European Respiratory Society guideline on non-CPAP therapies for obstructive sleep apnoea.

Treatment of obstructive sleep apnoea (OSA) in adults is evolving, as new therapies have been explored and introduced in clinical practice, while other approaches have been refined or reconsidered. In this European Respiratory Society (ERS) guideline on non-continuous positive airway pressure (CPAP) therapies for OSA, we present recommendations determined by a systematic review of the literature. It is an update of the 2011 ERS statement on non-CPAP therapies, advanced into a clinical guideline. A multidisciplinary group of experts, including pulmonary, surgical, dentistry and ear-nose-throat specialists, methodologists and patient representatives considered the most relevant clinical questions (for both clinicians and patients) relating to the management of OSA. Eight key clinical questions were generated and a systematic review was conducted to identify published randomised clinical trials that answered these questions. We used the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach to assess the quality of the evidence and the strength of recommendations. The resulting guideline addresses gastric bypass surgery, custom-made dual-block mandibular advancement devices, hypoglossal nerve stimulation, myofunctional therapy, maxillo-mandibular osteotomy, carbonic anhydrase inhibitors and positional therapy. These recommendations can be used to benchmark quality of care for people with OSA across Europe and to improve outcomes.

A Bag of Wavelet Features for Snore Sound Classification.

Snore sound (SnS) classification can support a targeted surgical approach to sleep related breathing disorders. Using machine listening methods, we aim to find the location of obstruction and vibration within a subject's upper airway. Wavelet features have been demonstrated to be efficient in the recognition of SnSs in previous studies. In this work, we use a bag-of-audio-words approach to enhance the low-level wavelet features extracted from SnS data. A Naïve Bayes model was selected as the classifier based on its superiority in initial experiments. We use SnS data collected from 219 independent subjects under drug-induced sleep endoscopy performed at three medical centres. The unweighted average recall achieved by our proposed method is 69.4%, which significantly ([Formula: see text] one-tailed z-test) outperforms the official baseline (58.5%), and beats the winner (64.2%) of the INTERSPEECH COMPARE Challenge 2017 Snoring sub-challenge. In addition, the conventionally used features like formants, mel-scale frequency cepstral coefficients, subband energy ratios, spectral frequency features, and the features extracted by the OPENSMILE toolkit are compared with our proposed feature set. The experimental results demonstrate the effectiveness of the proposed method in SnS classification.

European position paper on drug-induced sleep endoscopy: 2017 Update.

BACKGROUND: The first edition of the European position paper (EPP) on drug-induced sleep endoscopy (DISE) was published in 2014 with the aim to standardise the procedure, to provide an in-depth insight into the main aspects of this technique and to have a basis for future research. Since 2014, new studies have been published concerning new sedative agents or new insights into the pattern/levels of the obstruction depending on the depth of sedation. Therefore, an enlarged group of European experts in the field of sleep breathing disorders (SBD), including the most of the first DISE EPP main authors, has decided to publish an update of the European position paper on DISE, in order to include new evidence and to find a common language useful for reporting the findings of this endoscopic evaluation in adult population affected by SBD. METHODS: The authors have evaluated all the available evidence reported in the literature and have compared experience among various departments in leading European centres in order to provide an update regarding the standardisation of the DISE procedure and an in-depth insight into the main aspects of this technique. RESULTS: After the first European Position Consensus Meeting on DISE and its update, consensus was confirmed for indications, required preliminary examinations, where to perform DISE, technical equipment required, staffing, local anaesthesia, nasal decongestion, other medications, patient positioning, basics and special diagnostic manoeuvres, drugs and observation windows. So far, no consensus could be reached on a scoring and classification system. However, regarding this aim, the idea of an essential classification, such as VOTE with the possibility of its graded implementation of information and descriptions, seems to be the best way to reach a universal consensus on DISE classification at this stage. A common DISE language is mandatory, and attempts to come to a generally accepted system should be pursued.

Snoring classified: The Munich-Passau Snore Sound Corpus.

OBJECTIVE: Snoring can be excited in different locations within the upper airways during sleep. It was hypothesised that the excitation locations are correlated with distinct acoustic characteristics of the snoring noise. To verify this hypothesis, a database of snore sounds is developed, labelled with the location of sound excitation. METHODS: Video and audio recordings taken during drug induced sleep endoscopy (DISE) examinations from three medical centres have been semi-automatically screened for snore events, which subsequently have been classified by ENT experts into four classes based on the VOTE classification. The resulting dataset containing 828 snore events from 219 subjects has been split into Train, Development, and Test sets. An SVM classifier has been trained using low level descriptors (LLDs) related to energy, spectral features, mel frequency cepstral coefficients (MFCC), formants, voicing, harmonic-to-noise ratio (HNR), spectral harmonicity, pitch, and microprosodic features. RESULTS: An unweighted average recall (UAR) of 55.8% could be achieved using the full set of LLDs including formants. Best performing subset is the MFCC-related set of LLDs. A strong difference in performance could be observed between the permutations of train, development, and test partition, which may be caused by the relatively low number of subjects included in the smaller classes of the strongly unbalanced data set. CONCLUSION: A database of snoring sounds is presented which are classified according to their sound excitation location based on objective criteria and verifiable video material. With the database, it could be demonstrated that machine classifiers can distinguish different excitation location of snoring sounds in the upper airway based on acoustic parameters.

Snore sound recognition: On wavelets and classifiers from deep nets to kernels.

In this paper, we present a comprehensive comparison of wavelet features for the classification of snore sounds. Wavelet features have proven to be efficient in our previous work; however, the benefits of wavelet transform energy (WTE) and wavelet packet transform energy (WPTE) features were not clearly established. In this study, we firstly present our updated snore sounds database, expanded from 24 patients (collected by one medical centre) to 40 patients (collected by three medical centres). We then study the effects of varying frame sizes and overlaps for extraction of the wavelet low-level descriptors, the effect of which have yet to be fully established. We also compare the performance of the WTE and WPTE features when fed into multiple classifiers, namely, Support Vector Machines (SVM), K-Nearest Neighbours, Linear Discriminant Analysis, Random Forests, Extreme Learning Machines, Kernel Extreme Learning Machines, Multilayer Perceptron, and Deep Neural Networks. Key results presented indicate that, when fed into a SVM, WTE outperforms WPTE (one-tailed z-test, p<;0.002). Further, WPTE can achieve a significant improvement when trained by a k-nearest neighbours classifier (one-tailed z-test, p <; 0.001).

Drug-induced sleep endoscopy with target-controlled infusion using propofol and monitored depth of sedation to determine treatment strategies in obstructive sleep apnea.

BACKGROUND: Drug-induced sleep endoscopy (DISE) has become an important diagnostic examination tool in the treatment decision process for surgical therapies in the treatment of obstructive sleep apnea (OSA). Currently, there is a variety of regimes for the performance of DISE, which renders comparison and assessment across results difficult. It remains unclear how the different regimes influence the findings of the examination and the resulting conclusions and treatment recommendations. This study aimed to investigate the correlation between increasing levels of sedation (i.e., light, medium, and deep) induced by propofol using a target-controlled infusion (TCI) pump, with the obstruction patterns at the levels of the velum, oropharynx, tongue base, and epiglottis (i.e., VOTE classification). A second goal was the establishment of a sufficient sedation level to enable a reliable decision regarding treatment recommendations. MATERIAL AND METHODS: Forty-three patients with OSA underwent a DISE procedure using propofol TCI. Three levels of sedation were defined, depending on entropy levels and assessment of sedation: light sedation, medium sedation, and deep sedation. The evaluation of the upper airway at each level, with increasing sedation, was documented using the VOTE classification. The elapsed time at which each assessment was performed was recorded. RESULTS: Upper airway changes occurred and were measured throughout the DISE procedure. Clinically useful determinations of airway closure occurred at medium sedation; this level of sedation was most probably achieved with a blood propofol concentration of 3.2 µg/ml. In all 43 patients, definite treatment decisions could be made at medium sedation level. Increasing sedation did not result in changes in the treatment decision. CONCLUSIONS: Changes in upper airway collapse during DISE with propofol TCI occur at levels of medium sedation. Decisions regarding surgical treatment could be made at this level of sedation. CLINICAL TRIAL NAME: Upper Airway Collapse in Patients with Obstructive Sleep Apnea Syndrome by Drug Induced Sleep Endoscopy (URL: https://clinicaltrials.gov/ct2/results?term=NCT02588300&Search=Search ) REGISTRATION NUMBER: NCT02588300.

Classification of the Excitation Location of Snore Sounds in the Upper Airway by Acoustic Multifeature Analysis.

OBJECTIVE: Obstructive sleep apnea (OSA) is a serious chronic disease and a risk factor for cardiovascular diseases. Snoring is a typical symptom of OSA patients. Knowledge of the origin of obstruction and vibration within the upper airways is essential for a targeted surgical approach. Aim of this paper is to systematically compare different acoustic features, and classifiers for their performance in the classification of the excitation location of snore sounds. METHODS: Snore sounds from 40 male patients have been recorded during drug-induced sleep endoscopy, and categorized by Ear, Nose & Throat (ENT) experts. Crest Factor, fundamental frequency, spectral frequency features, subband energy ratio, mel-scale frequency cepstral coefficients, empirical mode decomposition-based features, and wavelet energy features have been extracted and fed into several classifiers. Using the ReliefF algorithm, features have been ranked and the selected feature subsets have been tested with the same classifiers. RESULTS: A fusion of all features after a ReliefF feature selection step in combination with a random forests classifier showed the best classification results of 78% unweighted average recall by subject independent validation. CONCLUSION: Multifeature analysis is a promising means to help identify the anatomical mechanisms of snore sound generation in individual subjects. SIGNIFICANCE: This paper describes a novel approach for the machine-based multifeature classification of the excitation location of snore sounds in the upper airway.

European position paper on drug-induced sedation endoscopy (DISE).

BACKGROUND: Although drug-induced sedation endoscopy (DISE) represents the most widespread diagnostic tool for upper airway endoscopic evaluation of snoring and obstructive sleep apnea hypopnea syndrome (OSAHS), many controversies exist about how to perform the sedation, the indications for DISE, and how to report DISE findings. The present position paper reports on a consensus as proposed by a group of European experts in the field of DISE after discussion during a recent dedicated meeting. METHODS: The authors have evaluated all the available evidence reported in the literature and have compared experience among various departments in leading European centers in order to provide a standardization of the DISE procedure and an in-depth insight in the main aspects of this technique. RESULTS: A proposal of the DISE procedure standardization has been achieved with a general agreement concerning the terminology, indications, contraindications, required preliminary examinations, setting, technical equipment required, staffing, local anesthesia and nasal decongestion, patient positioning, basis and special diagnostic maneuvers, and the applied sedation drugs and observation windows. Otherwise, no consensus has been reached on a scoring and classification system. CONCLUSIONS: Although consensus has been reached on several aspects of the DISE procedure, some topics remain open to future research, such as a better analysis of the importance of positional aspects during DISE and a further comparison of the differences in degree, level and pattern of upper airway collapse observed during DISE versus during natural sleep and awake endoscopy. Finally, a universally accepted scoring and classification system is lacking.

Observer variation in drug-induced sleep endoscopy: experienced versus nonexperienced ear, nose, and throat surgeons.

STUDY OBJECTIVE: To determine variations in interobserver and intraobserver agreement of drug-induced sleep endoscopy (DISE) in a cohort of experienced versus nonexperienced ear, nose, and throat (ENT) surgeons. DESIGN: Prospective, blinded agreement study. SETTING: Ninety-seven ENT surgeons (90 nonexperienced with DISE; seven experienced) observed six different DISE videos and were asked to score the upper airway (UA) level (palate, oropharynx, tongue base, hypopharynx, epiglottis), direction (anteroposterior, concentric, lateral), and degree of collapse (none; partial or complete collapse). Findings were collected and analyzed, determining interobserver and intraobserver agreement [overall agreement (OA), specific agreement (SA)] and kappa values per UA level. MEASUREMENT AND RESULTS: In the nonexperienced group, overall interobserver agreement on presence of tongue base collapse (OA = 0.63; kappa = 0.33) was followed by the agreement on epiglottis (OA = 0.57; kappa = 0.23) and oropharynx collapse (OA = 0.45; kappa = 0.09). Low overall interobserver agreement in this group was found for hypopharyngeal collapse (OA = 0.33; kappa = 0.08). A similar ranking was found for degree of collapse. For direction of collapse, high interobserver agreement was found for the palate (OA = 0.57; kappa = 0.16). Among the experienced observers, overall interobserver agreement was highest for presence of tongue base collapse (OA = 0.93; kappa = 0.71), followed by collapse of the palate (OA = 0.80; kappa = 0.51). In this group, lowest agreement was also found for hypopharyngeal collapse (OA = 0.47; kappa = 0.03). Interob-server agreement on direction of collapse was highest for epiglottis collapse (OA = 0.97; kappa = 0.97). Concerning the degree of collapse, highest agreement was found for degree of oropharyngeal collapse (OA = 0.82; kappa = 0.66). Among the experienced observers a statistically significant higher interobserver agreement was obtained for presence, direction, and degree of oropharyngeal collapse, as well as for presence of tongue base collapse and degree of epiglottis collapse. Among the nonexperienced observers, high intraobserver agreement was found in particular for tongue base and epiglottis collapse. Among the experienced observers, high agreement was found for all levels but to a lesser extent for hypopharyngeal collapse. Intraobserver agreement was statistically significantly higher in the experienced group, for all UA levels expect for the hypopharynx. CONCLUSION: This study indicates that both interobserver and intraobserver agreement was higher in experienced versus nonexperienced ENT surgeons. Agreement ranged from poor to excellent in both groups. The current results suggest that experience in performing DISE is necessary to obtain reliable observations.

Evaluation of drug-induced sleep endoscopy as a patient selection tool for implanted upper airway stimulation for obstructive sleep apnea.

STUDY OBJECTIVES: To study the possible predictive value of drug-induced sleep endoscopy (DISE) in assessing therapeutic response to implanted upper airway stimulation (UAS) for obstructive sleep apnea (OSA). METHODS: During DISE, artificial sleep is induced by midazolam and/or propofol, and the pharyngeal collapse patterns are visualized using a flexible fiberoptic nasopharyngoscope. The level (palate, oropharynx, tongue base, hypopharynx/epiglottis), the direction (anteroposterior, concentric, lateral), and the degree of collapse (none, partial, or complete) were scored in a standard fashion. RESULTS: We report on the correlation between DISE results and therapy response in 21 OSA patients (apnea-hypopnea index [AHI] 38.5 ± 11.8/h; body mass index [BMI] 28 ± 2 kg/m(2), age 55 ± 11 y, 20 male/1 female) who underwent DISE before implantation of a UAS system. Statistical analysis revealed a significantly better outcome with UAS in patients (n = 16) without palatal complete concentric collapse (CCC), reducing AHI from 37.6 ± 11.4/h at baseline to 11.1 ± 12.0/h with UAS (p < 0.001). No statistical difference was noted in AHI or BMI at baseline between the patients with and without palatal CCC. In addition, no predictive value was found for the other DISE collapse patterns documented. CONCLUSIONS: The absence of palatal CCC during DISE may predict therapeutic success with implanted UAS therapy. DISE can be recommended as a patient selection tool for implanted UAS to treat OSA.

Use of apneic oxygenation for the performance of pan-endoscopy.

OBJECTIVE: To evaluate the efficacy of apneic oxygenation for the performance of pan-endoscopy. STUDY DESIGN: Clinical retrospective study. SETTING: A university teaching hospital in Wuppertal, Germany. SUBJECTS: Forty-seven patients who underwent pan-endoscopy under apneic oxygenation during a period of 1 year. METHODS: After preoxygenation and induction of anesthesia, an 8 French catheter was introduced into the trachea for oxygen supply. Pan-endoscopy was carried out, as long as there were no signs of desaturation. The data were collected retrospectively from the anesthesia charts. RESULTS: Apnea was well tolerated up to 45 minutes in most of the patients. In 2 patients, the method was carried out incorrectly, and in 1 obese patient, it was not possible to get an acceptable oxygenation. CONCLUSION: With appropriate monitoring, sufficient nitrogen elution, and proper patient selection, we believe that this technique is superior to jet ventilation and intubation for pan-endoscopy, allowing unimpeded operative visualization.

Implanted upper airway stimulation device for obstructive sleep apnea.

OBJECTIVES/HYPOTHESIS: Previous feasibility studies have shown that electrical stimulation of the hypoglossal nerve can improve obstructive sleep apnea (OSA). The current study examined the safety and preliminary effectiveness of a second generation device, the Upper Airway Stimulation (UAS) system, and identified baseline predictors for therapy success. STUDY DESIGN: Two consecutive open prospective studies. METHODS: UAS systems were implanted in patients with moderate to severe OSA who failed or were intolerant of continuous positive airway pressure (CPAP). The study was conducted in 2 parts. In part 1, patients were enrolled with broad selection criteria. Apnea hypopnea index (AHI) was collected using laboratory-based polysomnography at preimplant and postimplant visits. Epworth Sleepiness Scale (ESS) and Functional Outcomes of Sleep Questionnaire (FOSQ) were also collected. In part 2, patients were enrolled using selection criteria derived from the experience in part 1. RESULTS: In part 1, 20 of 22 enrolled patients (two exited the study) were examined for factors predictive of therapy response. Responders had both a body mass index ≤32 and AHI ≤50 (P < .05) and did not have complete concentric palatal collapse. Part 2 patients (n = 8) were selected using responder criteria and showed an improvement on AHI from baseline, from 38.9 ± 9.8 to 10.0 ± 11.0 (P < .01) at 6 months postimplant. Both ESS and FOSQ improved significantly in part 1 and 2 subjects. CONCLUSIONS: The current study has demonstrated that therapy with upper airway stimulation is safe and efficacious in a select group of patients with moderate to severe OSA who cannot or will not use CPAP as primary treatment.

Drug-induced sleep endoscopy: the VOTE classification.

The surgical evaluation of obstructive sleep apnea is designed to characterize the pattern of upper airway obstruction in order to develop an effective treatment plan for an individual patient. Drug-induced sleep endoscopy (DISE) is one evaluation technique that involves assessment of individuals under pharmacologic sedation designed to simulate natural sleep, utilizing fiberoptic endoscopy to examine the upper airway. Developed in multiple centers throughout Europe, DISE was first described in 1991 and is performed widely around the world. Although multiple studies support a potential role for DISE in evaluation for treatment with surgery and mandibular repositioning appliances, important clinical questions remain unanswered. A major limitation in advancing our understanding of drug-induced sleep endoscopy has been the multiplicity and, in many cases, the complexity of classification systems that prevent the comparison of results across the studies and centers. We present the VOTE classification, a method for characterizing DISE findings that focuses on its core feature, the specific structures that contribute to obstruction.

Diagnosis and treatment of snoring in adults--S1 guideline of the German Society of Otorhinolaryngology, Head and Neck Surgery.

INTRODUCTION: Snoring has received increased attention over the last years. Given its high prevalence and its impact on quality of life, diagnosis and treatment of snoring are of major importance. AIM OF THE GUIDELINE: This guideline aims to promote high-quality care by medical specialists for adults who snore. DIAGNOSTIC MEASURES: Before every intervention, a medical history, clinical examination and sleep test need to be performed. INTERVENTIONS: There is no need to treat snoring unless requested by the snorer. Invasive treatments should be selected with care; for surgical treatment, minimally invasive procedures are preferred. Weight reduction; the avoidance of sleeping pills, alcohol and nicotine; and a regular sleep-wake cycle can be recommended, although convincing evidence is lacking. Since currently, there is not enough evidence to confirm the effectiveness of muscle stimulation or other forms of muscle training, these treatments cannot be recommended. Snoring can be treated successfully with intraoral devices, but it is essential to select suitable subjects. Devices preventing sleep in the supine position can also be helpful in selected cases. The data on the success rates of surgical intervention are often limited to short-term follow-up studies, and not all interventions have been sufficiently evaluated. The techniques used to treat nasal obstruction in snorers are identical to those used for general nasal obstruction. Nasal surgery is only indicated when subjects complain about nasal obstruction. A significant amount of data is available for laser-assisted resection of excessive mucosa; however, resections can be performed with other tools. The efficacy of radiofrequency surgery at the soft palate has been documented in placebo-controlled trials. Soft palate implants can reduce snoring. Tonsillectomy or uvulopalatopharyngoplasty should be selected with care, especially as less invasive alternatives are available.

Differences in clinical features of upper airway resistance syndrome, primary snoring, and obstructive sleep apnea/hypopnea syndrome.

BACKGROUND: The clinical features of patients with upper airway resistance syndrome (UARS) have previously been compared to patients with obstructive sleep apnea/hypopnea syndrome (OSAHS). No data regarding differences between patients with primary snoring (PS) or patients with obstructive sleep apnea/hypopnea without daytime sleepiness (OSAH) are available. We conducted a study to investigate clinical features of UARS, comparing them to those in patients with PS, OSAH, and OSAHS. METHODS: Retrospective chart analysis of 157 patients with PS, 424 patients with UARS, 562 patients with OSAH, and 1610 patients with OSAHS seen in two sleep disorders clinics between 1996 and 2006. All patients had a diagnostic polysomnography (PSG) and a comprehensive clinical history taken by board-certified sleep specialists. RESULTS: PS and UARS patients were significantly younger, less overweight and had lower weight gain during the past 5years. The female-to-male ratio was highest in the UARS group. UARS patients had significantly less stage non-rapid eye movement sleep (NREM) 1 and NREM 2 and significantly more NREM 3 and NREM 4 sleep than OSAH and OSAHS patients. Arousal indices between PS/UARS and OSAH/OSAHS patients were significantly lower, with no significant difference within these diagnostic categories. Patients with UARS presented the highest degree of subjective impairment. CONCLUSIONS: UARS patients share some clinical features of patients with OSAHS and PS, although these two groups differ in their presentation of clinical sleepiness. Patients with UARS were most impaired in terms of their daily functioning and perception of sleep quality. This finding could not be corroborated by objective measures.