Correlations between obstructive sleep apnea and adenotonsillar hypertrophy in children of different weight status

High Prevalence of Obstructive Sleep-Disordered Breathing in Pediatric Patients With Turner Syndrome

OBJECTIVE

Girls with Turner syndrome (TS) often have features that have been associated with obstructive sleep-disordered breathing (oSDB). However, little is known about oSDB in TS. Herein, we aimed to characterize oSDB in young patients with TS and identify associated risk factors.

STUDY DESIGN

Retrospective cross-sectional study.

SETTING

Tertiary care pediatric hospital.

METHODS

We reviewed medical records for patients diagnosed with TS seen at our institution between October 1, 2007 and December 31, 2019 with the first outpatient visit before age 6 years. The prevalence of oSDB was compared to the general pediatric population with 1-sample binomial proportion tests. Clinical characteristics were compared between those diagnosed with oSDB and those without oSDB, and risk factors for oSDB were identified.

RESULTS

Of 151 patients with TS, 73 (48%) were diagnosed with oSDB which is 4-fold higher than the general pediatric population (12%, P < 0.0001). In the multivariable model, adenoid, tonsillar, and inferior turbinate hypertrophy, birthweight, failure to thrive, and older age at the last clinic visit were all associated with increased odds for oSDB.

CONCLUSION

Young children with TS have a high prevalence of oSDB and thus should be screened for oSDB. Polysomnography should be performed in those with associated risk factors and symptoms oSDB. Treatment of oSDB is imperative as individuals with TS are already at increased risk of behavioral problems, neurocognitive deficits, and growth impairment that may be worsened with oSDB.

Analysis of possible risk factors for the severity of paediatric obstructive sleep apnoea syndrome

PURPOSE

This study aimed to determine the effect of body mass index (BMI) percentile, asthma, sex, and age on the paediatric obstructive sleep apnoea (OSA) severity. Furthermore, to determine the possible predictive role of the BMI percentile and age in severe OSA.

METHODS

This retrospective study included 921 children aged 2-18 years diagnosed with OSA by polysomnography. Analysis of Covariance (ANCOVA), Spearman's correlation, Receiver Operating Characteristics (ROC) analyses were performed and area under the curve (AUC) was determined.

RESULTS

We observed a significant association between a higher BMI percentile and the severity of OSA (p < 0.001, ρ = 0.15). The correlation also was significant under (p = 0.007, ρ = 0.11) and over 7 (p = 0.0002, ρ = 0.23) years of age. There was no association between the severity of OSA and the presence of asthma (p = 0.9) or sex (p = 0.891), respectively. Age was significantly related to OSA severity (p = 0.01, ρ = 0.08). Although both the BMI percentile (0.59 AUC [0.54-0.65]) and age (0.58 AUC [0.52-0.63]) predicted severe OSA, according to the sensitivity and specificity values of the ROC curve, the association presents a slight clinical relevance.

CONCLUSIONS

OSA severity is determined by the BMI percentile and age in children; however, these factors are unsuitable for predicting severe OSA in clinical practice. Based on our results, obesity is also a significant risk factor for OSA in younger children. Our study highlights that older, overweight, and obese children have a higher risk for severe OSA.

Adenotonsillectomy in Children with Obstructive Sleep Apnea Syndrome: Clinical and Functional Outcomes

Adenotonsillectomy (AT) is the first-line treatment for pediatric obstructive sleep apnea syndrome (OSAS). Relatively few studies have evaluated the clinical and functional outcomes of AT in children with OSAS, but these studies show that surgery improves behavior and quality of life (QOL). However, residual OSAS after AT is reported in severe cases. This study aimed to retrospectively evaluate the clinical and functional outcomes of AT in a cohort of children with OSAS. We consecutively enrolled children with OSAS who underwent AT and were admitted to our clinic from 1 July 2020 to 31 December 2022. For each participant, medical history and physical examinations were performed. Before and after surgery, all patients underwent a standard polygraphic evaluation, and caregivers completed the OSA-18 questionnaire. A total of 65 children with OSAS, aged 2-9 years, were included. After AT, 64 (98.4%) children showed a reduction in AHI, with median (IQR) values decreasing from 13.4/h (8.3-18.5/h) to 2.4/h (1.8-3.1/h) (p-value < 0.0001). Conversely, median (IQR) SpO2 nadir increased after surgery from 89% (84-92%) to 94% (93-95%) (p-value < 0.0001). Moreover, 27 children (18%) showed residual OSAS. The OSA-18 score decreased after AT from median (IQR) values of 84 (76-91) to values of 33 (26-44) (p-value < 0.0001). A positive significant correlation was found between OSA-18 post-operative scores and AHI post-operative scores (rho 0.31; p-value = 0.01). Our findings indicate that, in children with OSAS, AT is associated with significant improvements in behavior, QOL, and polygraphic parameters. However, long-term post-surgical follow-up to monitor for residual OSAS is highly recommended, especially in more severe cases.

Reliability of nasofibroscopy for the evaluation of adenoid hypertrophy and its correlation with clinical symptoms

OBJECTIVE

To analyze the reliability of estimating the percentage of rhinopharyngeal obstruction by the adenoid using nasofibroscopy and its correlation with clinical symptoms.

METHODS

Cross-sectional observational study was conducted, involving 80 patients between 4 and 14 years old, recruited from Santa Casa of São Paulo general otorhinolaryngology outpatient service during the years of 2020 and 2021. All patients underwent nasal endoscopy examination, and the recorded videos were randomly assigned to four evaluators in two different sessions, with a minimum interval of 1 month. The evaluators estimated the percentage of rhinopharyngeal obstruction caused by the adenoid. Intra- and inter-evaluator correlations were established by comparing the reports from each evaluator. The data were compared to the Pro Image J Software report, that also estimates a percentage of obstruction by computer graphics. To correlate the grading of obstruction with clinical symptoms, all patients completed the OSA (Obstructive Sleep Apnea) 18 questionnaire, a validated tool for assessing sleep apnea in children. The questionnaire data were then compared to the average scores assigned by the evaluators.

RESULTS

Satisfactory intra- and inter-rater correlations were observed, and the results were consistent with the Pro Image J Software. However, no correlation was found between the percentage of obstruction and the severity of clinical symptoms.

CONCLUSION

Nasofibroscopy demonstrates good reliability in assessing a percentage of rhinopharyngeal obstruction caused by adenoids. However, there is no correlation between the degree of obstruction of the rhinopharynx and the clinical symptoms.

LEVEL OF EVIDENCE: 4

People's knowledge, attitudes, practice, and healthcare education demand regarding OSA: a cross-sectional study among Chinese general populations

Background

Population knowledge and attitudes toward obstructive sleep apnea (OSA) syndrome are critical to public health initiatives to overcome the disease. Healthcare education is an appropriate approach to expediting the process to build active medical practice models in the public.

Objective

This study aimed to assess the level of knowledge, attitude, and practice (KAP) regarding OSA and healthcare education demand among the Chinese general population.

Methods

A cross-sectional survey was performed online via Wenjuanxing in China between 8 February and 8 March 2022, using a 34-item questionnaire designed and reviewed by multidisciplinary experts.

Results

This study enrolled 1507 respondents, aged 18 to 68, with a city-to-countryside ratio of approximately 2:1. Four-fifths of respondents reported that they had children (n = 1237), and mothers accounted for 57.7%. If they or their children had symptoms of OSA, nearly nine in 10 respondents would undertake positive medical practices, especially parents. A total of 89.4% of the respondents reported a desire to receive healthcare education through the new multimedia approach, and most were concerned about the etiology of OSA.

Conclusion

The current study indicated that even the higher educated and urban populations in China had insufficient knowledge about positive attitudes toward and practices regarding OSA, indicating an urgent demand for healthcare education. A special emphasis should be placed on appropriating population demand for healthcare education and promoting the benefits of active medical practice models in sleep medicine.

Diagnosis and Treatment of Sleep Apnea in Children: A Future Perspective Is Needed

Obstructive sleep apnea (OSA) in children is a prevalent, but still, today, underdiagnosed illness, which consists of repetitive episodes of upper airway obstruction during sleep with important repercussions for sleep quality. OSA has relevant consequences in the pediatric population, mainly in the metabolic, cardiovascular (CV), and neurological spheres. However, contrary to adults, advances in diagnostic and therapeutic management have been scarce in the last few years despite the increasing scientific evidence of the deleterious consequences of pediatric OSA. The problem of underdiagnosis and the lack of response to treatment in some groups make an update to the management of OSA in children necessary. Probably, the heterogeneity of OSA is not well represented by the classical clinical presentation and severity parameters (apnea/hypopnea index (AHI)), and new strategies are required. A specific and consensus definition should be established. Additionally, the role of simplified methods in the diagnosis algorithm should be considered. Finally, the search for new biomarkers for risk stratification is needed in this population. In conclusion, new paradigms based on personalized medicine should be implemented in this population.

[Prevalence of childhood obstructive sleep apnoea syndrome in a referral sleep unit]

INTRODUCTION

Obstructive sleep apnoea syndrome (OSAS) affects between 1% and 6% of children. Its diagnosis includes: a) snoring and/or apnoea; and b) an apnoea and hypopnoea index >3/hour obtained by polysomnography (PSG). The main aim of this work is to determine the prevalence of OSAS in our study population.

PATIENTS AND METHODS

We conducted a descriptive study with a sample of 151 children aged between 1 and 12 years, who had been referred to the sleep unit of the Hospital General Universitario Gregorio Maranon for a PSG. We analysed the demographic variables sex and age; the clinical variables snoring, apnoeas and tonsillar hypertrophy; and the presence of OSAS based on the polysomnographic diagnostic criterion of an apnoea and hypopnoea index >3/hour.

RESULTS

The mean age of the sample was 5.37 years (standard deviation: 3.05) and 64.9% were males. In 90.1% of cases, the reason for the visit was suspected OSAS. Snoring, apnoeas and tonsillar hypertrophy were observed in 73.5, 48.7 and 60% of cases, respectively. OSAS was diagnosed en 19 children (12.6%); in 13.5% of snorers; in 15.1% of those with apnoeas; and in 15.6% of the children with tonsillar hypertrophy.

CONCLUSIONS

In our study, the prevalence of OSAS in children was 12.6%, which is higher than that reported in most epidemiological studies that include PSG for the diagnosis of OSAS.

Persistence of RNA Viruses in the Respiratory Tract: An Overview

Respiratory RNA viruses are a major cause of acute lower respiratory tract infections and contribute substantially to hospitalization among infants, elderly, and immunocompromised. Complete viral clearance from acute infections is not always achieved, leading to persistence. Certain chronic respiratory diseases like asthma and chronic obstructive pulmonary disease have been associated with persistent infection by human respiratory syncytial virus and human rhinovirus, but it is still not clear whether RNA viruses really establish long-term infections as it has been recognized for DNA viruses as human bocavirus and adenoviruses. Herein, we summarize evidence of RNA virus persistence in the human respiratory tract, as well as in some animal models, to highlight how long-term infections might be related to development and/or maintenance of chronic respiratory symptoms.

Analysis of the Risk Factors Associated With Obstructive Sleep Apnea Syndrome in Chinese Children

Objective

The present study was developed to explore risk factors related to the incidence and severity of obstructive sleep apnea syndrome (OSAS) in children.

Methods

The present study enrolled pediatric patients who admitted to our department for snoring and/or open-mouth breathing. All children completed a questionnaire and underwent physical examination and polysomnography (PSG). The cases were separated into OSAS and primary snoring (PS) groups. Factors associated with these two groups were analyzed, with risk factors significantly associated with OSAS then being identified through logistic regression analyses. OSAS was further subdivided into mild, moderate, and severe subgroups, with correlations between risk factors and OSAS severity then being analyzed.

Results

In total, 1,550 children were included in the present study, of which 852 and 698 were enrolled in the OSAS and PS groups. In univariate analyses, obesity, family passive smoking, a family history of snoring, allergic rhinitis, asthma, adenoid hypertrophy, and tonsil hypertrophy were all related to pediatric OSAS (P < 0.05). In a multivariate logistic regression analysis, adenoid hypertrophy (OR:1.835, 95% CI: 1.482-2.271) and tonsil hypertrophy (OR:1.283, 95% CI:1.014-1.622) were independently associated with the risk of pediatric OSAS (P < 0.05). Stratification analyses revealed that OSAS incidence increased in a stepwise manner with increases in adenoid and tonsil grading (P < 0.01). Correlation analyses revealed that adenoid hypertrophy and tonsilar hypertrophy were not significantly associated with OSAS severity (r = 0.253, 0.069, respectively, P < 0.05), and tonsil and adenoid size were no correlation with obstructive apnea-hypopnea index (OAHI) (r = 0.237,0.193, respectively, P < 0.001).

Conclusion

Obesity, family passive smoking, a family history of snoring, allergic rhinitis, asthma, tonsil hypertrophy, and adenoid hypertrophy may be potential risk factors for pediatric OSAS. Adenoid hypertrophy and tonsil hypertrophy were independently related to the risk of pediatric OSAS, with OSAS incidence increasing with the size of the adenoid and tonsil, while the severity of OSAS is not parallel related to the adenoid or tonsil size.

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.

Changes in Cone-Beam Computed Tomography Pediatric Airway Measurements After Adenotonsillectomy in Patients With OSA

Importance

Early intervention using cone-beam computed tomography (CBCT) and adenotonsillectomy for children with obstructive sleep apnea (OSA) may prevent impaired growth, adverse cardiovascular consequences, learning deficits, and poor quality of life.

Objective

To assess changes in CBCT airway measurements and polysomnography (PSG) parameters that occur after adenotonsillectomy in children with OSA and to determine whether CBCT changes are correlated with apnea-hypopnea index (AHI) reduction.

Design, Setting, and Participants

This prospective cohort study was conducted at a tertiary medical center from 2013 to 2016. Children aged 7 to 13 years with PSG-confirmed OSA (ie, AHI ≥1) were recruited. Data analysis was performed from March to July 2021.

Exposures

All participants underwent CBCT and PSG before and after adenotonsillectomy.

Main Outcomes and Measures

Changes in PSG and CBCT parameters after adenotonsillectomy were analyzed.

Results

A total of 49 children (mean [SD] age, 9.5 [1.8] years; 34 boys [69.4%]) were recruited. Eighteen participants (36.7%) had obesity. After adenotonsillectomy, AHI significantly decreased from 11.4 to 1.2 events per hour (mean difference, -10.24 events per hour; 95% CI, -13.84 to -6.64 events per hour). The following CBCT parameters significantly increased: total airway volume (from 11 265 to 15 161 mm3; mean difference, 3896.6 mm3; 95% CI, 2788.0 to 5005.2 mm3), nasopharyngeal volume (from 2366 to 3826 mm3; mean difference, 1459.7 mm3; 95% CI, 1122.9 to 1796.5 mm3), minimal nasopharyngeal airway area (from 128 to 191 mm2; mean difference, 63.1 mm2; 95% CI, 47.4 to 78.8 mm2), mean nasopharyngeal airway area (from 144 to 231 mm2; mean difference, 86.8 mm2; 95% CI, 67.0 to 106.5 mm2), oropharyngeal volume (from 8898 to 11 335 mm3; mean difference, 2436.9 mm3; 95% CI, 1477.0 to 3396.8 mm3), minimal oropharyngeal airway area (from 82 to 158 mm2; mean difference, 76.2 mm2; 95% CI, 57.0 to 95.4 mm2), and mean oropharyngeal airway area (from 182 to 234 mm2; mean difference, 52.5 mm2; 95% CI, 33.6 to 71.4 mm2). Among all parameters, only body mass index percentile showed large effect size between the group with residual OSA (postoperative AHI ≥1) and the group with resolved disease, with the residual OSA group having a higher body mass index percentile (87.8 vs 61.4; mean difference, 26.33; 95% CI, 10.00 to 42.66). A quantile regression model revealed that total airway volume and minimal oropharyngeal airway area were significantly correlated with reductions in AHI.

Conclusions and Relevance

These findings suggest that in children undergoing adenotonsillectomy, improvements in total airway volume and oropharyngeal minimal airway area were correlated with reduction of AHI. Future studies are needed to assess whether CBCT has a role in the evaluation of children with OSA who are being considered for adenotonsillectomy.

Oral cavity morphology among children at risk of sleep disordered breathing

PURPOSE

The aim of this study was to evaluate oral cavity morphology in children at risk of sleep disordered breathing (SDB).

METHODS

The study included children 3-17 years of age. The risk of SDB was evaluated using the paediatric sleep questionnaire (PSQ); afterwards, children at risk of SDB were enrolled in the study group. A control group was randomly established from patients with negative PSQ results. The oral cavity morphology evaluation included assessment of the oropharynx using Mallampati classification (MC), palatine tonsil size using the Pirquet scale, occlusion and the presence of a high-arched palate and lingual frenulum.

RESULTS

A total of 131 children were evaluated, 65 in the study and 66 in the control group. The mean ages were 9.5 ± 3.0 and 9.4 ± 3.1 years, respectively. The presence of higher scores on the MC, higher scores in the Pirquet scale, a crossbite, a high-arched palate and a short frenulum were significantly more frequent in the study group than the control group.

CONCLUSION

The evaluation of oral morphology is an important part of paediatric examination. Enlarged palatine tonsils; higher scores on the MC; and the presence of a crossbite, short lingual frenulum and high-arched palate may suggest abnormal breathing during sleep in children.

Obstructive Sleep Apnea in Underweight Children

OBJECTIVES

To determine predictors of obstructive sleep apnea (OSA) in underweight children and to describe the demographic, clinical, and polysomnographic characteristics of an ethnically diverse population of underweight children with OSA.

STUDY DESIGN

Case-control study.

SETTING

University of Texas Southwestern Medical Center and Children's Medical Center of Dallas.

METHODS

Underweight children aged 2 to 18 years who underwent a polysomnogram for suspected OSA between January 2014 and December 2020 were included. Underweight was defined as body mass index <5th percentile per Centers for Disease Control and Prevention guidelines. Children with apnea-hypopnea index <1.0 served as a control group. Univariate and multiple logistic regression analysis was used to determine the predictors of OSA. Significance was set at P < .05.

RESULTS

An overall 124 children met inclusion criteria: mean age, 6.4 years; 50% female; 44% Hispanic, 31% African American, and 18% Caucasian. A total of 83 children had OSA (apnea-hypopnea index ≥1.0). Height was negatively correlated with OSA (odds ratio, 0.94; 95% CI, 0.88-0.99; P = .02) while allergic rhinitis (odds ratio, 2.97; 95% CI, 1.24-7.08; P = .01) and tonsillar hypertrophy (odds ratio, 3.38; 95% CI, 1.42-8.02; P = .01) were predictors for the presence of OSA. No demographic or clinical characteristics were predictors for severe OSA.

CONCLUSION

Underweight children with OSA, as compared with those without OSA, are more likely to have decreased height, tonsillar hypertrophy, and allergic rhinitis. There are no predictors of severe OSA in underweight children. We recommend polysomnography for the diagnosis of OSA in symptomatic underweight children with large tonsils, especially when they have a history of allergies.

Assessment of event-related evoked potentials and China-Wechsler intelligence scale for cognitive dysfunction in children with obstructive sleep apnea

OBJECTIVE

To explore the relationship between obstructive sleep apnea (OSA) and cognitive impairment by combining event-related evoked potentials (ERPs) and China-Wechsler Younger Children Scale (C-WISC) in children with sleep-disordered breathing (SDB) with vs. without OSA.

METHODS

This was a retrospective case-control study of all consecutive children (n = 148) with adenoid tonsil hypertrophy between July 2017 and March 2019 at the Hospital.

RESULTS

The children were divided into the OSA (n = 102) and non-OSA (n = 46) groups. The apnea-hypopnea index (AHI), obstructive apnea index (OAI), and obstructive apnea-hypopnea index (OAHI) in the OSA group were elevated compared with those of the non-OSA group (all P < 0.001). The mean oxygen saturation (SaO₂) and SaO₂ nadir were lower in the OSA group compared with the non-OSA group (both P < 0.001). The respiratory arousal index (RAI) values in the OSA group were larger than those of the non-OSA group (P < 0.001). The P300 and N100 latencies in the OSA group were longer than those of the non-OSA group (both P < 0.001). Pearson's correlation analysis revealed correlations of the P300 peak latency with full-scale intelligence quotient (FIQ) (P < 0.001 and r = -0.527), verbal intelligence quotient (VIQ) (P < 0.001 and r = -0.448), and performance intelligence quotient (PIQ) (P < 0.001 and r = -0.515). There was a correlation between the N100 peak latency and PIQ (P = 0.026 and r = -0.183).

CONCLUSION

ERPs, as an objective measurement, might help assess cognitive impairment in children with OSA.

Different Associations between Tonsil Microbiome, Chronic Tonsillitis, and Intermittent Hypoxemia among Obstructive Sleep Apnea Children of Different Weight Status: A Pilot Case-Control Study

The tonsil microbiome is associated with chronic tonsillitis and obstructive sleep apnea (OSA) in children, and the gut microbiome is associated with host weight status. In this study, we hypothesized that weight status may be associated with clinical profiles and the tonsil microbiome in children with OSA. We prospectively enrolled 33 non-healthy-weight (cases) and 33 healthy-weight (controls) pediatric OSA patients matched by the proportion of chronic tonsillitis. Differences in the tonsil microbiome between the non-healthy-weight and healthy-weight subgroups and relationships between the tonsil microbiome and clinical variables were investigated. Non-healthy weight was associated with significant intermittent hypoxemia (oxygen desaturation index, mean blood saturation (SpO₂), and minimal SpO₂) and higher systolic blood pressure percentile, but was not related to the tonsil microbiome. However, chronic tonsillitis was related to Acidobacteria in the non-healthy-weight subgroup, and oxygen desaturation index was associated with Bacteroidetes in the healthy-weight subgroup. In post hoc analysis, the children with mean SpO₂ ≤ 97% had reduced α and β diversities and a higher abundance of Bacteroidetes than those with mean SpO₂ > 97%. These preliminary findings are novel and provide insights into future research to understand the pathogenesis of the disease and develop personalized treatments for pediatric OSA.

Computational fluid dynamics modelling of human upper airway: A review

BACKGROUND AND OBJECTIVE

Human upper airway (HUA) has been widely investigated by many researchers covering various aspects, such as the effects of geometrical parameters on the pressure, velocity and airflow characteristics. Clinically significant obstruction can develop anywhere throughout the upper airway, leading to asphyxia and death; this is where recognition and treatment are essential and lifesaving. The availability of advanced computer, either hardware or software, and rapid development in numerical method have encouraged researchers to simulate the airflow characteristics and properties of HUA by using various patient conditions at different ranges of geometry and operating conditions. Computational fluid dynamics (CFD) has emerged as an efficient alternative tool to understand the airflow of HUA and in preparing patients to undergo surgery. The main objective of this article is to review the literature that deals with the CFD approach and modeling in analyzing HUA.

METHODS

This review article discusses the experimental and computational methods in the study of HUA. The discussion includes computational fluid dynamics approach and steps involved in the modeling used to investigate the flow characteristics of HUA. From inception to May 2020, databases of PubMed, Embase, Scopus, the Cochrane Library, BioMed Central, and Web of Science have been utilized to conduct a thorough investigation of the literature. There had been no language restrictions in publication and study design of the database searches. A total of 117 articles relevant to the topic under investigation were thoroughly and critically reviewed to give a clear information about the subject. The article summarizes the review in the form of method of studying the HUA, CFD approach in HUA, and the application of CFD for predicting HUA obstacle, including the type of CFD commercial software are used in this research area.

RESULTS

This review found that the human upper airway was well studied through the application of computational fluid dynamics, which had considerably enhanced the understanding of flow in HUA. In addition, it assisted in making strategic and reasonable decision regarding the adoption of treatment methods in clinical settings. The literature suggests that most studies were related to HUA simulation that considerably focused on the aspects of fluid dynamics. However, there is a literature gap in obtaining information on the effects of fluid-structure interaction (FSI). The application of FSI in HUA is still limited in the literature; as such, this could be a potential area for future researchers. Furthermore, majority of researchers present the findings of their work through the mechanism of airflow, such as that of velocity, pressure, and shear stress. This includes the use of Navier-Stokes equation via CFD to help visualize the actual mechanism of the airflow. The above-mentioned technique expresses the turbulent kinetic energy (TKE) in its result to demonstrate the real mechanism of the airflow. Apart from that, key result such as wall shear stress (WSS) can be revealed via turbulent kinetic energy (TKE) and turbulent energy dissipation (TED), where it can be suggestive of wall injury and collapsibility tissue to the HUA.

Diagnosis and management of childhood sleep-disordered breathing. Clinical approach

Sleep-disordered breathing (SDB) includes disorders of breathing that affect airway patency, which impair children's sleep and lead to negative consequences. Obstructive sleep apnea, hypoventilation and upper airway resistance syndrome are common causes of morbidity and mortality in childhood. These clinical practice guidelines, intended for use by pediatricians and primary care clinicians, provide a clear recommendation for the diagnosis and management of sleep-disordered breathing, focusing on the most serious disorder, obstructive sleep apnea syndrome (OSAS). These clinical guidelines formulate clear recommendations to identify patients with suspected OSAS. Further, the manuscript will highlight the potential consequences of SBD in children, and how to overcome such difficulties, what could be the therapeutic options, a 12 recommendations and what are the future direction for pediatric sleep medicine.