Flexible pressure delivery modification of continuous positive airway pressure for obstructive sleep apnea does not improve compliance with therapy: systematic review and meta-analysis

Early objective adherence to hypoglossal nerve stimulation therapy

STUDY OBJECTIVES

To assess early adherence to therapy with hypoglossal nerve stimulation therapy.

METHODS

This is a prospective study of consecutive patients with moderate to severe obstructive sleep apnea who underwent implantation of hypoglossal nerve stimulation therapy within a single academic practice and attended a follow-up appointment after greater than 30 days of therapy use. Objective adherence data were extracted from an objective monitoring database and compared to patient characteristics.

RESULTS

The study population was 79 participants who were 29.1% female with a mean age of 58.7 ± 12.8 years old, body mass index of 28.9 ± 3.4 kg/m², and baseline apnea-hypopnea index of 33.8 ± 17.6 events/h. In the first 7 days after device activation, average use was 7.8 h/night, with 91.9% of nights with greater than 4 hours of therapy use and an average of 0.2 pauses in therapy per night. These figures remained stable after 30 days of use: 7.7 h/night, 91.0% of nights longer than 4 hours, and 0.3 pauses per night. Objective evidence of difficulty with acclimatization was associated with age less than 60 years (odds ratio 2.8, 95% confidence interval 1.1-7.1, P = .03) and a history of prior upper airway surgery (3.9, 1.2-11.9, P = .015). Insomnia was present in 31 patients and was not associated with objective evidence of difficulty tolerating therapy.

CONCLUSIONS

Early adherence to hypoglossal nerve stimulation is excellent (92.4% >4 hours on >70% of nights), suggesting that the acclimatization period is straightforward in most. Younger age and a history of prior upper airway surgery appear to be associated with an increased risk of difficulty with acclimatization.

CITATION

Huyett P. Early objective adherence to hypoglossal nerve stimulation therapy. J Clin Sleep Med. 2022;18(2):631-636.

The Impact of Device Modifications and Pressure Delivery on Adherence

This article reviews the evidence to date examining whether adherence to positive airway pressure (PAP) therapy is affected by any device modifications to pressure delivery. To date there is no robust evidence from systematic reviews and meta-analyses indicating that any modification to standard fixed-pressure PAP makes a clinically significant difference to patient adherence to therapy. The main modifications are reviewed in this article and whether improving pressure could drive adherence, in turn improving patient outcomes, is discussed.

Summary and Update on Behavioral Interventions for Improving Adherence with Positive Airway Pressure Treatment in Adults

Continuous positive airway pressure (PAP) is still the most efficacious treatment for obstructive sleep apnea when used effectively. Since the availability of PAP 39 years ago there have been considerable technological advances, such as quieter, lighter and smaller machines with better humidification. However, adherence to treatment is still a major problem. This article reviews studies published on behavioral interventions aimed at improving the uptake and maintenance of PAP treatment (January 2016-February 2020). It discusses underlying factors in the poor uptake and discontinuation of treatment and the role of qualitative research to better understand the perspective of the patients.

Treatment of Obstructive Sleep Apnea: Choosing the Best Positive Airway Pressure Device

Positive airway pressure (PAP) remains primary therapy for most patients with obstructive sleep apnea (OSA). CPAP, APAP, and BPAP are all reasonable therapies that can be used for patients with uncomplicated OSA across the spectrum of disease severity. BPAP should be considered for patients who are nonadherent to CPAP or APAP therapy because of pressure intolerance. Several additional factors should be considered when choosing the type of PAP device for a given patient, including associated symptoms and comorbid medical problems, cost, access to online data management and patient portals, and the portability for the device for patients who travel frequently.

Managements for Obstructive Sleep Apnea in Adults: Review

Obstructive sleep apnea (OSA) is characterized by recurrent obstruction of the pharyngeal airway during sleep, with resultant hypoxia and sleep fragmentation. It is more common in middle-aged obese men and prevalence is higher in most obese people. However, prevalence is high in African-Americans. OSA is associated with major comorbidities including excessive daytime sleepiness and increased risk of cardiovascular diseases. First and foremost, OSA management starts from educating patients about short-term consequences like motor vehicle accidents, behavioral modifications, long term consequences like cardiopulmonary disease, and resistant high blood pressure. Various types of management options are available for OSA such as weight loss, CPAP, oral appliances, and surgery. The review aims to explain the pathophysiology and cause of the obstruction of the airway in order to choose proper management carefully to decrease the symptoms and cure the disease.

Pressure modification or humidification for improving usage of continuous positive airway pressure machines in adults with obstructive sleep apnoea

BACKGROUND

Obstructive sleep apnoea (OSA) is the repetitive closure of the upper airway during sleep. This results in disturbed sleep and excessive daytime sleepiness. It is a risk factor for long-term cardiovascular morbidity. Continuous positive airway pressure (CPAP) machines can be applied during sleep. They deliver air pressure by a nasal or oronasal mask to prevent the airway from closing, reducing sleep disturbance and improving sleep quality. Some people find them difficult to tolerate because of high pressure levels and other symptoms such as a dry mouth. Switching to machines that vary the level of air pressure required to reduce sleep disturbance could increase comfort and promote more regular use. Humidification devices humidify the air that is delivered to the upper airway through the CPAP circuit. Humidification may reduce dryness of the throat and mouth and thus improve CPAP tolerability. This updated Cochrane Review looks at modifying the delivery of positive pressure and humidification on machine usage and other clinical outcomes in OSA.

OBJECTIVES

To determine the effects of positive pressure modification or humidification on increasing CPAP machine usage in adults with OSA.

SEARCH METHODS

We searched Cochrane Airways Specialised Register and clinical trials registries on 15 October 2018.

SELECTION CRITERIA

Randomised parallel group or cross-over trials in adults with OSA. We included studies that compared automatically adjusting CPAP (auto-CPAP), bilevel positive airway pressure (bi-PAP), CPAP with expiratory pressure relief (CPAPexp), heated humidification plus fixed CPAP, automatically adjusting CPAP with expiratory pressure relief, Bi-PAP with expiratory pressure relief, auto bi-PAP and CPAPexp with wakefulness detection with fixed pressure setting.

DATA COLLECTION AND ANALYSIS

We used standard methods expected by Cochrane. We assessed the certainty of evidence using GRADE for the outcomes of machine usage, symptoms (measured by the Epworth Sleepiness Scale (ESS)), Apnoea Hypopnoea Index (AHI), quality of life measured by Functional Outcomes of Sleep Questionnaire (FOSQ), blood pressure, withdrawals and adverse events (e.g. nasal blockage or mask intolerance). The main comparison of interest in the review is auto-CPAP versus fixed CPAP.

MAIN RESULTS

We included 64 studies (3922 participants, 75% male). The main comparison of auto-CPAP with fixed CPAP is based on 36 studies with 2135 participants from Europe, USA, Hong Kong and Australia. The majority of studies recruited participants who were recently diagnosed with OSA and had not used CPAP previously. They had excessive sleepiness (ESS: 13), severe sleep disturbance (AHI ranged from 22 to 59), and average body mass index (BMI) of 35 kg/m2. Interventions were delivered at home and the duration of most studies was 12 weeks or less. We judged that studies at high or unclear risk of bias likely influenced the effect of auto-CPAP on machine usage, symptoms, quality of life and tolerability, but not for other outcomes. Primary outcome Compared with average usage of about five hours per night with fixed CPAP, people probably use auto-CPAP for 13 minutes longer per night at about six weeks (mean difference (MD) 0.21 hours/night, 95% confidence interval (CI) 0.11 to 0.31; 31 studies, 1452 participants; moderate-certainty evidence). We do not have enough data to determine whether auto-CPAP increases the number of people who use machines for more than four hours per night compared with fixed CPAP (odds ratio (OR) 1.16, 95% CI 0.75 to 1.81; 2 studies, 346 participants; low-certainty evidence). Secondary outcomes Auto-CPAP probably reduces daytime sleepiness compared with fixed CPAP at about six weeks by a small amount (MD -0.44 ESS units, 95% CI -0.72 to -0.16; 25 studies, 1285 participants; moderate-certainty evidence). AHI is slightly higher with auto-CPAP than with fixed CPAP (MD 0.48 events per hour, 95% CI 0.16 to 0.80; 26 studies, 1256 participants; high-certainty evidence), although it fell with both machine types from baseline values in the studies. Ten per cent of people in auto-CPAP and 11% in the fixed CPAP arms withdrew from the studies (OR 0.90, 95% CI 0.64 to 1.27; moderate-certainty evidence). Auto-CPAP and fixed CPAP may have similar effects on quality of life, as measured by the FOSQ but more evidence is needed to be confident in this result (MD 0.12, 95% CI -0.21 to 0.46; 3 studies, 352 participants; low-certainty evidence). Two studies (353 participants) provided data on clinic-measured blood pressure. Auto-CPAP may be slightly less effective at reducing diastolic blood pressure compared to fixed CPAP (MD 2.92 mmHg, 95% CI 1.06 to 4.77 mmHg; low-certainty evidence). The two modalities of CPAP probably do not differ in their effects on systolic blood pressure (MD 1.87 mmHg, 95% CI -1.08 to 4.82; moderate-certainty evidence). Nine studies (574 participants) provided information on adverse events such as nasal blockage, dry mouth, tolerance of treatment pressure and mask leak. They used different scales to capture these outcomes and due to variation in the direction and size of effect between the studies, the comparative effects on tolerability outcomes are uncertain (very low-certainty evidence).  The evidence base for other interventions is smaller, and does not provide sufficient information to determine whether there are important differences between pressure modification strategies and fixed CPAP on machine usage outcomes, symptoms and quality of life. As with the evidence for the auto-CPAP, adverse events are measured disparately.

AUTHORS' CONCLUSIONS

In adults with moderate to severe sleep apnoea starting positive airway pressure therapy, auto-CPAP probably increases machine usage by about 13 minutes per night. The effects on daytime sleepiness scores with auto-CPAP are not clinically meaningful. AHI values are slightly lower with fixed CPAP. Use of validated quality of life instruments in the studies to date has been limited, although where they have been used the effect sizes have not exceeded proposed clinically important differences. The adoption of a standardised approach to measuring tolerability would help decision-makers to balance benefits with harms from the different treatment options available. The evidence available for other pressure modification strategies does not provide a reliable basis on which to draw firm conclusions. Future studies should look at the effects of pressure modification devices and humidification in people who have already used CPAP but are unable to persist with treatment.

Strategies to augment adherence in the management of sleep-disordered breathing

Continuous positive airway pressure (CPAP) is highly effective in treating sleep-disordered breathing (SDB). However, unlike surgical interventions, this treatment modality relies heavily on patient acceptance and adherence. The current definition of adherence is largely arbitrary and is mainly used by third-party payers to determine CPAP reimbursement but CPAP adherence remains sub-optimal. Strategies to augment adherence, especially early in the course of a CPAP trial, are needed in the management of SDB. An understanding of the basis for observed differences in CPAP and oral appliance (OA) use is necessary in developing these strategies, but to date no single factor has been consistently identified. Consequently, a multidimensional approach using educational, behavioural, technological and potentially pharmacological strategies to target (i) disease characteristics, (ii) patient characteristics including psychosocial factors, (iii) treatment protocols and (iv) technological devices and side effects that may influence adherence, is likely required to augment the complex behaviour of CPAP and OA use. In the near future, we envision a personalized medicine approach to determine the risk of non-adherence and set individualized adherence goals aimed at treating specific symptoms (e.g. excessive daytime sleepiness) and reducing the risk of patient-specific SDB consequences (e.g. atherosclerosis). Resources for interventions to improve adherence such as educational programmes and telemedicine encounters could then be more efficiently allocated.

Predictors of Continuous Positive Airway Pressure Adherence in Patients with Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a common disease which impacts quality of life, mood, cardiovascular morbidity, and mortality. Continuous positive airway pressure (CPAP) is the first-line treatment for patients with moderate to severe OSA. CPAP ameliorates respiratory disturbances, leading to improvements in daytime sleepiness, quality of life, blood pressure, and cognition. However, despite the high efficacy of this device, CPAP adherence is often sub-optimal. Factors including: socio-demographic/economic characteristics, disease severity, psychological factors, and side-effects are thought to affect CPAP adherence in OSA patients. Intervention studies have suggested that augmented support/education, behavioral therapy, telemedicine and technological interventions may improve CPAP adherence. In this paper, we will extensively review the most common factors including age, gender, race/ethnicity, socioeconomic status, smoking status, severity of OSA, severity of OSA symptoms, psychological variables, social support, marital status/bed partner involvement, dry nose and mouth, mask leak, and nasal congestion that may predict CPAP adherence. We will also extensively review interventions that may increase adherence to CPAP.

Cardiovascular endpoints for obstructive sleep apnea with twelfth cranial nerve stimulation (CARDIOSA-12): Rationale and methods

OBJECTIVES/HYPOTHESIS

To determine the effect of therapeutic levels of hypoglossal nerve stimulation therapy (HGNS), compared to subtherapeutic levels of HGNS, on 24-hour ambulatory blood pressure, sympathetic activity, and vascular function.

STUDY DESIGN

Double-blind, sham-controlled, randomized crossover trial of 10-week duration at a university medical center METHODS: The target enrollment is 60 randomly assigned subjects. Interventions are active versus sham (subtherapeutic) HGNS therapy.

RESULTS

The primary outcome is 24-hour ambulatory systolic blood pressure. Secondary outcomes include 24-hour ambulatory diastolic blood pressure, nocturnal systolic and diastolic pressure, muscle sympathetic nerve activity, pre-ejection period, flow-mediated dilation, and pulse wave velocity.

CONCLUSIONS

The Cardiovascular Endpoints for Obstructive Sleep Apnea With Twelfth Cranial Nerve Stimulation study is designed to examine obstructive sleep apnea and test the effects of HGNS on the cardiovascular system through a sham-controlled trial in patients with moderate-severe obstructive sleep apnea.

LEVEL OF EVIDENCE

1 Laryngoscope, 2635-2643, 2018.

Treatment of Obstructive Sleep Apnea: Choosing the Best Positive Airway Pressure Device

Positive airway pressure (PAP) remains primary therapy for most patients with obstructive sleep apnea (OSA). CPAP, APAP, and BPAP are all reasonable therapies that can be used for patients with uncomplicated OSA across the spectrum of disease severity. BPAP should be considered for patients who are nonadherent to CPAP or APAP therapy because of pressure intolerance. Several additional factors should be considered when choosing the type of PAP device for a given patient, including associated symptoms and comorbid medical problems, cost, access to online data management and patient portals, and the portability for the device for patients who travel frequently.

Pressure-Relief Features of Fixed and Autotitrating Continuous Positive Airway Pressure May Impair Their Efficacy: Evaluation with a Respiratory Bench Model

STUDY OBJECTIVES

Pressure-relief features are aimed at improving the patient's comfort during continuous positive airway pressure (CPAP) treatment for obstructive sleep apnea. The objective of this study was to determine the effect of these therapy features on fixed CPAP and autotitrating CPAP (APAP) treatment efficacy.

METHODS

Seven pressure-relief features applied by three CPAP devices were included in our study (Remstar Auto: C-Flex 3, C-Flex+ 3, A-Flex 3, P-Flex; AirSense 10: EPR 3; Prisma 20A: SoftPAP 2 and 3). In fixed CPAP, the devices were subjected to a 10-min bench-simulated obstructive apnea sequence (initial apnea-hypopnea index, AHI = 60/h) with and without pressure-relief features. In APAP, the sequence was lengthened to 4.2 h (initial AHI = 58.6/h). The residual AHI and mean/median pressure were compared with and without pressure-relief features.

RESULTS

Compared to conventional CPAP, where pressure was adjusted to be just sufficient to control the simulated obstructive events, C-Flex+ 3, P-Flex, and EPR 3 failed to normalize the breathing flow and did not reduce the AHI. The mean pressures with the three features, respectively, were 1.8, 2.6, and 2.6 cmH2O lower than the conventional CPAP. Compared to conventional APAP, similar levels of control were observed with pressure-relief features, apart from P-Flex where the delivered mean pressure was lower and residual AHI greater. The device-reported mean/median pressures in APAP with A-Flex 3, P-Flex, EPR 3, and SoftPAP 3 were higher than that measured on the bench.

CONCLUSIONS

Pressure-relief features may attenuate CPAP efficacy if not adjusted for at the time of their introduction. In clinical practice, efficacy can be ensured by increasing the therapeutic pressure delivered by fixed CPAP or by enabling the pressure-relief features prior to initial pressure titration. Device-reported pressures in APAP devices with pressure relief activated may overstate delivered pressures.

Factors Contributing to Unintentional Leak During CPAP Treatment: A Systematic Review

CPAP is the first-line treatment for moderate to severe OSA syndrome. Up to 25% of patients with OSA syndrome discontinue CPAP treatment due to side effects. Unintentional leakage and its associated annoying consequences are the most frequently reported adverse effects of CPAP. Successive technological improvements have not succeeded in addressing this issue. A systematic review was conducted (1) to assess the impact of different technological advances on unintentional leaks and (2) to determine if any patient characteristics have already been identified as determinants of unintentional leakage. No CPAP modality was superior to another in reducing unintentional leaks and, surprisingly, oronasal masks were associated with higher unintentional leaks. Nasal obstruction, older age, higher BMI, central fat distribution, and male sex might be associated with an increased risk of unintentional leakage. Such leaks remain an important problem. Further studies are needed to improve the understanding of underlying clinical factors so that patients at risk of unintentional leaks may be identified and individualized solutions applied.

Work of Breathing in Fixed and Pressure Relief Continuous Positive Airway Pressure (C-Flex™): A post hoc Analysis

BACKGROUND

Expiratory pressure relief continuous positive airway pressure (pressure relief CPAP; C-Flex™) causes increases in inspiratory duty cycle and shortening of expiratory time. It has been suggested that these changes are caused by an increase in work of breathing.

OBJECTIVES

We studied the effects of C-Flex on work of breathing and intrinsic positive end-expiratory pressure as compared to fixed CPAP.

METHODS

Work of breathing was analyzed in 24 patients with obstructive sleep apnea during treatment with fixed CPAP and C-Flex with 3 different pressure relief settings in a randomized order during rapid-eye-movement (REM) and non-REM sleep. Work of breathing was assessed on a breath-by-breath basis using a piezoelectric esophageal pressure catheter and a pneumotachograph for measuring airflow.

RESULTS

We found there was no increase in inspiratory work of breathing observed using C-Flex compared to fixed CPAP. Instead, we found a linear decrease in inspiratory work of breathing with increasing pressure relief, with a mean difference of 1.22 J/min between CPAP and maximum pressure release (C-Flex 3; 90% of the value with nasal CPAP); however, the decrease was not statistically significant. The decrease in inspiratory work of breathing associated with C-Flex has a significant inverse correlation with BMI.

CONCLUSIONS

The C-Flex technology does not change work of breathing but shows a tendency towards a reduction of inspiratory work of breathing in patients with a lower BMI using higher C-Flex. The effect is probably caused by diminishing airway resistance generated by the positive end-expiratory pressure. Our findings may lead to additional fields of application of the C-Flex technology, such as chronic obstructive pulmonary disease or muscular dystrophy.

Positive Airway Pressure Therapy for Obstructive Sleep Apnea

Positive airway pressure (PAP) is considered first-line therapy for moderate to severe obstructive sleep apnea and may also be considered for mild obstructive sleep apnea, particularly if it is symptomatic or there are concomitant cardiovascular disorders. Continuous PAP is most commonly used. Other modes, such as bilevel airway pressure, autotitrating positive airway pressure, average volume assured pressure support, and adaptive support ventilation, play important roles in the management of sleep-related breathing disorders. This article outlines the indications, description, and comfort features of each mode. Despite the proven efficacy of PAP in treating obstructive sleep apnea syndrome and its sequelae, adherence to therapy is low. Close follow-up of patients for evaluation of adherence to and effectiveness of treatment is important.

Upper Airway Variation and Frequent Alcohol Consumption Can Affect Compliance With Continuous Positive Airway Pressure

Objectives

Compliance with continuous positive airway pressure (CPAP) treatment remains a primary concern for improving treatment outcomes of obstructive sleep apnea. There are few studies that have considered the role of upper airway anatomy on the compliance with CPAP. We hypothesized that upper airway anatomy would influence the compliance with CPAP.

Methods

One hundred out of 161 consecutive patients were enrolled in this study. The following possible determinants were tested against CPAP use: demographic and anthropometric data, minimal cross-sectional area on acoustic rhinometry, cephalometric and polysomnographic data, questionnaires of Epworth sleepiness scale and Beck depression index, and histories of previous upper airway surgery, degree of nasal obstruction, daily cigarette consumption, and weekly frequency of alcohol intake.

Results

Univariate analysis showed that histories of previous upper airway surgery and less frequent alcohol consumption, and longer mandibular plane-hyoid length (MP-H) on cephalometry were associated with longer average daily CPAP use. After adjustment for the confounding factors with multiple linear regression analysis, alcohol consumption and MP-H were still associated with the compliance with CPAP significantly.

Conclusion

To improve compliance with CPAP, careful evaluations of upper airway problems and life style are important before initiating CPAP.

Consensus and evidence-based Indian initiative on obstructive sleep apnea guidelines 2014 (first edition)

Obstructive sleep apnea (OSA) and obstructive sleep apnea syndrome (OSAS) are subsets of sleep-disordered breathing. Awareness about OSA and its consequences among the general public as well as the majority of primary care physicians across India is poor. This necessitated the development of the Indian initiative on obstructive sleep apnea (INOSA) guidelines under the auspices of Department of Health Research, Ministry of Health and Family Welfare, Government of India. OSA is the occurrence of an average five or more episodes of obstructive respiratory events per hour of sleep with either sleep-related symptoms or co-morbidities or ≥15 such episodes without any sleep-related symptoms or co-morbidities. OSAS is defined as OSA associated with daytime symptoms, most often excessive sleepiness. Patients undergoing routine health check-up with snoring, daytime sleepiness, obesity, hypertension, motor vehicular accidents, and high-risk cases should undergo a comprehensive sleep evaluation. Medical examiners evaluating drivers, air pilots, railway drivers, and heavy machinery workers should be educated about OSA and should comprehensively evaluate applicants for OSA. Those suspected to have OSA on comprehensive sleep evaluation should be referred for a sleep study. Supervised overnight polysomnography is the “gold standard” for evaluation of OSA. Positive airway pressure (PAP) therapy is the mainstay of treatment of OSA. Oral appliances (OA) are indicated for use in patients with mild to moderate OSA who prefer OA to PAP, or who do not respond to PAP or who fail treatment attempts with PAP or behavioral measures. Surgical treatment is recommended in patients who have failed or are intolerant to PAP therapy.

On the cutting edge of obstructive sleep apnoea: where next?

Obstructive sleep apnoea is a common disease that is now more widely recognised because of the rise in prevalence and the increasingly compelling data that shows major neurocognitive and cardiovascular sequelae. At the same time, the clinical practice of sleep medicine is changing rapidly, with novel diagnostics and treatments that have established a home-based (rather than laboratory-based) management approach. We review the most recent insights and discoveries in obstructive sleep apnoea, with a focus on diagnostics and therapeutics. As will be discussed, management of obstructive sleep apnoea could soon transition from a so-called one size fits all approach to an individualised approach.

Noninvasive ventilation in acute respiratory failure

After the institution of positive-pressure ventilation, the use of noninvasive ventilation (NIV) through an interface substantially increased. The first technique was continuous positive airway pressure; but, after the introduction of pressure support ventilation at the end of the 20th century, this became the main modality. Both techniques, and some others that have been recently introduced and which integrate some technological innovations, have extensively demonstrated a faster improvement of acute respiratory failure in different patient populations, avoiding endotracheal intubation and facilitating the release of conventional invasive mechanical ventilation. In acute settings, NIV is currently the first-line treatment for moderate-to-severe chronic obstructive pulmonary disease exacerbation as well as for acute cardiogenic pulmonary edema and should be considered in immunocompromised patients with acute respiratory insufficiency, in difficult weaning, and in the prevention of postextubation failure. Alternatively, it can also be used in the postoperative period and in cases of pneumonia and asthma or as a palliative treatment. NIV is currently used in a wide range of acute settings, such as critical care and emergency departments, hospital wards, palliative or pediatric units, and in pre-hospital care. It is also used as a home care therapy in patients with chronic pulmonary or sleep disorders. The appropriate selection of patients and the adaptation to the technique are the keys to success. This review essentially analyzes the evidence of benefits of NIV in different populations with acute respiratory failure and describes the main modalities, new devices, and some practical aspects of the use of this technique.

Home ventilation therapy in obstructive sleep apnea-hypopnea syndrome

Obstructive sleep apnea-hypopnea is a highly prevalent disease that is often underdiagnosed at present. It has a significant economic and social welfare impact, accounting for a large part of the resources assigned to home respiratory therapies. As part of the 2014 SEPAR Year of the Chronic Patient and Domiciliary Respiratory Care sponsored by the Spanish Society of Pulmonology and Thoracic Surgery, this article reviews the most recent publications on the indications and controversial issues in the treatment of sleep apnea, the latest evidence for indication of various positive pressure devices, and adjustment modes, ranging from the use of empirical formulae or mathematical estimations to modern auto-CPAP equipment, while not forgetting the gold standard of manual titration. Emphasis is placed on the need for monitoring required by patients to ensure treatment adherence and compliance. Finally, other therapies that are not the object of this article are briefly reviewed.

Improvements in current treatments and emerging therapies for adult obstructive sleep apnea

Obstructive sleep apnea (OSA) is common and is associated with a number of adverse outcomes, including an increased risk for cardiovascular disease. Typical treatment approaches, including positive airway pressure, oral appliances, various upper airway surgeries, and/or weight loss, can improve symptoms and reduce the severity of disease in select patient groups. However, these approaches have several potential limitations, including suboptimal adherence, lack of suitability for all patient groups, and/or absence of adequate outcomes data. Emerging potential therapeutic options, including nasal expiratory positive airway pressure (PAP), oral negative pressure, upper airway muscle stimulation, and bariatric surgery, as well as improvements in existing treatments and the utilization of improving technologies are moving the field forward and should offer effective therapies to a wider group of patients with OSA.

Flexible positive airway pressure improves treatment adherence compared with auto-adjusting PAP

STUDY OBJECTIVES

There are no clinical data comparing adherence and quality of life between auto-adjusting positive airway pressure (APAP) and two different flex positive airway pressure (PAP) devices (A-Flex, C-Flex) in patients with obstructive sleep apnea (OSA).

DESIGN AND SETTING

Ninety-three patients in whom OSA was newly diagnosed were randomly assigned to receive 3 mo of APAP (n = 31), APAP with C-Flex (n = 31), or APAP with A-Flex (n = 31). Objective adherence was determined after 3 mo of CPAP treatment, and the Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI), and Calgary Sleep Apnea Quality of Life Index (SAQLI) were examined at baseline and after 3 mo. After 3 mo, patients in the APAP with A-Flex group and those in the APAP with C-Flex group were crossed over and those in the APAP group were switched to A-Flex for an additional 3 mo.

MEASUREMENTS AND RESULTS

The groups were similar demographically. Treatment adherence during the first 3 mo was significantly greater in the APAP with C-Flex group (APAP with C-Flex: 5.19 ± 1.84 h/night versus APAP: 3.96 ± 1.66 h/night versus APAP with A-Flex: 4.27 ± 2.12 h/night, P = 0.04). There was a significant improvement in two of four of the SAQLI domain scores and in the ESS and PSQI in the APAP with C-Flex group. Adherence significantly improved among the poor compliers (< 4 h/night of use) in the APAP group after change to APAP with A-Flex (P = 0.01).

CONCLUSIONS

Of these three modes of PAP delivery, adherence was greatest with APAP with C-Flex.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00873977.

A randomized crossover trial of the effect of a novel method of pressure control (SensAwake) in automatic continuous positive airway pressure therapy to treat sleep disordered breathing

OBJECTIVES

To study the acute effect of the new SensAwake CPAP modality (reducing pressure on awakenings) on wake after sleep onset (WASO) and other polysomnographic measures in patients with obstructive sleep apnea (OSA).

STUDY DESIGN

Randomized crossover trial comparing an automatic continuous positive airway pressure device (AutoCPAP) with and without SensAwake on sleep architecture. CPAP naive patients received each therapy for a single night in the laboratory with at least 1-week washout. Both patients' and technicians' subjective satisfaction was assessed. Pressure data measured and stored by the AutoCPAP device were also analyzed.

RESULTS

OSA was controlled adequately by both modes (SensAwake ON apnea hypopnea index ± SD, AHI = 5.3 ± 5.6/h vs. SensAwake OFF = 5.4 ± 5.8, p = 0.9) in the 42 patients who completed the protocol. Mean and 90% pressures were significantly lower with SensAwake (mean ON = 6.9 ± 1.9 vs. OFF = 7.7 ± 2.5 cm H(2)O, p < 0.05; 90% pressure ON = 9.6 ± 2.7 vs. OFF = 10.6 ± 2.7 cm H(2)O, p < 0.02). SensAwake did not improve WASO (ON = 74 ± 54 min vs. OFF = 78 ± 51 min, p = 0.6). There were no differences in other sleep architecture measures or patient satisfaction between the 2 modalities. AutoCPAP-measured AHI closely approximated PSG-derived (ROC AUC = 0.81 [95% CI 0.71-0.92], p = 0.0001).

CONCLUSIONS

SensAwake provides similar control of the AHI to the standard AutoCPAP mode but does so at lower mean and 90% pressures. However, no measure of sleep architecture was significantly improved by the SensAwake mode during this initial acute exposure. The internal AutoCPAP AHI detection and calculation was similar to PSG-derived AHI measures. Longer term studies are needed to evaluate any long-term influence of SensAwake on WASO.