Examination of the diaphragm in obstructive sleep apnea using ultrasound imaging

A Comparative Investigation on Clinical Characteristics in Pediatric Obstructive Sleep Apnea Based on Two Distinct Guidelines

Objective

To investigate the differences in assessment of clinical characteristics between children with obstructive sleep apnea (OSA) diagnosed according to the 2007 and 2020 guidelines and those without OSA, together with the relationships between polysomnography (PSG) parameters and cognitive tests scores in preschool and school-aged children with OSA.

Methods

Eighty children were totally recruited and divided into OSA and non-OSA groups based on two distinct guidelines, with further subclassification into preschool and school-aged subgroups. Differences in PSG parameters and cognitive tests scores between groups and subgroups were analyzed and compared, followed by partial correlation analysis to determine the correlations between these characteristics.

Results

Compared to the 2007 guideline, the 2020 guideline demonstrated more significant between-group differences in clinical characteristics assessments, especially verbal intelligent quotient (VIQ). For preschool children in the OSA and non-OSA subgroups, there were significant differences in PSG parameters and Block Diagram between the two guidelines. Additionally, the 2007 guideline showed difference in Picture Vocabulary, where the 2020 guideline exhibited differences in performance IQ (PIQ) and Geometric Figure For school-aged children in the OSA and non-OSA subgroups, both guidelines showed significant differences in PSG parameters, full-scale IQ (FIQ) and Block Diagram. The 2007 guideline had significant differences in PIQ, while the 2020 guideline had difference in VIQ. Furthermore, significant correlations were observed between PSG parameters and cognitive tests scores across different subgroups.

Conclusion

The 2020 guideline has advantages in assessing the clinical characteristics of children with OSA, especially for verbal function, and is worthy of clinical promotion and application.

Elucidating the Interplay of Hypoxia-Inducible Factor and Circadian Clock Signaling in Obstructive Sleep Apnea Patients

BACKGROUND

Hypoxia-inducible factor 1 (HIF-1) affects the circadian clock in obstructive sleep apnea (OSA) and may have a bidirectional relationship with circadian mechanisms. This study examined the link between circadian clock and HIF-1 in OSA patients versus controls.

METHODS

70 participants underwent polysomnography (PSG), and were assigned into OSA (apnea-hypopnea index (AHI) ≥ 5, n = 54) or control (AHI < 5, n = 16) groups. BMAL1 (brain and muscle ARNT like 1), CLOCK (circadian locomotor output cycles kaput), PER1 (period 1), CRY1 (cryptochrome 1), HIF-1α, and HIF-1β gene expressions and protein levels were measured in evening and morning samples, collected before and after PSG.

RESULTS

The OSA group was characterized by increased CLOCK, CRY1, PER1 and HIF-1a protein levels, both in the morning and evening (all p < 0.05), and decreased morning expression of BMAL1 (p = 0.02). Associations between almost all circadian clock gene expressions and both HIF-1 subunits were observed in the OSA group at both time points (all p < 0.05), apart from association between PER1 and HIF-1α in the morning (R = 0.050, p = 0.73). In controls, only a correlation between HIF-1α levels and CRY1 expression in the morning (R = 0.588, p = 0.02) was found.

CONCLUSIONS

OSA affects the circadian clock and HIF-1 pathway, with increased CLOCK, CRY1, PER1, and HIF-1α protein levels observed in OSA patients. The interplay between these systems may involve complex posttranscriptional and posttranslational mechanisms.

Impact of COVID-19 on Diaphragmatic Function: Understanding Multiorgan Involvement and Long-Term Consequences

The COVID-19 pandemic has brought significant attention to the respiratory system, with much focus on lung-related disorders. However, the diaphragm, a crucial component of respiratory physiology, has not been adequately studied, especially in the context of long COVID. This review explores the multipotential role of the diaphragm in both respiratory health and disease, emphasizing its involvement in long-term complications following SARS-CoV-2 infection. The diaphragm's fundamental role in respiratory physiology and its impact on balance and posture control, breathing patterns, and autonomic nervous system regulation are discussed. This review examines complications arising from COVID-19, highlighting the diaphragm's involvement in neurological, musculoskeletal, and inflammatory responses. Particular attention is given to the neuroinvasive impact of SARS-CoV-2, the inflammatory response, and the direct viral effects on the diaphragm. The diaphragm's role in long COVID is explored, with a focus on specific symptoms such as voice disorders, pelvic floor dysfunction, and sleep disturbances. Diagnostic challenges, current methods for assessing diaphragmatic dysfunction, and the complexities of differentiating it from other conditions are also explored. This article is the first to comprehensively address diaphragmatic dysfunction resulting from COVID-19 and long COVID across various physiological and pathological aspects, offering a new perspective on its diagnosis and treatment within a multisystem context.

Prioritising Polysomnography in Children with Suspected Obstructive Sleep Apnoea: Key Roles of Symptom Onset and Sleep Questionnaire Scores

BACKGROUND/OBJECTIVES

Obstructive Sleep Apnoea Syndrome (OSA) in children disrupts normal breathing patterns and sleep architecture, potentially leading to severe consequences. Early identification and intervention are crucial to prevent these issues. This study explored the relationships between waiting times for polysomnography (PSG), clinical history, patient age at the time of PSG, and PSG outcomes in children.

METHODS

Two hundred and fourteen children were prospectively enrolled. Data were extracted from medical records regarding the patients' age at the time of a referral for PSG and their age at the time of its execution. Information on the waiting times for PSG, a diagnosis (primary snoring, mild, moderate, and severe OSA), and a history of snoring and apnoea were also collected. Additional data included medications, surgical interventions, passive smoke exposure, and allergies. The records also included the Paediatric Sleep Questionnaire (PSQ).

RESULTS

The patient age at the time of a PSG prescription was lower for patients with a short history of sleep apnoeas (≤12 months; 4.6 (SD 2.6) years) compared to those with a long history (>12 months; 5.5 (SD 2.7) years; p = 0.027). The waiting time from prescription to PSG execution was shorter for patients with a short history of sleep apnoea (4.1 (SD 3.8) months) compared to those with a longer history (5.9 (SD 3.8) months; p = 0.001). A higher frequency of having an adenotonsillectomies before a PSG prescription was observed in the long-history group compared to the short-history group (13.3% vs. 6.9%). Conversely, a higher frequency of adenoidectomies before a PSG prescription was noted in the short-history group compared to the long-history group (9.7% vs. 1.3%).

CONCLUSIONS

This study found that younger children with a shorter history of OSA are diagnosed and evaluated earlier than older children with a longer history of the condition, suggesting that prolonged symptoms may delay a diagnosis. ENT surgeries also vary among patients, with less invasive procedures (adenoidectomy) being more common in younger children with shorter histories of OSA. The increasing awareness of OSA highlights the need for improved access to diagnostic and treatment resources.

Association of Short Sleep Duration and Obstructive Sleep Apnea with Central Obesity: A Retrospective Study Utilizing Anthropometric Measures

Background

Central obesity, as measured by examination instruments, has been shown to be associated with both OSA and short sleep duration. However, objective measurement tools like CT, MRI, and DXA are expensive, cause radiation exposure, and have limited availability, especially in resource-limited settings. Thus, this study aimed to demonstrate the relevance of Body Mass Index (BMI) and Waist-to-Height Ratio (WHtR) as surrogate indicators of visceral obesity in the assessment of OSA and short sleep duration. We also intend to evaluate whether WHtR, in combination with BMI, can be a suitable surrogate marker for visceral adiposity.

Methods

We recruited 333 adults with complete polysomnographic (PSG) records retrospectively. Logistic regression helped to assess the association of BMI and WHtR as surrogates for central adiposity with OSA and short sleep duration. Moreover, ROC curve analysis was conducted to evaluate the predictive ability of BMI and WHtR.

Results

Following the relevant adjustments, logistic regression analysis results showed that the combination of WHtR and BMI acting as central obesity surrogates was significantly associated with OSA and short sleep duration (p<0.05). According to univariate regression analysis, sleep latency and wake after sleep onset were independent predictors of the risk of central obesity in patients with short sleep duration and OSA. Additionally, ROC curve analysis demonstrated that the combination of BMI and WHtR provided a better assessment of central adiposity in patients with OSA and short sleep duration, compared to each measure alone.

Conclusion

BMI and WHtR are significantly associated with OSA and short sleep duration, and might serve as a potential surrogate marker for central obesity. Sleep latency and wake after sleep onset can independently predict the risk of central obesity in patients with short sleep time and OSA. Thus, larger prospective studies are needed to verify our findings.

Obstructive Sleep Apnea Is Associated with Worsened Hospital Outcomes in Children Hospitalized with Asthma

BACKGROUND

Studies have shown a bidirectional relationship between asthma and obstructive sleep apnea (OSA). However, there is a paucity of national-level data evaluating the impact of OSA on hospital outcomes in pediatric hospitalizations for asthma.

METHODS

We analyzed the National Inpatient Sample and Kids Inpatient Database to include all pediatric hospitalizations with a primary diagnosis of asthma between 2003-2016. Using ICD codes, the pediatric asthma cohort was divided into two groups: those with and those without a concomitant diagnosis of OSA. The primary outcomes were in-hospital mortality and the need for mechanical ventilation. The secondary outcomes were the lengths of each hospital stay and total hospitalization charges.

RESULTS

We analyzed 1,606,248 hospitalizations during the 14-year study period. The overall prevalence rate of OSA was 0.7%. Patients with asthma and OSA were significantly older (8.2 versus 5.9 years) and were more often male, p < 0.001. The OSA group had several increased comorbidities. The overall mortality rate was 0.03%, and multivariate regression analysis showed that OSA was associated with 4.3 times higher odds of in-hospital mortality (95% CI: 2.4 to 7.6, p < 0.001). Furthermore, OSA was associated with a 5.2 times greater need for mechanical ventilation (95% CI: 4.8 to 5.5, p < 0.001). Linear regression analyses demonstrated that OSA independently contributed an additional 0.82 days to the hospital stay length (95% CI: 0.79 to 0.86, p < 0.001) and an extra 10,479 USD (95% CI: 10,110 to 10,848, p < 0.001) in hospitalization charges.

CONCLUSION

OSA in children admitted with asthma is associated with poor hospital outcomes such as increased mortality risk, the need for mechanical ventilation, and increased healthcare utilization.

Automatic prediction of obstructive sleep apnea in patients with temporomandibular disorder based on multidata and machine learning

Obstructive sleep apnea (OSA) is closely associated with the development and chronicity of temporomandibular disorder (TMD). Given the intricate pathophysiology of both OSA and TMD, comprehensive diagnostic approaches are crucial. This study aimed to develop an automatic prediction model utilizing multimodal data to diagnose OSA among TMD patients. We collected a range of multimodal data, including clinical characteristics, portable polysomnography, X-ray, and MRI data, from 55 TMD patients who reported sleep problems. This data was then analyzed using advanced machine learning techniques. Three-dimensional VGG16 and logistic regression models were used to identify significant predictors. Approximately 53% (29 out of 55) of TMD patients had OSA. Performance accuracy was evaluated using logistic regression, multilayer perceptron, and area under the curve (AUC) scores. OSA prediction accuracy in TMD patients was 80.00-91.43%. When MRI data were added to the algorithm, the AUC score increased to 1.00, indicating excellent capability. Only the obstructive apnea index was statistically significant in predicting OSA in TMD patients, with a threshold of 4.25 events/h. The learned features of the convolutional neural network were visualized as a heatmap using a gradient-weighted class activation mapping algorithm, revealing that it focuses on differential anatomical parameters depending on the absence or presence of OSA. In OSA-positive cases, the nasopharynx, oropharynx, uvula, larynx, epiglottis, and brain region were recognized, whereas in OSA-negative cases, the tongue, nose, nasal turbinate, and hyoid bone were recognized. Prediction accuracy and heat map analyses support the plausibility and usefulness of this artificial intelligence-based OSA diagnosis and prediction model in TMD patients, providing a deeper understanding of regions distinguishing between OSA and non-OSA.

Association of Sleep Patterns and Respiratory Disturbance Index with Physiological Parameters in Pediatric Patients with Self-Perceived Short Stature

OBJECTIVE

To investigate the relationships of sleep patterns and respiratory disturbance index (RDI) with key physiological parameters (height, body mass index (BMI), bone age (BA), and IGF-1 levels) in children aged 6 to 16 years with self-perceived short stature.

METHODS

For this cross-sectional study, conducted from October 2019 to November 2021, 238 children aged 6 to 16 years with self-perceived short stature were enrolled. The primary outcomes of sleep patterns and the RDI were non-invasively collected at home using the LARGAN Health AI-Tech Sleep Apnea and Sleep Quality Examination System, which operates based on polygraphy. Additionally, various physiological parameters, including height, BMI, bone age, and IGF-1 levels, were measured to assess their associations with sleep patterns and RDI.

RESULTS

Significant age-related reductions were observed in both the total and deep sleep durations. Children aged 6-9 years averaged 8.5 ± 1.0 h of total sleep, which decreased to 8.1 ± 1.1 h in ages 10-11 and further to 7.5 ± 0.9 h in ages 12-16 (p < 0.0001). Deep sleep followed a similar pattern, decreasing from 4.4 ± 1.1 h in the youngest group to 3.3 ± 1.0 h in the oldest (p < 0.0001). Notably, girls experienced significantly longer deep sleep than boys, averaging 4.0 ± 1.2 h compared to 3.6 ± 1.2 h (p = 0.0153). In a multivariable regression analysis, age (beta = 4.89, p < 0.0001) and RDI (beta = -0.54, p = 0.0022) were significantly associated with body height. Age and deep sleep duration (beta = -0.02, p = 0.0371) were significantly associated with BMI.

CONCLUSIONS

The results demonstrate significant age-related decreases in the total and deep sleep duration among children with self-perceived short stature, along with a notable association between RDI and body height and an association between deep sleep duration and BMI. These findings suggest that sleep disturbances in pediatric endocrine patients are intricately linked with physiological growth parameters. The identified correlations underline the importance of monitoring sleep patterns in this demographic to better understand the impact of endocrine disorders on developmental health. Further research is needed to explore interventions that could alleviate these sleep disturbances, thereby potentially improving outcomes for the affected children.

Ultrasonographic changes and impact factors of diaphragmatic function in patients with obstructive sleep apnea-hypopnea syndrome

PURPOSE

Diaphragmatic impairment has been reported in obstructive sleep apnea-hypopnea syndrome (OSAHS) patients. However, the risk factors of diaphragmatic dysfunction are unclear. This study was conducted to evaluate the diaphragmatic function and to investigate impact factors of ultrasonographic changes of the diaphragm in OSAHS patients.

METHODS

This cross-sectional study recruited 150 snoring patients. All patients were divided into the control group (AHI < 5/h, n = 20), the mild-to-moderate OSAHS group (5/h ≤ AHI ≤ 30/h, n = 61), and the severe OSAHS group (AHI > 30/h, n = 69). Diaphragmatic thickness at function residual capacity (TFRC) and total lung capacity (TTLC) were measured by two-dimensional ultrasound, and the diaphragmatic excursion during tidal and deep breath was measured by M-mode ultrasound. The diaphragmatic thickening fraction (TF) was calculated. Spearman analysis and multiple linear stepwise regression analysis were conducted to analyze the impact factors of diaphragmatic function.

RESULTS

TFRC in the control group, mild-to-moderate OSAHS group, and severe OSAHS group was 1.23 (1.10, 1.39) mm, 1.60 (1.43, 1.85) mm, and 1.90 (1.70, 2.25) mm; TTLC was 2.75 (2.53, 2.93) mm, 3.25 (2.90, 3.55) mm, and 3.60 (3.33, 3.90) mm, and TF was 119.23% (102.94, 155.97), 96.55% (74.34, 119.11), and 85.29% (60.68,101.22). There were across-group significant differences in TFRC, TTLC, and TF (P < 0.05). The oxygen desaturation index was the influencing factor of TFRC, TTLC, and TF (P < 0.05).

CONCLUSION

The diaphragm is thickened and diaphragmatic contractility is decreased in OSAHS patients. Nocturnal intermittent hypoxia is a risk factor for diaphragmatic hypertrophy and impaired diaphragmatic contractility.

Insights into Pediatric Sleep Disordered Breathing: Exploring Risk Factors, Surgical Interventions, and Physical and Scholastic Performance at Follow-Up

(1) Background: Sleep-disordered breathing represents a growing public health concern, especially among children and adolescents. The main risk factors for pediatric sleep-disordered breathing in school-age children are tonsillar and adenoid hypertrophy. Adenoidectomy, often in combination with tonsillectomy, is the primary treatment modality for pediatric sleep-disordered breathing. This study aims to comprehensively investigate various risk and protective factors in children with sleep-disordered breathing undergoing adenotonsillar or adenoidal surgeries. We also aim to explore the differences in neuropsychological profiles. (2) Methods: This is an observational, retrospective cohort study. We collected information on adenoidectomy or adenotonsillectomy in children referred to our center. We reviewed the clinical history and preoperative visits and collected data through a telephone questionnaire. The Pediatric Sleep Questionnaire (PSQ) and the Pediatric Quality of Life Inventory (PedsQL) screen sleep-disordered breathing and quality of life, respectively. The data were statistically analyzed using SPSS version 22.0 for Windows (SPSS Inc., Chicago, IL, USA). (3) Results: The study involved 138 patients, but only 100 children participated. A higher percentage of patients with sleep-disordered breathing were observed to have mothers who smoked during pregnancy. A smaller proportion of patients with sleep-disordered breathing habitually used a pacifier. A rise in physical score was associated with a reduced PSQ at follow-up (p = 0.051). An increase in the overall academic score was related to a decrease in the PSQ at follow-up (p < 0.001). A more significant proportion of patients undergoing adenotonsillectomy were observed to have a history of prematurity and cesarean birth. (4) This comprehensive study delves into the intricate interplay of risk and protective factors impacting children with sleep-disordered breathing undergoing adenotonsillectomy and adenoidectomy.

[Diaphragmatic ultrasonography for the pulmonologist: Technique and clinical use]

INTRODUCTION

Ultrasonography is an emerging tool that helps to assess diaphragmatic function. It is now widely used in ICUs to predict weaning from mechanical ventilation. Ultrasonography is readily available, harmless (no radiation), and repeatable with good interoperator reproducibility. Over the past few years, ultrasonography has seen increasing use in patients with chronic pulmonary pathologies.

STATE OF THE ART

The aim of this review is (1) to describe the ultrasound techniques used to assess diaphragmatic excursion and thickening, (2) to indicate the expected, normal values in healthy patients, and (3) to summarize the main findings and clinical applications in treatment of chronic respiratory disorders.

CONCLUSIONS

Chronic pulmonary diseases are associated with diaphragmatic dysfunction that can be assessed with ultrasound. Diaphragmatic dysfunction is primary in neuromuscular disorders and secondary to respiratory disease in other chronic pulmonary conditions (COPD, ILD). Ultrasound is correlated with the severity of the underlying disease (functional and clinical parameters).

PERSPECTIVES

The prognostic interest of diaphragm ultrasonography remains to be established, after which its utilization should become routine.

Insights into the Use of Point-of-Care Ultrasound for Diagnosing Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a sleeping disorder caused by complete or partial disturbance of breathing during the night. Existing screening methods include questionnaire-based evaluations which are time-consuming, vary in specificity, and are not globally adopted. Point-of-care ultrasound (PoCUS), on the other hand, is a painless, inexpensive, portable, and useful tool that has already been introduced for the evaluation of upper airways by anesthetists. PoCUS could also serve as a potential screening tool for the diagnosis of OSA by measuring different airway parameters, including retropalatal pharynx transverse diameter, tongue base thickness, distance between lingual arteries, lateral parapharyngeal wall thickness, palatine tonsil volume, and some non-airway parameters like carotid intima-media thickness, mesenteric fat thickness, and diaphragm characteristics. This study reviewed previously reported studies to highlight the importance of PoCUS as a potential screening tool for OSA.

Obstructive Sleep Apnea and Role of the Diaphragm

Obstructive sleep apnea (OSA) causes multiple local and systemic pathophysiological consequences, which lead to an increase in morbidity and mortality in patients suffering from this disorder. OSA presents with various nocturnal events of apnoeas or hypopneas and with sub-clinical airflow limitations during wakefulness. OSA involves a large percentage of the population, particularly men, but the estimate of OSA patients could be much broader than data from the literature. Most of the research carried out in the muscle field is to understand the causes of the presence of chronic nocturnal desaturation and focus on the genioglossus muscle and other muscles related to dilating the upper airways. Sparse research has been published regarding the diaphragm muscle, which is the main muscle structure to insufflate air into the airways. The article reviews the functional anatomy of the muscles used to open the upper respiratory tract and the non-physiological adaptation that follows in the presence of OSA, as well as the functional anatomy and pathological adaptive aspects of the diaphragm muscle. The intent of the text is to highlight the disparity of clinical interest between the dilator muscles and the diaphragm, trying to stimulate a broader approach to patient evaluation.