. REM-predominant OSA was defined as a ratio of REM/NREM AHI ≥ 2. REM AHI minus NREM AHI and REM AHI minus oAHI helped to identify patients with a larger distribution of REM AHI.

RESULTS

A total of 353 patients were included. Postoperative persistent OSA was seen in 232 (65.7%) children. The preoperative REM AHI, REM AHI minus NREM AHI, and REM AHI minus oAHI of children with persistent OSA did not differ significantly from children with resolution of OSA. Rates of persistence were not different between those with REM-predominant OSA and REM-independent OSA (63.8% vs 70.7%, P = .218).

CONCLUSION

This study suggests that preoperative REM AHI may be a poor predictor of OSA persistence after adenotonsillectomy. Further study is needed to help characterize how pre-operative REM AHI should impact clinicians' decision making, family counseling and recommendations.

Sleep Disorders in Childhood

OBJECTIVE

This article provides a comprehensive review of pediatric sleep disorders including the clinical features, diagnosis, and treatment of sleep-disordered breathing, insomnia, parasomnias, restless sleep disorder, restless legs syndrome, narcolepsy in childhood, and Kleine-Levin syndrome.

LATEST DEVELOPMENTS

Our understanding of pediatric sleep pathophysiology continues to evolve, and diagnostic and treatment modalities have expanded. A low-sodium oxybate formulation was approved in July 2020 in the United States to treat cataplexy and excessive daytime sleepiness in patients 7 years old and older with narcolepsy. A validated pediatric hypersomnolence survey for pediatric narcolepsy and idiopathic hypersomnia with high sensitivity, specificity, and interrater reliability is now available.

ESSENTIAL POINTS

The clinical presentation, diagnostics, and treatment of children with sleep disorders differ from those of adults. Untreated sleep disorders in childhood can lead to adverse physical and psychological consequences in adults. Correctly diagnosing and treating sleep disorders in youth can prevent a significant burden of disease in adulthood.

Pediatric sleep-disordered breathing in Shanghai: characteristics, independent risk factors and its association with malocclusion

OBJECTIVES

This study aimed to determine the prevalence and independent risk factors of SDB, and explore its association with malocclusion among 6-11-year-old children in Shanghai, China.

METHODS

A cluster sampling procedure was adopted in this cross-sectional study. Pediatric Sleep Questionnaire (PSQ) was applied to evaluate the presence of SDB. Questionnaires including PSQ, medical history, family history, and daily habits/environment were completed by parents under instruction, and oral examinations were implemented by well-trained orthodontists. Multivariable logistic regression was applied to identify independent risk factors for SDB. Chi-square tests and Spearman's Rank Correlation were used to estimate the relationship between SDB and malocclusion.

RESULTS

A total of 3433 subjects (1788 males and 1645 females) were included in the study. The SDB prevalence was about 17.7%. Allergic rhinitis (OR 1.39, 95% CI 1.09-1.79), adenotonsillar hypertrophy (OR 2.39, 95% CI 1.82-3.19), paternal snoring (OR 1.97, 95% CI 1.53-2.53), and maternal snoring (OR 1.35, 95% CI 1.05-1.73) were independent risk factors for SDB. The SDB prevalence was higher in children with retrusive mandibles than in proper or excessive ones. No significant difference was observed in the correlation between SDB and lateral facial profile, mandible plane angle, constricted dental arch form, the severity of anterior overjet and overbite, degree of crowding and spacing, and the presence of crossbite and open bite.

CONCLUSIONS

The prevalence of SDB in primary students in the Chinese urban population was high and highly associated with mandible retrusion. The independent risk factors included Allergic rhinitis, adenotonsillar hypertrophy, paternal snoring, and maternal snoring. More efforts should be made to enhance public education about SDB and related dental-maxillofacial abnormalities.

Determinants of awake oropharyngeal volume reduction between sitting and supine positions in children evaluated for snoring

Pharyngeal collapsibility is a major determinant of obstructive sleep apnea (OSA) pathophysiology, but its anatomical predictors in children are largely unknown. We hypothesised that anatomical (tonsillar hypertrophy, narrow palate, nasal obstruction, dental/skeletal malocclusion, obesity) and OSA-related (apnea-hypopnea index, AHI) parameters could be related to a measure of awake pharyngeal collapsibility. We performed acoustic pharyngometry in children evaluated for suspected OSA, allowing us to measure the reduction of oropharyngeal volume in supine versus sitting position normalised for the volume in supine position (ΔV%), a measure of pharyngeal collapsibility. In addition to polysomnography and a clinical examination (anatomical parameters), acoustic rhinometry was used to assess nasal obstruction. A total of 188 snoring children were included, 118 (63%) of whom were obese and 74 (39%) of whom had moderate to severe OSA (AHI ≥5/h). The median (25th-75th percentiles) ΔV% in the whole population was 20.1% (4.7; 43.3). ΔV% was independently and positively associated with AHI (p = 0.023), z-score of BMI (p = 0.001), tonsillar hypertrophy (p = 0.007), narrow palate (p = 0.035), and African (p < 0.001) ancestry. By contrast, ΔV% was not modified by dental or skeletal malocclusion, Friedman palate position class or nasopharyngeal obstruction. Tonsillar hypertrophy, obesity, narrow palate and African ancestry are independently associated with an increase in pharyngeal collapsibility in snoring children, thus increasing the risk of OSA. Increased pharyngeal compliance in African children may explain the increased risk of residual OSA after adenotonsillectomy observed in this population.

Carotid Anomalies and Their Implication in ENT Surgery

Carotid Anomalies are with significant surgical implication to an Otorhinolaryngologist. The authors discuss the evaluation and management of a child with Pierre Robin Syndrome who presented with severe OSA, secondary to bilateral midline carotids that compromised the airway, and an adult with cervical bolus and dysphagia who presented similar to chronic tonsillitis but found to have Retropharyngeal Carotids. This case study emphasizes the need for awareness and a high index of suspicion to identify the variation of the carotid artery in nasopharyngeal and oropharyngeal surgery that has a propensity to result in catastrophic consequences if operated upon.

The effect of iron deficiency on quality of life outcomes after surgery for obstructive sleep apnoea

AIM

This study aimed to assess the effect of iron deficiency on parent-reported changes in quality of life (QOL) among children receiving an adenotonsillectomy for paediatric obstructive sleep apnoea (OSA).

METHODS

This was a retrospective review study that recruited children under 16 years of age undergoing an adenotonsillectomy, adenoidectomy, or tonsillectomy for clinically diagnosed paediatric OSA between June 2020 and January 2021 inclusive, in Western Australia. The main outcome measures for this study were changes in QOL by age group and iron status, defined by an absolute change of more than 3 points on OSA-18 survey domains.

RESULTS

About 249 participants had iron studies performed on perioperative blood samples drawn at operation and completed both pre-operative and post-operative OSA-18 QOL questionnaires at initial consultation and 8-12 weeks post-surgery, respectively. 41.8% were iron deficient, 53.8% were borderline iron deficient and 4.4% had normal iron levels. Following surgery, a decrease was observed for all OSA-18 score domains in post-operation scores compared to pre-operation scores in both iron-deficient and borderline iron-deficient cohorts. 'Daytime Problems' in the <2 years group, within the iron-deficient cohort, was the only domain that found to be non-superior (i.e. 'not better') following surgery.

CONCLUSIONS

Following adenotonsillectomy, patients with paediatric OSA reported significant improvements in QOL regardless of their iron status. Those undergoing an adenotonsillectomy for paediatric OSA had a high prevalence of iron deficiency at operation, especially those under 6 years of age.

Comparison of superior airway dimensions and cephalometric anatomic landmarks between 8–12-year-old children with obstructive sleep apnea and healthy children using CBCT images

Background. The etiology of obstructive sleep apnea (OSA) syndrome in children significantly differs from adults. In previous studies, only some of the indices have been investigated using CBCT. This study compares all the measurable indices of airway dimensions and anatomical cephalometric landmarks between children with OSA and healthy ones using cone-beam computed tomography (CBCT).

Methods. Dimensions of the airway and cephalometric values were measured on CBCT scans of 50 children aged 8–12 (25 patients with OSA and 25 healthy subjects) and then compared between the two groups. The results of this study were analyzed with independent t test using SPSS 17 at a significance level of P<0.05.

Results. Area, length, volume, anteroposterior length, and size of the upper airway in subjects with OSA were lower than those in healthy children, while the average values of SNA, SNB, and ANB in the OSA group were higher than those in the healthy group (P=0.366, P=0.012, and P=0.114, respectively). Also, BaSN, PNS/AD1, and PNS/AD2 measurements in subjects with OSA were lower than healthy subjects (P=0.041, P=0.913, and P=0.015, respectively). In addition, the width and anteroposterior length of the upper airway, SNB, BaSN, PNS/AD1, and PNS/AD2 indices were significantly different between the healthy group and those with OSA (P<0.05).

Conclusion. Reduced upper airway dimensions, adenoid tissue enlargement, and cranial base flexion might play an important role in OSA development in children. However, most skeletal variables, such as the anteroposterior relationship of jaws and jaw rotation, were not significantly different between the two groups.

Use of facial stereophotogrammetry as a screening tool for pediatric obstructive sleep apnea by dental specialists

STUDY OBJECTIVES

To evaluate facial 3-dimensional (3D) stereophotogrammetry's effectiveness as a screening tool for pediatric obstructive sleep apnea (OSA) when used by dental specialists.

METHODS

One hundred forty-four participants aged 2-17 years, including children fully diagnosed with pediatric OSA through nocturnal polysomnography or at high-risk or low-risk of pediatric OSA, participated in this study. 3D stereophotogrammetry, Craniofacial Index, and Pediatric Sleep Questionnaire were obtained from all participants. Ten dental specialists with interest in pediatric sleep breathing disorders classified OSA severity twice, once based only on 3D stereophotogrammetry and then based on 3D stereophotogrammetry, Craniofacial Index, and Pediatric Sleep Questionnaire. Intrarater and interrater reliability and diagnostic accuracy of pediatric OSA classification were calculated. A cluster analysis was performed to identify potential homogeneous pediatric OSA groups based on their craniofacial features classified through the Craniofacial Index .

RESULTS

Intrarater and interrater agreement suggested a poor reproducibility when only 3D facial stereophotogrammetry was used and when all tools were assessed simultaneously. Sensitivity and specificity varied among clinicians, indicating a low screening ability for both 3D facial stereophotogrammetry, ranging from 0.36-0.90 and 0.10-0.70 and all tools ranging from 0.53-1.0 and 0.01-0.49, respectively. A high arched palate and reversed or increased overjet contributed to explaining how participating dental clinicians classified pediatric OSA.

CONCLUSIONS

3D stereophotogrammetry-based facial analysis does not seem predictive for pediatric OSA screening, alone or combined with the Pediatric Sleep Questionnaire and Craniofacial Index when used by dental specialists interested in sleep-disordered breathing. Some craniofacial traits, more specifically significant sagittal overjet discrepancies and an arched palate, seem to influence participating dental specialists' classification.

CITATION

Fernandes Fagundes NC, Carlyle T, Dalci O, et al. Use of facial stereophotogrammetry as a screening tool for pediatric obstructive sleep apnea by dental specialists. J Clin Sleep Med. 2022;18(1):57-66.

Sleep-disordered breathing and malocclusion in children and adolescents-a systematic review

BACKGROUND

Sleep-disordered breathing (SDB) has negative influence on children's development and well-being. Malocclusion due to some craniofacial anatomical characteristics may be associated with SDB.

OBJECTIVES

The aim of this paper is to ascertain whether SDB is associated with malocclusion in children/adolescents, aged 6-15 years compared to healthy controls.

METHODS

Prospero ID: CRD42021232103. A systematic electronic literature search following PRISMA was performed in PubMed, Embase and Cochrane Library. Inclusion criteria were as follows: Healthy children/adolescents aged 6-15 years with malocclusion undergoing polysomnography (PSG) or polygraphy (PG) and/or sleep questionnaire and orthodontic screening; compared to a healthy age-matched control group with neutral or minor deviation in the occlusion without requirement for orthodontic treatment; publications in English, Danish, Norwegian or Swedish published until 23 March 2021. JBI Critical Appraisal Tools and GRADE were used to evaluate the risk of bias and level of evidence.

RESULTS

The search resulted in 1996 records, 610 duplicates were removed, 1386 records were screened, and 1322 records were excluded. Sixty-four studies were selected for full-text reading, and four publications fulfilled the inclusion criteria. The included studies had moderate risk of bias, and the quality of evidence was low.

CONCLUSION

No firm conclusion can be drawn regarding an association between specific malocclusion traits and SDB. Thus, the studies found no association between molar relationship and crowding and SDB symptoms in children. It may be recommended that future studies include objective PSG or PG in diagnosis of SDB and compare groups of children with skeletal malocclusion and controls with neutral malocclusion.

Much Ado about Sleep: Current Concepts on Mechanisms and Predisposition to Pediatric Obstructive Sleep Apnea

Obstructive Sleep Apnea (OSA) is a form of sleep-disordered breathing characterized by upper airway collapse during sleep resulting in recurring arousals and desaturations. However, many aspects of this syndrome in children remain unclear. Understanding underlying pathogenic mechanisms of OSA is critical for the development of therapeutic strategies. In this article, we review current concepts surrounding the mechanism, pathogenesis, and predisposing factors of pediatric OSA. Specifically, we discuss the biomechanical properties of the upper airway that contribute to its primary role in OSA pathogenesis and examine the anatomical and neuromuscular factors that predispose to upper airway narrowing and collapsibility.

The Effect of Adenotonsillectomy on Children's Behavior and Cognitive Performance with Obstructive Sleep Apnea Syndrome: State of the Art

(1) Background: This systematic review was designed to analyze adenotonsillectomy’s role in treating behavioural disorders and sleep-related quality of life in pediatric OSAS. (2) Methods: Papers that report pre-operative and post-operative outcomes by using the Epworth sleepiness scale, OSA-18, NEPSY, Conners’ rating scale, BRIEF, PSQ-SRBD, PedsQL and CBCL. We performed a comprehensive review of English papers published during the last 20 years regarding behavioural disorders in OSAS patients and adenotonsillectomy. (3) Results: We included 11 studies reporting behavioral outcomes and sleep related quality of life after surgery. We investigated changes in behavior and cognitive outcomes after AT, and we found significant improvements of the scores post-AT in almost all studies. After comparing the AT group and control group, only one study had no difference that reached significance at one year post-AT. In another study, it did not show any significant improvement in terms of all behavioural and cognitive outcomes. The questionnaires on sleep-related quality of life after AT (PSQ-SRBD or ESS or OSA-18 or KOSA) may improve with positive changes in sleep parameters (AHI, ODI and SpO2). Furthermore, there is a significantly higher decrease in OSAS symptoms than the pre-AT baseline score. (4) Conclusion: Future studies should pay more attention to characterizing patient populations as well as rapid surgical treatments through existing criteria.

Journey towards a personalised medicine approach for OSA: Can a similar approach to adult OSA be applied to paediatric OSA?

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.

Drug-induced sleep endoscopy findings in surgically-naïve obese vs non-obese children

OBJECTIVE

To determine if drug-induced sleep endoscopy (DISE) findings are different in obese versus non-obese pediatric patients with obstructive sleep apnea (OSA) or sleep-disordered breathing (SDB).

METHODS

Prospective, observational cohort study from June 2017 to June 2018 at a tertiary academic pediatric medical center that included surgically-naïve children ages 2-12 with diagnoses of OSA or sleep-disordered breathing. Subjects with a known diagnosis of craniofacial syndromes, genetic disorders, prior adenoidectomy or tonsillectomy, or chronic tonsillitis as the indication for surgery were excluded. Two groups were assessed for patterns of obstruction based on DISE videos at each anatomic airway level using a previously published DISE scoring system. The groups included obese subjects (BMI ≥ 95th percentile) and non-obese controls (BMI <85th percentile). Each video was graded by two blinded, fellowship-trained Pediatric Otolaryngologists.

RESULTS

Fifty-one patients were included, 26 non-obese and 25 obese. Based on anatomic airway level, there was no statistically significant difference in airway obstruction at the velum (p = 0.134), adenoid (p = 0.592), lateral pharyngeal walls (p = 0.867), tongue base (p = 0.977), or supraglottis (p = 0.428) between obese and non-obese children.

CONCLUSION

Our prospective study did not associate severity of obstruction with obesity status based on anatomic airway levels. Further studies are needed to elucidate the etiology of the high rate of persistent obstructive sleep apnea in obese children.

Tonsillectomy versus tonsillotomy for obstructive sleep-disordered breathing in children

BACKGROUND

Obstructive sleep-disordered breathing (oSDB) is a condition encompassing breathing problems when asleep due to upper airway obstruction. In children, hypertrophy of the tonsils and/or adenoids is thought to be the commonest cause. As such, (adeno)tonsillectomy has long been the treatment of choice. A rise in partial removal of the tonsils over the last decade is due to the hypothesis that tonsillotomy is associated with lower postoperative morbidity and fewer complications.

OBJECTIVES

To assess whether partial removal of the tonsils (intracapsular tonsillotomy) is as effective as total removal of the tonsils (extracapsular tonsillectomy) in relieving signs and symptoms of oSDB in children, and has lower postoperative morbidity and fewer complications.

SEARCH METHODS

We searched the Cochrane ENT Trials Register; Central Register of Controlled Trials (CENTRAL); MEDLINE; EMBASE; CINAHL; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials. The search date was 22 July 2019.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing the effectiveness of (adeno)tonsillectomy with (adeno)tonsillotomy in children aged 2 to 16 years with oSDB.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods and assessed the certainty of the evidence for our pre-defined outcomes using GRADE. Our primary outcomes were disease-specific quality of life, peri-operative blood loss and the proportion of children requiring postoperative medical intervention (with or without hospitalisation). Secondary outcomes included postoperative pain, return to normal activity, recurrence of oSDB symptoms as a result of tonsil regrowth and reoperation rates.

MAIN RESULTS

We included 22 studies (1984 children), with predominantly unclear or high risk of bias. Three studies used polysomnography as part of their inclusion criteria. Follow-up duration ranged from six days to six years. Although 19 studies reported on some of our outcomes, we could only pool the results from a few due both to the variety of outcomes and the measurement instruments used, and an absence of combinable data. Disease-specific quality of life Four studies (540 children; 484 (90%) analysed) reported this outcome; data could not be pooled due to the different outcome measurement instruments used. It is very uncertain whether there is any difference in disease-specific quality of life between the two surgical procedures in the short (0 to 6 months; 3 studies, 410 children), medium (7 to 13 months; 2 studies, 117 children) and long term (13 to 24 months; 1 study, 67 children) (very low-certainty evidence). Peri-operative blood loss We are uncertain whether tonsillotomy reduces peri-operative blood loss by a clinically meaningful amount (mean difference (MD) 14.06 mL, 95% CI 1.91 to 26.21 mL; 8 studies, 610 children; very low-certainty evidence). In sensitivity analysis (restricted to three studies with low risk of bias) there was no evidence of a difference between the groups. Postoperative complications requiring medical intervention (with or without hospitalisation) The risk of postoperative complications in the first week after surgery was probably lower in children who underwent tonsillotomy (4.9% versus 2.6%, risk ratio (RR) 1.75, 95% CI 1.06 to 2.91; 16 studies, 1416 children; moderate-certainty evidence). Postoperative pain Eleven studies (1017 children) reported this outcome. Pain was measured using various scales and scored by either children, parents, clinicians or study personnel. When considering postoperative pain there was little or no difference between tonsillectomy and tonsillotomy at 24 hours (10-point scale) (MD 1.09, 95% CI 0.88 to 1.29; 4 studies, 368 children); at two to three days (MD 0.93, 95% CI -0.14 to 2.00; 3 studies, 301 children); or at four to seven days (MD 1.07, 95% CI -0.40 to 2.53; 4 studies, 370 children) (all very low-certainty evidence). In sensitivity analysis (restricted to studies with low risk of bias), we found no evidence of a difference in mean pain scores between groups. Return to normal activity Tonsillotomy probably results in a faster return to normal activity. Children who underwent tonsillotomy were able to return to normal activity four days earlier (MD 3.84 days, 95% CI 0.23 to 7.44; 3 studies, 248 children; moderate-certainty evidence). Recurrence of oSDB and reoperation rates We are uncertain whether there is a difference between the groups in the short (RR 0.26, 95% CI 0.03 to 2.22; 3 studies, 186 children), medium (RR 0.35, 95% CI 0.04 to 3.23; 4 studies, 206 children) or long term (RR 0.21 95% CI 0.01 to 4.13; 1 study, 65 children) (all very low-certainty evidence).

AUTHORS' CONCLUSIONS

For children with oSDB selected for tonsil surgery, tonsillotomy probably results in a faster return to normal activity (four days) and in a slight reduction in postoperative complications requiring medical intervention in the first week after surgery. This should be balanced against the clinical effectiveness of one operation over the other. However, this is not possible to determine in this review as data on the long-term effects of the two operations on oSDB symptoms, quality of life, oSDB recurrence and need for reoperation are limited and the evidence is of very low quality leading to a high degree of uncertainty about the results. More robust data from high-quality cohort studies, which may be more appropriate for detecting differences in less common events in the long term, are required to inform guidance on which tonsil surgery technique is best for children with oSDB requiring surgery.

Role of ventilatory control instability in children with sleep-disordered breathing

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.

[Etiological treatment of Obstructive Sleep Apnea]

Research in the field of Obstructive Sleep Apnea (OSA) has been organized, and has profoundly transformed the quality of life of apneic patients, while even inviting dentofacial orthopedists to contribute to their symptomatic treatment. However, among the points still to be elucidated, the initial cause of the snoring that destabilizes the pharynx occupies a place apart. The objective of this article was to develop the proposal by Jacques Talmant regarding a mechanism capable of explaining the onset of OSA and for a therapy to treat pharyngeal destabilization during sleep. Based on published data, the etiopathogenesis of snoring and its consequences are described. Structural changes secondary to the vibratory trauma caused by snoring can affect each component of the pharyngeal structures and contribute to the collapsibility of this airway segment. By directly optimizing the development of ventilatory capabilities in their patients, orthodontists contribute, indirectly, to optimizing their cardiovascular and neuropsychological functions.

Apnea hypopnea indices categorized by REM/NREM sleep and sleep positions in 100 children with adenotonsillectomy for obstructive sleep apnea disease

OBJECTIVES

In pediatric obstructive sleep apnea (OSA), the relationship between rapid eye movement sleep and upper airway collapse, and between sleep position and airway dimensions are well known. However, the interrelations between these factors and the obstructive apnea hypopnea index (O-AHI) have not been thoroughly investigated.

METHODS

A retrospective study including 100 children who underwent adenotonsillectomy between March 2010 and July 2017. Total O-AHI was divided into four subcategories by sleep stage and position.

RESULTS

Preoperatively 14 of 47 mild cases of OSA (1 ≤ total O-AHI) and 17 of 18 moderate (5 ≤ total O-AHI) had time showing severe apnea (10 ≤ subcategorized O-AHI). Twenty-two of 24 severe cases (10 ≤ total O-AHI) exhibited very severe apnea (30 ≤ subcategorized O-AHI). All 11 very severe cases (30 ≤ total O-AHI) experienced more than 50 apnea events per hour in at least one of the O-AHI subcategories. After surgery, 23 of 70 cases classified as completely resolved (total O-AHI < 1) still had mild apnea in the O-AHI subcategories, and six of 13 cases who continued to experience apnea events had moderate-to-severe apnea. Seventeen cases worsened in the O-AHI subcategories, and total O-AHI deteriorated in two cases of the 17. The amount of REM sleep and use of the supine position increased significantly postoperatively in the quartile groups with the lowest baseline values (p < 0.0001).

CONCLUSIONS

When an unexpected AHI value is encountered, the O-AHI subcategories may be informative regarding the indications for surgery and evaluating the efficacy thereof.

Maxillary protraction to treat pediatric obstructive sleep apnea and maxillary retrusion: a preliminary report

INTRODUCTION

Midface retrusion creates a size deficiency problem in the upper airway that has been improved in children using surgical midface advancement and orthopedic protraction of the maxilla. The results of these treatments have been mostly promising at enlarging the pharyngeal airway. Recently introduced bone anchored maxillary protraction (BAMP) uses implant inserted devices in the jaws to pull the maxilla forward against a backward pressure to the lower jaw. This is a pilot study that examines the use of BAMP as a strategy to treat maxillary retrusion, malocclusion and children with obstructive sleep apnea.

METHODS

15 children, ages 9-16 years with maxillary retrusion creating a skeletal malocclusion were treated with bone anchored maxillary protraction (BAMP) and the results were compared against an untreated control group. 8 children in the treatment group also had sleep disordered breathing/obstructive sleep apnea. All subjects had lateral cephalograms before and after BAMP therapy. The OSA cohort completed the pediatric sleep questionnaire (PSQ) and polysomnography prior to and at the end of BAMP.

RESULTS

The majority of the OSA children (n = 5) showed improvement in their apnea-hypopnea index (AHI) and OSA symptoms after BAMP. Preliminary results of BAMP therapy show improvement in respiratory and airway parameters in OSA children with a highly significant change in the forward position of the upper jaw and enlargement in the nasopharyngeal to oropharyngeal junction as compared to an age and sex matched untreated control group. The outcomes were dependent on the age of treatment initiation and patient compliance.

CONCLUSIONS

This preliminary work suggests that bone anchored maxillary protraction may be considered as an adjunctive treatment option in adolescents for improving midface retrusion and sleep apnea, but further work is needed to explore this therapy.

Obstructive Sleep Apnea Detection Using Difference in Feature and Modified Minimum Distance Classifier

The current gold standard of Obstructive Sleep Apnea (OSA) diagnosis involves the use of a Polysomnography (PSG) system which requires the patient to stay in the hospital for overnight recording. The process is uncomfortable for the patient and it disturbs the patient's sleep pattern. On the other hand, it is well known that some acoustic features of the snoring sounds are good indicators of the presence of OSA, and a variety of acoustic OSA detection algorithms have been reported in the literature. Typically, these algorithms use multiple features and a relatively complex classifier, which are not ideal for handling the huge over-night data. In this paper, we propose an algorithm that uses a single feature and a relatively simple classifier. The proposed feature is the difference between two carefully selected Mel-frequency cepstral coefficients (MFCCs) of the snoring sound samples. The proposed classifier is derived based on a modified minimum distance criterion. The proposed algorithm has been tested with patient data. The results show that the proposed algorithm outperforms existing algorithms and is able to achieve up to 97.1% detection accuracy.

Update on pathophysiology and treatment of childhood obstructive sleep apnea syndrome

Obstructive sleep apnea syndrome (OSAS) is common in childhood and is characterized by recurrent upper airway obstructive events during sleep that produce significant neurocognitive and cardiovascular sequelae. The pathophysiology of childhood OSAS is complex and involves mechanical airway obstruction often secondary to adenotonsillar hypertrophy. However, neuromotor abnormalities and instability of central ventilatory control are also implicated. Several surgical and non-surgical treatment options for childhood OSAS are available, and will be discussed. Some of these include adenotonsillectomy, lingual tonsillectomy, supraglottoplasty, continuous positive airway pressure (CPAP), rapid maxillary expansion, oral appliance therapy, anti-inflammatory treatments, and supplemental oxygen.

High-Flow, Heated, Humidified Air Via Nasal Cannula Treats CPAP-Intolerant Children With Obstructive Sleep Apnea

STUDY OBJECTIVES

Continuous positive airway pressure (CPAP) is effective but challenging for children with obstructive sleep apnea (OSA). High-flow air via open nasal cannula (HFNC) as treatment in children remains controversial. We report the efficacy of HFNC in children with OSA and CPAP intolerance, a titration protocol, and a discussion of potential mechanisms.

METHODS

Patients aged 1 to 18 years with OSA (defined by obstructive apnea-hypopnea index [OAHI] greater than 1 event/h) and CPAP intolerance were enrolled. Routine polysomnography data obtained during 1 night wearing HFNC was compared with diagnostic data by Wilcoxon rank-sum test.

RESULTS

Ten school-age subjects (representing all patients attempting HFNC at our institution to date) with varied medical conditions, moderate to severe OSA, and CPAP intolerance wore HFNC from 10 to 50 L/min of room air with oxygen supplementation if needed (room air alone for 6 of the 10). HFNC reduced median OAHI from 11.1 events/h (interquartile range 8.7-18.8 events/h) to 2.1 events/h (1.7-2.2 events/h; P = .002); increased oxyhemoglobin saturation (SpO₂) mean from 91.3% (89.6% to 93.5%) to 94.9% (92.4% to 96.0%; P < .002); increased SpO₂ nadir from 76.0% (67.3% to 82.3%) to 79.5% (77.2% to 86.0%; P = .032); decreased SpO₂ desaturation index from 19.2 events/h (12.7-25.8 events/h) to 6.4 events/h (4.7-10.7 events/h; P = .013); and reduced heart rate from 88 bpm (86-91 bpm) to 74 bpm (67-81 bpm; P = .004). Stratified analysis of the 6 subjects with only room air via HFNC, the OAHI, obstructive hypopnea index, and mean SpO₂ still demonstrated improvements (P = .031).

CONCLUSIONS

High-flow nasal cannula reduces respiratory events, improves oxygenation, reduces heart rate, and may be effective for CPAP intolerant children with moderate to severe OSA. Our data suggest HFNC warrants further study and consideration by payers as OSA therapy.

From oral facial dysfunction to dysmorphism and the onset of pediatric OSA

The upper airway is a collapsible tube, and its collapsibility increases during sleep. Extrinsic factors such as atypical craniofacial features may increase the risks of airway collapse. We review early development of oral-facial structures and the anatomical variants that may be present at birth and can impact nasal breathing. After birth, there is a continuous interaction between orofacial functions and growth of anatomic features. We review the dysfunctions identified to date that may impact orofacial development leading to sleep-disordered-breathing through changes in the orofacial growth. The identification of risk-factors, ultimately leading to full-blown obstructive sleep apnea, may allow early recognition of these factors and the development of treatments to eliminate early problems or at least decrease their impact.

Upper Airway Reflexes are Preserved During Dexmedetomidine Sedation in Children With Down Syndrome and Obstructive Sleep Apnea

STUDY OBJECTIVES

The assessment of pharyngeal collapsibility is difficult to perform in children under normal sleep. An alternative is to perform the assessment under an anesthetic, such as dexmedetomidine (DEX), that induces non-rapid eye movement (NREM) sleep. The objectives of this study were to compare critical closing airway pressure (Pcrit) obtained during natural sleep to that obtained under DEX in patients with Down syndrome (DS) and persistent obstructive sleep apnea (OSA) and determine whether Pcrit measured under sedation predicts the severity of OSA.

METHODS

The passive and active Pcrit, which represent airway passive mechanical properties and active dynamic responses to airway obstruction, respectively, were measured. Upper airway reflex activity was estimated by calculating the difference between active and passive Pcrit. Subjects underwent overnight polysomnography during which Pcrit was measured during normal sleep. Pcrit was also measured during DEX sedation at a dose of 2 μg/kg/h.

RESULTS

The study included 50 patients with median age of 11.4 years (interquartile range: 7.0-13.9) and median body mass index of 23.0 kg/m² (interquartile range: 18.4-29.1), 66% male and 80% Caucasian. Passive Pcrit was significantly higher than active Pcrit when measured during normal sleep and DEX-induced sleep. There was a positive association between apnea-hypopnea index and passive Pcrit (Spearman r = 0.53, P = .0001) and active Pcrit (r = 0.55, P = .0002) under DEX-induced sleep. There were no significant differences between the Pcrit measurements during natural sleep and during DEX sedation.

CONCLUSION

Patients with OSA can compensate for airway obstruction under DEX-induced sleep. The close association between Pcrit and apnea-hypopnea index suggests that airway responses with DEX sedation parallel those seen during natural sleep.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT01902407.

Physical Stability of 20% Lipid Injectable EmulsionsviaSimulated Syringe Infusion: Effects of GlassvsPlastic Product Packaging

BACKGROUND

The United States Pharmacopeia (USP) has proposed large-globule-size limits to ensure the physical stability of lipid injectable emulsions, expressed as the percent fat >5 microm, or PFAT(5), not exceeding 0.05%. Visibly obvious phase separation as free oil has been shown to occur in some samples if PFAT(5) is >0.4%. We recently found that lipids, newly packaged in plastic (P), exceed the proposed USP limits and seem to produce less stable total nutrient admixtures compared with those made from conventional glass (G), which do meet proposed USP standards. We tested the possible stability differences between 20% lipid injectable emulsions in either P or G in a simulated neonatal syringe infusion study.

METHODS

Eighteen individual syringes were prepared from each 20% lipid injectable emulsion product (n = 36) and attached to a syringe pump set at an infusion rate of 0.5 mL/hour. The starting PFAT(5) levels were measured at time 0 and after 24 hours of infusion, using a laser-based light obscuration technique as described by the USP Chapter <729>. The data were assessed by a 2-way analysis of variance (ANOVA) with Container (G vs P) and Time as the independent variables and PFAT as the dependent variable.

RESULTS

At time 0, the starting PFAT(5) level for lipids packaged in G was 0.006% +/- 0.001% vs 0.162% +/- 0.026% for P, whereas at the end of the infusion they were 0.013% +/- 0.003% and 0.328% +/- 0.046%, respectively. Significant differences were noted overall between groups for Container, Time, and Container-Time interaction (all p < .001). Bonferroni tests showed significant differences in PFAT(5) levels between Containers at time 0 (T-0; p < .001) and T-0 vs T-24 for P-based lipids (p < .001), whereas no such differences were noted for Time for the G-based lipids. Similar results were noted for PFAT(10) levels.

CONCLUSIONS

We confirm that presently available lipid injectable emulsions packaged in newly introduced plastic containers exceed the proposed USP <729> PFAT(5) limits and subsequently become significantly less stable during a simulated syringe-based infusion. Although modest growth (p = NS) in large-diameter fat globules was observed for the glass-based lipids, they remained within proposed USP globule size limits throughout the study. Glass-based lipids seem to be a more stable dosage form and potentially a safer way to deliver lipids via syringe infusion to critically ill neonates.

Indications for tonsillectomy stratified by the level of evidence

Background: One of the most significant clinical trials, demonstrating the efficacy of tonsillectomy (TE) for recurrent throat infection in severely affected children, was published in 1984. This systematic review was undertaken to compile various indications for TE as suggested in the literature after 1984 and to stratify the papers according to the current concept of evidence-based medicine. Material and methods: A systematic Medline research was performed using the key word of "tonsillectomy" in combination with different filters such as "systematic reviews", "meta-analysis", "English", "German", and "from 1984/01/01 to 2015/05/31". Further research was performed in the Cochrane Database of Systematic Reviews, National Guideline Clearinghouse, Guidelines International Network and BMJ Clinical Evidence using the same key word. Finally, data from the "Trip Database" were researched for "tonsillectomy" and "indication" and "from: 1984 to: 2015" in combination with either "systematic review" or "meta-analysis" or "metaanalysis". Results: A total of 237 papers were retrieved but only 57 matched our inclusion criteria covering the following topics: peritonsillar abscess (3), guidelines (5), otitis media with effusion (5), psoriasis (3), PFAPA syndrome (6), evidence-based indications (5), renal diseases (7), sleep-related breathing disorders (11), and tonsillitis/pharyngitis (12), respectively. Conclusions: 1) The literature suggests, that TE is not indicated to treat otitis media with effusion. 2) It has been shown, that the PFAPA syndrome is self-limiting and responds well to steroid administration, at least in a considerable amount of children. The indication for TE therefore appears to be imbalanced but further research is required to clarify the value of surgery. 3) Abscesstonsillectomy as a routine is not justified and indicated only for cases not responding to other measures of treatment, evident complications, or with a significant history of tonsillitis. In particular, interval-tonsillectomy is not justified as a routine. 4) TE, with or without adenoidectomy, is efficacious to resolve sleep-related breathing disorders resulting from (adeno)tonsillar hypertrophy in children. However, the benefit is reduced by co-morbidities, such as obesity, and further research is required to identify prognostic factors for this subgroup of patients. Further research is indicated to clarify selection criteria not only for this subpopulation that may benefit from less invasive procedures such as tonsillotomy in the long-term. 5) Further trials are also indicated to evaluate the efficacy of TE on the clinical course in children with psoriasis guttata as well as on psoriasis vulgaris in adults, not responding to first-line therapy. 6) Conflicting results were reported concerning the role of TE in the concert to treat Ig-A nephropathy, mandating further clinical research. 7) Most importantly, randomized-controlled clinical trials with an adequate long-term follow-up are desirable to clarify the benefit of TE in patients with recurrent episodes of tonsillitis, with or without pharyngitis. Factors like age, spontaneous healing rate and postoperative quality of life have to be included when comparing TE with antibiotic therapy.

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.

Application of desaturation index in post-surgery follow-up in children with obstructive sleep apnea syndrome

Adenotonsillectomy is recommended for children who need surgery for obstructive sleep apnea syndrome (OSAS). Overnight, polysomnography (PSG) is suggested for post-surgery follow-up, but this diagnostic technique is time consuming and inconvenient. Desaturation index (DI) has been reported as a good tool for predicting both the presence and severity of OSAS in children. The purpose of this study was to determine the usefulness of the DI for post-surgery follow-up of children with OSAS. This retrospective study enrolled 42 children, aged 3-12 years, who were snorers diagnosed with OSAS by overnight PSG and who underwent an adenotonsillectomy. Pre- and postoperative PSG parameters, nocturnal pulse oximetry data, and modified Epworth sleepiness scale scores were assessed. Previously determined cut-off DI values (2.05, 3.50, and 4.15 for mild, moderate, and severe OSAS, respectively) were used to predict residual OSAS. Of the 42 children, obvious improvements were observed in apnea-hypopnea index (AHI, decreased 45.5 %), arousal index (decreased 30.5 %), DI (decreased 40.4 %), and snore index (decreased 100.3 %) compared with the preoperative measurements. Among these objective PSG measures, DI had the strongest correlation with AHI both pre- and post-surgeries (r = 0.947 and r = 0.954, respectively; p all <0.001). The DI change, before and after surgery, also had the strongest positive correlation to the AHI change (r = 0.482 and p = 0.001). Using the previously determined DI cut-off values to predict postoperative residual OSAS, there was a good positive predictive value (92.6 %) for mild residual OSAS and a good negative predictive value for moderate and severe residual OSAS (85.2 and 89.7 %, respectively). These findings suggest that DI, as determined using a nocturnal pulse oximeter, may be an alternative tool for postoperative evaluation and follow-up of children with OSAS.

Computational fluid dynamics upper airway effective compliance, critical closing pressure, and obstructive sleep apnea severity in obese adolescent girls

Obstructive sleep apnea syndrome (OSAS) is associated with anatomical abnormalities restricting upper airway size and functional factors decreasing pharyngeal dilator activity in sleep. In this study we hypothesized that OSAS is also associated with altered pharyngeal mechanical compliance during wakefulness. Five OSAS and six control obese girls between 14 and 18 years of age were studied. All underwent polysomnography, critical closing pressure (P_crit) studies, and dynamic MRI of the upper airway during awake tidal breathing. Effective airway compliance was defined as the slope of cross-sectional area vs. average pressure between maximum inspiration and maximum expiration along the pharyngeal airway. Pharyngeal pressure fields were calculated by using image-based computational fluid dynamics and nasal resistance. Spearman correlations were calculated to test associations between apnea-hypopnea index (AHI), P_crit, and airway compliance. Effective compliances in the nasopharynx (C_NP) and velopharynx (C_VP) were lower and negative in OSAS compared with controls: -4.4 vs. 1.9 (mm²/cmH₂O, P = 0.012) and -2.1 vs. 3.9 (mm²/cmH₂O, P = 0.021), respectively, suggesting a strong phasic pharyngeal dilator activity during inspiration in OSAS compared with controls. For all subjects, C_NP and AHI correlated negatively (r_S = -0.69, P = 0.02), and passive P_crit correlated with C_NP (r_S = -0.76, P = 0.006) and with AHI (r_S = 0.86, P = 0.0006). Pharyngeal mechanics obtained during wakefulness could be used to characterize subjects with OSAS. Moreover, negative effective compliance during wakefulness and its correlation to AHI and P_crit suggest that phasic dilator activity of the upper pharynx compensates for negative pressure loads in these subjects.

Analogue simulation of pharyngeal airflow response to Twin Block treatment in growing patients with Class II(1) and mandibular retrognathia

The flow dynamics of respiratory airflow is the basic factor that influences the ventilation function of the upper airway. This research aimed to investigate the pharyngeal flow field characteristics after Twin Block (TB) treatment in growing patients with Class II(1) and mandibular retrognathia by computation fluid dynamics (CFD) simulation. Cone beam computed tomography (CBCT) scans of patients who have completed TB treatment (n = 30) and about to accept TB treatment (n = 30) were reconstructed. After CFD simulation, correlations between the pharyngeal pressure drop and morphological parameters were further analyzed. During inspiration, we found that the pressure minimum occurred in the hypopharynx, while the maximum pressure drop and velocity was located in the oropharynx. After TB treatment, the oropharynx and hypopharynx showed significant differences in airflow features, and the most obvious change was observed in the oropharynx. A significant correlation was discovered between the change amount of oropharyngeal pressure drop and volume (r = 0.694, p = 0.001), mean cross-sectional area (r = 0.859, p = 0.000), and ratio of the minimum and mean cross-sectional area (r = 0.898, p = 0.000) of the oropharynx. Our research suggested that the pharyngeal airflow characteristics response positively to mandibular advancement with the enlargement in volume, cross-sectional area and more uniform oropharyngeal area distribution.

Outcome of Adenotonsillectomy for Obstructive Sleep Apnea in Obese and Normal-Weight Children

OBJECTIVES: 1) To evaluate the relative severity of obstructive sleep apnea (OSA) in obese and normal-weight children; 2) to compare changes in respiratory parameters after adenotonsillectomy in obese and normal-weight children.

STUDY DESIGN AND SETTING: Prospective controlled trial that included children aged 3 to 18 years. All study participants underwent pre- and postoperative polysomnography.

RESULTS: The study population included 33 obese children and 39 normal-weight controls. Preoperatively, the median obstructive apnea-hypopnea index (AHI) was 23.4 (range 3.7-135.1) for obese and 17.1 (range 3.9-36.5) for controls ( P < 0.001). Postoperatively, the AHI was 3.1 (range 0-33.1) for obese and 1.9 (range 0.1-7.0) for controls ( P < 0.01). Twenty-five obese children (76%) and 11 controls (28%) had persistent OSA.

CONCLUSION AND SIGNIFICANCE: AHI scores are higher in obese than in normal-weight children with OSA. Both groups show a dramatic improvement in AHI after adenotonsillectomy, but persistent OSA is more common in obese children.

Airway Resistance in Children with Obstructive Sleep Apnea Syndrome

STUDY OBJECTIVES

Enlarged tonsils and adenoids, the main cause of obstructive sleep apnea syndrome (OSAS) in children, results in upper airway (UA) loading. This contributes to the imbalance between structural and neuromotor factors ultimately leading to UA collapse during sleep. However, it is unknown whether this UA loading can cause elevated airway resistance (AR) during wakefulness. We hypothesized that children with OSAS have elevated AR compared to controls and that this improves after OSAS treatment.

METHODS

Case control study performed at an academic hospital. Children with OSAS and nonsnoring healthy controls underwent baseline polysomnography and spirometry, and AR measurement by body plethysmography while breathing via an orofacial mask. Children with OSAS repeated the previously mentioned tests after adenotonsillectomy.

RESULTS

31 OSAS participants (mean age ± SD = 9.7 ± 3.0 y, obstructive apnea-hypopnea index (OAHI) median [range] = 14.9 [2-58.7] events/h, body mass index [BMI] z = 1.5 ± 1) and 31 controls (age = 10.5 ± 2.5 y, P = 0.24; OAHI = 0.4 [0-1.4], P < 0.001; BMI z = 0.9 ± 1, P = 0.01) were tested. OSAS AR at baseline was 3.9 [1.5-10.3] cmH2O/L/sec and controls 2.8 [1.4 - 6.2] (P = 0.027). Both groups had similar spirometry results. 20 patients with OSAS were tested 6.4 ± 6.6 mo after adenotonsillectomy. OAHI decreased from 15.2 [2.1-58.7] to 0.5 [0 - 5.1] events/h postoperatively (P < 0.001), and AR decreased from 4.3 [1.5 - 10.3] to 2.8 [1.7 - 4.7] cmH2O/L/sec (P = 0.009).

CONCLUSIONS

Children with OSAS have elevated AR that decreases after treatment. This is likely because of upper airway loading secondary to adenotonsillar hypertrophy and may contribute to the increased frequency of respiratory diseases in untreated children with OSAS.

Utilizing inspiratory airflows during standard polysomnography to assess pharyngeal function in children during sleep

OBJECTIVES

Obstructive sleep apnea (OSA) is the result of pharyngeal obstruction that occurs predominantly during REM in children. Pathophysiologic mechanisms responsible for upper airway obstruction, however, are poorly understood. Thus, we sought to characterize upper airway obstruction in apneic compared to snoring children during sleep. We hypothesized that apneic compared to snoring children would exhibit an increased prevalence and severity of upper airway obstruction, that would be greater in REM compared to non-REM, and would improve following adenotonsillectomy.

STUDY DESIGN

Apneic children were assessed with routine polysomnography before and after adenotonsillectomy, and compared to snoring children matched for gender, age, and BMI z-score. In addition to traditional scoring metrics, the following were used to characterize upper airway obstruction: maximal inspiratory airflow (%VI max) and percent of time with inspiratory flow-limited breathing (%IFL).

RESULTS

OSA compared to snoring children had similar degrees of upper airway obstruction in non-REM; however, during REM, children with sleep apnea exhibited a higher %IFL (98 ± 2% vs.73 ± 8%, P < 0.01) and lower %VI max (56 ± 6 vs.93 ± 10%, P < 0.01). In children with OSA, CO2 levels were elevated during both wake and sleep. Following adenotonsillectomy, upper airway obstruction improved during REM manifest by decreased %IFL (98 ± 2 to 63 ± 9%, P = 0.04), increased %VI max (56 ± 6 to 95 ± 5%, P = 0.01) and decreased CO2 levels.

CONCLUSIONS

Differences in the prevalence and severity upper airway obstruction suggest impaired compensatory responses during REM in children with OSA, which improved following adenotonsillectomy.

Symbolic dynamics of pulse transit time and heart period in children with upper airway obstruction

Upper airway obstruction (UAO) is a relatively common condition during childhood that is characterized by periods of partial or complete upper airway closure, resulting in restless sleep. It has also been suggested that UAO triggers early cardiovascular changes that may predispose to an increased risk of developing cardiovascular diseases later in life. The aim of this study was to assess the temporal dynamics of heart period (HP) and pulse transit time (PTT) during quite, event-free periods of sleep in children with UAO (n = 40) and matched healthy controls. The dynamics of HP and PTT were symbolized based on the sextiles of their distribution and words of length three were formed and classified into four types based on their patterns. Joint symbolic dynamics represent the concomitant occurrence of words in HP and PTT. Children with UAO showed a significantly increased frequency in word types of monotonously increasing and decreasing HP and PTT as well as joint dynamics across all stages of sleep. The dynamics of HP showed a marked sleep stage dependence, while PTT dynamics appeared to be relatively unaffected. In conclusion, cardiovascular dynamics are altered in children with UAO during scored event-free sleep, indicative of frequent bursts in sympathetic nervous system activity, possibly reflecting subcortical arousal responses to brief and subtle increases in UAO.

Negative Expiratory Pressure Technique: An Awake Test to Measure Upper Airway Collapsibility in Adolescents

STUDY OBJECTIVES

Upper airway (UA) collapsibility is a major pathophysiologic feature of the obstructive sleep apnea syndrome (OSAS). In adolescents, it is measured by obtaining the slope of pressure-flow relationship (SPF) while applying negative nasal pressure during sleep. An easier technique to assess UA collapsibility, consisting of application of negative expiratory pressure (NEP) during wakefulness, has demonstrated differences between control and OSAS subjects. We hypothesized that the NEP technique would correlate with SPF as a measurement of UA collapsibility in adolescents.

DESIGN

During wakefulness, NEP of -5 cm H2O in the seated and supine position was applied during the first second of expiration. The area under the expiratory flow-volume curve during NEP was compared to tidal breathing (RatioNEP). In addition, adolescents underwent SPF measurements during sleep. Two SPF techniques were performed to measure the activated and relatively hypotonic UA.

SETTING

Pediatric sleep laboratory.

PARTICIPANTS

Seven adolescents with OSAS and 20 controls.

RESULTS

In the seated position, there was a correlation between RatioNEP and both hypotonic SPF (r = -0.39, P = 0.04) and activated SPF (r = -0.62, P = 0.001). In the supine position, there was a correlation between RatioNEP and activated SPF (r = -0.43, P = 0.03) and a trend for hypotonic SPF (r = -0.38, P = 0.06).

CONCLUSIONS

The negative expiratory pressure (NEP) technique correlates with the hypotonic and activated slope of pressure-flow relationship measurements. The seated position showed the strongest correlation. The NEP technique can be used as an alternative method to evaluate upper airway collapsibility in adolescents.

Predictors of complications following adenotonsillectomy in children with severe obstructive sleep apnea

OBJECTIVE

To identify pre-operative risk factors predicting complications following adenotonsillectomy in children with severe OSA.

METHODS

Retrospective chart review in an academic tertiary care center. Children with symptoms of OSA with overnight polysomnography (PSG) revealing apnea-hypopnea index (AHI) >10, who underwent adenotonsillectomy with overnight postoperative observation between 2008 and 2012. Univariate logistic regression was used to assess odds ratio (OR) of individual risk factors versus postoperative complications such as overnight desaturations <90%, length of stay (LOS)>24 h, supplemental oxygen requirement, and transfer to a higher level of care.

RESULTS

All patients (n=157) with severe OSA were observed overnight. Mean age was 5.3±3.7 years. Twenty-five (15.9%) patients had LOS>24 h. Forty-two (26.8%) had overnight desaturations <90%. AHI ≥15 and O2 saturation nadir <80% on preop polysomnography (PSG) were independent predictors of post-op O2 saturation <90% and LOS>24 h. (p<0.05). PSG minimum saturation <80% was the strongest predictor of all variables examined with an OR of 6.98 (3.15-15.48, 95% CI) for desaturation <90% and 5.19 (2.11-12.75, 95% CI) for LOS>24 h. Preop PSG O2 saturation<90% predicted overnight post op oxygen requirement with an OR of 3.38 (1.39-8.25, 95%CI).

CONCLUSIONS

Preoperative polysomnography yields significant independent predictors of post-op complications in children with OSA. While AHI is a significant independent predictor, minimum O2 saturation on preop PSG appeared the strongest predictor when <80%. Patients with these risk factors, especially low O2 on PSG, warrant overnight observation with continuous pulse oximetry.

Tonsillectomy or adenotonsillectomy versus non-surgical management for obstructive sleep-disordered breathing in children

BACKGROUND

Obstructive sleep-disordered breathing (oSDB) is a condition that encompasses breathing problems when asleep, due to an obstruction of the upper airways, ranging in severity from simple snoring to obstructive sleep apnoea syndrome (OSAS). It affects both children and adults. In children, hypertrophy of the tonsils and adenoid tissue is thought to be the commonest cause of oSDB. As such, tonsillectomy - with or without adenoidectomy - is considered an appropriate first-line treatment for most cases of paediatric oSDB.

OBJECTIVES

To assess the benefits and harms of tonsillectomy with or without adenoidectomy compared with non-surgical management of children with oSDB.

SEARCH METHODS

We searched the Cochrane Register of Studies Online, PubMed, EMBASE, CINAHL, Web of Science, Clinicaltrials.gov, ICTRP and additional sources for published and unpublished trials. The date of the search was 5 March 2015.

SELECTION CRITERIA

Randomised controlled trials comparing the effectiveness and safety of (adeno)tonsillectomy with non-surgical management in children with oSDB aged 2 to 16 years.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by The Cochrane Collaboration.

MAIN RESULTS

Three trials (562 children) met our inclusion criteria. Two were at moderate to high risk of bias and one at low risk of bias. We did not pool the results because of substantial clinical heterogeneity. They evaluated three different groups of children: those diagnosed with mild to moderate OSAS by polysomnography (PSG) (453 children aged five to nine years; low risk of bias; CHAT trial), those with a clinical diagnosis of oSDB but with negative PSG recordings (29 children aged two to 14 years; moderate to high risk of bias; Goldstein) and children with Down syndrome or mucopolysaccharidosis (MPS) diagnosed with mild to moderate OSAS by PSG (80 children aged six to 12 years; moderate to high risk of bias; Sudarsan). Moreover, the trials included two different comparisons: adenotonsillectomy versus no surgery (CHAT trial and Goldstein) or versus continuous positive airway pressure (CPAP) (Sudarsan). Disease-specific quality of life and/or symptom score (using a validated instrument): first primary outcomeIn the largest trial with lowest risk of bias (CHAT trial), at seven months, mean scores for those instruments measuring disease-specific quality of life and/or symptoms were lower (that is, better quality of life or fewer symptoms) in children receiving adenotonsillectomy than in those managed by watchful waiting:- OSA-18 questionnaire (scale 18 to 126): 31.8 versus 49.5 (mean difference (MD) -17.7, 95% confidence interval (CI) -21.2 to -14.2);- PSQ-SRBD questionnaire (scale 0 to 1): 0.2 versus 0.5 (MD -0.3, 95% CI -0.31 to -0.26);- Modified Epworth Sleepiness Scale (scale 0 to 24): 5.1 versus 7.1 (MD -2.0, 95% CI -2.9 to -1.1).No data on this primary outcome were reported in the Goldstein trial.In the Sudarsan trial, the mean OSA-18 score at 12 months did not significantly differ between the adenotonsillectomy and CPAP groups. The mean modified Epworth Sleepiness Scale scores did not differ at six months, but were lower in the surgery group at 12 months: 5.5 versus 7.9 (MD -2.4, 95% CI -3.1 to -1.7). Adverse events: second primary outcomeIn the CHAT trial, 15 children experienced a serious adverse event: 6/194 (3%) in the adenotonsillectomy group and 9/203 (4%) in the control group (RD -1%, 95% CI -5% to 2%).No major complications were reported in the Goldstein trial.In the Sudarsan trial, 2/37 (5%) developed a secondary haemorrhage after adenotonsillectomy, while 1/36 (3%) developed a rash on the nasal dorsum secondary to the CPAP mask (RD -3%, 95% CI -6% to 12%). Secondary outcomesIn the CHAT trial, at seven months, mean scores for generic caregiver-rated quality of life were higher in children receiving adenotonsillectomy than in those managed by watchful waiting. No data on this outcome were reported by Sudarsan and Goldstein.In the CHAT trial, at seven months, more children in the surgery group had normalisation of respiratory events during sleep as measured by PSG than those allocated to watchful waiting: 153/194 (79%) versus 93/203 (46%) (RD 33%, 95% CI 24% to 42%). In the Goldstein trial, at six months, PSG recordings were similar between groups and in the Sudarsan trial resolution of OSAS (Apnoea/Hypopnoea Index score below 1) did not significantly differ between the adenotonsillectomy and CPAP groups.In the CHAT trial, at seven months, neurocognitive performance and attention and executive function had not improved with surgery: scores were similar in both groups. In the CHAT trial, at seven months, mean scores for caregiver-reported ratings of behaviour were lower (that is, better behaviour) in children receiving adenotonsillectomy than in those managed by watchful waiting, however, teacher-reported ratings of behaviour did not significantly differ.No data on these outcomes were reported by Goldstein and Sudarsan.

AUTHORS' CONCLUSIONS

In otherwise healthy children, without a syndrome, of older age (five to nine years), and diagnosed with mild to moderate OSAS by PSG, there is moderate quality evidence that adenotonsillectomy provides benefit in terms of quality of life, symptoms and behaviour as rated by caregivers and high quality evidence that this procedure is beneficial in terms of PSG parameters. At the same time, high quality evidence indicates no benefit in terms of objective measures of attention and neurocognitive performance compared with watchful waiting. Furthermore, PSG recordings of almost half of the children managed non-surgically had normalised by seven months, indicating that physicians and parents should carefully weigh the benefits and risks of adenotonsillectomy against watchful waiting in these children. This is a condition that may recover spontaneously over time.For non-syndromic children classified as having oSDB on purely clinical grounds but with negative PSG recordings, the evidence on the effects of adenotonsillectomy is of very low quality and is inconclusive.Low-quality evidence suggests that adenotonsillectomy and CPAP may be equally effective in children with Down syndrome or MPS diagnosed with mild to moderate OSAS by PSG.We are unable to present data on the benefits of adenotonsillectomy in children with oSDB aged under five, despite this being a population in whom this procedure is often performed for this purpose.

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.

Symbolic dynamics of respiratory cycle related sleep EEG in children with sleep disordered breathing

Childhood sleep disordered breathing (SDB) is characterized by an increased work of breathing, restless night sleep and excessive daytime sleepiness and has been associated with cognitive impairment, behavioral disturbances and early cardiovascular changes. Compared to normal controls, children with SDB have elevated arousal thresholds and their sleep EEG may elicit cortical activation associated with arousals but often too subtle to be visually scored. The aim of this study was to assess EEG complexity throughout the respiratory cycle based on symbolic dynamics in children with SDB (n=40) and matched healthy controls. EEG amplitude values were symbolized based on the quartiles of their distribution and words of length 3 were formed and classed into 4 types based on their patterns. Children with SDB showed less complex EEG dynamics in non-REM sleep that was unrelated to the respiratory phase. In REM sleep normal children showed a respiratory phase-related reduction in EEG variability during the expiratory phase compared to inspiration, which was not apparent in children with SDB. In conclusion, respiratory cycle related EEG dynamics are altered in children with SDB during REM sleep and indicate changes in cortical activity.

Respiratory cortical processing to inspiratory resistances during wakefulness in children with the obstructive sleep apnea syndrome

Children with the obstructive sleep apnea syndrome (OSAS) have impaired respiratory afferent cortical processing during sleep that persists after treatment of OSAS. However, it is unknown whether this impairment is present during wakefulness and, if so, whether it improves after OSAS treatment. We hypothesized that children with OSAS, during wakefulness, have abnormal cortical processing of respiratory stimuli manifested by blunted respiratory-related evoked potentials (RREP) and that this resolves after OSAS treatment. We measured RREP during wakefulness in 26 controls and 21 children with OSAS before and after treatment. Thirteen participants with OSAS repeated testing 3-6 mo after adenotonsillectomy. RREP were elicited by interruption of inspiration by total occlusion and 30 and 20 cmH2O/l per s resistances. Nf at Fz latency elicited by occlusion was longer in children with OSAS at baseline compared with controls (78.8 ± 24.8 vs. 63.9 ± 19.7 ms, P = 0.05). All other peak amplitudes and latencies were similar between the two groups. After OSAS treatment, Nf at Fz latency elicited by 30 cmH2O/l per s decreased significantly (before, 88 ± 26 vs. after, 71 ± 25 ms, P = 0.02), as did that elicited by 20 cmH2O/l per s (85 ± 27 vs. 72 ± 24 ms, P = 0.004). The amplitude of N1 at Cz elicited by occlusion increased from -3.4 ± 5.6 to -7.4 ± 3 μV (P = 0.049) after treatment. We concluded that children with OSAS have partial delay of respiratory afferent cortical processing during wakefulness that improves after treatment.

Confronting the challenges of effective pain management in children following tonsillectomy

Tonsillectomy is an extremely common surgical procedure associated with significant morbidity and mortality. The post-operative challenges include: respiratory complications, post-tonsillectomy hemorrhage, nausea, vomiting and significant pain. The present model of care demands that most of these children are managed in an ambulatory setting. The recent Federal Drug Agency (FDA) warning contraindicating the use of codeine after tonsillectomy in children represents a significant change of practice for many pediatric otolaryngological surgeons. This introduces a number of other safety concerns when deciding on a safe alternative to codeine, especially since most tonsillectomy patients are managed by lay primary caregiver's at home. This review outlines the safety issues and proposes, based on currently available evidence, a preventative multi-modal strategy to manage pain, nausea and vomiting without increasing the risk of post-tonsillectomy bleeding.

Pediatric obstructive sleep apnea

Obstructive sleep apnea syndrome (OSAS) is a disorder of airway obstruction with multisystem implications and associated complications. OSAS affects children from infancy to adulthood and is responsible for behavioral, cognitive, and growth impairment as well as cardiovascular and perioperative respiratory morbidity and mortality. OSAS is associated commonly with comorbid conditions, including obesity and asthma. Adenotonsillectomy is the most commonly used treatment option for OSAS in childhood, but efforts are underway to identify medical treatment options.

Respiratory cycle-related electroencephalographic changes during sleep in healthy children and in children with sleep disordered breathing

STUDY OBJECTIVE

To investigate respiratory cycle-related electroencephalographic changes (RCREC) in healthy children and in children with sleep disordered breathing (SDB) during scored event-free (SEF) breathing periods of sleep.

DESIGN

Interventional case-control repeated measurements design.

SETTING

Paediatric sleep laboratory in a hospital setting.

PARTICIPANTS

Forty children with SDB and 40 healthy, age- and sex-matched children.

INTERVENTIONS

Adenotonsillectomy in children with SDB and no intervention in controls.

MEASUREMENTS AND RESULTS

Overnight polysomnography; electroencephalography (EEG) power variations within SEF respiratory cycles in the overall and frequency band-specific EEG within stage 2 nonrapid eye movement (NREM) sleep, slow wave sleep (SWS), and rapid eye movement (REM) sleep. Within both groups there was a decrease in EEG power during inspiration compared to expiration across all sleep stages. Compared to controls, RCREC in children with SDB in the overall EEG were significantly higher during REM and frequency band specific RCRECs were higher in the theta band of stage 2 and REM sleep, alpha band of SWS and REM sleep, and sigma band of REM sleep. This between-group difference was not significant postadenotonsillectomy.

CONCLUSION

The presence of nonrandom respiratory cycle-related electroencephalographic changes (RCREC) in both healthy children and in children with sleep disordered breathing (SDB) during NREM and REM sleep has been demonstrated. The RCREC values were higher in children with SDB, predominantly in REM sleep and this difference reduced after adenotonsillectomy.

CITATION

Immanuel SA, Pamula Y, Kohler M, Martin J, Kennedy D, Saint DA, Baumert M. Respiratory cycle-related electroencephalographic changes during sleep in healthy children and in children with sleep disordered breathing.