Obstructive Hypopnea Research Articles

Insights, recommendations, and research priorities for central sleep apnea: report from an expert panel.

Central sleep apnea (CSA) is commonly encountered among patients with sleep-disordered breathing, however its clinical consequences are less well-characterized. We therefore convened an expert panel to discuss the common presentations of CSA, as well as challenges and knowledge gaps in the diagnosis and management of CSA. The panel identified several key research priorities essential for advancing our understanding of the disorder. Within the diagnostic realm, panel members discussed the utility of multi-night assessments, and importance of the development and validation of novel metrics and automated assessments for differentiating central versus obstructive hypopneas, such that their impact on clinical outcomes and management may be better evaluated. The panel also discussed the current therapeutic landscape for the management of CSA and agreed that therapies should primarily aim to alleviate sleep-related symptoms, after optimizing treatment to address the underlying cause. Most importantly, the panel concluded that there is a need to further investigate the clinical consequences of CSA, as well as the implications of therapy on clinical outcomes, particularly among those who are asymptomatic. Future research should focus on endo-phenotyping central events for a better mechanistic understanding of the disease, validating novel diagnostic methods for implementation in routine clinical practice, as well as the use of combination therapy and comparative effectiveness trials in elucidating the most efficacious interventions for managing CSA.

Multidimensional phenotyping to distinguish among central (CSA), obstructive (OSA) and co-existing central and obstructive sleep apnea (CSA-OSA) phenotypes in real-world data

PurposeWhen navigating the landscape of obstructive sleep apnea (OSA), central sleep apnea (CSA) and intersection of the two diseases (co-existing CSA-OSA), there are significant knowledge gaps. Data are scarce regarding the respective prevalence and differences in clinical presentation of the three conditions. One major issue for characterization of the prevalence of the different sleep apnea entities is the scoring of central versus obstructive hypopneas which is not included in the routine practice of many sleep laboratories. MethodWe prospectively assessed multidomain symptoms and collected data on comorbidities, medications and treatment indications in a large monocentric real-life dataset (n > 2400) of patients referred for suspicion of sleep apnea. We have systematically distinguished central versus obstructive hypopneas to define OSA, CSA and co-existing CSA-OSA. ResultsWhen CSA was defined by the proportion of central apneas (and hypopneas were considered obstructive by default), the prevalence of CSA was 4.59 % (co-existing CSA-OSA: 11.03 %, and OSA: 84.37 %). When the distinction between obstructive and central hypopneas was used to classify the sleep disordered breathing, the prevalence of CSA was fourfold higher at 19.69 % (co-existing: 19.16 %, OSA: 61.16 %). The burden of cardiovascular and metabolic comorbidities was the highest in the CSA and co-existing sleep apnea subgroups. The three sleep apnea groups exhibited different constellations of symptoms but most of the patients with CSA, co-existing and OSA were symptomatic after comprehensive evaluation. The CSA group exhibited the most severe disturbances in sleep architecture on polysomnography. Therapeutic indications differed depending on the subtype of respiratory events. ConclusionOur findings imply that not differentiating between central and obstructive hypopneas will underestimate the severity of central sleep disordered breathing abnormalities that mislead therapeutic decisions and might limit improvements in quality of life and sleepiness that are expected in appropriately treated patients with CSA.

Validation of Tracheal Sound-Based Respiratory Effort Monitoring for Obstructive Sleep Apnoea Diagnosis.

Background: Respiratory effort is considered important in the context of the diagnosis of obstructive sleep apnoea (OSA), as well as other sleep disorders. However, current monitoring techniques can be obtrusive and interfere with a patient's natural sleep. This study examines the reliability of an unobtrusive tracheal sound-based approach to monitor respiratory effort in the context of OSA, using manually marked respiratory inductance plethysmography (RIP) signals as a gold standard for validation. Methods: In total, 150 patients were trained on the use of type III cardiorespiratory polygraphy, which they took to use at home, alongside a neck-worn AcuPebble system. The respiratory effort channels obtained from the tracheal sound recordings were compared to the effort measured by the RIP bands during automatic and manual marking experiments. A total of 133 central apnoeas, 218 obstructive apnoeas, 263 obstructive hypopneas, and 270 normal breathing randomly selected segments were shuffled and blindly marked by a Registered Polysomnographic Technologist (RPSGT) in both types of channels. The RIP signals had previously also been independently marked by another expert clinician in the context of diagnosing those patients, and without access to the effort channel of AcuPebble. The classification achieved with the acoustically obtained effort was assessed with statistical metrics and the average amplitude distributions per respiratory event type for each of the different channels were also studied to assess the overlap between event types. Results: The performance of the acoustic effort channel was evaluated for the events where both scorers were in agreement in the marking of the gold standard reference channel, showing an average sensitivity of 90.5%, a specificity of 98.6%, and an accuracy of 96.8% against the reference standard with blind expert marking. In addition, a comparison using the Embla Remlogic 4.0 automatic software of the reference standard for classification, as opposed to the expert marking, showed that the acoustic channels outperformed the RIP channels (acoustic sensitivity: 71.9%; acoustic specificity: 97.2%; RIP sensitivity: 70.1%; RIP specificity: 76.1%). The amplitude trends across different event types also showed that the acoustic channels exhibited a better differentiation between the amplitude distributions of different event types, which can help when doing manual interpretation. Conclusions: The results prove that the acoustically obtained effort channel extracted using AcuPebble is an accurate, reliable, and more patient-friendly alternative to RIP in the context of OSA.

1168 Snoring Cessation in a Case of Vagal Nerve Stimulator Induced Obstructive Hypopnea

1168 Snoring Cessation in a Case of Vagal Nerve Stimulator Induced Obstructive Hypopnea

Influence of skeletal classes and facial patterns on the positioning of the craniovertebral junction, dimensions of the pharyngeal airway space, and pre-vertebral soft tissue thickness: A cone beam computed tomography study

This study employed cone beam computed tomography (CBCT) to assess the influence of skeletal classes and facial patterns on the craniovertebral complex, pharyngeal airway space (PAS) dimensions, and pre-vertebral soft tissue thickness. The analysis of 150 CBCTs involved measurements between various vertebrae and layers of soft tissue. Significant findings included a lower odontoid process in Class II and hyperdivergent individuals, while hypodivergent subjects exhibited a larger area and volume in the PAS. A negative correlation between PAS size and pre-vertebral soft tissue thickness was observed. Gender differences were noteworthy, with males consistently displaying higher values. Significant age-related variations were also identified, with the age groups of 18-30 and 31-45 exhibiting distinct characteristics. The study underscores the impact of facial patterns and skeletal classes on the craniovertebral complex, emphasizing an inverse relationship between PAS and pre-vertebral soft tissue thickness. The intricate connections between gender and age highlight their influence on anatomical characteristics. Understanding how facial patterns and skeletal classes affect the craniovertebral complex has implications for respiratory disorders, including Obstructive Sleep Apnea and Hypopnea Syndrome (OSAHS).

Radar-based Non-contact Obstructive Apnea and Hypopnea Event Detection Using Quadrature-Temporal Point Clouds with Modified PointNet

Radar-based Non-contact Obstructive Apnea and Hypopnea Event Detection Using Quadrature-Temporal Point Clouds with Modified PointNet

Pharmacological and Non-Pharmacological Management of Obstructive Sleep Apnea

Obstructive sleep apnea (O.S.A.), also referred to as obstructive sleep hypopnea – is a sleep disorder that involvescessation or significant decrease in airflow in the presence of breathing effort. It is the most common type of sleep-disorderedbreathing. It is characterized by episodes of total or partial airway collapse and decreased oxygen saturation or sleep arousal. Asa result of this disturbance, sleep is interrupted and non-restorative. It significantly raises morbidity and mortality in both developedand developing countries. This review aims to review relevant studies on obstructive sleep apnea. The method used is acomputerized search method, the pathophysiology, clinical presentation, complications, diagnostic procedures, and therapeuticchoices from the literature. The effects of O.S.A. on cardiovascular health, mental disease, quality of life, and driving safety aresevere. This course of action highlights the interprofessional team's involvement in treating obstructive sleep apnea, itspathophysiology, and its causes.

Catathrenia in severe obstructive sleep apnea: A novel entity never described before

Study objectivesCatathrenia, derived from the Greek κατά (kata) meaning below and θρηνώ (threnia) to lament, is characterized by expiratory groaning episodes during sleep. In a case series of nine patients with severe obstructive sleep apnea, we observed a peculiar groaning entity that has not been described before. MethodsWe described and illustrated the cases with polysomnographic tracings and additional audio recordings. ResultsAll patients were men, obese (body mass index 39 ± 6 kg/m2) with an apnea-hypopnea index ranging from 47 to 125/h. In addition, we identified groaning events that were consistently preceded by a cortical arousal associated with a “rescue” respiration after an obstructive hypopnea or apnea. These events exhibited characteristics of “mixed apnea’s”, but the “central apnea-like part” was a prolonged expiratory groaning phase, with immediately after the terminal expiratory snort appearance of an obstructive apnea. In case the duration of this expiration was at least 10 s we calculated these events separately and the index was 8.4 ± 7.7/h. More rarely (index 0.6 ± 0.5/h) a “central apnea mimicking event” with groaning not followed by an obstruction, was observed. We also observed groaning episodes during expiration with a shorter duration (less than 10 s), not calculated separately. Positive airway pressure, which was well tolerated, eliminated these events. ConclusionsThis novel catathrenia entity preceded by a cortical arousal and “rescue” respiration in response to obstructive events is intriguing. Possible explanations for these observations are further discussed in this article.

Oxidative stress and optical coherence tomography angiography evaluation of choriocapillaris and retinal vessel density in children with obstructive sleep apnea.

To investigate the vascular networks of the retina and choroid using optical coherence tomography angiography (OCTA) to identify early biomarkers of obstructive sleep apnea (OSA) severity and to evaluate correlations with blood levels of oxidative stress. Patients with OSA were diagnosed based on video-polysomnography (PSG) and blood samples were collected to evaluate oxidative stress markers: total antioxidant status (TAS), biological antioxidant potential (BAP) test, Diacron reactive oxygen metabolites (d-ROMs) test. The eyes of children with OSA were evaluated and compared with eyes of healthy age-matched children. OCTA imaging was carried out to evaluate the choroidal and retinal vascular network density indices. A total of 31 children with OSA were recruited and compared with 10 healthy children. Choriocapillaris flow area decreased (p = 0.006) and superficial capillary plexus vessel density increased (p=0.01) with increasing severity of OSA. Children with OSA showed significant differences in TAS and d-ROMs test when compared to normal pediatric values (p<0.05). In calculating the correlations between PSG, oxidative stress, and OCTA variables, there was a negative correlation between choriocapillaris flow area and apnea hypopnea index (AHI) (p = 0.02, r2 -0.5) and between choriocapillaris flow area and the d-ROMs test (p 0.03; r2 0.5). The severity of OSA was associated with the choroidal and retinal capillary vascular networks. The correlation of the choriocapillaris flow area with AHI and the d-ROMs test indicates the connection of the choroidal microvasculature with the number of obstructive apnea and hypopnea events and oxidative stress.

Multidisciplinary sequential treatment for obstructive sleep apnea hypopnea syndrome and malocclusion in children

With the high incidence of chronic rhinitis, mouth breathing is becoming the hot topic in orthodontics. The incidence of obstructive sleep apnea hypopnea syndrome (OSAHS) with malocclusion in children is also increasing. Dentofacial deformities such as maxillary constriction and mandibular retrognathia may be the primary cause of OSAHS, or they may be complications caused by chronic mouth breathing. Orthodontic treatment is of great significance in relieving obstructive sleep apnea and hypopnea. More attention should be paid by orthodontists to sleep disordered breathing. Orthodontists should routinely consider the condition of patients' upper airway in treatment designs. For children with malocclusion and OSAHS, the point of diagnosis and treatment is to carefully identify the complex pathogenesis and formulate a multidisciplinary sequential treatment plan.

How does obstructive sleep apnea alter cerebral hemodynamics?

We aimed to characterize the cerebral hemodynamic response to obstructive sleep apnea/hypopnea events, and evaluate their association to polysomnographic parameters. The characterization of the cerebral hemodynamics in obstructive sleep apnea (OSA) may add complementary information to further the understanding of the severity of the syndrome beyond the conventional polysomnography. Severe OSA patients were studied during night sleep while monitored by polysomnography. Transcranial, bed-side diffuse correlation spectroscopy (DCS) and frequency-domain near-infrared diffuse correlation spectroscopy (NIRS-DOS) were used to follow microvascular cerebral hemodynamics in the frontal lobes of the cerebral cortex. Changes in cerebral blood flow (CBF), total hemoglobin concentration (THC), and cerebral blood oxygen saturation (StO2) were analyzed. We considered 3283 obstructive apnea/hypopnea events from sixteen OSA patients (Age (median, interquartile range) 57 (52-64.5); females 25%; AHI (apnea-hypopnea index) 84.4 (76.1-93.7)). A biphasic response (maximum/minimum followed by a minimum/maximum) was observed for each cerebral hemodynamic variable (CBF, THC, StO2), heart rate and peripheral arterial oxygen saturation (SpO2). Changes of the StO2 followed the dynamics of the SpO2, and were out of phase from the THC and CBF. Longer events were associated with larger CBF changes, faster responses and slower recoveries. Moreover, the extrema of the response to obstructive hypopneas were lower compared to apneas (p < .001). Obstructive apneas/hypopneas cause profound, periodic changes in cerebral hemodynamics, including periods of hyper- and hypo-perfusion and intermittent cerebral hypoxia. The duration of the events is a strong determinant of the cerebral hemodynamic response, which is more pronounced in apnea than hypopnea events.

Auditory Receptive Field Net Based Automatic Snore Detection for Wearable Devices.

Although obstructive sleep apnea and hypopnea syndrome (OSAHS) is a common sleep disease, it is sometimes difficult to be detected in time because of the inconvenience of polysomnography (PSG) examination. Since snoring is one of the earliest symptoms of OSAHS, it can be used for early OSAHS prediction. With the recent development of wearable and IoT sensors, we proposed a deep learning-based accurate snore detection model for long-term home monitoring of snoring during sleep. To enhance the discriminability of features between snoring and non-snoring events, an auditory receptive field (ARF) net was proposed and integrated into the feature extraction network. Based on the feature maps derived by the feature extraction network, the detection model predicted a series of candidate boxes and corresponding confidence scores for each candidate box, which denoted whether the candidate box contained a snore event from the input sound waveforms. A snore detection dataset with a total duration of more than 4600 min was developed to evaluate the proposed model. The experimental results on this dataset revealed that the proposed model outperformed other traditional approaches and deep learning models.

Evaluation of Neutrophil-Lymphocyte Ratio and Platelet-Lymphocyte Ratio in Obstructive Sleep Apnea Patients

Background: Obstructive sleep apnea (OSA) is a condition marked by recurrent total or partial collapses of the upper airway during sleep, which result in obstructive apneas, hypopneas, and/or respiratory effort-related arousals.

Paediatric sleep apnea event prediction using nasal air pressure and machine learning.

Sleep-disordered breathing is an important health issue for children. The objective of this study was to develop a machine learning classifier model for the identification of sleep apnea events taken exclusively from nasal air pressure measurements acquired during overnight polysomnography for paediatric patients. A secondary objective of this study was to differentiate site of obstruction exclusively from hypopnea event data using the model. Computer vision classifiers were developed via transfer learning to either normal breathing while asleep, obstructive hypopnea, obstructive apnea or central apnea. A separate model was trained to identify site of obstruction as either adeno-tonsillar or tongue base. In addition, a survey of board-certified and board-eligible sleep physicians was completed to compare clinician versus model classification performance of sleep events, and indicated very good performance of our model relative to human raters. The nasal air pressure sample database available for modelling comprised 417 normal, 266 obstructive hypopnea, 122 obstructive apnea and 131 central apnea events derived from 28 paediatric patients. The four-way classifier achieved a mean prediction accuracy of 70.0% (95% confidence interval [67.1-72.9]). Clinician raters correctly identified sleep events from nasal air pressure tracings 53.8% of the time, whereas the local model was 77.5% accurate. The site of obstruction classifier achieved a mean prediction accuracy of 75.0% (95% confidence interval [68.7-81.3]). Machine learning applied to nasal air pressure tracings is feasible and may exceed the diagnostic performance of expert clinicians. Nasal air pressure tracings of obstructive hypopneas may "encode" information regarding the site of obstruction, which may only be discernable by machine learning.

Distinguishing central from obstructive hypopneas on a clinical polysomnogram.

Javaheri S, Rapoport DM, Schwartz AR. Distinguishing central from obstructive hypopneas on a clinical polysomnogram. J Clin Sleep Med. 2023;19(4):823-834.

Obstructive hypopnea sleep apnea syndrome in the elderly

obstructive sleep apnea hypopnea syndrome (OSAHS) is a common but often under diagnosed disease among elderly persons. The aim of our study was to determine the clinical and polygraphic characteristics of OSAHS in elderly by comparing them to younger patients. a retrospective study was performed at Pavillon D pneumology at Abderrahmen Mami Hospital in Ariana including 222 patients with OSAHS, divided into two groups: group 1 including 72 patients aged 18 to 45 years and Group 2 including 150 patients aged 65 and over. Clinical and polygraphic data was collected. elderly patients were more female, less exposed to tobacco but more exposed to biomass smoke. The average consultation time was significantly longer for elderly patients compared to young patients. Diurnal fatigue and memory impairment were more observed in elderly patients. Asthma, hypothyroidism, diabetes, dyslipidemia, hypertension and atrial fibrillation were most commonly observed in elderly patients. Pauses in airflow and tonsillary hypertrophy were less observed in this group. There was no significant difference in OSAHS severity between the 2 groups. Logistic regression analysis showed that elderly apneic patients were more likely to be female, to have more memory impairment and to have more comorbidities with HTA, atrial fibrillation, diabetes and hypothyroidism. the frequency of cardiovascular, metabolic and cognitive comorbidities requires sleep investigation in apneic elderly subject, whether the clinical presentation is typical or not.

Obstructive sleep apnea in young infants: Sleep position dependence and spontaneous improvement.

The natural evolution of obstructive sleep apnea (OSA) in young infants is not established. We re-evaluated 10-year pediatric sleep center infant polysomnography (PSG) data, excluding infants with syndromes, genetic defects, structural anomalies or periodic breathing > 5% of sleep time. Obstructive events > 1 h-1 were evident in 255 infants, of which 91 were eligible for the study. Of the 38 infants in a follow-up study, 30 (79%) were male, 15 (40%) were born prematurely, 25 (66%) had observed apneas, and 13 (33%) had experienced a brief, unexplained event or had a sibling of the infant died suddenly. The first PSG was performed at a median corrected age of 4 weeks (interquartile range [IQR] 2-7) and the second at 11 weeks (IQR 9-14). The obstructive apnea and hypopnea index (OAHI) was greater in the supine compared to side-sleeping position in both recordings (p < 0.001), whereas OAHI dropped from 10 h-1 (IQR 6-24) in the first PSG to 3 h-1 (IQR 1-9) in the second PSG (p < 0.001). OSA alleviation was also observable as a decrease in the number of oxygen desaturations (p < 0.001), as a decrease in transcutaneous (p = 0.001) and end-tidal carbon dioxide (p = 0.01) 95th percentile levels, and work of breathing (p = 0.002). Seven infants had a third PSG to verify a satisfactory improvement of OSA. OSA in young infants without a clear syndrome or structural anomaly is sleep position dependent and shows improvement during the following few months.

Impact of Unintentional Air Leaks on Automatic Positive Airway Pressure Device Performance in Simulated Sleep Apnea Events.

Positive airway pressure (PAP) is the accepted standard treatment for obstructive sleep apnea. In the last decades, automatic PAP (APAP) adjustment modes have been increasingly used. Pressure auto adjustment offers better comfort to the patient and represents a valuable help for the clinician to provide optimal treatment. However, device performance differs among manufacturers. Furthermore, the success of the therapy relies greatly on unintentional air leak level for many reasons, hence the importance to investigate the performance of the most common devices. The aim of this study was to compare the performance of 3 APAP devices from the most common manufacturers in specific conditions (ie, obstructive sleep apnea, central sleep apnea, hypopnea), with and without unintentional air leak. This was a bench test study. Performance tests were conducted on a breathing simulator using a Starling resistor, representing the upper airways, and an adjustable unintentional air leak valve. Three APAP devices (AirSense 10, DreamStation, and Prisma 20A) were tested in different scenarios. Without unintentional air leak, performance of the 3 devices was similar to existing literature. However, performance was altered with the addition of unintentional air leak in some scenario. The AirSense 10 was not able to respond correctly to obstructive apnea (intraclass correlation coefficient [ICC] 0.021, P = .61) and hypopnea (ICC 0.059, P = .26). Prisma 20A lowest performance was seen during simulated obstructive apnea (ICC 0.708, P < .001). DreamStation lowest performance was seen during simulated hypopnea events (ICC 0.755, P < .001). All 3 APAP devices reacted differently to the added unintentional air leak. Performance was altered with some devices, which could affect the therapy success in patients with sleep apnea syndrome. The variability of performance of some APAP devices with unintentional air leak should make clinicians evaluate their use in a home setting.

Noninvasive Ventilation Automated Technologies: A Bench Evaluation of Device Responses to Sleep-Related Respiratory Events.

Noninvasive ventilation (NIV) is the reference standard treatment for most situations of chronic respiratory failure. NIV settings must be titrated to both preserve upper-airway patency and control hypoventilation. Automatic adjustment of pressure support (PS) and expiratory positive airway pressure (EPAP) may facilitate the initiation and follow-up of domiciliary NIV. However, whether the automatic-adjustment algorithms embedded into current devices accurately detect, respond to, and score common sleep-related respiratory events remains unclear. A bench was set up to simulate central hypopnea (CH), central apnea (CA), obstructive hypopnea (OH), and obstructive apnea (OA). Four home ventilators were evaluated, with their dedicated modes for automatic PS and EPAP adjustment. All 4 devices increased PS during CH, CA, and OH. However, PS adjustment varied widely in magnitude, with tidal volumes within 100 ± 20% of the target being provided by only 3 devices for CH, one for CA, and one for OH. Two devices increased EPAP for OH and 3 for OA, including one that also increased EPAP for CA. Only 2 devices scored residual hypopnea after simulated CA, and only one scored a residual event after OH. One device scored no event. Current NIV devices differed markedly in their responses to, and reporting of, standardized sleep-related respiratory events. Further improvements in embedded NIV algorithms are needed to allow more widespread out-of-laboratory initiation and follow-up of NIV.

Clinical Characteristics and Post-Operative Outcomes in Children with Very Severe Obstructive Sleep Apnea.

Available information on clinical characteristics and post-operative outcomes in children with very severe obstructive sleep apnea (OSA) is limited. Our study evaluates the clinical features and polysomnographic (PSG) variables that predict post-operative outcomes in children with an obstructive apneal hypopnea index (AHI) of more than 25 events/hr. In this study from a single tertiary care center, we performed a retrospective chart review of patients with an AHI > 25/hr, who underwent tonsillectomy and adenoidectomy (T&A) between January 2016 and September 2021. In total, 50 children were included in the study: 26.0% (13/50) of children experienced post-operative respiratory events and four children needed intubation and ventilator support. Compared with children without respiratory events, children requiring post-operative respiratory interventions were younger (4.4 ± 5.2 vs. 8.0 ± 5.2 years; p = 0.04), had higher pre-operative AHI (73.6 ± 27.4 vs. 44.8 ± 24.9; p < 0.01), lower oxygen nadirs (70.0 ± 13.0% vs. 83.0 ± 7.0%; p < 0.01), and had lower body metabolic index Z-scores (−0.51 ± 2.1 vs. 0.66 ± 1.5; p < 0.04). Moderate to severe residual OSA was identified in 70% (24/34) of children with available post-operative PSG; younger children had better PSG outcomes. Our study shows that post-operative respiratory events are frequent in children with very severe OSA, particularly with an AHI > 40/h, younger children (<2 years of age), lower oxygen saturation (SpO2), and poor nutritional status, necessitating close monitoring.