Positive airway pressure initiation: a randomized controlled trial to assess the impact of therapy mode and titration process on efficacy, adherence, and outcomes

Factors Affecting Long-Term Compliance of CPAP Treatment-A Single Centre Experience

Continuous positive airway pressure (CPAP) has been the standard treatment of obstructive sleep apnoea/hypopnoea syndrome (OSA) for almost four decades. Though usually effective, this treatment suffers from poor long-term compliance. Therefore, the aim of our one centre retrospective study was to assess factors responsible for treatment failure and long-term compliance. Four hundred subsequent patients diagnosed with OSA and qualified for CPAP treatment were chosen from our database and compliance data were obtained from medical charts. Many differing factors kept patients from starting CPAP or led to termination of treatment. Overall, almost half of patients ended treatment during the mean time of observation of 3.5 years. Survival analysis revealed that 25% of patients failed at a median time of 38.2 months. From several demographic and clinical covariates in Cox’s hazard model, only the presence of a mild OSA, i.e., AHI (apnoea/hypopnoea index) below 15/h was a factor strongly associated with long term CPAP failure. The compliance results of our study are in line with numerous studies addressing this issue. Contrary to them, some demographic or clinical variables that we used in our survival model were not related to CPAP adherence.

Transition from APAP to CPAP may be a cost-effective health intervention in OSA patients

OBJECTIVE

Obstructive sleep apnea (OSA) is a common disorder associated with a significant economic burden. Continuous positive airway pressure (CPAP) and auto-titrating positive airway pressure (APAP) are recognized therapeutic options in patients with OSA, although treatment costs are higher with APAP. We conducted a study aimed at evaluating the effectiveness and potential cost savings resulting from the implementation of a protocol guiding the transition to CPAP in OSA patients previously treated with APAP.

METHODS

This prospective study included patients with OSA under APAP who were followed up at the Sleep Medicine outpatient clinic of a tertiary referral hospital between January 2019 and January 2021. Treatment was switched to CPAP in patients who met the following criteria: satisfactory adaptation and adherence to APAP, residual apnea-hypopnea index (AHI) of < 5/hour, and no relevant air leaks. APAP and CPAP outcomes were compared and an estimate of the savings obtained by the transition from APAP to CPAP was calculated.

RESULTS

Ninety-three patients were included in the study. APAP and CPAP were both effective in correcting obstructive events and improving daytime sleepiness. No significant differences were found regarding treatment adherence and tolerance between both PAP modalities. The selection of fixed-pressure CPAP through 90th or 95th percentile APAP pressure proved to be effective and an alternative strategy to titration polysomnography. At the end of this two-year study, the transition from APAP to CPAP enabled savings of at least 10,353€.

CONCLUSION

The transition from APAP to CPAP may be an effective, well-tolerated, safe, and cost-saving strategy in patients with OSA.

PAP Adherence and Nasal Resistance. A Randomized Controlled Trial of CPAPflex versus CPAP in World Trade Center Responders

Rationale: Continuous positive airway pressure (CPAP) adherence is often poor in obstructive sleep apnea (OSA) and may be influenced by nasal resistance. CPAP with a reduction of expiratory pressure (CPAPflex) may reduce discomfort in those with high nasal resistance and improve adherence in this subgroup.Objectives: To evaluate the association of positive airway pressure (PAP) treatment adherence to nasal resistance and examine if CPAPflex improves adherence over CPAP in subjects with high nasal resistance.Methods: A randomized double-blind crossover trial of 4 weeks each of CPAPflex versus CPAP in subjects exposed to World Trade Center dust with OSA stratified by nasal resistance, measured by 4-Phase Rhinomanometry.Results: Three hundred seventeen subjects with OSA (mean, apnea-hypopnea index with 4% O₂ desaturation for hypopnea = 17 ± 14/h) were randomized. Overall, PAP adherence was poor, but adherence to CPAP (n = 239; mean hours per night [95% confidence interval (CI)]), 1.97 h (1.68 to 2.26) was greater than adherence to CPAPflex (n = 249; 1.65 h [1.39 to 1.91]; difference of 0.31 h [0.03; 0.6]; P < 0.05). Contrary to our hypothesis there was no correlation between nasal resistance and adherence to CPAP (r = 0.098; P = not significant) or CPAPflex (r = 0.056; P = not significant). There was no difference in adherence between CPAP and CPAPflex (mean Δ hours [95% CI]) in subjects with low resistance (0.33 h [-0.10 to 0.76]) or high nasal resistance (0.26 h [-0.14 to 0.66]). No significant differences were observed in any of the secondary outcomes between PAP modes.Conclusions: Contrary to expectations, our data do not show better adherence to CPAPflex than to CPAP in subjects with high or low nasal resistance and do show clinically insignificant better adherence overall with CPAP.Clinical trial registered with www.clinicaltrials.gov (NCT01753999).

Effect of cloud-based sleep coaches on positive airway pressure adherence

STUDY OBJECTIVES

Decreased early positive airway pressure (PAP) adherence is predictive of poor long-term adherence. We hypothesized that cloud-based sleep coaches (CBSC) providing protocol-driven live telephone contact with patients starting treatment would improve early adherence.

METHODS

At PAP set-up patients were randomized to: (1) standard care (SC) including respiratory therapist PAP setup, wireless adherence monitoring, and elective use of a mobile adherence feedback application (PAPapp); or (2) SC+CBSC. Primary 3-month endpoints were adherence (all nights, nights used, % of nights ≥ 4 hours use, and % participants with ≥ 4 hours use on ≥ 70% of nights [% ≥ 4 ≥ 70%]) and secondary endpoints were change in Epworth sleepiness scale (ESS) and satisfaction with treatment and PAPapp use.

RESULTS

Two hundred fifty participants were randomized (SC 126, SC+CBSC 124). Characteristics SC versus SC+CBSC (mean ± SD) for age (55.2 ± 13.4 versus 54.9 ± 11.5 years), diagnostic apnea-hypopnea index (36.7 ± 21.1 versus 36.6 ± 20.6 events/h), and ESS (10.8 ± 6.1 versus 11.2 ± 6.0) did not differ. At 3 months, the % of days with ≥ 4 hours of PAP use (SC: 48.1 ± 36.8% versus SC+CBSC: 57.9 ± 35.4%, P = 0.032), use all nights (SC:3.7 ± 2.7 hours versus SC + CBSC: 4.4 ± 2.6 hours, P=0.027), and PAPapp use satisfaction were greater with SC+CBSC (intention to treat analysis). The [% ≥ 4 ≥ 70%] did not differ between groups in the intention to treat analysis but was higher in those completing CBSC interventions. The ESS improvement and patient satisfaction did not differ between groups.

CONCLUSIONS

The CBSC system improved PAP adherence at 3 months.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Title: ThErapy Adherence Management in Veterans; Identifier: NCT03243487; URL: https://clinicaltrials.gov/ct2/show/NCT03243487.

The efficacy of different treatment approaches for pediatric OSAHS patients with mandibular retrognathia: study protocol for a multicenter randomized controlled trial

Background

Pediatric obstructive sleep apnea/hypopnea syndrome (OSAHS) is a multifactorial syndrome caused by many risk factors, such as craniofacial anomalies, adenotonsillar hypertrophy, obesity, and airway inflammation. Although new treatment patterns have recently been proposed, treatment methods for children remain particularly challenging and controversial. This randomized controlled trial was designed to investigate the efficacy of adenotonsillectomy and/or orthodontic treatment for children who have mild OSAHS with mandibular retrognathia.

Methods

A sample of 352 children with mild OSAHS and mandibular retrognathia, who are aged between 7 and 10 years, will be enrolled in the study. They will be randomized into four groups: the drug treatment group, the surgical treatment group, the orthodontic treatment group, or the surgery and postoperative orthodontic group. After randomization the children will receive treatments within 4 weeks. Outcome assessment will take place at the following points: (1) baseline, (2) 7 months after the treatment starting point, (3) 12 months after the treatment starting point, and (4) 24 months after the treatment starting point. The primary endpoint of the trial is the mean change in obstructive apnea/hypopnea index. Other endpoints will consist of the lowest oxygen saturation, apnea index, and hypopnea index assessed by polysomnography, subjective symptoms (assessed by the OSA-20 questionnaire), cephalometric measurements, and morphologic analysis of the upper airway.

Discussion

The results of this study will provide valuable evidence for the merits and long-term efficacy of different treatment approaches and contribute to facilitating the multidisciplinary treatment of pediatric OSAHS.

Trial registration

ClinicalTrials.gov: NCT03451318. Registered on 2 March 2018 (last update posted 19 April 2018).

Educational, supportive and behavioural interventions to improve usage of continuous positive airway pressure machines in adults with obstructive sleep apnoea

BACKGROUND

Although highly effective in the treatment of obstructive sleep apnoea (OSA), continuous positive airway pressure (CPAP) is not universally accepted by users. Educational, supportive and behavioural interventions may help people with OSA initiate and maintain regular and continued use of CPAP.

OBJECTIVES

To assess the effectiveness of educational, supportive, behavioural, or mixed (combination of two or more intervention types) strategies that aim to encourage adults who have been prescribed CPAP to use their devices.

SEARCH METHODS

Searches were conducted on the Cochrane Airways Group Specialised Register of trials. Searches are current to 29 April 2019.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that assessed intervention(s) designed to inform participants about CPAP/OSA, to support them in using CPAP, or to modify their behaviour to increase use of CPAP devices.

DATA COLLECTION AND ANALYSIS

We assessed studies to determine their suitability for inclusion in the review. Data were extracted independently and were entered into RevMan for analysis. 'Risk of bias' assessments were performed, using the updated 'Risk of bias 2' tool, for the primary outcome, CPAP usage. Study-level 'Risk of bias' assessments were performed using the original 'Risk of bias' tool. GRADE assessment was performed using GRADEpro.

MAIN RESULTS

Forty-one studies (9005 participants) are included in this review; 16 of these studies are newly identified with updated searches. Baseline Epworth Sleepiness Scale (ESS) scores indicate that most participants suffered from excessive daytime sleepiness. The majority of recruited participants had not used CPAP previously. When examining risk of bias for the primary outcome of hourly machine usage/night, 58.3% studies have high overall risk (24/41 studies), 39.0% have some concerns (16/41 studies), and 2.4% have low overall risk (1/41 studies). We are uncertain whether educational interventions improve device usage, as the certainty of evidence was assessed as very low. We were unable to perform meta-analyses for number of withdrawals and symptom scores due to high study heterogeneity. Supportive interventions probably increase device usage by 0.70 hours/night (95% confidence interval (CI) 0.36 to 1.05, N = 1426, 13 studies, moderate-certainty evidence), and low-certainty evidence indicates that the number of participants who used their devices ≥ 4 hours/night may increase from 601 to 717 per 1000 (odds ratio (OR), 1.68, 95% CI 1.08 to 2.60, N = 376, 2 studies). However, the number of withdrawals may also increase from 136 to 167 per 1000 (OR 1.27, 95% CI 0.97 to 1.66, N = 1702, 11 studies, low-certainty evidence). Participants may experience small improvements in symptoms (ESS score -0.32 points, 95% CI -1.19 to 0.56, N = 470, 5 studies, low-certainty evidence), and we are uncertain whether quality of life improves with supportive interventions, as the certainty of evidence was assessed as very low. When compared with usual care, behavioural interventions produce a clinically-meaningful increase in device usage by 1.31 hours/night (95% CI 0.95 to 1.66, N = 578, 8 studies, high-certainty evidence), probably increase the number of participants who used their machines ≥ 4 hours/night from 371 to 501 per 1000 (OR 1.70, 95% CI 1.20 to 2.41, N = 549, 6 studies, high-certainty evidence), and reduce the number of study withdrawals from 146 to 101 per 1000 (OR 0.66, 95% CI 0.44 to 0.98, N = 939, 10 studies, high-certainty evidence). Behavioural interventions may reduce symptoms (ESS score -2.42 points, 95% CI -4.27 to -0.57, N = 272, 5 studies, low-certainty evidence), but probably have no effect on quality of life (Functional Outcomes of Sleep Questionnaire (FOSQ), standardised mean difference (SMD) 0.00, 0.95% CI -0.26 to 0.26, N = 228, 3 studies, moderate-certainty evidence). We are uncertain whether behavioural interventions improve apnoea hypopnoea index (AHI), as the certainty of evidence was assessed as very low. We are uncertain if mixed interventions improve device usage, increase the number of participants using their machines ≥ 4 hours/night, reduce study withdrawals, improve quality of life, or reduce anxiety symptoms, as the certainty of evidence for these outcomes was assessed to be very low. Symptom scores via the ESS could not be measured due to considerable heterogeneity between studies.

AUTHORS' CONCLUSIONS

In CPAP-naïve people with OSA, high-certainty evidence indicates that behavioural interventions yield a clinically-significant increase in hourly device usage when compared with usual care. Moderate certainty evidence shows that supportive interventions increase usage modestly. Very low-certainty evidence shows that educational and mixed interventions may modestly increase CPAP usage. The impact of improved CPAP usage on daytime sleepiness, quality of life, and mood and anxiety scores remains unclear since these outcomes were not assessed in the majority of included studies. Studies addressing the choice of interventions that best match individual patient needs and therefore result in the most successful and cost-effective therapy are needed.

New physiological bench test reproducing nocturnal breathing pattern of patients with sleep disordered breathing

Previous studies have shown that Automatic Positive Airway Pressure devices display different behaviors when connected to a bench using theoretical respiratory cycle scripts. However, these scripts are limited and do not simulate physiological behavior during the night. Our aim was to develop a physiological bench that is able to simulate patient breathing airflow by integrating polygraph data. We developed an algorithm analyzing polygraph data and transformed this information into digital inputs required by the bench hardware to reproduce a patient breathing profile on bench. The inputs are respectively the simulated respiratory muscular effort pressure input for an artificial lung and the sealed chamber pressure to regulate the Starling resistor. We did simulations on our bench for a total of 8 hours and 59 minutes for a breathing profile from the demonstration recording of a Nox T3 Sleep Monitor. The simulation performance results showed that in terms of relative peak-valley amplitude of each breathing cycle, simulated bench airflow was biased by only 1.48% ± 6.80% compared to estimated polygraph nasal airflow for a total of 6,479 breathing cycles. For total respiratory cycle time, the average bias ± one standard deviation was 0.000 ± 0.288 seconds. For patient apnea events, our bench simulation had a sensitivity of 84.7% and a positive predictive value equal to 90.3%, considering 149 apneas detected both in polygraph nasal simulated bench airflows. Our new physiological bench would allow personalizing APAP device selection to each patient by taking into account individual characteristics of a sleep breathing profile.

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.

NightBalance Sleep Position Treatment Device Versus Auto-Adjusting Positive Airway Pressure for Treatment of Positional Obstructive Sleep Apnea

STUDY OBJECTIVES

Compare treatment efficacy and objective adherence between the NightBalance sleep position treatment (SPT) device and auto-adjusting positive airway pressure (APAP) in patients with exclusive positional obstructive sleep apnea (ePOSA) defined as a supine apnea-hypopnea index (sAHI) ≥ 2 times the nonsupine AHI (nsAHI) and a nsAHI < 10 events/h.

METHODS

This prospective multicenter randomized crossover trial enrolled treatment naive participants with ePOSA (AHI ≥ 15 events/h and nsAHI < 10 events/h) or (AHI > 10 and < 15 events/h with daytime sleepiness and nsAH < 5 events/h). Polysomnography and objective adherence determination (device data) were performed at the end of each 6-week treatment. Patient device preference was determined at the end of the study.

RESULTS

A total of 117 participants were randomized (58 SPT first, 59 APAP first). Of these, 112 started treatment with the second device (adherence cohort) and 110 completed the study (AHI cohort). The AHI on SPT was higher (mean ± standard deviation, 7.29 ± 6.8 versus 3.71 ± 5.1 events/h, P < .001). The mean AHI difference (SPT-APAP) was 3.58 events/h with a one sided 95% confidence interval upper bound of 4.96 events/h (< the prestudy noninferiority margin of 5 events/h). The average nightly adherence (all nights) was greater on SPT (345.3 ± 111.22 versus 286.98 ± 128.9 minutes, P < .0001). Participants found the SPT to be more comfortable and easier to use and 53% reported a preference for SPT assuming both devices were equally effective.

CONCLUSIONS

Treatment with SPT resulted in non-inferior treatment efficacy and greater adherence compared to APAP in ePOSA suggesting that SPT is an effective treatment for this group.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Title: The POSAtive Study: Study for the Treatment of Positional Obstructive Sleep Apnea; Identifier: NCT03061071; URL: https://clinicaltrials.gov/ct2/show/NCT03061071.

Treatment of Adult Obstructive Sleep Apnea With Positive Airway Pressure: An American Academy of Sleep Medicine Systematic Review, Meta-Analysis, and GRADE Assessment

INTRODUCTION

The purpose of this systematic review is to provide supporting evidence for the clinical practice guideline for the treatment of obstructive sleep apnea (OSA) in adults using positive airway pressure (PAP).

METHODS

The American Academy of Sleep Medicine commissioned a task force of experts in sleep medicine. A systematic review was conducted to identify studies that compared the use of PAP with no treatment as well as studies that compared different PAP modalities. Meta-analyses were performed to determine the clinical significance of using PAP in several modalities (ie, continuous PAP, auto-adjusting PAP, and bilevel PAP), to treat OSA in adults. In addition, meta-analyses were performed to determine the clinical significance of using an in-laboratory versus ambulatory strategy for the initiation of PAP, educational and behavioral interventions, telemonitoring, humidification, different mask interfaces, and flexible or modified pressure profile PAP in conjunction with PAP to treat OSA in adults. Finally, the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) process was used to assess the evidence for making recommendations.

RESULTS

The literature search resulted in 336 studies that met inclusion criteria; 184 studies provided data suitable for meta-analyses. The data demonstrated that PAP compared to no treatment results in a clinically significant reduction in disease severity, sleepiness, blood pressure, and motor vehicle accidents, and improvement in sleep-related quality of life in adults with OSA. In addition, the initiation of PAP in the home demonstrated equivalent effects on patient outcomes when compared to an in-laboratory titration approach. The data also demonstrated that the use of auto-adjusting or bilevel PAP did not result in clinically significant differences in patient outcomes compared with standard continuous PAP. Furthermore, data demonstrated a clinically significant improvement in PAP adherence with the use of educational, behavioral, troubleshooting, and telemonitoring interventions. Systematic reviews for specific PAP delivery method were also performed and suggested that nasal interfaces compared to oronasal interfaces have improved adherence and slightly greater reductions in OSA severity, heated humidification compared to no humidification reduces some continuous PAP-related side effects, and pressure profile PAP did not result in clinically significant differences in patient outcomes compared with standard continuous PAP.

Distance to Specialist Medical Care and Diagnosis of Obstructive Sleep Apnea in Rural Saskatchewan

Obstructive sleep apnea (OSA) is the most common sleep-disordered breathing condition. Patients with OSA symptoms are often not diagnosed clinically, which is a concern, given the health and safety risks associated with unmanaged OSA. The availability of fewer practicing medical specialists combined with longer travel distances to access health care services results in barriers to diagnosis and treatment in rural communities. This study aimed to (1) determine whether the proportion of adults reporting OSA symptoms in the absence of a sleep apnea diagnosis in rural populations varied by travel distance to specialist medical care and (2) assess whether any distance-related patterns were attributable to differences in the frequency of diagnosis among adults who likely required this specialist medical care. We used a cross-sectional epidemiologic study design, augmented by analysis of follow-up survey data. Our study base included adults who completed a 2010 baseline questionnaire for the Saskatchewan Rural Health Study. Follow-up occurred until 2015. 6525 adults from 3731 households constituted our sample. Statistical models used log-binomial regression. Rural adults who reported the largest travel distances (≥250 km) to specialist medical care were 1.17 (95% CI: 1.07, 1.29) times more likely to report OSA symptoms in the absence of a sleep apnea diagnosis than those who reported the smallest (<100 km; referent) distances. However, the proportion of sleep apnea diagnoses was low and unaffected by reported travel distance among adults who likely required this specialist medical care. Our findings suggest factors other than travel distance may be contributing to the low sleep apnea diagnostic rate. This remains important as undiagnosed and untreated OSA has serious implications on the health of people and populations, but effective treatments are available. Health care access barriers to the diagnosis and treatment of OSA require evaluation to inform health care planning and delivery.

The prevention of delirium in elderly with obstructive sleep apnea (PODESA) study: protocol for a multi-centre prospective randomized, controlled trial

Background

Delirium is a common problem that occurs in 5–50% of elderly individuals following surgery. Patients who develop delirium after surgery are at increased risk for serious complications. Recent studies suggest that patients with obstructive sleep apnea (OSA), a sleep disorder characterized by repeated episodes of complete or partial blockage of the upper airway – are at greater risk to develop delirium. OSA is more common in elderly individuals but is often undiagnosed. Identification and treatment of unrecognized OSA may reduce the incidence of postoperative delirium. However, few studies have investigated the effect of perioperative treatment of OSA to prevent postoperative delirium.

Methods

This multi-centre randomized controlled trial will enrol 634 elderly patients undergoing elective hip/knee replacement surgery. The study has been approved by the Research Ethics Boards of the three participating institutions. Patients will be screened with the STOP-Bang questionnaire. Those with a score of 3 or greater will have a portable home sleep study using the ApneaLink™ Air device. Patients identified to have OSA will be randomized to 1) Auto-titrating continuous positive airway pressure (APAP) applied during sleep for 72 h after surgery or until discharge if they are discharged before 72 h or 2) Control group – routine care, no APAP. All patients will be evaluated for delirium for 72 h after surgery or until discharge if they are discharged before 72 h. The primary outcome is the occurrence of delirium – assessed twice daily using the Confusion Assessment Method for 72 h or until discharge if the hospital stay is <72 h.

Discussion

Delirium is associated with increased morbidity and mortality, and higher healthcare costs. With the aging population, the incidence of postoperative delirium will likely increase as the number of elderly individuals undergoing surgery rises. The results of our study will be published in a peer-reviewed journal and presented at local and international medical conferences. Our study findings may lead to improved surgical outcomes, enhanced patient safety and reduced healthcare costs.

Trial registration

This study was retrospectively registered at clinicaltrials.gov NCT02954224 on November 3, 2016.

Identification of significant obstructive sleep apnoea in the obese patient: development of the novel DX-OSA score

BACKGROUND AND OBJECTIVES

There is a high prevalence of undiagnosed obstructive sleep apnoea (OSA) in obese surgical patients. We investigated the extent to which anthropometric measurements can be used to identify the presence of significant OSA (Apnoea/Hypopnoea Index (AHI) ≥ 20) in adult patients.

MATERIALS AND METHODS

We prospectively studied 1357 adult patients scheduled for elective laparoscopic bariatric surgery. Prior to surgery, body mass index (BMI), gender, neck circumference, STOP-Bang score, SpO₂, neck and trunk fat (by dual X-ray absorptiometry) were recorded. All patients with a STOP-Bang score ≥ 5 underwent polysomnography. Auto-titrated Positive Airway Pressure (APAP) therapy was instituted when AHI ≥ 20/h. Predictors of OSA were identified and their cut-off values determined.

RESULTS

In total, 1357 patients were screened; 345 patients underwent preoperative polysomnography; 190 had AHI ≥ 20/h and received APAP treatment. The novel Dual X-Ray-Obstructive Sleep Apnoea (DX-OSA) score was derived from the data. The score included 6 items: the STOP-Bang score, BMI, neck fat, trunk fat, baseline SpO₂, and Expiratory Reserve Volume (ERV), and its sensitivity, specificity, positive-predictive values, negative-predictive values, likelihood ratios, and post-test probabilities determined. At a cut-off of 3, the DX-OSA score had the same sensitivity as the STOP-bang score, but better specificity. The lowest likelihood ratio was found for STOP-Bang and the highest for the DX-OSA score (OSA probability > 83%).

CONCLUSION

The DX-OSA score may be useful for identifying obese patients with significant OSA who require CPAP (continuous positive airway pressure) treatment, and CPAP could be commenced without the need for polysomnography, therefore, without delaying surgery.

High-Flow, Heated, Humidified Air Via Nasal Cannula Treats CPAP-Intolerant Children With Obstructive Sleep Apnea

STUDY OBJECTIVES

Continuous positive airway pressure (CPAP) is effective but challenging for children with obstructive sleep apnea (OSA). High-flow air via open nasal cannula (HFNC) as treatment in children remains controversial. We report the efficacy of HFNC in children with OSA and CPAP intolerance, a titration protocol, and a discussion of potential mechanisms.

METHODS

Patients aged 1 to 18 years with OSA (defined by obstructive apnea-hypopnea index [OAHI] greater than 1 event/h) and CPAP intolerance were enrolled. Routine polysomnography data obtained during 1 night wearing HFNC was compared with diagnostic data by Wilcoxon rank-sum test.

RESULTS

Ten school-age subjects (representing all patients attempting HFNC at our institution to date) with varied medical conditions, moderate to severe OSA, and CPAP intolerance wore HFNC from 10 to 50 L/min of room air with oxygen supplementation if needed (room air alone for 6 of the 10). HFNC reduced median OAHI from 11.1 events/h (interquartile range 8.7-18.8 events/h) to 2.1 events/h (1.7-2.2 events/h; P = .002); increased oxyhemoglobin saturation (SpO₂) mean from 91.3% (89.6% to 93.5%) to 94.9% (92.4% to 96.0%; P < .002); increased SpO₂ nadir from 76.0% (67.3% to 82.3%) to 79.5% (77.2% to 86.0%; P = .032); decreased SpO₂ desaturation index from 19.2 events/h (12.7-25.8 events/h) to 6.4 events/h (4.7-10.7 events/h; P = .013); and reduced heart rate from 88 bpm (86-91 bpm) to 74 bpm (67-81 bpm; P = .004). Stratified analysis of the 6 subjects with only room air via HFNC, the OAHI, obstructive hypopnea index, and mean SpO₂ still demonstrated improvements (P = .031).

CONCLUSIONS

High-flow nasal cannula reduces respiratory events, improves oxygenation, reduces heart rate, and may be effective for CPAP intolerant children with moderate to severe OSA. Our data suggest HFNC warrants further study and consideration by payers as OSA therapy.

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.

Trends in CPAP adherence over twenty years of data collection: a flattened curve

BACKGROUND

Obstructive sleep apnea (OSA) is a common disorder, and continuous airway positive pressure (CPAP) is considered to be the gold standard of therapy. CPAP however is known to have problems with adherence, with many patients eventually abandoning the device. The purpose of this paper is to assess secular trends in CPAP adherence over the long term to see if there have been meaningful improvements in adherence in light of the multiple interventions proposed to do so.

METHODS

A comprehensive systematic literature review was conducted using the Medline-Ovid, Embase, and Pubmed databases, searching for data regarding CPAP adherence over a twenty year timeframe (1994-2015). Data was assessed for quality and then extracted. The main outcome measure was reported CPAP non-adherence. Secondary outcomes included changes in CPAP non-adherence when comparing short versus long-term, and changes in terms of behavioral counseling.

RESULTS

Eighty-two papers met study inclusion/exclusion criteria. The overall CPAP non-adherence rate based on a 7-h/night sleep time that was reported in studies conducted over the twenty year time frame was 34.1 %. There was no significant improvement over the time frame. Behavioral intervention improved adherence rates by ~1 h per night on average.

CONCLUSIONS

The rate of CPAP adherence remains persistently low over twenty years worth of reported data. No clinically significant improvement in CPAP adherence was seen even in recent years despite efforts toward behavioral intervention and patient coaching. This low rate of adherence is problematic, and calls into question the concept of CPAP as gold-standard of therapy for OSA.

Reconsidering first-line treatment for obstructive sleep apnea: a systematic review of the literature

BACKGROUND

Continuous positive airway pressure (CPAP) is typically recommended as first line therapy for obstructive sleep apnea, but the adherence rate of CPAP is problematic. This study's objective was to systematically review the literature relating to CPAP as first line therapy for OSA and compare it to surgical literature on the same topic.

METHODS

A systematic review was conducted according to PRISMA guidelines, examining Medline-Ovid, Embase, and Pubmed databases. The primary search objective was to identify all papers reporting the results of (1) randomized clinical trials (RCT) of CPAP for the treatment of adults with OSA; and (2) both randomized and non-randomized clinical trials and case series on the surgical treatment of OSA in adults. A PhD-level biostatistician first screened papers, and then those that met study criteria were retrieved and analyzed using standardized forms for each author. The primary outcomes were adherence rates of CPAP.

RESULTS

A total of 82 controlled clinical trials for CPAP and 69 controlled and non-controlled surgery trials were identified for analysis. Variation in CPAP use within reported RCT trials were identified, and the majority of patients in the studies would eventually be considered non-adherent to CPAP.

CONCLUSIONS

When considering the numerous patient-related factors that come into play when CPAP is prescribed, the concept of CPAP as gold-standard therapy for OSA should be reconsidered. In many cases surgery can provide a better overall outcome. This study's results suggest that certain patients with OSA may be managed more effectively with surgery than CPAP, without confounding issues of treatment adherence.

CPAP in the Perioperative Setting: Evidence of Support

OSA is a commonly encountered comorbid condition in surgical patients. The risk of cardiopulmonary complications is increased by two to threefold with OSA. Among the different treatment options for OSA, CPAP is an efficacious modality. This review examines the evidence regarding the use of CPAP in the preoperative and postoperative periods in surgical patients with diagnosed and undiagnosed OSA.

A comparison of CPAP and CPAPFLEX in the treatment of obstructive sleep apnea in World Trade Center responders: study protocol for a randomized controlled trial

Background

Following the World Trade Center disaster, a large number of individuals involved in rescue and recovery activity were exposed to significant amounts of dust, and reported symptoms of chronic nasal and sinus inflammation. An unusually high prevalence of obstructive sleep apnea (OSA) has also been observed in this World Trade Center Responder population. This project aims to examine the relationship between nasal pathology and OSA. Our hypothesis is that increased nasal resistance due to nasal inflammation predisposes to OSA in this population. Continuous Positive Airway Pressure (CPAP) is the standard therapy for OSA but despite its efficacy has poor adherence. Subjects with high nasal resistance may have greater difficulty in tolerating this therapy than those who do not have high nasal resistance. Reduction of excess expiratory positive pressure by the modality known as Cflex™ during Continuous Positive Airway Pressure therapy (CPAP_Flex) has been suggested to improve comfort without compromising efficacy. We will compare CPAP to CPAP_Flex in subjects with OSA.

Study Design

Subjects with new onset habitual snoring will be screened for OSA using home sleep studies and rhinomanometry will be used to determine nasal resistance. In 400 subjects with OSA we will perform a randomized double blind cross-over study comparing CPAP to CPAP_flex, and relate nasal resistance to adherence to CPAP therapy.

Discussion

This is the first multicenter trial designed to test the hypothesis that adherence to CPAP therapy relates to nasal resistance and CPAP_Flex will improve adherence to CPAP in those subjects with high nasal resistance.

We anticipate the following results from this trial: 1. Increased nasal resistance is associated with decreased adherence to CPAP therapy. 2. Use of CPAP_Flex improves adherence with CPAP therapy in subjects with high nasal resistance, but not in those with low nasal resistance. 3. The benefit of CPAP_Flex on adherence is greatest when offered at CPAP therapy initiation rather than as a “rescue” therapy in subjects with high nasal resistance.

Trial Registration

ClinicalTrials.gov Identifier: NCT01753999, Date: 12 December 2012

Clinical effectiveness and cost-effectiveness results from the randomised controlled Trial of Oral Mandibular Advancement Devices for Obstructive sleep apnoea-hypopnoea (TOMADO) and long-term economic analysis of oral devices and continuous positive airway pressure

BACKGROUND

Obstructive sleep apnoea-hypopnoea (OSAH) causes excessive daytime sleepiness (EDS), impairs quality of life (QoL) and increases cardiovascular disease and road traffic accident risks. Continuous positive airway pressure (CPAP) treatment is clinically effective but undermined by intolerance, and its cost-effectiveness is borderline in milder cases. Mandibular advancement devices (MADs) are another option, but evidence is lacking regarding their clinical effectiveness and cost-effectiveness in milder disease.

OBJECTIVES

(1) Conduct a randomised controlled trial (RCT) examining the clinical effectiveness and cost-effectiveness of MADs against no treatment in mild to moderate OSAH. (2) Update systematic reviews and an existing health economic decision model with data from the Trial of Oral Mandibular Advancement Devices for Obstructive sleep apnoea-hypopnoea (TOMADO) and newly published results to better inform long-term clinical effectiveness and cost-effectiveness of MADs and CPAP in mild to moderate OSAH.

TOMADO

A crossover RCT comparing clinical effectiveness and cost-effectiveness of three MADs: self-moulded [SleepPro 1™ (SP1); Meditas Ltd, Winchester, UK]; semibespoke [SleepPro 2™ (SP2); Meditas Ltd, Winchester, UK]; and fully bespoke [bespoke MAD (bMAD); NHS Oral-Maxillofacial Laboratory, Addenbrooke's Hospital, Cambridge, UK] against no treatment, in 90 adults with mild to moderate OSAH. All devices improved primary outcome [apnoea-hypopnoea index (AHI)] compared with no treatment: relative risk 0.74 [95% confidence interval (CI) 0.62 to 0.89] for SP1; relative risk 0.67 (95% CI 0.59 to 0.76) for SP2; and relative risk 0.64 (95% CI 0.55 to 0.76) for bMAD (p < 0.001). Differences between MADs were not significant. Sleepiness [as measured by the Epworth Sleepiness Scale (ESS)] was scored 1.51 [95% CI 0.73 to 2.29 (SP1)] to 2.37 [95% CI 1.53 to 3.22 (bMAD)] lower than no treatment (p < 0.001), with SP2 and bMAD significantly better than SP1. All MADs improved disease-specific QoL. Compliance was lower for SP1, which was unpopular at trial exit. At 4 weeks, all devices were cost-effective at £20,000/quality-adjusted life-year (QALY), with SP2 the best value below £39,800/QALY.

META-ANALYSIS

A MEDLINE, EMBASE and Science Citation Index search updating two existing systematic reviews (one from November 2006 and the other from June 2008) to August 2013 identified 77 RCTs in adult OSAH patients comparing MAD with conservative management (CM), MADs with CPAP or CPAP with CM. MADs and CPAP significantly improved AHI [MAD -9.3/hour (p < 0.001); CPAP -25.4/hour (p < 0.001)]. Effect difference between CPAP and MADs was 7.0/hour (p < 0.001), favouring CPAP. No trials compared CPAP with MADs in mild OSAH. MAD and CPAP reduced the ESS score similarly [MAD 1.6 (p < 0.001); CPAP 1.6 (p < 0.001)].

LONG-TERM COST-EFFECTIVENESS

An existing model assessed lifetime cost-utility of MAD and CPAP in mild to moderate OSAH, using the revised meta-analysis to update input values. The TOMADO provided utility estimates, mapping ESS score to European Quality of Life-5 Dimensions three-level version for device cost-utility. Using SP2 as the standard device, MADs produced higher mean costs and mean QALYs than CM [incremental cost-effectiveness ratio (ICER) £6687/QALY]. From a willingness to pay (WTP) of £15,367/QALY, CPAP is cost-effective, although the likelihood of MADs (p = 0.48) and CPAP (p = 0.49) being cost-effective is very similar. Both were better than CM, but there was much uncertainty in the choice between CPAP and MAD (at a WTP £20,000/QALY, the probability of being the most cost-effective was 47% for MAD and 52% for CPAP). When SP2 lifespan increased to 18 months, the ICER for CPAP compared with MAD became £44,066. The ICER for SP1 compared with CM was £1552, and for bMAD compared with CM the ICER was £13,836. The ICER for CPAP compared with SP1 was £89,182, but CPAP produced lower mean costs and higher mean QALYs than bMAD. Differential compliance rates for CPAP reduces cost-effectiveness so MADs become less costly and more clinically effective with CPAP compliance 90% of SP2.

CONCLUSIONS

Mandibular advancement devices are clinically effective and cost-effective in mild to moderate OSAH. A semi-bespoke MAD is the appropriate first choice in most patients in the short term. Future work should explore whether or not adjustable MADs give additional clinical and cost benefits. Further data on longer-term cardiovascular risk and its risk factors would reduce uncertainty in the health economic model and improve precision of effectiveness estimates.

TRIAL REGISTRATION

This trial is registered as ISRCTN02309506.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 18, No. 67. See the NIHR Journals Library website for further project information.

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.

Effect of addition of chin strap on PAP compliance, nightly duration of use, and other factors

STUDY OBJECTIVES

A chinstrap is potentially useful to reduce unintentional air leak by preventing mouth opening during PAP treatment. This study examines whether the addition of a chinstrap to PAP therapy has any effect on adherence, nightly duration of use, air leak, and residual AHI.

METHODS

This was a retrospective study performed at an AASM-accredited VAMC sleep center. Clinical sleep data of veterans (n = 124) prescribed PAP therapy for sleep apnea was evaluated, and the effect of chinstrap use vs non-use on the above parameters was assessed.

RESULTS

Chinstrap users had significantly greater PAP adherence, longer nightly duration of PAP use, lower residual AHI and lower leak compared to chinstrap non-users at first follow up visit.

CONCLUSIONS

The addition of a chin strap to PAP therapy is a simple and inexpensive method of increasing PAP adherence.

Sleep laboratory test referrals in Canada: sleep apnea rapid response survey

BACKGROUND

An estimated 5.4 million Canadian adults have been diagnosed with sleep apnea or are at high risk of experiencing obstructive sleep apnea (OSA). There are no recent Canadian data regarding access to and predictors of referral for diagnostic testing in these populations.

METHODS

The Sleep Apnea Rapid Response survey sampled 8647 Canadian adults and captured information about risk, testing, diagnosis and treatment of sleep apnea. Predictors of sleep laboratory test referrals were assessed using log-linked binomial regression modelling. Information regarding sleep testing facilities was updated at the provincial and regional levels.

RESULTS

Approximately 76.8% (95% CI 70.1% to 83.6%) of adult Canadians with sleep apnea and 5.1% (95% CI 3.4% to 6.7%) of those at high risk for OSA reported being referred to a sleep laboratory. Significant predictors of sleep laboratory referral in the general population were male sex, middle age, overweight or obese, a chronic condition, having a regular medical doctor and reporting symptoms of sleep apnea. Region of residence was also a predictor of reported sleep laboratory referral, with individuals from Ontario being more likely to report being referred to a sleep laboratory versus individuals from other regions.

CONCLUSION

Individuals reporting risk factors and symptoms associated with OSA were more likely to report a sleep laboratory testing referral compared with those without risk factors or symptoms. However, Canada's diagnostic sleep laboratory testing capacity varies across regions and is believed to be inadequate given the number of individuals at high risk for OSA who did not report testing referral.

A multicenter evaluation of oral pressure therapy for the treatment of obstructive sleep apnea

OBJECTIVE

We aimed to evaluate the impact of a novel noninvasive oral pressure therapy (OPT) (Winx®, ApniCure) system on polysomnographic measures of sleep-disordered breathing, sleep architecture, and sleep stability in obstructive sleep apnea (OSA).

SUBJECTS AND METHODS

A 4-week, multicenter, prospective, open-label, randomized, crossover, first-night order of control vs treatment, single-arm trial was conducted in five American Academy of Sleep Medicine (AASM) - accredited sleep clinics and one research laboratory. Sixty-three subjects (analysis cohort) were studied from a screening cohort of 367 subjects. The analysis cohort was 69.8% men, ages 53.6±8.9 years (mean±SD), body mass index of 32.3±4.5kg/m(2), with mild to severe OSA. At treatment initiation, subjects received random assignment to one night with and one without (control) treatment, and they were assessed again following 28 nights of treatment. Breathing and sleep architecture were assessed each night based on blind scoring by a single centralized scorer using AASM criteria.

RESULTS

Average nightly usage across the take-home period was 6.0±1.4h. There were no severe or serious device-related adverse events (AEs). Median apnea-hypopnea index (AHI) was 27.5 events per hour on the control night, 13.4 events per hour on the first treatment night, and 14.8 events per hour after 28days of treatment. A clinically significant response (treatment AHI ⩽10/h and ⩽50% of control values) was seen in 20 of the 63 subjects evaluated. Rapid eye movement percentage (REM%) was significantly increased, and N1%, stage shifts to N1 sleep, overall stage shifts, total awakenings, and arousals per hour were all significantly reduced at both treatment nights compared to controls. Mean Epworth sleepiness scale (ESS) was significantly reduced from 12.1 to 8.6 (Cohen d effect size, 0.68) in those untreated for two or more weeks prior to OPT study participation and remained unchanged in subjects who directly switched from continuous positive airway pressure (CPAP) therapy to OPT.

CONCLUSION

Clinically significant improvements in sleep quality and continuity, AHI, ODI, ESS, and overall clinical status were achieved in an easily identified subgroup. OPT was safe and well-tolerated and nightly usage was high.

Multinight recording and analysis of continuous positive airway pressure airflow in the home for titration and management of sleep disordered breathing

OBJECTIVES

The authors examined magnitude/variability of residual sleep disordered breathing (SDB) at pressures around the therapeutic continuous positive airway pressure (CPAP), and described a multinight approach to CPAP titration/retitration consisting of recording airflow and summarizing SDB over multiple nights at multiple pressures and choosing an optimal pressure from these summarized data.

DESIGN

Prospective, single-center nonblinded study.

PATIENTS

Ten female/18 male patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) (respiratory disturbance index [RDI] 67/h), 17 newly-initiated, 11 chronic CPAP users.

INTERVENTIONS

A custom CPAP device (Fisher & Paykel Healthcare) recording airflow and pre-programmed to vary CPAP between 2-3 cm H2O below and 1-2 cm H2O above prescription pressure as determined by a full laboratory titration.

RESULTS

Airflow and pressure continuously recorded for multiple nights (15.9 ± 5.1 nights) at four to seven different pressures in each patient. SDB events manually scored from the airflow as apnea (airflow reduction > 90%), hypopnea (airflow reduction > 30% lasting 10 to 120 sec with inspira-tory flow limitation [IFL]) and runs of sustained IFL > 2 min identified. RDI = (apnea + hypopnea)/total sleep time calculated for each night and an obstruction index, including sustained IFL, also was calculated. PressureMultinight was obtained for each patient from multiple nights of data using two mathematical techniques. Night-to-night variability of SDB indices was low in some patients and significant in others. PressureMultinight could be determined in 17 of 28 patients and was similar to the in-laboratory pressure.

CONCLUSIONS

This study showed that recording multiple nights of CPAP airflow in the home and analyzing these data for residual SDB provided useful information, including the possibility of determining a therapeutic prescription for fixed CPAP in most patients and identification of others with significant physiologic variability of SDB.

Effects of positive airway pressure treatment on clinical measures of hypertension and type 2 diabetes

PURPOSE

Mechanistic and observational studies support an independent increase in risk of hypertension and abnormal glucose metabolism associated with obstructive sleep apnea (OSA). However, the specific populations and outcomes that improve with treatment of OSA in clinical practice are not established. We examined the effectiveness of OSA treatment on clinical blood pressure and diabetes control measures in men with preexisting systemic hypertension or type 2 diabetes.

METHODS

A retrospective cohort of veterans (n = 221) with a new diagnosis of OSA and initiation of positive airway pressure treatment was identified using administrative databases and clinical records.

MEASUREMENTS AND RESULTS

Outcomes were changes in blood pressure (BP; mean of 3 highest recordings; systolic and diastolic) and glycemic control (mean of 3 highest fasting glucose and hemoglobinA1C values) at 3-6 months (T1) and 9-12 months (T2) following treatment compared to pretreatment. A generalized estimating equation model was used with adjustment for potential confounders: demographics, body mass index (BMI), OSA severity, Charlson comorbidity index, and pharmacologic treatment for hypertension and diabetes. Sustained independent effects of OSA treatment (mean change [95% CI]) were noted in both systolic BP (T1; -7.44 [-10.41 to -4.47] and T2; -6.81 [-9.94 to -3.67]) and diastolic BP (T1; -3.14, [-4.99 to -1.29] and T2; -3.69, [-5.53 to -1.85]). Diabetes control measures did not change with OSA treatment.

CONCLUSIONS

Treatment of OSA improves office blood pressure in hypertensive men. Prospective studies are necessary to better characterize specific populations with OSA that benefit from treatment with respect to progression of hypertension and type 2 diabetes.

Sleep quality, short-term and long-term CPAP adherence

STUDY OBJECTIVES

Adherence to CPAP therapy is low in patients with obstructive sleep apnea/hypopnea syndrome (OSAHS). The purpose of the present study was to evaluate the utility of measures of sleep architecture and sleep continuity on the CPAP titration study as predictors of both short- and long-term CPAP adherence.

METHODS

93 patients with OSAHS (RDI 42.8 ± 34.3/h) underwent in-laboratory diagnostic polysomnography, CPAP titration, and follow-up polysomnography (NPSG) on CPAP. Adherence to CPAP was objectively monitored. Short-term (ST) CPAP adherence was averaged over 14 days immediately following the titration study. Long-term (LT) CPAP adherence was obtained in 56/93 patients after approximately 2 months of CPAP use. Patients were grouped into CPAP adherence groups for ST (< 2 h, 2-4 h, and > 4 h) and LT adherence (< 4 h, > 4 h). Sleep architecture, sleep disordered breathing (SDB) indices, and daytime outcome variables from the diagnostic and titration NPSGs were compared between CPAP adherence groups.

RESULTS

There was a significant relationship between ST and LT CPAP adherence (r = 0.81, p < 0.001). Neither ST nor LT adherence were related to demographic variables, baseline severity of untreated SDB, sleep architecture, or measures of daytime impairment. Good CPAP adherence groups had significantly lower %N2 and greater %REM on the titration NPSG. A model combining change in sleep efficiency and change in sleep continuity between the diagnostic and titration NPSGs predicted 17% of the variance in LT adherence (p = 0.006).

CONCLUSIONS

These findings demonstrate that characteristics of sleep architecture, even on the titration NPSG, may predict some of the variance in CPAP adherence. Better sleep quality on the titration night was related to better CPAP adherence, suggesting that interventions to improve sleep on/prior to the CPAP titration study might be used as a therapeutic intervention to improve CPAP adherence.

Respiratory event detection by a positive airway pressure device

STUDY OBJECTIVES

Compare automatic event detection (AED) of respiratory events using a positive airway pressure (PAP) device with manual scoring of polysomnography (PSG) during PAP treatment of obstructive sleep apnea (OSA).

DESIGN

Prospective PSGs of patients using a PAP device.

SETTING

Six academic and private sleep disorders centers.

PATIENTS

A total of 148 PSGs from 115 participants with OSA (apnea-hypopnea index [AHI] ≥ 15 events/hr) were analyzed.

INTERVENTIONS

A signal generated by the PAP device identifying the AED of respiratory events based on airflow was recorded during PSG.

MEASUREMENTS AND RESULTS

The PSGs were manually scored without visualization of the AED signal and scoring of a hypopnea required a ≥ 4% oxygen desaturation. The apnea index (AI), hypopnea index (HI), and AHI by manual score and PAP AED were compared. A customized computer program compared individual events by manual scoring and AED to determine the true positive, false positive, false negative, or true negative events and found a sensitivity of 0.58 and a specificity of 0.98. The AHI, AI, and HI by the two methods were highly correlated. Bland-Altman analysis showed better agreement for AI than HI. Using a manually scored AHI of ≥ 10 events/hr to denote inadequate treatment, an AED AHI ≥ 10 events/hr had a sensitivity of 0.58 and a specificity of 0.94.

CONCLUSIONS

An AHI < 10 events/hr by PAP AED is usually associated with good treatment efficacy. Differences between manually scored and AED events were primarily due to different criteria for hypopnea detection.