Severe Obstructive Sleep Apnea Cases Research Articles

Inclusion of blood pressure parameter increases predictive capability of severe obstructive sleep apnea: A decision tree approach.

Few studies included objective blood pressure (BP) to construct the predictive model of severe obstructive sleep apnea (OSA). This study used binary logistic regression model (BLRM) and the decision tree method (DTM) to constructed the predictive models for identifying severe OSA, and to compare the prediction capability between the two methods. Totally 499 adult patients with severe OSA and 1421 non-severe OSA controls examined at the Sleep Medicine Center of a tertiary hospital in southern Taiwan between October 2016 and April 2019 were enrolled. OSA was diagnosed through polysomnography. Data on BP, demographic characteristics, anthropometric measurements, comorbidity histories, and sleep questionnaires were collected. BLRM and DTM were separately applied to identify predictors of severe OSA. The performance of risk scores was assessed by area under the receiver operating characteristic curves (AUCs). In BLRM, body mass index (BMI) ≥27kg/m2, and Snore Outcomes Survey score ≤55 were significant predictors of severe OSA (AUC 0.623). In DTM, mean SpO2<96%, average systolic BP ≥135mmHg, and BMI ≥39kg/m2 were observed to effectively differentiate cases of severe OSA (AUC 0.718). The AUC for the predictive models produced by the DTM was higher in older adults than in younger adults (0.807vs. 0.723) mainly due to differences in clinical predictive features. In conclusion, DTM, using a different set of predictors, seems more effective in identifying severe OSA than BLRM. Differences in predictors ascertained demonstrated the necessity for separately constructing predictive models for younger and older adults.

Obstrüktif Uyku Apnede (OUA) Ortalama Trombosit Hacmi (OTH) ve OUA'da Sürekli Pozitif Hava Yolu Basıncı (CPAP) Tedavisinin OTH Üzerine Etkisi

Aims: In this study, our objective was to evaluate mean platelet volume (MPV), an indirect marker of platelet activation, in patients with obstructive sleep apnea (OSA), and assess the effect of OSA treatment with continuous positive airway pressure (CPAP) on MPV&#x0D; Methods: In this study, records of consecutive patients who underwent polysomnographic evaluation for OSA symptoms in the Sleep Disorders Laboratory during a one-year period were reviewed retrospectively. Patients who had both complete blood count and MPV measurements were included in the study.&#x0D; Results: A total of 158 patients, including 51 females (32.3%) and 107 males (67.7%), were included in the study. The mean age of the patients was 51±13 (min-18, max-82) years. OSA was detected in 74.1% (117/158) of the patients. It was determined that as the severity of OSA increased, hemoglobin and hematocrit values increased significantly. There was no significant difference in platelet count according to the presence and severity of OSA. The MPV was significantly lower in severe OSA cases compared to those without OSA and mild OSA cases. A negative correlation was observed between MPV and the apnea-hypopnea index, desaturation index, and the amount of oxygen saturation below 90% during sleep. There was no significant difference in median erythrocyte and thrombocyte counts, hematocrit percentage and hemoglobin values before and after treatment in OSA patients who used CPAP therapy. However, a significant decrease in MPV was observed after OSA treatment compared to pre-treatment. (p=0.021).&#x0D; Conclusions: The results of the study do not support an increase in MPV and hence platelet activation in severe OSA patients compared with those without OSA. However, the results suggest that one month of CPAP treatment reduces MPV and thus platelet activation in severe OSA patients. Further controlled, prospective studies including treatment outcomes are needed on this subject.

0904 Exaggerated hypoxia burden of sleep apnea in patients with hyperacute lateral medullary infarction

Abstract Introduction Acute lateral medullary infarction (LMI) can sometimes appear with respiratory failure in the acute stage. Polysomnographic investigations have shown a specific association between LMI and sleep apnea syndrome. The aim of our study was to investigate this association in hyperacute stage of LMI. Methods We investigated 8 patients who underwent polysomnography (PSG) for sleep apnea during hyperacute stage of LMI and compared the data to 8 healthy control subjects matched according to age, sex, body-mass index (BMI), and apnea-hypopnea index (AHI). The PSG was performed within an average of 1.5 days after the onset of neurological symptoms. PSG recordings in the hyperacute phase of LMI were analyzed. Results Six patients were males (75%) and two were females (25%). The average age of the patients was 51.9 ± 14.5 years and the average BMI was 27.2 ± 3.5. According to the AHI results of patients with LMI in the hyperacute phase, there were 2 (25%) cases of mild obstructive sleep apnea (OSA), 2 (25%) cased of moderate OSA, and 4 (50%) cases of severe OSA. The central sleep apnea index was higher in the patient group (4.3 ± 5.4/hr) than the control group 0.6 ± 0.4/hr) and was statistically significant (p=0.035). On the other hand, sleep parameters (obstructive sleep apnea index, respiratory arousal index, mean saturation) related to obstructive sleep apnea were poor in the control group. Conclusion Our study showed that sleep apnea syndrome, particularly CSA, is common in the hyperacute phase of LMI compared to control group. Early recognition of this problem and appropriate intervention may minimize the adverse effects on the respiratory system and improve the prognosis. Further and follow-up studies are needed to clarify the clinical significance and appropriate treatment options in these patients. Support (if any)

The role of 3D speckle tracking echocardiography in the diagnosis of obstructive sleep apnea and its severity

There is a consistent relationship between obstructive sleep apnea (OSA) and cardiovascular diseases. It is already recognized that OSA may influence the geometry and function of the right ventricle (RV). This has encouraged the development of echocardiographic evaluation for screening of OSA and its severity. Three-dimensional speckle tracking echocardiography (3D STE) is in assumption better, compared with 2D STE, because it overcomes the standard 2D echo limitations. Thus, the purpose of our study is to evaluate whether 3D STE measurements, could predict the positive diagnosis and severity of OSA. We enrolled 69 patients with OSA and 37 healthy volunteers who underwent a cardiorespiratory sleep study. 2DE was performed in all patients. RVEF and 3D RVGLS were measured by 3DSTE. NT pro BNP plasma level was also assessed in all participants. 3D RV GLS (− 13.5% vs. − 22.3%, p < 0.001) and 3D RVEF (31.9% vs. 50%, p < 0.001) were reduced in patients with OSA, compared with normal individuals. 3D Strain parameters showed better correlation to standard 2D variables, than 3D RVEF. Except for NT pro BNP (p = 0.059), all parameters served to distinguish between severe and mild-moderate cases of OSA. 3D STE may be a reliable and accurate method for predicting OSA. Consequently, 3D RV GLS is a good tool of assessing the RV global function in OSA, because it correlates well with other established measurements of RV systolic function. Furthermore, 3D RV GLS was a precise parameter in identifying severe cases of OSA, while NT pro BNP showed no association.

O071 The performance accuracy of wrist-worn oximetry and its automated output parameters for screening obstructive sleep apnoea in children

Abstract Introduction Children with obstructive sleep apnea (OSA) are at increased risk for perioperative adverse events. Whilst polysomnography (PSG) remains the reference standard for OSA diagnosis, oximetry is a valuable screening tool; visual analysis of desaturation clusters derived from a tabletop oximeter is the traditional practice. However, wearable oximetry with automated analysis could be an alternative option. This study investigated the accuracy of a wrist-worn oximeter as an OSA screening tool for a paediatric surgical population. Method Children scheduled for adenotonsillectomy without significant co-morbidities underwent concurrent overnight PSG and oximetry (Nonin WristOx2 3150) preoperatively. To determine the obstructive apnea-hypopnea index (OAHI), PSG was scored manually, and oximetry data were auto-analysed by Nonin proprietary software to determine the 3% oxygen desaturation index (oximetric ODI3). Logistic regression assessed the predictive performance of ODI3 and covariates (age, gender, BMI z-score) for detecting any OSA and moderate-severe OSA. Results Seventy-six children (34 females, aged (mean±SD) 5.7±1.6years) were classified based on PSG-derived OAHI as having no OSA (n=31), mild (n=31), and moderate-severe OSA (n=14). The moderate-severe OSA (OAHI≥5 events/hr) prediction analysis showed that oximetric ODI3 (OR 1.38, 95% CI 1.15, 1.65, p=0.001) was the sole OSA predictor. At a cut-off of ODI3=5events/hr, sensitivity and specificity were 78.6% and 75.8%, respectively, capturing all severe OSA cases (ROC-AUC=0.857). For any OSA (OAHI≥ 1 event/hr), prediction analysis showed reduced accuracy in performance: 75.6% sensitivity, 61.3% specificity (ROC-AUC=0.7097). Conclusion Wrist-worn oximetry-derived automated ODI3 can reliably identify moderate-severe OSA. Easy acquisition and interpretation may expedite the preoperative identification of OSA at-risk children.

The Correlation between BMI and Severity of Obstructive Sleep Apnea: A Single-Center Study in Dhaka, Bangladesh

Background: Obstructive sleep apnea (OSA) which is a very common form of sleep-disorder with associated health risks has been associated with much more insidious conditions, like hypertension, heart disease, diabetes, stroke and even daytime somnolence. But we have not enough research-based information regarding the co-relation between BMI and severity of obstructive sleep apnea. Aim of the Study: The aim of this study was to assess the co-relation between BMI and severity of obstructive sleep apnea. Methods: This was an observational study which was conducted in the Department of Otolaryngology &amp;, Head Neck Surgery, Bashundara Ad-Din Medical College and Hospital, Bangladesh during the period from January 2121 to December 2021. A total of 57 patients with obstructive sleep apnea (OSA) were included as the subjects. The ethical committee of the mentioned hospital approved this study. All demographic data along with BMI and the severity of OSA of the participants were recorded and analyzed. Data were processed and analyzed by using MS Office and SPSS version 23 programs as per need. Results: In this study, in analyzing the correlation between BMI and severity of OSA as per patient’s diagnosis and titration based on two nights’ study, we observed that, there was not any significant correlation of BMI of the patients with mild, moderate or even severe stage OSA. In comparing the mild, moderate and severe cases of OSA with their mean BMI values 30.66±6.23, 28.47±6.78 and 30.43±4.32 and the P values were found as 0.755, 0.554 and 0.454 respectively. Conclusion: According to the findings of this study we can conclude that, there is not any significant correlation of patient’s BMI with their mild, moderate or even severe conditions of obstructive sleep apnea.

Correlations between Morphology, the Functional Properties of Upper Airways, and the Severity of Sleep Apnea.

Obstructive sleep apnea (OSA) is considered the silent killer pathology of the new millennium. This is due to increased risk factors such as obesity. Healthcare systems face an increasing burden from severe cases of OSA. We performed a study on a group of 152 Romanian patients with OSA recording data obtained through polysomnography and cephalometric variables, recorded in lateral plain X-rays. The results confirmed some of the data available from previous studies worldwide, but some of the variables presented a positive statistical correlation specific to our study group. For example, the apnea-hypopnea index (AHI) correlated with the uvula length but surprisingly did not correlate with body mass index (BMI) because obesity tends to become endemic in Romania. To our knowledge, this is one of the first studies focusing on cephalometric data in Romanian OSA patients. The results obtained through this study will be further analyzed in research on larger groups of Romanian OSA patients.

A telemonitoring system to support CPAP therapy in patients with obstructive sleep apnea: a participatory approach in analysis, design, and evaluation

BackgroundContinues positive airway pressure (CPAP) therapy is a gold standard treatment for moderate to severe cases of OSA (obstructive sleep apnea). The present research aimed to describe the analysis, design, and evaluation of a telemonitoring system to improve CPAP adherence in patients afflicted with OSA.MethodsThe telemonitoring system was developed in five phases. In the exploratory phase, the body of related literature was reviewed. Then a need analysis was conducted through a focus group discussion with sleep medicine specialists and sales company representatives and an interview with patients. The third phase involved data integration. Then the content and system development were done based on the previous phases. Finally, usability and functionality tests were used to evaluate the system.ResultsThe exploratory phase and the needs analysis were conducted by four sleep medicine specialists, two medical informatics specialists, six key figures of the sales companies, two system developers, and 46 patients in different phases. Based on the results obtained from the data integration phase, the telemonitoring system involved three main parts: a patient’s application, a doctor’s portal, a selling companies’ portal (operator’s portal) along with facilitating software for patients to send the CPAP data. Usability and functionality tests were given to 7 and 10 patients, respectively. The total number of usability issues reported by users in the evaluation process was 18, with an average of 2.5 issues per user. The installation problems, disrupted links and improper playing of videos were the main functionalities problems that were solved.ConclusionThe telemonitoring system, as a means of communication between patients, doctors, and selling companies, can be used to support patients clinically and technically. It has the potential to improve CPAP adherence in patients with OSA.

Diagnostic accuracy and feasibility of portable sleep monitoring in patients with obstructive sleep apnea: Re-exploring the utility in the current COVID-19 pandemic.

Portable sleep monitoring (PSM) is a promising alternative diagnostic tool for Obstructive Sleep Apnea (OSA) especially in high burden resource limited settings. We aimed to determine the diagnostic accuracy and feasibility of PSM device-based studies in patients presenting for evaluation of OSA at a tertiary care hospital in North-India. PSM studies (using a Type-III PSM device) were compared for technical reliability and diagnostic accuracy with the standard laboratory-based Type-I polysomnography (PSG). Patients were also interviewed about their experience on undergoing an unsupervised PSM studies. Fifty patients (68% males) were enrolled in the study, of which only 30% patients expressed their concerns about undergoing unsupervised PSM studies which included safety issues, ease of use, diagnostic accuracy, etc. Technical acceptability criteria were easily met by the PSM studies with signal loss in 12% studies (complete data loss and inaccessible data in 6% studies), warranting repetition sleep studies in four patients. The overall sensitivity of PSM device (AHI ≥5) was 93.5% (area under curve; AUC: 0.87). The diagnostic accuracy was 68.5%, 80%, and 91.4% for mild, moderate, and severe cases of OSA, respectively. An overall strong correlation was observed between PSM-AHI (apnoea-hypopnoea index) and PSG (r>0.85, p≤0.001), especially in severe OSA. The observed sensitivity was >90% for AHI>20 (clinically significant OSA), with high specificity of 91% for severe OSA (AUC: 0.94, 0.97 for AHI>20, AHI>30 respectively). The overall Bland-Altman concordance analysis also demonstrated only a small dispersion for PSM studies with a Cronbach's coefficient of 0.95.Therefore, there is good diagnostic accuracy as well as feasibility of home-based portable sleep studies in Indian patients. It can be promoted for widespread use in high burden countries like India for diagnosing and managing appropriately selected stable patients with high clinical probability of OSA, especially during the ongoing crises of COVID-19 pandemic.

A 3D-printed microfluidic platform for simulating the effects of CPAP on the nasal epithelium

Obstructive sleep apnea (OSA) is a chronic disorder that involves a decrease or complete cessation of airflow during sleep. It occurs when the muscles supporting the soft tissues in the throat relax during sleep, causing narrowing or closure of the upper airway. Sleep apnea is a serious medical condition with an increased risk of cardiovascular complications and impaired quality of life. Continuous positive airway pressure (CPAP) is the most effective treatment for moderate to severe cases of OSA and is effective in mild sleep apnea. However, CPAP therapy is associated with the development of several nasal side effects and is inconvenient for the user, leading to low compliance rates. The effects of CPAP treatment on the upper respiratory system, as well as the pathogenesis of side effects, are incompletely understood and not adequately researched. To better understand the effects of CPAP treatment on the upper respiratory system, we developed an in vitro 3D-printed microfluidic platform. A nasal epithelial cell line, RPMI 2650, was then exposed to certain conditions to mimic the in vivo environment. To create these conditions, the microfluidic device was utilized to expose nasal epithelial cells grown and differentiated at the air–liquid interface. The airflow was similar to what is experienced with CPAP, with pressure ranging between 0 and 20 cm of H2O. Cells exposed to pressure showed decreased barrier integrity, change in cellular shape, and increased cell death (lactate dehydrogenase release into media) compared to unstressed cells. Stressed cells also showed increased secretions of inflammatory markers IL-6 and IL-8 and had increased production of ATP. Our results suggest that stress induced by airflow leads to structural, metabolic, and inflammatory changes in the nasal epithelium, which may be responsible for developing nasal side-effects following CPAP treatment.

The Utility of Epworth Sleepiness Scale to Screen Moderate and Severe Obstructive Sleep Apnea Preoperatively to Predict Difficult Airway

Abstract Introduction Obstructive sleep apnea (OSA) is sleep-disordered breathing characterized by repetitive episodes of partial or complete upper airway collapse in sleep leading to apnea and/or hypopnea, desaturations, sleep disruptions, and cardiovascular changes. OSA is a known cause for difficult airway, especially mask ventilation. Daytime sleepiness is one of the hallmark symptoms of OSA. So, we used the Epworth sleepiness score (ESS) in patients suspected of OSA undergoing a sleep study. Methods Overall, 44 subjects suspected to have OSA and undergoing polysomnography were included in the study. The socio-demographic details and the complaints were recorded and the Epworth sleepiness questionnaire was administered. The severity of OSA was graded as per the American Academy of Sleep Medicine using the apnea hypopnea index. Results A total of 44 patients were included in the study. Out of these, 19 were mild, 13 moderate, and 12 severe OSA cases, respectively. ESS of more than 10 showed a positive predictive value of 81.25% and specificity of 85% in screening patients with moderate and severe OSA. But the sensitivity and negative predictive value was only 54.16 and 60.71%, respectively. Conclusion ESS being a simple questionnaire can be easily used preoperatively. A score of more than 10 effectively diagnoses moderate and severe OSA, but less than 10 cannot rule out OSA

Prevalence of obstructive sleep apnea in diabetic patients.

Context:Obstructive sleep apnea (OSA)-related hypoxemia stimulates release of acute-phase proteins and reactive oxygen species that exacerbate insulin resistance and lipolysis and cause an augmented prothrombotic and proinflammatory state which can leads to premature death.Aims:This study aims to study the prevalence of OSA in diabetic patients.Setting and Design:It was a cross-sectional study, done over a period of 1 year in a tertiary care hospital.Materials and Methods:A total of 149 type 2 diabetic patients were enrolled after taking written consent. All patients were subjected to STOP BANG questionnaire and patients falling in intermediate-high risk (score 3–8), were taken for overnight polysomnography to confirm the diagnosis of OSA (apnea hypopnea index ≥ 5).Statistical Analysis Used:Statistical Package for Social Sciences (SPSS) Version 21.0 statistical analysis software.Results:Fifty-five percent of our diabetic population were having OSA. The age of patients enrolled in the study ranged between 30 and 86 years and prevalence increases with an increase in age groups. Majority (61.7%) of our cases were males. Incremental trend in weight, body mass index (BMI), neck circumference, and waist circumference of OSA cases were found with increasing in severity of OSA. Mean levels of raised blood sugar and HbA1c were higher in severe OSA cases.Conclusions:OSA has a high prevalence in patients with type 2 diabetes mellitus. Patients with type 2 diabetes should be screened for OSA, even in the absence of symptoms, especially in individuals with higher waist circumference and BMI.

Applying composite physiological characteristics to assess the severity of obstructive sleep apnea

Obstructive Sleep Apnea (OSA) is a common sleep disorder which causes poor sleep quality, daytime drowsiness, memory loss, and lack of attention, and can contribute to accidents. Long-term OSA is associated with cardiovascular disease, high blood pressure, arrhythmia and diabetes. Early discovery and treatment of OSA can significantly reduce the difficulty and cost of treatment. OSA detection uses a scale method which is prone to subjective errors. Polysomnography (PSG) requires long detection times, entails equipment which can be difficult to obtain and high cost, and does not provide immediate diagnosis or the establishment of preventative treatment. Human biosignals have been found to provide a faster and more objective means of sleep apnea diagnosis, allowing for the early treatment of OSA. By identifying key physiological characteristics and observing their change over time, one can assess the severity of the patient’s condition, and appropriate treatment can reduce the likelihood of disease onset or slow its progression. This study applies machine learning techniques to electroencephalography (EEG), electrocardiography (ECG), oxygen saturation (SpO2) and other complex physiological characteristics to establish a model for OSA severity and evaluate the effectiveness of various machine learning methods to detect sleep apnea. In addition, the fuzzy C-mean (FCM) algorithm is used to construct a predictive model for OSA to assist physicians in the early clinical detection of symptoms. The study found that patients with severe sleep apnea have a self-rescue condition which causes wakening due to respiratory arrest. Only relying on SpO2 and the Apnea Hypopnea Index (AHI) will cause severe OSA cases to be misidentified as mild, and this study found that the A5 band brain wave can help detect sleep apnea, reducing the possibility of miscategorization and assisting physicians in accurate clinical diagnosis.

Recent advances in the management of secondary hypertension-obstructive sleep apnea.

Since obstructive sleep apnea (OSA) is known as a common cause of secondary hypertension, it is necessary to consider OSA a differential diagnosis in treating patients with hypertension. Apnea during sleep causes temporary and repeated hypoxia and subsequent sympathetic nerve activation. Furthermore, dysfunction of endothelial cells due to hypoxia is considered another mechanism leading to enhanced stiffness of the elastic artery and eventually, elevation of blood pressure (BP). As a result, OSA induces a nighttime or morning surge in BP, and long-standing severe OSA also causes daytime hypertension. Therefore, treatment of OSA may be important for BP control, especially in severe OSA cases. For the treatment of OSA, continuous positive airway pressure (CPAP) is a major treatment option, though alternative devices may be useful in CPAP-intolerant cases.

Role of serum periostin in severe obstructive sleep apnea with albuminuria: an observational study

BackgroundPeriostin is a matricellular protein and is a useful marker in respiratory diseases. However, the roles of periostin in patients with obstructive sleep apnea (OSA) remain unclear. Several in vitro studies have suggested that mechanical stress, hypoxia, impaired metabolism, and kidney injury, which often accompany OSA, may upregulate the expression of periostin. Meanwhile, serum periostin level has been negatively associated with body mass index (BMI) in the general population. In this study, we hypothesized that a high level of serum periostin despite being overweight/obese may discriminate severe OSA or OSA with comorbidities from mild OSA with obesity alone. We aimed to clarify the roles of periostin in patients with OSA to assist in elucidating the heterogeneity of OSA with comorbidities.MethodsAmong patients diagnosed as OSA, we examined the associations between serum periostin levels and clinical indices, including the severity of OSA, BMI, and comorbidities, using a multifaceted approach. The serum periostin levels and clinical indices were assessed after 3 months of continuous positive airway pressure (CPAP) treatment.ResultsIn 96 patients with OSA, serum periostin level was negatively correlated with BMI, albeit marginally, and tended to be higher in severe OSA than in others when adjusted for BMI. Cluster analysis identified four clusters, including two severe OSA clusters, one of which was characterized by high serum periostin levels and the presence of comorbidities, including albuminuria. In a comparative analysis of severe OSA cases (n = 53), the level of serum-free fatty acids and the frequency of albuminuria were higher in patients with high serum periostin level of ≥87 ng/mL, which was the highest quintile among all participants, than in those with low serum periostin levels (< 87 ng/mL, n = 41). In patients with severe OSA and high serum periostin levels, the levels of serum periostin and urinary albumin significantly decreased after 3 months of CPAP treatment.ConclusionsElevated serum periostin in patients with OSA despite being overweight/obese may be an indicator of severe OSA with comorbidities, particularly albuminuria.

Exploring the STOP-BANG questionnaire for obstructive sleep apnea screening in seniors.

The accuracy of obstructive sleep apnea (OSA) screening instruments in seniors may change as the predictive role of sex, age, and body mass index (BMI) changes with aging. We investigated the diagnostic performance of the STOP-BANG questionnaire in older individuals with aging-adapted scores and thresholds. Independent community-dwelling adults aged 65 years or older were screened for OSA. The STOP-BANG questionnaire was tested with different configurations and compared to the apnea-hypopnea index (AHI) obtained from home sleep apnea testing (HSAT). Epworth Sleepiness Scale (ESS) and Athens Insomnia Scale (AIS) were tested as possible supplementary screening criteria. We recruited 458 individuals with a mean age of 71 ± 5 years, 41% men, BMI of 28.5 ± 4.6 kg/m². Mild, moderate, and severe OSA were present in, respectively, 34%, 30%, and 19% of the sample. The STOP questions had an area under the curve (AUC) of the receiver operating characteristic curve significantly lower than the STOP-BANG and the STOP+BMI > 28 kg/m² (STOP-B28). Both STOP-BANG and STOP-B28 had high sensitivity and low specificity in all OSA levels with similar AUC to predict AHI ≥ 5 events/h, 0.64. ESS and AIS were nonsignificant as adjunctive instruments. Novel modifications of a standard instrument created the STOP-B28, a simpler-to-obtain and similarly performing variation of the STOP-BANG using fewer inputs, and useful to exclude OSA. Screening seniors via questionnaires to detect OSA is problematic. Considering the 83% OSA prevalence in this age group, it may be a sensible option to indicate objective tests, oximetry, HSAT, or even polysomnography, as a first step in OSA investigation.

Role of limited vs full polysomnography as a diagnostic tool of obstructive sleep apnea

Introduction Obstructive sleep apnea (OSA) is the commonest breathing disorder during sleep and usually presents with sleep fragmentation, hypoxia, and excessive day sleepiness. Polysomnography (PSG) is still the device of choice for OSA diagnosis. Objective The aim was to compare the validity of limited PSG (measuring nasal flow of air, effort of respiratory muscles, heart rate, and oxygen saturation) with full PSG in diagnosis of OSA. Patients and methods Any patient who presented with snoring associated with excessive daytime sleepiness, Epworth sleep scale greater than or equal to 10, BMI greater than 30, or apnea-hypopnea index (AHI) greater than or equal to 5 events/h admitted to Chest Department, Faculty of Medicine, Tanta University Hospitals during the period from June 2018 to April 2019 was included in the study and subjected to full and limited PSG for two consecutive nights. Limited PSG included the following channels: nasal cannula and nasal thermistor, snoring microphone, the abdominal belt, the thoracic belt, the SOMNO screen plus, and the pulse oximetry lead. Results Limited PSG was comparable to full one, with insignificant difference in measuring AHI in total, moderate, and severe OSA cases. There was a significant positive correlation between AHI measured by full and limited PSG in both moderate and severe OSA cases. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy in measurement of AHI by limited PSG were higher in severe than in moderate OSA cases, which indicates that the limited PSG is more sensitive, more specific, and more accurate in the diagnosis of severe cases than moderate ones. Conclusion Limited PSG is a reliable diagnostic device of OSA, as it has excellent agreement with AHIs determined by full PSG besides its lower cost.

Diagnosis of Sleep-Disordered Breathing in the Home Environment.

Polysomnography, a gold standard for the diagnosis of sleep-disordered breathing, is a complex investigation requiring access to the sleep laboratory. Thus, sleep-disordered breathing could be underdiagnosed. The aim of this paper was to investigate the feasibility and effectiveness of self-performed investigation of obstructive sleep apnea (OSA) in the home setting, using a portable device, and to assess the comfort and simplicity of the procedure from the patient's perspective. The study included 68 middle-aged patients (21 women and 47 men), who were examined at home with the ApneaLink Air device in search for the underlying reason of reported nighttime snoring and occasionally disordered breathing pattern. The apnea-hypopnea index was quantified and matched with body mass index (BMI), age, and other characteristics. OSA was diagnosed in 37 patients (27 men and 10 women): 22 had mild, 4 had moderate, and 11 patients had severe OSA. All cases of severe OSA were present in men. Patients with severe OSA had significantly higher BMI than those from the other groups. All of the patients pointed to the comfort and ease of the diagnostic device. We conclude that home diagnosis of OSA is a relatively easy and cost-effective way to substitute for the hospital-linked polysomnography, particularly in severely ill patients who have a movement difficulty. A wider implementation of home-based diagnosis of OSA may substantially increase the number of patients investigated in a short time span, also leading to the plausibly upward correction of the disease prevalence.

Efficacy of Oral Appliance Therapy in the Treatment of Severe OSA in CPAP-Resistant Cases

Continuous positive airway pressure (CPAP) is the current standard of care for the treatment of obstructive sleep apnea (OSA). It is known that there is a low rate of adherence in many patients. Oral appliance therapy (OAT) is effective in patients with mild-to-moderate OSA. The efficacy of OAT in severe patients is unknown. The aim of this study is to evaluate treatment using an in-laboratory titration method to determine whether OAT might be appropriate for patients with severe OSA. This is an IRB approved, retrospective study of 41 adults (mean age 51 years; 73% male) with severe OSA who were intolerant of CPAP therapy. All patients were treated with OAT (OASYS Oral–Nasal Airway System™). The sample was sub-divided into severe [Apnea–Hypopnea Index (AHI > 30 50) groups. Informed consent was obtained from all patients included in the study. The device was custom fit by a dentist. After patients reported subjective symptom improvement, titration polysomnography was performed. If obstructive events were still noted after 90 min of the sleep study, an attending sleep technologist titrated the device in vivo in 1 mm increments for a maximum of 3 mm to optimize effectiveness. For severe cases, almost half (46%) were resolved with a post-treatment AHI < 5, while two-thirds (66%) had an AHI < 10. For very severe cases, 43% were resolved with a post-treatment AHI < 5, while 64% had an AHI < 10. All findings were statistically significant (p < 0.001). This preliminary study supports the notion that oral appliance therapy using the OASYS Oral–Nasal Airway System™ may be effective in severe cases of OSA.

Symptom-Based Subgroups of Koreans With Obstructive Sleep Apnea

Recently, the Icelandic Sleep Apnea Cohort (ISAC) identified three subgroups in patients with obstructive sleep apnea (OSA) recruited from the sleep clinic based on clinical symptoms and comorbidities: excessively sleepy, minimally symptomatic, and disturbed sleep. This study sought to determine whether the three OSA subgroups are applicable to a population-based cohort in Korea. Study subjects are participants of an ongoing cohort study in Korea. Of the 2,918 participants, 422 new moderate to severe OSA cases (apneahypopnea index [AHI] ≥ 15 events/h) were diagnosed by home sleep studies. All participants completed a detailed questionnaire on sleep-related symptoms, comorbidities, medication, and other information. A latent class analysis was performed. When examining solutions for up to 10 clusters, the a priori three-cluster solution was the optimal clustering solution. The three-cluster solution demonstrated a subgroup presentation similar to the clusters identified in the ISAC. The minimally symptomatic subgroup was most prevalent (55.7%) in the Korean cohort. Among the three subgroups, there were no differences in mean AHI and body mass index; however, the disturbed sleep subgroup was older and had more females. Combined with the ISAC data, we suggest that the three-symptom cluster solution for patients with OSA may be more widely applicable, irrespective of ethnicity and study population.