Nasal Positive Airway Pressure and Sleep Apnea. Reflections on an Experimental Method That Became a Therapy

Acceptability, adaptability and adherence to CPAP therapy among Aboriginal Australians with OSA - "The A5 study"

BACKGROUND

Studies examining how Australian Aboriginal people will accept, adapt and adhere to interventions such as continuous positive airway pressure (CPAP) therapy in the management of obstructive sleep apnoea (OSA) are sparsely reported.

METHODS

In this study, clinical, demographic, polysomnographic (PSG) and CPAP data were utilised to assess and predict acceptance and adherence to CPAP therapy among adult Aboriginal Australians diagnosed to have OSA.

RESULTS

Of the 649 Aboriginal patients with OSA, 49% accepted to trial CPAP therapy. Patients who accepted to trial CPAP showed more severe OSA (65vs.35% with severe OSA), reported higher daytime sleepiness (median 10vs.9), and had a higher BMI (83vs.73% obese). Of those who accepted to trial CPAP, 62% adapted to therapy (used the device for more than 30 days). Patients who adapted had more severe OSA (71vs.54% with severe OSA), and were more likely to live in urban areas (63vs.40%). Of those who adapted, 32% were adherent to therapy. Adherent patients were more likely to live in urban areas (84vs.53%), though there was no difference in OSA severity between adherent and non-adherent patients. In multivariate models remote location and more severe OSA predicted CPAP acceptance, while urban location and more severe OSA predicted adaptation, and urban location and higher oxygen saturation nadir predicted adherence.

CONCLUSIONS

Acceptance to trial CPAP therapy was observed in the presence of symptomatic and severe OSA. However, long term adherence to CPAP therapy was significantly influenced by patients' residential location, with patients residing in remote/rural settings demonstrating significantly lower adherence rates.

Therapieadhärenz drei Monate nach Einleitung einer nichtinvasiven CPAP-Therapie bei 1078 Patienten mit obstruktiver Schlafapnoe (OSA)

Einleitung Die nächtliche kontinuierliche positive Überdruckatmung (CPAP) gilt als therapeutischer Goldstandard einer obstruktiven Schlafapnoe (OSA). Die CPAP-Therapie stellt zumeist eine Dauertherapie mit geringen Nebenwirkungen dar. Trotzdem ist die Therapietreue unbefriedigend. In dieser Arbeit wurden die Therapietreue betrachtet und typische Probleme katalogisiert.

Methode 1078 OSA-Patienten wurden nach diagnostischer Polygrafie (PG) oder Polysomnografie (PSG) auf eine CPAP-Therapie eingestellt. Die Therapietreue wurde nach 3 Monaten nachverfolgt. Folgende Therapieadhärenz-Gruppen wurden festgelegt: 1. gute CPAP-Einstellung und Nutzung, 2. CPAP-Abbruch nach anfänglicher Nutzung, 3. mangelnde CPAP-Nutzung wegen Nebenwirkungen, 4. Abbruch aufgrund fehlender Motivation/geringem Leidensdruck, 5. Masken-Unverträglichkeit, 6. CPAP-Versagen aufgrund fehlenden Therapieeffekts, 7. Umstellung auf anderes Beatmungsverfahren, 8. keine Kontrolle erfolgt.

Ergebnisse Von 1078 CPAP-Patienten erschienen 830 Patienten (77 %) zur Therapiekontrolle. Hiervon waren 450 Patienten (54,2%) in Gruppe 1, 216 Patienten (26%) in Gruppe 2, 71 Patienten (8,5%) in Gruppe 3, 35 Patienten (4,2%) in Gruppe 4, 14 Patienten (1,7%) in Gruppe 5, 3 Patienten (0,4 %) in Gruppe 6 und 41 Patienten (4,9%) in Gruppe 7. Ein geringer obstruktiver Ereignisindex, niedriger CPAP-Druck und tendenziell auch ein geringer Epworth-Sleepiness-Score waren Prädiktoren für CPAP-Versagen. Für die Therapietreue konnten keine signifikanten Prädiktoren dargestellt werden.

Diskussion Eine effektive Therapienutzung von 54% nach 3 Monaten ist ein suboptimales Ergebnis. Prädiktoren für CPAP-Versagen waren Parameter, die vor Therapie auf geringen Leidensdruck der Patienten deuteten. Trotz großer Patientenkohorte konnten keine signifikanten CPAP-Adhärenz-Prädiktoren durch anthropometrische oder PSG-Daten dargestellt werden. Vielmehr könnten Erfahrungen in den ersten Therapietagen ausschlaggebend sein. CPAP-Geräte bieten Komforteinstellungen, die kenntnisgerecht auf den Patienten individualisiert werden müssen. Eine große Auswahl an unterschiedlichen Maskenformen erfordert Erfahrung und Training bei der patientenorientierten Maskenanpassung. Eine 3-monatige Wiedervorstellung erscheint zu lang, um Therapieprobleme zeitnah mit dem Patienten zu besprechen. Telemedizinische Möglichkeiten oder kurzfristige telefonische Beratungsoptionen sollten in Betracht gezogen werden.

Sleep function: an evolutionary perspective

Prospective epidemiological studies in industrial societies indicate that 7 h of sleep per night in people aged 18 years or older is optimum, with higher and lower amounts of sleep predicting a shorter lifespan. Humans living a hunter-gatherer lifestyle (eg, tribal groups) sleep for 6-8 h per night, with the longest sleep durations in winter. The prevalence of insomnia in hunter-gatherer populations is low (around 2%) compared with the prevalence of insomnia in industrial societies (around 10-30%). Sleep deprivation studies, which are done to gain insights into sleep function, are often confounded by the effects of stress. Consideration of the duration of spontaneous daily sleep across species of mammals, which ranges from 2 h to 20 h, can provide important insights into sleep function without the stress of deprivation. Sleep duration is not related to brain size or cognitive ability. Rather, sleep duration across species is associated with their ecological niche and feeding requirements, indicating a role for wake-sleep balance in food acquisition and energy conservation. Brain temperature drops from waking levels during non-rapid eye movement (non-REM) sleep and rises during REM sleep. Average daily REM sleep time of homeotherm orders is negatively correlated with average body and brain temperature, with the largest amount of REM sleep in egg laying (monotreme) mammals, moderate amounts in pouched (marsupial) mammals, lower amounts in placental mammals, and the lowest amounts in birds. REM sleep might, therefore, have a key role in the regulation of temperature and metabolism of the brain during sleep and in the facilitation of alert awakening.

Open-Source Hardware May Address the Shortage in Medical Devices for Patients with Low-Income and Chronic Respiratory Diseases in Low-Resource Countries

Respiratory diseases pose an increasing socio-economic burden worldwide given their high prevalence and their elevated morbidity and mortality. Medical devices play an important role in managing acute and chronic respiratory failure, including diagnosis, monitoring, and providing artificial ventilation. Current commercially available respiratory devices are very effective but, given their cost, are unaffordable for most patients in low- and middle-income countries (LMICs). Herein, we focus on a relatively new design option—the open-source hardware approach—that, if implemented, will contribute to providing low-cost respiratory medical devices for many patients in LMICs, particularly those without full medical insurance coverage. Open source reflects a set of approaches to conceive and distribute the comprehensive technical information required for building devices. The open-source approach enables free and unrestricted use of the know-how to replicate and manufacture the device or modify its design for improvements or adaptation to different clinical settings or personalized treatments. We describe recent examples of open-source devices for diagnosis/monitoring (measuring inspiratory/expiratory pressures or flow and volume in mechanical ventilators) and for therapy (non-invasive ventilators for adults and continuous positive airway pressure support for infants) that enable building simple, low-cost (hence, affordable), and high-performance solutions for patients in LMICs. Finally, we argue that the common practice of approving clinical trials by the local hospital ethics board can be expanded to ensure patient safety by reviewing, inspecting, and approving open hardware for medical application to maximize the innovation and deployment rate of medical technologies.

Treatment options in obstructive sleep apnea

Treatment of OSA with CPAP is currently the recommended treatment and has the greatest evidence of efficacy on AHI, symptoms and comorbidities. Symptomatic patients with moderate-severe OSA generally have good adherence to CPAP therapy, while those with mild OSA, female, young and generally paucisymptomatic, have lower CPAP adherence, especially in the medium and long term. The recent identification of different clinical and pathophysiological phenotypes of OSA has paved the way for alternative treatments to CPAP, leading to an increasingly personalized therapy. Weight loss and lifestyle modifications are highly recommended in all obese or overweight patients. Mandibular advancement devices (MAD), positional therapy (PT) and hypoglossal nerve stimulation (HSN) are recent and personalized alternative therapies on which there is promising and encouraging data but with still little strong scientific evidence. The purpose of this review is to compare the efficacy, adherence and costs of various therapeutic options for OSA patients in the light of recent evidence and to provide useful guidance for specialists.

[Adherence to CPAP Three Months after Starting Therapy in 1078 Patients with Obstructive Sleep Apnea (OSA)]

INTRODUCTION

 Nocturnal Continuous Positive Airway Pressure (CPAP) is considered the gold standard treatment for obstructive sleep apnoea (OSA). The CPAP therapy is a long-term treatment but does come with few possible side effects. The adherence to the therapy is frequently suboptimal. In this paper, adherence to therapy was assessed and typical problems were classified.

METHODS

 1078 OSA patients received CPAP therapy after a diagnostic polygraphy (PG) or polysomnography (PSG). Adherence to therapy was followed up three months after treatment induction. The following therapy adherence groups were defined: 1. correctly calibrated CPAP and good adherence, 2. CPAP non-acceptance, after initial use, 3. CPAP intolerance use due to side effects, 4. discontinuation due to lack of motivation/low rates of symptoms. 5. mask intolerance, 6. CPAP failure due to a lack of perceived treatment effect, 7. Change to another non-invasive ventilation method, 8. No control carried out.

RESULTS

 Out of 1078 OSA patients a therapy control was performed in 830 patients (77 %). Of these, 450 patients (54.2 %) were placed in group 1, 216 patients (26 %) in group 2, 71 patients (8.5 %) in group 3, 35 patients (4.2 %) in group 4, 14 patients (1.7 %) in group 5, 3 patients (0.4 %) in group 6 and 41 patients (4.9 %) in group 7. A mild obstructive index, low CPAP pressure and, as a trend, a low Epworth- Sleepiness score were predictors of CPAP failure. No significant predictors could be shown for adherence to therapy.

DISCUSSION

 An effective treatment use of 54 % after 3 months is a suboptimal result. Predictors of CPAP failure were parameters that indicated that the patient was less symptomatic prior to therapy. Despite a large patient cohort, neither anthropometric nor PSG-data provided any significant CPAP adherence predictors. Rather, experiences in the first nights of use could be decisive. CPAP devices offer comfort settings that have to be personalised to patients' needs and wants. A large selection of different mask shapes requires experience and training in patient-centred mask fitting. A three-month follow-up appointment seems too long to discuss therapy problems with the patient in a timely manner. Telemedical options or short-term telephone appointments should be considered.

Alternative Procedure to Individual Nasal Pressure Titration for Sleep Apnea

In the treatment of obstructive sleep apnea (OSA), the current standard of "CPAP titration" in the laboratory or at home is a resource demanding and costly approach that, in developed economies, markedly augments healthcare costs and in low resource economies precludes access to care altogether. Here, we discuss that current guidelines for titration of CPAP could be obviated by taking a different route that in many ways is similar to the institution of treatment in many other medical conditions. To this effect, we present novel population based data from 16,780 patients, showing that after individualized and labor-intensive and expensive CPAP titration, 86.4% of OSA patients are treated with nasal pressure settings within the range of 9 ± 2 cmH₂O, and review the literature to justify the potential adoption of a standard therapeutic CPAP setting as the initial intervention which would be subsequently followed by any necessary adjustments in only a minority of patients who would not derive the necessary benefit from such standardized intervention. Assuming an 80-85% success rate as derived from our analyses, our personal view if extensively adopted could radically reduce healthcare costs and enable markedly improve access to diagnostics.

Low-cost, easy-to-build noninvasive pressure support ventilator for under-resourced regions: open source hardware description, performance and feasibility testing

Aim

Current pricing of commercial mechanical ventilators in low-/middle-income countries (LMICs) markedly restricts their availability, and consequently a considerable number of patients with acute/chronic respiratory failure cannot be adequately treated. Our aim was to design and test an affordable and easy-to-build noninvasive bilevel pressure ventilator to allow a reduction in the serious shortage of ventilators in LMICs.

Methods

The ventilator was built using off-the-shelf materials available via e-commerce and was based on a high-pressure blower, two pressure transducers and an Arduino Nano controller with a digital display (total retail cost <75 USD), with construction details provided open source for free replication. The ventilator was evaluated, and compared with a commercially available device (Lumis 150 ventilator; Resmed, San Diego, CA, USA): 1) in the bench setting using an actively breathing patient simulator mimicking a range of obstructive/restrictive diseases; and b) in 12 healthy volunteers wearing high airway resistance and thoracic/abdominal bands to mimic obstructive/restrictive patients.

Results

The designed ventilator provided inspiratory/expiratory pressures up to 20/10 cmH₂O, respectively, with no faulty triggering or cycling; both in the bench test and in volunteers. The breathing difficulty score rated (1–10 scale) by the loaded breathing subjects was significantly (p<0.005) decreased from 5.45±1.68 without support to 2.83±1.66 when using the prototype ventilator, which showed no difference with the commercial device (2.80±1.48; p=1.000).

Conclusion

The low-cost, easy-to-build noninvasive ventilator performs similarly to a high-quality commercial device, with its open-source hardware description, which will allow for free replication and use in LMICs, facilitating application of this life-saving therapy to patients who otherwise could not be treated.

Patients in under-resourced areas cannot be treated by mechanical ventilation given the unaffordable cost of conventional devices; here a low-cost, easy-to-build ventilator with open access details for free replication is designed and testedhttps://bit.ly/34UcbWp

[Non-surgical treatment of the sleep related breathing disorders in adults]

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.

Solriamfetol for Excessive Sleepiness in Obstructive Sleep Apnea (TONES 3). A Randomized Controlled Trial

Rationale: Primary treatment of obstructive sleep apnea can be accompanied by a persistence of excessive sleepiness despite adherence. Furthermore, effectiveness of sleep apnea treatment is limited by poor adherence. Currently available pharmacologic options for the treatment of sleepiness in this population are limited. Objectives: To evaluate the efficacy and safety of solriamfetol (JZP-110), a selective dopamine and norepinephrine reuptake inhibitor with robust wake-promoting effects, for the treatment of excessive sleepiness in participants with obstructive sleep apnea with current or prior sleep apnea treatment. Methods: This was a double-blind, randomized, placebo-controlled, parallel-group, 12-week trial comparing solriamfetol, 37.5, 75, 150, and 300 mg, with placebo. Measurements and Main Results: Of 476 randomized participants, 459 were included in the prespecified efficacy analyses. Coprimary endpoints (Maintenance of Wakefulness Test sleep latency and Epworth Sleepiness Scale score) were met at all solriamfetol doses (P < 0.05), with dose-dependent effects observed at Week 1 maintained over the study duration. All doses except 37.5 mg resulted in higher percentages of participants reporting improvement on Patient Global Impression of Change (key secondary endpoint; P < 0.05). Adverse events were reported in 47.9% of placebo- and 67.9% of solriamfetol-treated participants; five participants experienced serious adverse events (two [1.7%] placebo, three [0.8%] solriamfetol); none were deemed related to study drug. The most common adverse events with solriamfetol were headache (10.1%), nausea (7.9%), decreased appetite (7.6%), anxiety (7.0%), and nasopharyngitis (5.1%). Conclusions: Solriamfetol significantly increased wakefulness and reduced sleepiness in participants with obstructive sleep apnea and excessive sleepiness; most adverse events were mild or moderate in severity. Clinical trial registered with www.clinicaltrials.gov (NCT02348606) and www.eudract.ema.europa.eu (EudraCT 2014-005514-31).