Patterns of adaptive servo-ventilation settings in a real-life multicenter study: pay attention to volume! : Adaptive servo-ventilation settings in real-life conditions.

BACKGROUNDS: To explain the excess cardiovascular mortality observed in the SERVE-HF study, it was hypothesized that the high-pressure ASV default settings used lead to inappropriate ventilation, cascading negative consequences (i.e. not only pro-arrythmogenic effects through metabolic/electrolyte abnormalities, but also lower cardiac output). The aims of this study are: i) to describe ASV-settings for long-term ASV-populations in real-life conditions; ii) to describe the associated minute-ventilations (MV) and therapeutic pressures for servo-controlled-flow versus servo-controlled-volume devices (ASV-F Philips®-devices versus ASV-V ResMed®-devices). METHODS: The OTRLASV-study is a cross-sectional, 5-centre study including patients who underwent ASV-treatment for at least 1 year. The eight participating clinicians were free to adjust ASV settings, which were compared among i) initial diagnosed sleep-disordered-breathing (SBD) groups (Obstructive-Sleep-Apnea (OSA), Central-Sleep-Apnea (CSA), Treatment-Emergent-Central-Sleep-Apnea (TECSA)), and ii) unsupervised groups (k-means clusters). To generate these clusters, baseline and follow-up variables were used (age, sex, body mass index (BMI), initial diagnosed Obstructive-Apnea-Index, initial diagnosed Central-Apnea-Index, Continuous-Positive-Airway-Pressure used before ASV treatment, presence of cardiopathy, and presence of a reduced left-ventricular-ejection-fraction (LVEF)). ASV-data were collected using the manufacturer's software for 6 months. RESULTS: One hundred seventy-seven patients (87.57% male) were analysed with a median (IQ25-75) initial Apnea-Hypopnea-Index of 50 (38-62)/h, an ASV-treatment duration of 2.88 (1.76-4.96) years, 61.58% treated with an ASV-V. SDB groups did not differ in ASV settings, MV or therapeutic pressures. In contrast, the five generated k-means clusters did (generally described as follows: (C1) male-TECSA-cardiopathy, (C2) male-mostly-CSA-cardiopathy, (C3) male-mostly-TECSA-no cardiopathy, (C4) female-mostly-elevated BMI-TECSA-cardiopathy, (C5) male-mostly-OSA-low-LVEF). Of note, the male-mostly-OSA-low-LVEF-cluster-5 had significantly lower fixed end-expiratory-airway-pressure (EPAP) settings versus C1 (p = 0.029) and C4 (p = 0.007). Auto-EPAP usage was higher in the male-mostly-TECSA-no cardiopathy-cluster-3 versus C1 (p = 0.006) and C2 (p < 0.001). MV differences between ASV-F (p = 0.002) and ASV-V (p < 0.001) were not homogenously distributed across clusters, suggesting specific cluster and ASV-algorithm interactions. Individual ASV-data suggest that the hyperventilation risk is not related to the cluster nor the ASV-monitoring type. CONCLUSIONS: Real-life ASV settings are associated with combinations of baseline and follow-up variables wherein cardiological variables remain clinically meaningful. At the patient level, a hyperventilation risk exists regardless of cluster or ASV-monitoring type, spotlighting a future role of MV-telemonitoring in the interest of patient-safety. TRIAL REGISTRATION: The OTRLASV study was registered on ClinicalTrials.gov (Identifier: NCT02429986 ). 1 April 2015.

Evening sock marks as an adjunct to the clinical prediction of obstructive sleep apnea.

STUDY OBJECTIVES: Fluid overload shifting from the legs to the upper airway during sleep promotes obstructive sleep apnea (OSA) and interventions targeting fluid attenuate OSA. Fluid shift has been previously measured by bioelectrical impedance, a complex and time-consuming technique not applicable in the daily clinical settings. The aim of this study is to evaluate the presence of clinically detectable fluid overload and shift and its association with OSA. METHODS: Patients undergoing sleep study for suspected OSA were asked to report the presence of 11 signs/symptoms associated to excessive accumulation of fluid in different parts of the body at different times of the day. RESULTS: Among 392 patients (male: 53%, median [interquartile range] age: 56 years [1], body mass index, BMI: 29 kg/m2 [2]) included in the study, 135 (34%) had moderate-to-severe OSA (apnea hypopnea index, AHI ≥ 15). Daytime fluid accumulation and nocturnal fluid shift, clinically detectable by patient-reported "evening sock marks," "heavy legs during the day," and "morning stuffed nose," were prevalent in the entire population (46%, 43%, and 33%, respectively). In multivariate analysis, evening sock marks was an independent correlate of having an AHI ≥ 15, together with male sex, older age, and self-reported snoring and apneas. CONCLUSIONS: Clinically detectable fluid overload and shift are prevalent in patients addressed for suspected OSA, and evening sock marks, a marker for leg swelling, is an independent correlate of moderate-to-severe OSA. This sign might contribute to OSA diagnosis and identification of patients likely to be treated by interventions targeting fluid overload and shift.

What is the remaining status of adaptive servo-ventilation? The results of a real-life multicenter study (OTRLASV-study) : Adaptive servo-ventilation in real-life conditions.

BACKGROUNDS: As a consequence of the increased mortality observed in the SERVE-HF study, many questions concerning the safety and rational use of ASV in other indications emerged. The aim of this study was to describe the clinical characteristics of ASV-treated patients in real-life conditions. METHODS: The OTRLASV-study is a prospective, 5-centre study including patients who underwent ASV-treatment for at least 1 year. Patients were consecutively included in the study during the annual visit imposed for ASV-reimbursement renewal. RESULTS: 177/214 patients were analysed (87.57% male) with a median (IQ25-75) age of 71 (65-77) years, an ASV-treatment duration of 2.88 (1.76-4.96) years, an ASV-usage of 6.52 (5.13-7.65) hours/day, and 54.8% were previously treated via continuous positive airway pressure (CPAP). The median Epworth Scale Score decreased from 10 (6-13.5) to 6 (3-9) (p < 0.001) with ASV-therapy, the apnea-hypopnea-index decreased from 50 (38-62)/h to a residual device index of 1.9 (0.7-3.8)/h (p < 0.001). The majority of patients were classified in a Central-Sleep-Apnea group (CSA; 59.3%), whereas the remaining are divided into an Obstructive-Sleep-Apnea group (OSA; 20.3%) and a Treatment-Emergent-Central-Sleep-Apnea group (TECSA; 20.3%). The Left Ventricular Ejection Fraction (LVEF) was > 45% in 92.7% of patients. Associated comorbidities/etiologies were cardiac in nature for 75.7% of patients (neurological for 12.4%, renal for 4.5%, opioid-treatment for 3.4%). 9.6% had idiopathic central-sleep-apnea. 6.2% of the patients were hospitalized the year preceding the study for cardiological reasons. In the 6 months preceding inclusion, night monitoring (i.e. polygraphy or oximetry during ASV usage) was performed in 34.4% of patients, 25.9% of whom required a subsequent setting change. According to multivariable, logistic regression, the variables that were independently associated with poor adherence (ASV-usage ≤4 h in duration) were TECSA group versus CSA group (p = 0.010), a higher Epworth score (p = 0.019) and lack of a night monitoring in the last 6 months (p < 0.05). CONCLUSIONS: In real-life conditions, ASV-treatment is often associated with high cardiac comorbidities and high compliance. Future research should assess how regular night monitoring may optimize devices settings and patient management. TRIAL REGISTRATION: The OTRLASV study is registered on ClinicalTrials.gov (Identifier: NCT02429986 ) on 1 April 2015.

Lamentations in the night: A systematic review on catathrenia.

Catathrenia is a loud expiratory moan during sleep that is a social embarrassment and is sometimes confused with central apnea on polysomnography. It affects about 4% of adults, but cases are rarely referred to sleep centers. Catathrenia affects males and females, children and adults, who are usually young and thin. A "typical" catathrenia begins with a deep inhalation, followed by a long, noisy exhalation, then a short, more pronounced exhalation, followed by another deep inhalation, often accompanied by arousal. The many harmonics of the sound indicate that it is produced by the vocal cords. It is often repeated in clusters, especially during REM sleep and at the end of the night. It does not disturb the sleepers, but their neighbors, and is associated with excessive daytime sleepiness in one-third of cases. The pathophysiology and treatment of typical catathrenia are still unknown. Later, a more atypical catathrenia was described, consisting of episodes of short (2 s), regular, semi-continuous expiratory moans during NREM sleep (mainly in stages N1 and N2) and REM sleep, often in people with mild upper airway obstruction. This atypical catathrenia is more commonly reduced by positive airway pressure and mandibular advancement devices that promote vertical opening.

Novel mathematical processing method of nocturnal oximetry for screening patients with suspected sleep apnoea syndrome.

AIM: Polysomnography (PSG) is the current standard for diagnosing sleep apnea syndrome (SAS). A reliable test would be useful to reduce the considerable resources required for PSG. METHODS: We developed a new mathematical analysis, which quantifies amplitude variations of pulse oximetry (SpO(2)) and heart rate (HR) throughout the night, allowing measurement of the total time in which ΔSpO(2) >4% and presented as a new oximetric index ventilatory hypoxemic index (VHI). VHI was compared prospectively with standard PSG parameters apnea-hypopnea index (AHI) and oxygen desaturation index (ODI) in 106 patients (aged, 57 ± 14 years; BMI, 29 ± 5 kg/m(2)) suspected of having SAS. The criterion for diagnosis of SAS was AHI >15/h of sleep during PSG. The relationship between ΔSpO(2) and ΔΗR was also investigated. RESULTS: We observed a significant correlation between the AHI and VHI (R = 0.87, p < 0.0001). Using VHI >15 as the criterion for SpO(2), oximetry had a sensitivity of 81%, specificity of 98%, positive predictive value (PPV) of 98%, and negative predictive value (NPV) of 84% as a screening test for SAS. We also observed a clear linear relationship between ΔSpO(2) and ΔΗR, and concomitant use of VHI and the ΔSpO(2)/ΔHR slope improved the NPV to 90%. CONCLUSIONS: The present findings from wavelet-aggregate processing of oximeter data and the relationship between ΔSpO(2) and ΔΗR show promise as a useful summary prediction of screening SAS.

[Sleep-related breathing disorders in adults: diagnosis, consequences and comorbidities]. / Troubles respiratoires obstructifs du sommeil de l'adulte: diagnostic, conséquences et comorbidités.

Obstructive sleep apnea/hypopnea syndrome (OSAHS) is a collapse of the upper airways leading to a decrease (hypopneas) or interruption of air flow (apneas). Since its identification, only forty years ago, definitions, diagnostic techniques have evolved, the consequences of this syndrome have been widely studied but establishing it as an independent cardiovascular (CV) risk factor has come up against the existence of many confounding factors, such as obesity, high blood pressure (hypertension)… Paraclinical diagnosis is based on the results of poly(somno)graphy. Recommendations on measurement techniques and scoring are regularly published, evolving in parallel with technological progress, with the aim of standardizing and ensuring the reliability of the diagnosis. At the same time, large cohort studies were set up in the 1990s, allowing for transversal and longitudinal follow-up of thousands of patients. Finally, the pathophysiological mechanisms of the consequences of SAHOS were explored. OSA has been shown to be responsible for a particularly high accidental risk due to sleep fragmentation induced by abnormal respiratory events. It has been possible to establish an independent statistical relationship between SAHOS and CV diseases, metabolic disorders and more recently cancer, mainly explained by intermittent hypoxia. OSAHOS is a frequent disease, diagnosed on the basis of clinical signs and poly(somno)graphy, now established as an independent risk factor for morbidity and mortality (accidental and CV).

[Non-surgical treatment of the sleep related breathing disorders in adults]. / Traitement non chirurgical des troubles respiratoires obstructifs du sommeil de l'adulte.

The treatment of obstructive sleep apnoea/hypopnoea syndrome (OSAHS) must allow for the suppression of symptoms and also prevent its immediate and long-term consequences. The evaluation of the effectiveness of treatments is now based on a normal apnea/hypopnea index, a normal oxygen saturation and the disappearance of sleep fragmentation. Clinical and biological follow-up of co-morbidities must be ensured. Compliance with treatment, a major element of success, must be monitored. Continuous Positive Airway Pressure (CPAP) is still the most effective and widely used treatment. However, mandibular advancement orthosis is now recommended as a first-line treatment in moderate forms in the absence of severe cardiovascular comorbidities (CV) and remains a therapeutic alternative in the event of refusal or intolerance to CPAP. Nutritional management in cases of obesity and a physical activity program must be systematically offered. A reduction in nocturnal breathing disorders can also be achieved by using a device in the event of positional OSAHS, or by limiting fluid movements. The contribution of myofunctional therapy is currently being evaluated. Very recently, a study testing the efficiency of pharmacological treatment on the severity of OSAHS and the reactivity of geniogloss appears to be promising. The evaluation of these different treatments and their combination should make it possible to evolve towards a personalised management adapted to each patient.

Automatic Sleep Stages Classification Combining Semantic Representation and Dynamic Expert System.

Interest in sleep has been growing in the last decades, considering its benefits for well-being, but also to diagnose sleep troubles. The gold standard to monitor sleep consists of recording the course of many physiological parameters during a whole night. The human interpretation of resulting curves is time consuming. We propose an automatic knowledge-based decision system to support sleep staging. This system handles temporal data, such as events, to combine and aggregate atomic data, so as to obtain high-abstraction-levels contextual decisions. The proposed system relies on a semantic reprentation of observations, and on contextual knowledge base obtained by formalizing clinical practice guidelines. Evaluated on a dataset composed of 131 full night polysomnographies, results are encouraging, but point out that further knowledge need to be integrated.

OSA treatment with CPAP: Randomized crossover study comparing tolerance and efficacy with and without humidification by ThermoSmart.

OBJECTIVES: Adherence to continuous positive airway pressure (CPAP) remains an issue, as adverse effects (AE) such as rhinitis, dry/congested nose, dry mouth or throat are commonly experienced. The aim of the study was to compare CPAP efficacy and tolerance in severe obstructive sleep apnea (OSA) patients with or without (w/o) heated humidification using the ThermoSmart system. METHODS: Multicenter RCT study in which CPAP-naive patients with severe OSA and meeting one or more of the following criteria: >65 years, using >1 drying medication, previous nasal symptoms or nasal surgery, were included. Patients were randomized to CPAP w/o heated humidification for 1 month and then crossed-over to the other treatment arm for another month. Naso-pharyngeal symptoms, Quality of life (FOSQ-10), sleepiness (ESS) and CPAP compliance and efficacy data were collected. RESULTS: Forty patients were enrolled: age 62 ± 9 years, diagnostic AHI 46.7 ± 15.3/hour. About 70% were using >1 drying medication, mainly antihypertensives. Both treatment modalities were found to normalize AHI and decrease sleepiness with no differences between 2 modes, compliance (4.63 ± 0.39 vs 4.70 ± 0.36 h/night) or leaks (32.4 ± 2.0 versus 31.1 ± 1.7l/min). With heated humidification, there was a significant decrease in nasal symptoms such as dry/congested nose. At the study end, 26 patients preferred ThermoSmart ON, 3 did not have preference and 11 preferred ThermoSmart OFF. CONCLUSION: ThermoSmart helps to decrease nose and throat discomfort because of CPAP therapy, these effects did not translate to better compliance but patients had a preference for ThermoSmart.

Residual subjective daytime sleepiness under CPAP treatment in initially somnolent apnea patients: a pilot study using data mining methods.

BACKGROUND AND PURPOSE: Despite correct treatment with positive airway pressure (PAP), obstructive sleep apnea (OSA) patients sometimes remain subjectively somnolent. The reliability of the Epworth Sleepiness Scale (ESS) has been established for healthy subjects and patients under stable conditions; the ESS may eventually vary among treated OSA patients, biasing the results of a cross-sectional analysis of persisting sleepiness. The objective of this study was to depict the evolution of subjective vigilance under treatment using an index of ESS variability (DeltaESS). METHODS: In 80 OSA patients (apnea-hypopnea index [AHI]=54+/-26/h), initially somnolent (ESS=15+/-3) and treated with auto-titrating PAP (APAP) (oxyhaemoglobin desaturation index 3% [ODIapap]=3.4+/-2.2/h; daily APAP use=5.3+/-1.5 h) during 434+/-73 days, ESS scores were regularly collected four times every 109+/-36 days. DESS was calculated and data mining methods (Segmentation and Decision Tree) were used to determine homogeneous groups according to the evolution of ESS scores. RESULTS: When assessed cross-sectionally, 14-25% of the subjects were recognized as somnolent, depending on the moment when ESS was administered. Using data mining methods, three groups were clearly identifiable: two without residual somnolence - group 1, n=38 (47%), with high DeltaESS=-2.9+/-0.8, baseline ESS=16.3+/-3.3, AHI=58.5+/-26.1/h, mean ESSapap=5.1+/-2.4 and group 2, n=31 (39%), with low DeltaESS=-1.1+/-0.5, baseline ESS=13.2+/-1.4, AHI=53+/-27.3/h, mean ESSapap=8.8+/-1.9; and one with persisting sleepiness; group 3, n=11 (14%), with low DeltaESS=-0.3+/-0.8, baseline ESS=16.3+/-3, AHI=38.7+/-10.8/h, mean ESSapap=14.1+/-1.9. Compliance to PAP was high and comparable in the three groups. Age and body mass index (BMI) did not differ. CONCLUSION: Data mining methods helped to identify 14% of subjects with persisting sleepiness. Validation needs to be done on a larger population in order to determine predictive rules.

OPTISAS a new method to analyse patients with Sleep Apnea Syndrome.

OPTISAS is a visualization method that allows describing very precisely a patient with Sleep Apnea Syndrome. Using the events scored by the physician, our method gives a set of graphs that are a detailed representation of the condition, sleep stage and position, in which the events occur. This helps for the diagnosis. This is possible thanks to the application of Generalized Caseview method. The method proceeds in two steps, defining the reference frame and using this reference frame to visualize data. The reference frame is built by using a supin/unsupine binary criterion, a six type event criterion and a sleep stage ordinal criterion. The main result is the visualization of the indexes (average number of events by hour) associated with the events. This allows a more accurate diagnosis showing the precise influence of the position and of the sleep stage on the events.

Towards a Wireless Smart Polysomnograph Using Symbolic Fusion.

Polysomnography is the gold standard test for sleep disorders among which the Sleep Apnea Syndrome (SAS) is considered a public health issue because of the increase of the cardio-and cerebro-vascular risk it is associated with. However, the reliability of this test is questioned since sleep scoring is a time-consuming task performed by medical experts with a high inter- and intra-scorers variability, and because data are collected from 15 sensors distributed over a patient's body surface area, using a wired connection which may be a source of artefacts for the patient's sleep. We have used symbolic fusion to support the automated diagnosis of SAS on the basis of the international guidelines of the AASM for the scoring of sleep events. On a sample of 70 patients, and for the Apnea-Hypopnea Index, symbolic fusion performed at the level of sleep experts (97.1% of agreement). The next step is to confirm these preliminary results and move forward to a smart wireless polysomnograph.

Personalized sleep staging system using evolutionary algorithm and symbolic fusion.

This paper presents a novel system for automatic sleep staging based on evolutionary technique and symbolic intelligence. Proposed system mimics decision making process of clinical sleep staging using Symbolic Fusion and considers personal singularity with an adaptive thresholds setting up system using Evolutionary Algorithm. It proved to be an effective and promising system in personalizing sleep staging. This system can also be integrated with other medical systems to realize remote sleep monitoring or home-care.

Decision System Integrating Preferences to Support Sleep Staging.

Scoring sleep stages can be considered as a classification problem. Once the whole recording segmented into 30-seconds epochs, features, extracted from raw signals, are typically injected into machine learning algorithms in order to build a model able to assign a sleep stage, trying to mimic what experts have done on the training set. Such approaches ignore the advances in sleep medicine, in which guidelines have been published by the AASM, providing definitions and rules that should be followed to score sleep stages. In addition, these approaches are not able to solve conflict situations, in which criteria of different sleep stages are met. This work proposes a novel approach based on AASM guidelines. Rules are formalized integrating, for some of them, preferences allowing to support decision in conflict situations. Applied to a doubtful epoch, our approach has taken the appropriate decision.

Home unattended vs hospital telemonitored polysomnography in suspected obstructive sleep apnea syndrome: a randomized crossover trial.

STUDY OBJECTIVE: To compare home unattended polysomnography (H-PSG) with polysomnography performed in a local hospital and telemonitored by a sleep laboratory (T-PSG) in the diagnosis of obstructive sleep apnea syndrome (OSAS). DESIGN: Randomized crossover trial. PATIENTS: Ninety-nine patients with suspected OSAS who underwent H-PSG and T-PSG on 2 consecutive nights, according to a randomized order. MEASUREMENTS: H-PSG and T-PSG were compared in terms of (1) effectiveness, only recordings providing interpretable signals from at least one EEG, the electro-oculograph, the electromyograph, air flow, thoracic or abdominal movements, and arterial oxygen saturation for 180 min of sleep were considered to be effective; (2) patient preference assessed by a questionnaire; and (3) polysomnographic indexes and final interpretative results in patients for whom both recordings were legible. RESULTS: Recordings were considered to be ineffective in 11.2% of T-PSG (95% confidence interval [CI], 4.9 to 17.4%) and in 23.4% of H-PSG (95% CI, 19.12 to 27.68%). Thermistor problems were the main cause of failure of H-PSG. Forty-one percent of patients preferred H-PSG, and 55% preferred T-PSG. H-PSG and T-PSG did not differ in terms of sleep and respiratory indexes in the 65 patients in whom both recordings were legible. H-PSG and T-PSG were concordant in 58 of 65 patients using a 10-event-per-hour apnea-hypopnea index cutoff value for the diagnosis of OSAS. CONCLUSIONS: T-PSG is clearly superior to H-PSG from a technical point of view and tends to be preferred by patients. The site of recording (home vs hospital) has no influence on polysomnographic indexes.

Evaluating OPTISAS, a visual method to analyse sleep apnea syndromes.

The sleep apnea syndrome is a real public health problem. Improving its diagnosis using the polysomnography is of huge importance. Optisas was a visual method allowing translating the polysomnographic data into a meaningful image. In a previous paper, it was shown to bring extra information in 62% of cases. Here its capacity for displaying information of the same relevance as the one got using the classical report of the polysomnography is studied. The main result is that this capacity is weak and seems to be present only to identify the obstructive sleep apnea syndrome. Moreover this study suggests to improve the standardization of the classical report in the framework of a quality insurance process.