Determinants of Unintentional Leaks During CPAP Treatment in OSA

Enhancing artificial intelligence-driven sleep apnea diagnosis: The critical importance of input signal proficiency with a focus on mandibular jaw movements

PURPOSE

This review aims to highlight the pivotal role of the mandibular jaw movement (MJM) signal in advancing artificial intelligence (AI)-powered technologies for diagnosing obstructive sleep apnea (OSA).

METHODS

A scoping review was conducted to evaluate various aspects of the MJM signal and their contribution to improving signal proficiency for users.

RESULTS

The comprehensive literature analysis is structured into four key sections, each addressing factors essential to signal proficiency. These factors include (1) the comprehensiveness of research, development, and application of MJM-based technology; (2) the physiological significance of the MJM signal for various clinical tasks; (3) the technical transparency; and (4) the interpretability of the MJM signal. Comparisons with the photoplethysmography (PPG) signal are made where applicable.

CONCLUSIONS

Proficiency in biosignal interpretation is essential for the success of AI-driven diagnostic tools and for maximizing the clinical benefits through enhanced physiological insight. Through rigorous research ensuring an enhanced understanding of the signal and its extensive validation, the MJM signal sets a new benchmark for the development of AI-driven diagnostic solutions in OSA diagnosis.

Mouth Leak Is Associated with Sleep Fragmentation During Nasal Continuous Positive Airway Pressure Treatment of Obstructive Sleep Apnea and May Be Detected by Leak Waveform Analysis

Rationale: Mouth air leak is a major cause of low adherence to nasal continuous positive airway pressure (CPAP) in patients with obstructive sleep apnea (OSA). However, CPAP reports do not distinguish mouth leak from mask leak. We hypothesized that mouth air leak is terminated abruptly by an arousal from sleep and mouth closing that can be detected by CPAP leak waveform analysis. Objectives: To describe patterns of mouth air leak waveform during polysomnography (PSG) in patients with OSA treated with well-fitted nasal CPAP. Methods: PSG recordings with a jaw motion sensor to detect mouth opening were performed in patients with OSA treated with nasal CPAP with suspected mouth air leak. Careful mask fitting and visual inspection excluded mask leak. Mouth leak episodes were characterized by an increase (⩾20%) above the intentional leak. Leak episodes were classified as intermittent (<5 minutes) or continuous (⩾5 minutes). Results: Twenty patients (80% men; age, 63 ± 11 years; body mass index, 29.9 ± 6 kg/m2; baseline apnea-hypopnea index, 46.9 ± 19 events per hour) treated with nasal CPAP and documented mouth leak completed the study. All but one patient experienced an overlap of intermittent and continuous mouth leak. Most mouth leak episodes ended with mouth closure (97.7%) and an arousal (52.7%) or awakening (38.6%). Only 34.9% of the leak episodes were associated with respiratory events. Intermittent mouth air leak was more common in sleep stages N1 and N2 (P < 0.01), whereas continuous leak was more common in sleep stage N3 (P < 0.01). Continuous episodes of air leak were associated with a higher amplitude of mouth opening. The CPAP report waveform was able to detect only 29.6% of the leak episodes detected by PSG. Only 10 patients (50%) had a high unintentional leak according to the criteria adopted by ResMed, and only 2 patients (10%) presented large leak according to the Philips criteria. Conclusions: Intermittent and continuous mouth leak during nasal CPAP frequently coexist and contribute to sleep fragmentation. Identification of leak waveform patterns may help detect mouth air leak, which, in turn, is an important cause of poor CPAP adherence.

Impact of Obstructive Sleep Apnea and Continuous Positive Airway Pressure Treatment on Dry Eye Disease: A Systematic Review and Meta-Analysis

Obstructive sleep apnea (OSA) has been reported to influence the ocular surface and may lead to dry eye disease (DED). Continuous positive airway pressure (CPAP) is the first-line conservative treatment for OSA. However, CPAP might also have mask-related side effects that could deteriorate DED simultaneously. This study investigated the impact of OSA on DED (Aim 1), and CPAP on DED (Aim 2). Five databases were searched for articles published up to May, 2024. OSA severity, CPAP usage, and DED parameters, including tear breakup time (TBUT), Schirmer test, Ocular Surface Disease Index (OSDI), and Corneal Fluorescence Staining Score (CFS), were analyzed. For Aim 1, the random-effects model was used for meta-analysis, and the leave-one-out method was used for sensitivity analysis. For Aim 2, a narrative synthesis with critical appraisal of the literature was performed. Eleven studies with 1,526 patients for Aim 1 and three studies with 180 patients for Aim 2 were included. For Aim 1, OSA patients had poorer dry eye profiles of TBUT, Schirmer test, and OSDI when compared to non-OSA patients. For Aim 2, it seemed that those wearing CPAP for less than half a year did not have enough improvement in dry eye status. Instead, those wearing CPAP for at least a year reached greater therapeutic effects for OSA and DED. We concluded that OSA patients may suffer from poorer dry eye condition compared to non-OSA patients. Besides, wearing CPAP for long enough duration (at least 1 year) seemed to have better improvement in DED.

Combination Therapies with an Oral Appliance in the Management of Obstructive Sleep Apnea

Combination therapy (CT) with a mandibular advancement device (MAD) and positive airway pressure (PAP) has been advocated for patients for whom neither MAD nor PAP alone provides an efficacious and tolerated therapy. This article reviews the small and limited, but growing body of evidence in support of CT and highlights details in its implementation. In most studies, CT was found to be preferred by many, but not all PAP-intolerant patients. CT can be more efficacious than either MAD or PAP alone.

Respiratory monitoring dataset, with rapid expiratory occlusions, over increasing positive airway pressure ventilation

Resting breathing data was collected from 80 smokers, vapers, asthmatics, and otherwise healthy people in the low-risk clinical unit at the University of Canterbury. Subjects were asked to breathe normally through a full-face mask connected to a Fisher and Paykel Healthcare SleepStyle SPSCAA CPAP device. PEEP (Positive End-Expiratory Pressure) support was increased from 4 to 12 cmH2O in 0.5 cmH2O increments. Data was also collected during resting breathing at ZEEP (0 cmH2O) before and after the PEEP trial. The trial was conducted under University of Canterbury Human Research Ethics Committee consent (Ref: HREC 2023/04/LR-PS). Data was collected by and Dräeger PulmoVista 500 EIT machine and a custom Venturi-based pressure and flow sensor device connected in series with the CPAP and full-face mask. The outlined dataset includes pressure, flow, volume, dynamic circumference (thoracic and abdominal, and cross-sectional aeration. Subject demographic data was self-reported using a questionnaire given prior to the trial.

Effect of a digital patient motivation and support tool on CPAP/APAP adherence and daytime sleepiness: a randomized controlled trial

The purpose of this study was to assess the effect of a digital patient support (DPS) tool, complementary to standard care on continuous or automatic positive airway pressure (auto)CPAP adherence and daytime sleepiness after 12 weeks in patients diagnosed with severe obstructive sleep apnea (OSA). All patients with apnea-hypopnea index (AHI) ≥ 30 per hour were prospectively included and randomized to receive standard care (SC) or standard care with personalized DPS via a mobile app prototype version (SC + DPS). Patients in the SC + DPS arm received additionally automated feedback on their therapy, motivational messages and therapy recommendations. 100 patients completed the study (SC: 50, SC + DPS: 50). No differences were found in characteristics of SC vs. SC + DPS (mean ± SD) for age (53.9 ± 10.8 vs. 51.7 ± 12.3 years), initial diagnostic apnea-hypopnea index (51.1 ± 15.5 vs. 50.9 ± 17.7 events/h), BMI (33.8 ± 6.7 vs. 33.5 ± 4.5 kg/m), and Epworth Sleepiness Scale (ESS) baseline score (9.5 ± 4.2 vs. 9.1 ± 5.2). After 12 weeks, mean ESS score was significantly lower (SC: 7.6 ± 4.1 vs. SC + DPS: 5.5 ± 3.9; p = 0.006) in the SC + DPS group vs. standard care group. Therapy adherence was significantly higher (SC: 268.7 ± 122.1 vs. SC + DPS: 338.8 ± 106.8 min; p = 0.002) in the SC + DPS group compared to standard care group. No difference was found in the residual AHI between both groups. However, SC + DPS group showed a trend towards fewer phases with increased leakage compared to SC group. Intention-to-treat analysis (112 (56/56) patients) showed similar results. After 12 weeks, (auto)CPAP adherence and daytime sleepiness improved significantly in patients with severe OSA using the digital patient support tool. Clinical Trial Registration (retrospectively registered): Registry: NCT05440279; Title: Effects of Telemedical Support on Therapeutic Results of CPAP Patients; URL: https://clinicaltrials.gov/ct2/show/NCT05440279; Date of registration: June 30, 2022.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41105-023-00479-9.

Current treatment strategies in managing side effects associated with domiciliary positive airway pressure (PAP) therapy for patients with sleep disordered breathing: A systematic review and meta-analysis

Sleep disordered breathing is commonly treated with positive airway pressure therapy. Positive airway pressure therapy is delivered via a tight-fitting mask with common side effects including: leak, ineffective treatment, residual sleep disordered breathing, eye irritation, nasal congestion, pressure ulcers and poor concordance with therapy. This systematic review and meta-analysis aimed to identify the effectiveness of current treatment strategies for managing side effects associated with positive airway pressure therapy. Five databases were searched and 10,809 articles were screened, with 36 articles included in the review. Studies investigated: dressings, nasal spray/douche, chin straps, heated humidification and interfaces. No intervention either improved or detrimentally affected: positive airway pressure concordance, Epworth Sleepiness Score, residual apnoea hypopnea index or interface leak. The review was limited by study heterogeneity, particularly for outcome measures. Additionally, patient demographics were not reported, making it difficult to apply the findings to a broad clinical population. This review highlights the paucity of evidence supporting treatment strategies to manage side effects of positive airway pressure therapy.

Airflow and dynamic circumference of abdomen and thorax for adults at varied continuous positive airway pressure ventilation settings and breath rates

Continuous positive airway pressure (CPAP) ventilation is a commonly prescribed respiratory therapy providing positive end-expiratory pressure (PEEP) to assist breathing and prevent airway collapse. Setting PEEP is highly debated and it is thus primarily titrated based on symptoms of excessive or insufficient support. However, titration periods are clinician intensive and can result in barotrauma or under-oxygenation during the process. Developing model-based methods to more efficiently personalise CPAP therapy based on patient-specific response requires clinical data of lung/CPAP interactions. To this end, a trial was conducted to establish a dataset of healthy subjects lung/CPAP interaction. Pressure, flow, and tidal volume were recorded alongside secondary measures of dynamic chest and abdominal circumference, to better validate model outcomes and assess breathing modes, muscular recruitment, and effort. N = 30 subjects (15 male; 15 female) were included. Self-reported asthmatics and smokers/vapers were included, offering a preliminary assessment of any potential differences in response to CPAP from lung stiffness changes in these scenarios. Additional demographics associated with lung function (sex, age, height, and weight) were also recorded.

Factors associated with treatment outcomes after use of auto-titrating CPAP therapy in adults with obstructive sleep apnea

OBJECTIVES

To determine factors that are associated with OSA therapy outcomes with auto-titrating positive airway pressure (APAP).

METHODS

We sequentially grouped patients from a retrospective cohort based on APAP efficacy (sufficiently vs. insufficiently treated; insufficiently treatment defined as residual AHI of ≥ 5), therapy adherence (adherent vs. non-adherent, non-adherence defined as < 70% usage for ≥ 4 h/night), and therapy outcomes (optimal vs. non-optimal and non-optimal outcomes defined as non-adherent and/or insufficiently treated). We subsequently compared each group.

RESULTS

The insufficiently treated were older (68.4 ± 12.5 vs. 60.4 ± 13.1 years, p < 0.01) and had lower BMI (31.9 ± 6.3 vs. 37.9 ± 9.1 kg/m², p < 0.01). They had higher baseline central apnea indices (CAI), longer leaks, higher peak pressures, and were less compliant. The non-adherent were younger (61.1 ± 12.6 vs. 65.5 ± 13.2 years, p = 0.03) and comprised more females (56.1 vs. 43.9%, p = 0.04). The leak duration per usage hour was higher in the non-compliant (median: 1.5; IQR 7.9 vs. median: 0.3; IQR 1.9 min/h; p < 0.01). The non-optimally treated had lower BMI, longer leaks, and less nightly usage. Multivariate analyses showed that leak duration was the common factor associated with treatment effectiveness and optimal therapy outcomes.

CONCLUSIONS

Various demographic and clinical factors were associated with treatment efficacy and adherence. However, leak duration was the common factor related to treatment efficacy and overall optimal therapy outcomes.

In search of a better CPAP interface: A network meta-analysis comparing nasal masks, nasal pillows and oronasal masks

Until now, no study has directly network meta-analysed the impact of nasal masks, nasal pillows and oronasal masks on continuous positive airway pressure therapy in patients with obstructive sleep apnea. This study aimed to meta-analyse the impact of three kinds of nasal interfaces with both network meta-analysis and pairwise comparison. PubMed, EMBASE, CENTRAL and ClinicalTrials.gov were systematically searched from inception to December 2020 for studies that compared the three types of nasal interfaces for treating obstructive sleep apnea with continuous positive airway pressure. The outcomes were residual apnea-hypopnea index, continuous positive airway pressure, and nightly average usage. The network meta-analysis was conducted using multivariate random-effects in a frequentist framework where three interfaces were ranked with the surface under the cumulative ranking probabilities. The pairwise comparison was conducted using random-effects meta-analysis. Twenty-nine articles comprising 6378 participants were included. The pairwise comparison showed both nasal masks and nasal pillows were associated with lower residual apnea-hypopnea index, lower continuous positive airway pressure, and higher continuous positive airway pressure adherence compared with oronasal masks. The surface under the cumulative ranking confirmed that nasal masks were associated with the lowest residual apnea-hypopnea index and highest adherence, while pillows were associated with the lowest continuous positive airway pressure. The meta-regression identified that lower pretreatment apnea-hypopnea index and continuous positive airway pressure determined during continuous positive airway pressure titration (versus determined during continuous positive airway pressure therapy) was associated with lower continuous positive airway pressure with nasal masks and nasal pillows. In conclusion, compared with oronasal masks, nasal masks and nasal pillows are better interfaces, especially in patients with lower pretreatment apnea-hypopnea index and those with the therapeutic pressure determined during continuous positive airway pressure titration.

Responses of Bilevel Ventilators to Unintentional Leak: A Bench Study

BACKGROUND

The impact of leaks has mainly been assessed in bench models using continuous leak patterns which did not reflect real-life leakage. We aimed to assess the impact of the pattern and intensity of unintentional leakage (UL) using several respiratory models.

METHODS

An active artificial lung (ASL 5000) was connected to three bilevel-ventilators set in pressure mode; the experiments were carried out with three lung mechanics (COPD, OHS and NMD) with and without upper airway obstruction. Triggering delay, work of breathing, pressure rise time, inspiratory pressure, tidal volume, cycling delay and the asynchrony index were measured at 0, 6, 24 and 36 L/min of UL. We generated continuous and inspiratory UL.

RESULTS

Compared to 0 L/min of UL, triggering delays were significantly higher with 36 L/min of UL (+27 ms) and pressure rise times were longer (+71 ms). Cycling delays increased from -4 [-250-169] ms to 150 [-173-207] ms at, respectively 0 L/min and 36 L/min of UL and work of breathing increased from 0.15 [0.12-0.29] J/L to 0.19 [0.16-0.36] J/L. Inspiratory leakage pattern significantly increased triggering delays (+35 ms) and cycling delays (+263 ms) but decreased delivered pressure (-0.94 cmH₂O) compared to continuous leakage pattern. Simulated upper airway obstruction significantly increased triggering delay (+199 ms), cycling delays (+371 ms), and decreased tidal volume (-407 mL) and pressure rise times (-56 ms).

CONCLUSIONS

The pattern of leakage impacted more the device performances than the magnitude of the leakage per se. Flow limitation negatively reduced all ventilator performances.

The right interface for the right patient in noninvasive ventilation: a systematic review

INTRODUCTION

Research in the field of noninvasive ventilation (NIV) has contributed to the development of new NIV interfaces. However, interface tolerance plays a crucial role in determining the beneficial effects of NIV therapy.

AREAS COVERED

This systematic review explores the most significant scientific research on NIV interfaces, with a focus on the potential impact that their design might have on treatment adherence and clinical outcomes. The rationale on the choice of the right interface among the wide variety of devices that are currently available is discussed here.

EXPERT OPINION

The paradigm "The right mask for the right patient" seems to be difficult to achieve in real life. Ranging from acute to chronic settings, the gold standard should include the tailoring of NIV interfaces to patients' needs and preferences. However, such customization may be hampered by issues of economic nature. High production costs and the increasing demand represent consistent burdens and have to be considered when dealing with patient-tailored NIV interfaces. New research focusing on developing advanced and tailored NIV masks should be prioritized; indeed, interfaces should be designed according to the specific patient and clinical setting where they need to be used.

Analysis of risk factors for air leakage in auto-titrating positive airway pressure users: a single-center study

STUDY OBJECTIVES

Because air leakage from masks is known as a common cause of low adherence to continuous positive airway pressure therapy, we analyzed the risk factors for air leakage related to parameters associated with auto-titrating positive airway pressure, polysomnography, InBody Test, and rhinomanometry.

METHODS

Usage data and medical records of 120 auto-titrating positive airway pressure users were reviewed retrospectively. All patients used a nasal or pillow mask and were carefully monitored at scheduled follow-ups.

RESULTS

Use of a pillow mask, sex (male), age, and abdominal fat percentage were significantly associated with high average air leakage. The higher the auto-titrating positive airway pressure average and mean pressure, the more likely patients exhibited high rates of air leakage. The percentage of patients with high average air leakage increased over time (up to 6 months of follow-up).

CONCLUSIONS

Older male patients using a pillow mask and those with a high abdominal fat percentage and high auto-titrating positive airway pressure may require close follow-up and continuous monitoring for air leakage. Because air leakage from a mask can change over time, mask-sealing capacity should be reassessed and masks should be changed regularly.

CITATION

Kang YJ, Cho J-H, Park C-S. Analysis of risk factors for air leakage in auto-titrating positive airway pressure users: a single-center study. J Clin Sleep Med. 2022;18(1):75-88.

A longitudinal study of the accuracy of positive pressure therapy machine-detected apnea-hypopnea events

STUDY OBJECTIVES

During positive airway pressure (PAP) therapy for sleep apnea syndromes, the machine detected respiratory event index (REI_FLOW) is an important method for clinicians to evaluate the beneficial effects of PAP. There are concerns about the accuracy of this detection, which also confounds a related question-how common and severe are residual events on PAP.

METHODS

Subjects with OSA who underwent a split night polysomnography were recruited prospectively. Those treated with PAP and tracked by the EncoreAnywhere system were analyzed. The ones who stopped PAP within one month were excluded for this analysis. Compliance, therapy data and waveform data were analyzed. Machine detected versus manually scored events were compared at the 1st, 3rd, 6th and 12th month from PAP initiation. Logistic regression was used to determine factors associated with a high REI_FLOW difference.

RESULTS

One hundred and seventy-nine patients with a mean age 59.06 ± 13.97 years old, median body mass index 33.60 (29.75-38.75) kg/m², and median baseline AHI 46.30 (31.50-65.90) times/hour were included. The difference between the machine detected REI_FLOW and manually scored REI_FLOW was 10.72 ±8.43 in the first month and remained stable for up to 12 months. Male sex and large leak ≥ 1.5% were more frequent in patients who had an REI_FLOW difference of ≥ 5 / hour of use. A titration arousal index ≥ 15/ hour of sleep, and higher ratio of unstable to stable breathing were also associated with an REI_FLOW difference ≥ 5 times/hour of use.

CONCLUSIONS

There is a substantial and sustained difference between manual and automated event estimates during PAP therapy, and some associated factors were identified.

Efficacy and adherence of noninvasive ventilation treatment in children with Down syndrome

OBJECTIVE

Children with Down syndrome (DS) have an increased prevalence of obstructive sleep apnea (OSA). Noninvasive ventilation (NIV) is a common modality of OSA treatment in this cohort. This study aimed to measure adherence and efficiency of NIV delivery in children with DS.

STUDY DESIGN

This was a retrospective cohort study involving 106 children with confirmed OSA and home NIV with downloadable data capacity. Children were divided into DS (n = 44) and non-DS cohorts (n = 62). Adherence, clinical outcomes apnea-hypopnoea index (AHI), positive airway pressure delivery, and leakage were recorded and compared between DS and non-DS cohorts and within the DS cohort based on past surgical history.

RESULTS

Significantly greater NIV usage was observed in the DS cohort, they showed more consistent use with an increased percentage of days used relative to their non-DS counterparts (78.95 ± 2.26 vs. 72.11 ± 2.14, p = .031). However, despite greater usage, poorer clinical outcomes in the form of increased AHI (p = .0493) was observed in the DS cohort, where significantly greater leakage was also shown 41.00 ± 1.61 L/min versus 36.52 ± 1.18 L/min (p = .022). Twenty children with DS had prior cardiac surgery; compliance across all parameters was significantly reduced relative to those without.

CONCLUSION

These data confirm that satisfactory NIV adherence is achievable in children with DS. However, we have identified excessive system leak at the machine-patient interface as a factor, which could undermine NIV efficacy in children with DS.

Continuous Positive Airway Pressure-Mandibular Advancement Device Combination Therapy for Moderate-to-Severe Obstructive Sleep Apnea: A Preliminary Study

Objectives  The purpose of this pilot study was to determine whether compliance to auto-adjusting positive airway pressure (APAP) improves with the addition of a mandibular advancement device (MAD). Secondary outcome measures included were APAP pressure, subjective daytime sleepiness, apnea–hypopnea index (AHI), and mask leaks.

Setting and Sample Population  Participants included were diagnosed with moderate-to-severe obstructive sleep apnea (OSA) and became noncompliant to prescribed APAP. Thirteen participants with a mean age of 61.6 years were recruited for this study.

Materials and Methods  All participants were given a MAD to use with their APAP. Parameters measured included APAP pressure, AHI, mask leak reported via ResMed AirViewTM software, and self-reported daytime sleepiness (Epworth Sleepiness Scale [ESS]). A paired two-sample for mean t -test was performed to determine significance.

Results  The mean difference of pre- and postintervention APAP compliance was 23.1%, which was statistically significant ( p = 0.015). The mean APAP air pressures were unchanged. The difference between pre- and postintervention mean ESS scores was 1.4 and was statistically significant ( p = 0.027). The mean difference between pre- and postintervention AHI values and mask leak showed no significant difference.

Conclusion  This study showed that combination of APAP-MAD therapy, for patients with moderate-to-severe OSA who were noncompliant to APAP use, significantly increased compliance with APAP therapy, and significantly decreased the daytime sleepiness of participants.

Feasibility of Type 3 Polygraphy for Evaluating Leak Determinants in CPAP-Treated OSA Patients: A Step Toward Personalized Leak Management

BACKGROUND

Unintentional leaks (ULs) are frequent adverse effects in CPAP-treated patients. We previously published a novel methodology for analyzing the determinants of UL using polysomnography. We now propose a simplified recording system using a type 3 polygraphic device (Somnolter; Nomics S.A.).

RESEARCH QUESTION

(1) To describe individual UL determinants provided by the Somnolter software in automatic-CPAP-treated OSA patients; (2) To subsequently describe the clinical consensus of four physicians on how to manage each individual UL situation.

STUDY DESIGN AND METHODS

Somnoler recordings performed under nasal automatic-CPAP were automatically analyzed with APIOS software. For each polygraphic recording, APIOS provided the OR and the CIs for potential determinants of UL: mouth opening, CPAP pressure, body position, and mandibular oscillation. Based on these results, each of four physicians was asked to choose one of four strategies: (1) increase or decrease therapeutic pressure; (2) change nasal mask for oro-nasal mask/chinstrap; (3) favor a nonsupine or supine position; (4) no action for individual leak management. Subsequently, a meeting was held to determine a consensus choice for each individual case.

RESULTS

Seventy-eight consecutive patients underwent home-polygraphy with Somnolter. Fifty recordings were analyzed (16 females; 65 [57-75] years of age; BMI = 31.1 [27.4-35.3]). Individual diagnosis of UL was routinely feasible. The determinants of UL were heterogeneous in the population, and diagnosis of UL was not feasible in 10 patients. Based on the results from this analysis, we established consensus leak management strategies at the individual level. The average Cohen κ coefficient for the four raters was 0.58. Pressure modification was proposed in 36% of patients, no action in 24%, installation of a facial mask/chinstrap in 22%, and positional treatment in 18%.

INTERPRETATION

The use of type 3 polygraphy for characterizing leak determinants in patients treated with nasal automatic-CPAP is feasible in routine practice. Leak determinants are patient specific. Interrater concordance for determining individual leak management strategies demonstrated a "fair" level of agreement.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT03381508; URL: www.clinicaltrials.gov).

[Telemonitoring in continuous positive airway pressure-treated patients with obstructive sleep apnoea syndrome: An algorithm proposal]

Most of the continuous positive airway pressure (CPAP) devices currently in use allow telemonitoring of observance, leaks and the apnoea-hypopnoea index (AHI). La Société française de recherche et de médecine du sommeil (SFRMS) and La Société de pneumologie de langue française (SPLF) workgroup offer to CPAP prescribers and to home care providers a scientific document which has the following purposes: to underline the relevance of the telemonitoring of leaks and the AHI, to define alert thresholds, to describe the principal mechanisms generating excessive leaks and high AHI, and to propose a diagnostic algorithm.

Is the 2013 American Thoracic Society CPAP-tracking system algorithm useful for managing non-adherence in long-term CPAP-treated patients?

Background

Whereas telemedicine usage is growing, the only clinical algorithm for Continuous Positive Airway Pressure (CPAP) adherence management is that stipulated by the 2013 American Thoracic Society (ATS). The capacity of the latter to predict non-adherence in long-term CPAP-treated patients has not been validated.

Methods

Patients from the prospective real-life InterfaceVent study (NCT03013283, study conducted in an adult cohort undergoing at least 3 months of CPAP) and eligible for ATS algorithm usage were analysed. The residual device Apnea–Hypopnea-Index (AHI_flow) and High Large Leak (HLL) thresholds proposed in the ATS algorithm were evaluated for predicting adherence (i.e. AHI_flow > 10/h, HLLs 95th > 24 L/min for ResMed® devices and ResMed® nasal mask, HLLs 95th > 36 l/min for ResMed® devices and ResMed® oronasal masks, HLLs > 1 h for Philips® devices and HHLs > 60 l/min for Fisher & Paykel® devices). Adherence was defined according to the 2013 ATS algorithm (i.e. CPAP use > 4 h/j for at least 70% of days).

Results

650/1484 patients eligible for ATS algorithm usage were analysed (15.38% non-adherent, 74% male with a median (IQ_25–75) age of 68 (61–77) years, a body mass index of 30.8 (27.7–34.5) kg/m², an initial AHI of 39 (31–55) events/h, and CPAP-treatment-duration of 5.1 (2.2–7.8) years). Logistic regression analysis demonstrated no significant relationship between the ATS proposed AHI_flow or HLL thresholds and non-adherence. Complementary ROC curve analysis failed to determine satisfactory AHI_flow and HLL thresholds.

Conclusion

When managing non-adherence in long-term CPAP-treated patients, our data do not validate absolute AHI_flow or HLL thresholds in general.

Trial registration

The INTERFACE-VENT study is registered on ClinicalTrials.gov (Identifier: study (NCT03013283).

Comparison of Auto- and Fixed-Continuous Positive Airway Pressure on Air Leak in Patients with Obstructive Sleep Apnea: Data from a Randomized Controlled Trial

Auto-CPAP may cause sleep fragmentation due to variations in pressure and unintentional leaks. The aim of this study was to compare air leak between fixed-CPAP and auto-CPAP after 4 months of CPAP treatment. This study is an ancillary analysis of a randomized, double-blind, parallel, controlled trial over 4 months, comparing fixed- and auto-CPAP in newly diagnosed patients with OSA. The following data were extracted from the CPAP devices: mean and 90th percentile pressure, residual apnea-hypopnea index, mean CPAP use, and amount of leak. Within each arm, patients were also randomly allocated to use of one of the three different brands of devices. Since the leak was reported differently for each device, median leak value was determined for each brand and leaks were classified as “above the median” or “below the median”. Data from 269 patients were analyzed. The univariate analysis showed that tobacco consumption, CPAP level, and oronasal masks were associated with leaks above the median value but not the type of CPAP. The multivariate analysis showed that only CPAP level and oronasal masks were associated with leaks below the median. There were no differences in the types of mask used between fixed- and auto-CPAP. There was no impact of the type of CPAP on leaks or the type of interface used. We used a method based on the median leak value to standardize comparisons across devices which report leaks with different definitions.

Prevention of leakage due to mouth opening through applying an oral shield device (Sominpax™) during nasal CPAP therapy of patients with obstructive sleep apnea

BACKGROUND/OBJECTIVE

The first line treatment for obstructive sleep apnea (OSA) is nasal continuous positive airway pressure (nCPAP), for which a variety of masks are available. While nasal masks (NM) are the first choice; oronasal masks (ONM) are also frequently used to prevent mouth dryness resulting from mouth opening. Our cross-sectional, prospective, randomized, un-blinded study addressed the efficacy of wearing an oral shield in addition to NM in preventing mouth leakage METHODS: Patients with OSA and established therapy using NM and complaining about mouth dryness (n = 29) underwent three polysomnographies (PSGs) using NM, ONM or a nose mask in combination with an oral shield (NMS). Mask leakage was continuously documented and objective sleep quality was assessed.

RESULTS

There were significant differences in the apnea-hypopnea-index (AHI) between ONM (8.5/h; SD 6,7) and NM/nasal mask combined with oral shield device (NMS) (2.6/h; SD 2,3; 2.7/h; SD 2,6) (p < 0,05) as well as in leakage [ONM (39.7 l/min SD 12,4); NM (34.6 l/min SD 9,4); NMS (33.1 l/min SD 9,6)] (p = 0.011). Furthermore, analysis of sleep quality (NREM3) favored NM and NMS over ONM (p = 0.02). There were no significant differences between NM and NMS in any objective outcome.

CONCLUSIONS

Our data consistently confirmed the NM as the first choice for continuous positive airway pressure (CPAP) therapy of OSA. Notably, we demonstrated a high potential of the oral shield for patients with mouth opening to achieve additional comfort and thereby possibly compliance, without affecting nCPAP therapy effectiveness.

The Persistent Gender Bias in the Diagnosis of Obstructive Sleep Apnea

Prevalence estimates of obstructive sleep apnea (OSA) continue to rise, partially due to better recognition of and screening for the disease, in part due to increase in obesity and in part due to changes in definitions of obstructive hypopneas. Despite increasing knowledge of the deleterious impact of OSA on health, underrecognition continues to be a major concern, especially in women. A middle-aged man that snores and is sleepy has been the accepted “textbook” picture of OSA; women may present with more atypical symptoms and excessive sleepiness that are not reflected on sleepiness scale questionnaires. Even when presenting with snoring and sleepiness, and in the presence of comorbidities, women are less likely to be evaluated for OSA. Symptom burden and poor health outcomes have been documented in women with OSA and treatment improves their health. In this article, we explore possible causes for this underrecognition of OSA in women, including gender bias and healthcare inequity, and propose solutions.