The PAP-RES algorithm: Defining who, why and how to use positive airway pressure therapy for OSA.

Obstructive sleep apnea (OSA) is a common condition that is increasing in prevalence worldwide. Untreated OSA has a negative impact on health-related quality of life and is an independent risk factor for cardiovascular diseases. Despite available data suggesting that cardiovascular risk might differ according to clinical phenotypes and comorbidities, current approaches to OSA treatment usually take a "one size fits all" approach. Identification of cardiovascular vulnerability biomarkers and clinical phenotypes associated with response to positive airway pressure (PAP) therapy could help to redefine the standard treatment paradigm. The new PAP-RES (PAP-RESponsive) algorithm is based on the identification of OSA phenotypes that are likely to impact therapeutic goals and modalities. The paradigm shift is to propose a simplified approach that defines therapeutic goals based on OSA phenotype: from a predominantly "symptomatic phenotype" (individuals with high symptom burden that negatively impacts on daily life and/or accident risk or clinically significant insomnia) to a "vulnerable cardiovascular phenotype" (individuals with comorbidities [serious cardiovascular or respiratory disease or obesity] that have a negative impact on cardiovascular prognosis or a biomarker of hypoxic burden and/or autonomic nervous system dysfunction). Each phenotype requires a different PAP therapy care pathway based on differing health issues and treatment objectives.

Seasonal changes in positive airway pressure adherence.

Through their effects on sleep duration, bedroom environments, and pollen allergies, seasonal variations may impact positive airway pressure (PAP) adherence. We analyzed daily PAP telemonitoring data from 25,846 adults (median age 64 years, 67.8% male) treated with PAP for at least 4 months [mean (standard deviation, SD) duration of PAP: 5.5 years (SD 4.1)] to examine seasonal changes in PAP adherence, leaks, and residual apnea-hypopnea index. We demonstrate a significant decrease in PAP adherence in June compared to January (mean (SD): 0.37 (1.54) h/night) that achieved the minimal clinically important difference (MCID) of 30 min in 13.9% of adults. Furthermore, we provide novel data supporting the association of rising temperatures with seasonal changes in PAP use. Indeed, the most pronounced decline in PAP adherence was observed during the hottest days, while PAP adherence was only slightly reduced during the coolest days of June. Clinicians should be aware of seasonal changes in PAP adherence that are likely to be exacerbated by climate change.

Health trajectories before initiation of non-invasive ventilation for chronic obstructive pulmonary disease: a French nationwide database analysis.

Background: Chronic obstructive pulmonary disease (COPD) is the most common indication for long-term domiciliary non-invasive ventilation (NIV) but there is uncertainty in data supporting current guidelines. This study described health trajectories before initiation of at-home NIV in people with COPD, and compared mortality outcomes between groups with different pre-NIV health trajectories. Methods: Data were from the French national health insurance reimbursement system database for individuals with COPD aged ≥40 years and ≥1 reimbursement for NIV between 1 January 2015 and 31 December 2019. Common health trajectories were determined using time sequence analysis through K-clustering (TAK analysis). Findings: Data from 54,545 individuals were analysed; the population was elderly (median age 70 years) with multiple comorbidities. Four clusters were generated. Cluster 1 (n = 35,975/54,545; 66%) had NIV initiated in ambulatory settings or after the first acute event/exacerbation. Cluster 2 (6653/54,545; 12%) started NIV after ≥2 severe exacerbations in the previous 6 months. Cluster 3 (11,375/54,545; 21%) started NIV after frequent severe COPD-related exacerbations in the previous year. Cluster 4 (652/54,545; 1%) started NIV after many long-lasting severe exacerbations. The four clusters differed in age, sex, comorbidities, pre-NIV investigations, and prescriber/location of NIV initiation. Mortality differed significantly between clusters: highest in Cluster 4 and lowest in Cluster 1. Interpretation: The significant heterogeneity in clinical initiation of NIV probably reflects the current lack of strong evidence and guideline recommendations. Knowledge about the characteristics and outcomes in different clusters should be used to address inequities and facilitate more consistent and personalised use domiciliary NIV in COPD. Funding: JLP and SB are supported by the French National Research Agency in the framework of the "Investissements d'avenir" program (ANR-15-IDEX-02) and the "e-health and integrated care and trajectories medicine and MIAI artificial intelligence (ANR-19-P3IA-0003)" Chairs of excellence from the Grenoble Alpes University Foundation. This work was supported by ResMed.

A biphasic effect of age on CPAP adherence: a cross-sectional study of 26,343 patients.

BACKGROUND: As the prevalence of OSA increases in older patients, the proportion of elderly patients treated with CPAP is expected to become even higher. We studied CPAP-adherence in a real-life cohort involving a large population of elderly patients with OSA. METHODS: eQUALISAS is a cross-sectional study of CPAP treated OSA patients for at least 4 months who received remote monitoring during 2021. CPAP adherence, device-reported residual AHI (AHICPAP) and 95th percentile non-intentional leaks were software collected during January 2021. Age and sex were also collected. RESULTS: Data from 26,343 patients including 1656 patients aged [80-85] years and 639 patients aged ≥ 85 years were analysed. Median CPAP adherence increases from 6.3 h (< 50 years) to 7 h (75-80 years) and decreases after this age (p < 0.001). The decrease in CPAP adherence observed after the age of 80 was associated with an increase in the proportion of patients with a CPAP-adherence < 4 h/day (p < 0.001). Proportion of CPAP treated female, patients having AHICPAP mean ≥ 10 events per hour or 95th percentile non-intentional leaks mean over 24 l/min increase with aging of the population. However, for patients over 80 years old, Chi square test showed no association of adherence with gender, AHICPAP and leaks (p > 0.05). CONCLUSION: This study demonstrates that adherence gradually increases with age until 80 years. The proportion of non-adherent patients grows with age after 80 years old. No significative relationship was found between adherence after 80 years old and gender, leaks and AHICPAP. TRIAL REGISTRATION: The study is registered on Health Data Hub platform (No. F20220715144543).

Home NIV treatment quality in patients with chronic respiratory failure having participated to the French nationwide telemonitoring experimental program (The TELVENT study).

BACKGROUND: The ETAPES program is a national telemedicine experiment conducted in France between 2018 and 2023 to investigate whether home non-invasive ventilation (NIV) telemonitoring improves healthcare pathways in patients with chronic respiratory failure (CRF) and impacts healthcare organization. The program provides a combination of therapeutic education and NIV telemonitoring with data processed by an algorithm generating alerts. The TELVENT study objective was to analyze the evolution of ventilation quality in patients included in the ETAPES program. METHODS: Multicentric cohort study on patients undergoing long-term NIV included in the ETAPES program between September 2018 and December 2020 and who did not refuse the use of their data for this research. Data were obtained from homecare provider databases. The primary endpoint was to attain successful NIV treatment, which was determined by a combination of daily NIV usage for > 4 h per day, low leaks, and a low apnea-hypopnea index (AHI) identified by the NIV device. Respiratory disability was assessed using the DIRECT questionnaire. RESULTS: 329 patients were included in the study of which 145 had COPD and 83 had started NIV and ETAPES within one-month delay. Approximately 25% of patients did not achieve the criteria for successful NIV at ETAPES entry. The proportion of patients with successful NIV treatment increased to 86.8% at six months (p = 0.003, Cochran-Armitage trend test) regardless of NIV history and continued to increase at 12 months in newly equipped NIV patients (93.8%, at month 12, p = 0.0026 for trend test). Over time, a significant increase in NIV use and compliance was observed, while AHI significantly decreased in the overall population. No significant decrease was observed for non-intentional leaks. Approximately 4.9 alerts were generated per patient per 6 months. Their number and type (low NIV use, high AHI or leaks) differed among patients based on their NIV history. Respiratory disability score decreased over time compared with baseline. CONCLUSION: The TELVENT study highlights the importance of remote NIV monitoring to rapidly identify patients with unsuccessful ventilation. The combination of remote monitoring and therapeutic education may improve the quality of home NIV, especially in the first months of treatment.

Effect of switching from continuous to bilevel positive airway pressure on sleep quality in patients with obstructive sleep apnea: the prospective POP IN VAuto study.

Background: Issues with tolerability and side effects can decrease continuous positive airway pressure (CPAP) device usage and the benefits of therapy. Different positive airway pressure (PAP) therapy modes providing expiratory pressure relief or using a different pressure during inspiration vs. expiration (bilevel PAP) may alleviate some of these issues. This multicenter, prospective study evaluated the effects of switching from CPAP to bilevel PAP (VAuto mode) on respiratory parameters, device usage, side effects and patient-reported outcomes in patients with obstructive sleep apnea (OSA). Methods: Eligible OSA patients had started CPAP ≥3 months previously, had good compliance (mean 6.1±2.0 h/night) and well-controlled OSA [residual apnea-hypopnea index (AHI) 4.9±3.1/h] but had pressure tolerance issues or persistent side effects/discomfort. All were switched from CPAP to bilevel PAP (AirCurve 10 VAuto; ResMed). Effectiveness (residual AHI), sleep quality, daytime sleepiness, fatigue, therapy-related side effects, and patient satisfaction/preference were assessed after 3 months and 1 year. Results: Forty patients were analyzed (68% male, age 64±11 years, body mass index 30.7±5.8 kg/m2). At 3 months and 1 year after switching to bilevel PAP, median [interquartile range] residual AHI was 4/h [2-5.3] and 3.7/h [1.8-5], respectively, and device usage was 7.0 [4.9-7.5] and 6.4 [4.4-7.3] h/night, respectively. Device switch was associated with significant reductions from baseline in expiratory PAP {from 12 [11-13] to 8 [7-9] cmH2O at 3 months (P<0.001) and 9 [8-12] cmH2O at 1 year (P=0.005)}, 95th percentile pressure {from 14 [12-14] to 10 [9-11] and 10 [8-11] cmH2O; P<0.001 and P=0.001, respectively} and leak {from 1 [0-6] to 0 [0-1] and 0 [0-2] L/min; P=0.049 and P=0.033, respectively}. The Pittsburgh Sleep Quality Index score decreased significantly from baseline to 3 and 6 months [7.2±4.0 to 5.0±3.2 (P=0.005) and 4.5±2.7 (P<0.001), respectively]. CPAP-related mouth dryness, choking sensation and aerophagia were significantly improved one year after switching to bilevel PAP. Bilevel PAP was preferred over CPAP by 90% of patients. Conclusions: Switching to bilevel PAP had several benefits in patients struggling with CPAP, facilitating therapy acceptance and ongoing device usage.

Factors Associated With Residual Apnea-Hypopnea Index Variability During CPAP Treatment.

BACKGROUND: CPAP is the first-line therapy for OSA. A high or variable residual apnea-hypopnea index (rAHI) reflects treatment failure and potentially is triggered by exacerbation of cardiovascular comorbidities. Previous studies showed that high rAHI and large rAHI variability are associated with underlying comorbidities, OSA characteristics at diagnosis, and CPAP equipment, including mask type and settings. RESEARCH QUESTION: What factors are associated with predefined groups with low to high rAHI variability? STUDY DESIGN AND METHODS: This registry-based study included patients with a diagnosis of OSA who were receiving CPAP treatment with at least 90 days of CPAP remote monitoring. We applied the hidden Markov model to analyze the day-to-day trajectories of rAHI variability using telemonitoring data. An ordinal logistic regression analysis identified factors associated with a risk of having a higher and more variable rAHI with CPAP treatment. RESULTS: The 1,126 included patients were middle-aged (median age, 66 years; interquartile range [IQR], 57-73 years), predominantly male (n = 791 [70.3%]), and obese (median BMI, 30.6 kg/m2 (IQR, 26.8-35.2 kg/m2). Three distinct groups of rAHI trajectories were identified using hidden Markov modeling: low rAHI variability (n = 393 [35%]), moderate rAHI variability group (n = 420 [37%]), and high rAHI variability group (n = 313 [28%]). In multivariate analysis, factors associated with high rAHI variability were age, OSA severity at diagnosis, heart failure, opioids and alcohol consumption, mental and behavioral disorders, transient ischemic attack and stroke, an oronasal mask, and level of leaks when using CPAP. INTERPRETATION: Identifying phenotypic traits and factors associated with high rAHI variability will allow early intervention and the development of personalized follow-up pathways for CPAP treatment.

Solitary-like and modulated wavepackets in the Couette-Taylor flow with a radial temperature gradient.

We have performed numerical and experimental studies of the flow in a large aspect ratio Couette-Taylor system with a rotating inner cylinder and a fixed radial temperature gradient. The base flow state is a superposition of an azimuthal flow induced by rotation and an axial large convective cell induced by the temperature gradient. For a relatively large temperature gradient, the rotation rate of the inner cylinder destabilizes the convective cell to give rise to travelling wave pattern through a subcritical bifurcation. This wave pattern is associated with a temperature mode and it consists of helical vortices travelling in the annulus. In a small range of the rotation rate, helical vortices have longitudinal meandering leading to the formation of kinks randomly distributed, leading to spatio-temporal disordered patterns. The flow becomes regular for a large interval of rotation rate. The friction, the momentum and the heat transfer coefficients are computed and found to be independent of the heating direction. This article is part of the theme issue 'Taylor-Couette and related flows on the centennial of Taylor's seminal Philosophical Transactions paper (part 1)'.

CPAP telemonitoring can track Cheyne-Stokes respiration and detect serious cardiac events: The AlertApnée Study.

BACKGROUND AND OBJECTIVE: Case reports have suggested that continuous positive airway pressure (CPAP) telemonitoring can detect the onset of acute cardiac events such as decompensated heart failure (HF) or atrial fibrillation through an increase in the apnoea-hypopnoea index (AHI) and onset of Cheyne-Stokes Respiration (CSR). This study addressed whether long-term remote CPAP treatment telemonitoring revealing CSR can help detect serious cardiac events (SCEs) in obstructive sleep apnoea (OSA) patients. METHODS: This monocentric prospective cohort study included adults receiving CPAP therapy for OSA with daily telemonitoring. Any sudden increase in AHI generated an alert for the home healthcare provider to download CPAP data to identify CSR. A medical consultation was scheduled if CSR was detected. RESULTS: We included 555 adults (412 men; 57% with known cardiovascular comorbidities). During the 1-year follow-up, 78 CSR episodes were detected in 74 patients (CSR+). The main conditions associated with incident CSR were HF (24 patients [30.8%]), ventilatory instability (21, 26.9%), leaks (13, 16.7%), medications inducing central apnoeas (baclofen, ticagrelor, opioids) (7, 9.0%), arrhythmias (6, 7.7%) and renal failure (2, 2.6%). Fifteen (20.3%) CSR+ patients had a confirmed SCE. In univariable analysis, a CSR episode increased the risk of an SCE by 13.8-fold (5.7-35.6) (p < 0.0001), with an adjusted OR of 5.7 (2.0-16.8) in multivariable analysis. CONCLUSION: Long-term telemonitoring of patients on CPAP treatment can alert CSR episodes and allows early detection of SCEs in patients with or without known cardiac comorbidities.

Interrelated atrial fibrillation and leaks triggering and maintaining central sleep apnoea and periodic breathing in a CPAP-treated patient.

We report the case of a 71-year-old obese continuous positive airway pressure (CPAP)-treated man who developed an acute cardiac failure (ACF) triggered by atrial fibrillation. CPAP data downloaded from the CPAP software (Rescan®) retrospectively demonstrated the progressive development of a high residual central apnoea-hypopnoea index (AHI) with Cheyne-Stokes respiration (CSR). The AHI decreased after cardioversion allowing normalization of cardiac rhythm and function. Raw data extracted from CPAP software showed a gradual decrease in the periodic breathing cycle length related to a simultaneous improvement in left ventricular ejection fraction (LVEF) after cardioversion. During this clinical period of respiratory instability in the presence of cardiac failure, CSR episodes were exacerbated by ventilation overshoots followed by micro-arousals induced by leaks. This might explain the high night to night variability of CSR occurrence in susceptible patients with impaired cardiac function. Beyond attempts to improve cardiac function, leak reduction might represent an important target for CSR management.

A large thermal turbulent Taylor-Couette (THETACO) facility for investigation of turbulence induced by simultaneous action of rotation and radial temperature gradient.

A thermal turbulent Taylor-Couette facility has been designed to investigate turbulent flows generated by differential rotation and radial temperature gradient. It consists of a cylindrical annulus with a rotating inner cylinder and a fixed outer cylinder. The electric heating system is installed inside the inner cylinder, and the annulus is immersed in a large cylindrical container filled with cooling fluid. Temperature regulators independently control the temperature of the inner surface of the inner cylinder and that of the cooling fluid. The facility allows us to reach values of the Reynolds number (Re ∼ 5 × 105) and of the Rayleigh number (Ra ∼ 3 × 106) for water as the working fluid. The facility provides torque measurements, a full optical access at the side and from the bottom for velocity measurements using particle image velocimetry (2D, stereoscopic, and tomographic). Temperature measurements in the flow can be performed by thermochromic liquid crystals or laser induced fluorescence.

Marital quality, partner's engagement and continuous positive airway pressure adherence in obstructive sleep apnea.

BACKGROUND: Continuous positive airway pressure (CPAP) is the first line therapy for obstructive sleep apnea (OSA) but its effectiveness requires high adherence. We aimed to assess the impacts of the spouse's/partner's involvement and the quality of the couple's relationship on CPAP adherence. METHODS: In a multicenter prospective study conducted in France, patients reported their subjective views regarding their partner's engagement in their CPAP treatment and the quality of their marital relationship using the Quality of Marriage Index. A hierarchical linear model was built to assess the predictors of CPAP adherence at day 120. Structural equation modeling was performed to evaluate the direct and indirect effects of the spouse's/partner's engagement and the quality of the couple's relationship on CPAP adherence. RESULTS: The 290 OSA patients were predominantly male (77%), with a median age of 53 years IQR: [46; 62], median BMI: 32 kg/m2 [28.6; 35.9] and median apnea + hypopnea index: 43/per hour [33; 58]. Independent factors for CPAP adherence at day 120 were the partner's encouragement of CPAP usage and a stable relationship exceeding 30 years, although emotional support or collaboration were not associated with CPAP adherence. Structural equation modeling demonstrated that spouse's/partner's engagement is directly related to CPAP adherence and improvement of symptoms, and that CPAP adherence is a mediator of disease-specific health-related quality of life. Marital quality was a significant moderator of these interactions meaning that a spouse's/partner's engagement improved adherence only when the quality of marriage index was high. CONCLUSION: Future research and integrated OSA management should systematically include and document the role of the spouse/partner in CPAP adherence.

Kinesthetic stimulation for obstructive sleep apnea syndrome: An "on-off" proof of concept trial.

Obstructive sleep apnea (OSA) occurs when the upper airway narrows or collapses due to the loss of upper airway muscle activation at sleep onset. This study investigated the effectiveness of triggered kinesthetic stimulation in patients with OSA. This proof-of-concept, open-label, multicenter prospective study was conducted on 24 patients with severe OSA. During a one night evaluation, kinesthetic stimulation was intermittently delivered in 30 minute periods. The duration of apneas and hypopneas during Stim on and Stim off periods were compared. Five hospital-based university centers in France participated. Sleep studies were evaluated by a single scorer at a core laboratory (CHU Grenoble). Results show that during the Stim on phases, statistically significant decreases in durations of apneas and hypopneas were observed in 56% and 46% of patients, respectively. Overall, 75% of patients showed an improvement in apneas or hypopneas durations. The mean reduction in durations for patients with a significant decrease was 4.86 seconds for apneas and 6.00 seconds for hypopneas. This proof of concept study is the first to identify kinesthetic stimulation as a potentially effective therapy for OSA. These data justify evaluation in a controlled study.

Efficacy of the Addition of a Cervical Collar in the Treatment of Persistent Obstructive Apneas Despite Continuous Positive Airway Pressure.

ABSTRACT: Continuous positive airway pressure (CPAP) is currently the reference treatment for obstructive sleep apnea (OSA). The use of a face mask, although sometimes necessary, is often associated with increased airway obstruction due to mandibular retrusion. We report a small group of patients in whom addition of a cervical collar to a face mask allowed correction of obstructive events.

Large-scale finite-wavelength modulation within turbulent shear flows.

We show that turbulent "spirals" and "spots" observed in Taylor-Couette and plane Couette flow correspond to a turbulence-intensity modulated finite-wavelength pattern which in every respect fits the phenomenology of coupled noisy Ginzburg-Landau (amplitude) equations with noise. This suggests the existence of a long-wavelength instability of the homogeneous turbulence regime.