Compliance with positive airway pressure treatment for obstructive sleep apnea

Sleep time on back as a predictor of adherence to positive airway pressure therapy

Upper airway collapse can be effectively dealt with positive airway pressure (PAP), and patient adherence is considered as a major determining factor for success of PAP therapy. This study was performed to determine the potential factors affecting the adherence to PAP in patients with OSA by using polysomnography (PSG) parameters recorded for diagnosis of OSA. The data of 158 patients between December 2018 and July 2021 were collected. They were prescribed with PAP and used the device during the adaptation period for 90 days. They were categorized into adherent and non-adherent group according to the criteria of good adherence as use of PAP ≥ 4 h per night on 70% of nights. Demographic, clinical characteristics, and PSG results were reviewed. Among 158 patients engaged in PAP therapy, 121 patients (76.6%) met the criteria of good adherence. No significant differences were found in good adherence rate regarding demographic and clinical characteristics. None of the polysomnographic factors showed significant differences between adherent and non-adherent groups. However, the percentage of sleep time on back in the adherent group was significantly higher than non-adherent group (p = 0.041). The cut-off value was determined to be 41.45% (95% confidence interval 0.43 to 0.79) by receiver operating characteristic curve analysis and the odds ratio was calculated as 2.97. Only the percentage of sleep time on back appeared to be polysomnographic predictor for identifying good adherence to PAP therapy in OSA patients. However, the conclusions may be limited in generalization due to the small sample size.

Craniofacial Phenotype in Obstructive Sleep Apnea and Its Impact on Positive Airway Pressure (PAP) Adherence

Positive airway pressure (PAP) is an important treatment tool for patients with moderate and severe obstructive sleep apnea (OSA), and adherence to PAP significantly affects treatment outcomes. Disease severity, adverse effects, and psychosocial factors are known to predict medication adherence. Cephalometric parameters have been reported to positively correlate with upper airway collapse. However, research on the correlation between these cephalometric parameters and PAP adherence remains insufficient. This study aimed to identify this relationship. This study included 185 patients with OSA who were prescribed PAP. Polysomnography (PSG) was performed to diagnose OSA, and paranasal sinus computed tomography (PNS CT) was performed to check for comorbidities of the upper airway. In addition, cephalometric parameters such as the hyoid-posterior nasal spine (H-PNS), posterior nasal spine-mandibular plane (PNS-MP), and hyoid-mandibular plane (H-MP) were measured in the midsagittal and axial CT views. Adherence was evaluated 3-12 months after the PAP prescription. A total of 136 patients were PAP-adherent, and 49 were nonadherent. There were more males in the adherent group and a higher average height in the adherent group. The PSG results showed that the apnea-hypopnea index (AHI), respiratory disturbance index (RDI), oxygen desaturation index (ODI), arousal index (AI), rapid eye movement (REM) AHI, and supine AHI were significantly higher, and the lowest oxygen saturation was lower in the adherent group. In the analysis of covariance (ANCOVA) model adjusted for sex and height, among the cephalometric parameters, H-MP was significantly longer in the adherent group (p = 0.027), and H-PNS showed a longer tendency (p = 0.074). In the logistic regression analysis model, the odds ratio (OR) and 95% confidence intervals (95% CI) of adherence and severe OSA in the third tertile compared to the first tertile of H-MP were 2.93 (1.25-6.86) and 4.00 (1.87-8.56). In the case of H-PNS, they were 2.58 (1.14-5.81) and 4.86 (2.24-10.54), respectively. This study concluded that an inferiorly placed hyoid bone in adult patients is associated with PAP adherence and disease severity.

Compliance After Re-Prescription for Positive Airway Pressure in Obstructive Sleep Apnea Patients Who Failed Positive Airway Pressure Therapy

Background and Objectives: Little is known about studies evaluating positive airway pressure (PAP) compliance after re-prescription. Therefore, the aim of this study was to investigate PAP compliance after re-prescription in obstructive sleep apnea (OSA) patients who failed initial PAP therapy.Methods: We retrospectively reviewed OSA patients who had received a re-prescription for PAP from March 2020 to June 2021. We compared the compliance rate between initial prescription and re-prescription for PAP and investigated the reasons for PAP failure after the first prescription.Results: A total of 10 consecutive OSA patients (mean age=45.6±13.7 years and male:female=8:2) who received a re-prescription for PAP were included. Of them, 8 patients (80%) met the compliance criteria (i.e., Korean National Health Insurance criteria) for PAP after re-prescription. The compliance rate increased from 36.3±18.2% (initial prescription) to 61.3±28.8% (re-prescription); this was not of statistical significance (p=0.074). PAP/mask-related discomfort was the most common reason for PAP failure, followed by nasal obstruction, unintentional mask removal, and pressure-related discomfort.Conclusion: Even if initial PAP therapy fails, the proportion of patients who meet the compliance criteria may be improved through various forms of clinical aid and support after re-prescription of PAP.

Titration studies overestimate continuous positive airway pressure requirements in uncomplicated obstructive sleep apnea

STUDY OBJECTIVES

Attended manual CPAP titration is the standard practice for determining optimal positive airway pressures for OSA treatment. However, an unattended single night auto-titrating positive airway pressure (APAP) titration is an alternative. The goal of this study was to determine whether therapeutic CPAP pressures determined during manual titrations are higher than APAP generated surrogate pressures.

METHODS

We conducted a retrospective review of 165 adults with uncomplicated OSA who had full/split-night manual CPAP titrations prior to commencing treatment with APAP. Demographic and clinical data including 30-day APAP compliance data were obtained. We compared the recommended CPAP pressure from manual titrations with the 90th/95th percentile pressure generated from APAP usage over 30 days.

RESULTS

The recommended CPAP pressures during the manual titrations were higher than the 90th/95th percentile pressures generated from APAP. (11.4 ± 3.4 vs. 10.3 ± 2.4, p=0.000). Almost half the group (41.9%) had their manually derived titration pressure at least 1.5 cm above the 90th/95th percentile pressure. In multivariate analyses, BMI was the only variable that predicted higher manual titration pressures. Notably, the average residual AHI on 30-day APAP data was less than the average residual AHI observed at the recommended pressure during the manual titration (5.0 ± 4.3 vs. 7.2 ± 8.5, p= 0.006).

CONCLUSIONS

Manual CPAP titrations may overestimate pressure requirements particularly in patients with higher BMI and may not be necessary in managing patients with uncomplicated OSA. APAP appears to be at least as effective as single pressure CPAP, while delivering lower positive airway pressure.

Obstructive sleep apnoea and adherence to continuous positive airway therapy among Australian women

BACKGROUND

Clinical characteristics of women with different obstructive sleep apnoea (OSA) severity and adherence to Continuous Positive Airway Pressure (CPAP) therapy have not been previously explored. Therefore, in this retrospective study we assessed OSA prevalence. predictors, clinical and polysomnographic (PSG) characteristics and adherence to CPAP therapy among adult Australian women.

METHODS

All female patients who underwent a diagnostic PSG between 2014/2015 were included. CPAP adherence was assessed during the study period between 2018/2019 using multiple regression model.

RESULTS

Among a total of 591 females included in this study (Aboriginal n=86), OSA was diagnosed in 458/591 (78%) patients; mild, moderate and severe OSA was present in 44%, 27% and 29% respectively. Older age, higher BMI and hypertension predicted the presence and severity of OSA. The Epworth Sleepiness Scale (ESS) score was not significantly different with [10 (5, 13)] or without [8 (5, 12)] OSA. PSG showed rapid eye movement (REM) sleep associated apnoea hypopnea index (AHI) was higher with all severity of OSA. Adherence to CPAP therapy was noted in 171 (57%) patients; 47% mild, 57% moderate and 63% with severe OSA respectively. Three multiple regression models [clinical, PSG parameters, OSA severity, combined (clinical and PSG)] showed combined model had strongest predictive value and demonstrated that higher ESS and more severe oxygen desaturation were associated with CPAP adherence irrespective of OSA severity.

CONCLUSION

Older age, higher BMI and presence of hypertension predicted the presence of OSA. REM sleep related AHI was higher. Adherence to CPAP was associated with symptomatic OSA and severe oxygen desaturation. This article is protected by copyright. All rights reserved.

Maxillomandibular Advancement and Upper Airway Stimulation: Extrapharyngeal Surgery for Obstructive Sleep Apnea

There are many ways to categorize surgery for obstructive sleep apnea (OSA), one of which is to distinguish between intrapharyngeal and extrapharyngeal procedures. While the general otolaryngologist treating OSA is familiar with intrapharyngeal procedures, such as uvulopalatopharyngoplasty and tongue base reduction, extrapharyngeal sleep operations such as maxillomandibular advancement (MMA) and upper airway stimulation (UAS) have evolved rapidly in the recent decade and deserve a dedicated review. MMA and UAS have both shown predictable high success rates with low morbidity. Each approach has unique strengths and limitations, and for the most complex of OSA patients, the two in combination complement each other. Extrapharyngeal airway operations are critical for achieving favorable outcomes for sleep surgeons.

The use of oral appliances in obstructive sleep apnea: a retrospective cohort study spanning 14 years of private practice experience

PURPOSE

In 2005, the American Academy of Sleep Medicine stated, "Oral appliances are indicated for use in patients with mild to moderate obstructive sleep apnea (OSA) who prefer them to CPAP therapy, or who do not respond to, are not appropriate candidates for, or who fail treatment attempts with CPAP." However, this recommendation is based upon variable results from only six studies with more than 100 participants. These studies have assessed the effectiveness of mandibular advancement devices (MADs) in specific groups (military populations, academic institutions, or hospital settings) with no large study conducted in a fee-for-service private practice where the majority of patients receive MADs for OSA. The purpose of this study is to report outcomes of a board-certified dental sleep practitioner managing mild, moderate, and severe OSA using customized titratable MADs. We hypothesize that patients will demonstrate a significant reduction in apnea-hypopnea index (AHI) scores after adjusting their customized titratable MADs.

METHODS

This is a 14-year retrospective study design with pre- and post-treatment sleep studies. An AHI score < 10 respiratory events per hour with therapy is defined as treatment success. This study was performed by a single private practitioner.

RESULTS

Of 2419 patient records analyzed, 544 (22%) had pre- and post-treatment sleep studies (89% polysomnograms). Of 510 patients with complete data, 459 (90%) revealed a decrease in AHI score < 10 respiratory events per hour indicating treatment success. Only 51 of these patients (10%) had a final AHI ≥ 10 and were considered treatment failures. Among the patients who lacked post overnight polysomnogram, 66/1921 (3%) discontinued the MAD due to adverse effects. Considering these patients as treatment failures as well, and therefore adding their number to the patients with complete sleep study data, the total treatment failures were 117/576 or 20%. Of the treatment successes, OSA was categorized by AHI at baseline as mild in 170 (34%), moderate in 181 (36%), and severe in 138 (28%).

CONCLUSIONS

In patients with evaluable data, there was an 80% success rate for treatment of OSA using a custom-fabricated adjustable MAD including substantial numbers of patients with moderate and severe disease.

Barriers to CPAP Use in India: An Exploratory Study

STUDY OBJECTIVES

To investigate adherence to continuous positive airway pressure (CPAP) therapy and identify barriers to CPAP use among patients with obstructive sleep apnea (OSA) in India.

METHODS

A self-devised semistructured questionnaire (which collected patients' demographic information, socioeconomic position, and information about disease status, symptoms, and complications) was administered to consecutive patients with moderate to severe OSA from June 2015 to August 2016. Patients were grouped according to CPAP device buying behavior (buyers versus nonbuyers) and CPAP compliance behavior (compliant versus noncompliant).

RESULTS

Out of 187 patients with moderate-severe OSA, 79 patients were enrolled for this study. The overall adherence rate (usage > 4 hours per night on > 70% nights) was 30.3%. Among the patients in the buyer group, adherence was 82.7%. Fifty patients did not buy a CPAP device; 30 of these 50 patients (60%) said financial constraints were the most important reason for not buying a CPAP device. Patients without financial constraints had higher chances-odds ratio (95% confidence interval) = 4.85 (1.6-16.1)-of buying a CPAP device than patients with financial constraints. Patients with more severe disease (ie, lower nadir oxygen saturation during sleep, higher apnea-hypopnea index, or presence of obesity hypoventilation syndrome) were more likely to buy and use a CPAP device.

CONCLUSIONS

The main cause of nonuse of CPAP in India is the inability to buy a CPAP device. In patients who are able to buy a CPAP device, adherence was significantly higher (82.7%) compared to adherence in the study's overall population (30.3%). Furthermore, patients with more severe OSA were more likely to buy a device and adhere to CPAP. Patients' behaviors and attitudes are also important barriers in using CPAP. There needs to be increased awareness of the benefits of CPAP therapy among patients.

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.

Medium Increased Risk for Central Sleep Apnea but Not Obstructive Sleep Apnea in Long-Term Opioid Users: A Systematic Review and Meta-Analysis

STUDY OBJECTIVE

Opioids are associated with higher risk for ataxic breathing and sleep apnea. We conducted a systematic literature review and meta-analysis to assess the influence of long-term opioid use on the apnea-hypopnea and central apnea indices (AHI and CAI, respectively).

METHODS

A systematic review protocol (Cochrane Handbook guidelines) was developed for the search and analysis. We searched Embase, Medline, ACP Journal Club, and Cochrane Database up to November 2014 for three topics: (1) narcotics, (2) sleep apnea, and (3) apnea-hypopnea index. The outcome of interest was the variation in AHI and CAI in opioid users versus non-users. Two reviewers performed the data search and extraction, and disagreements were resolved by discussion. Results were combined by standardized mean difference using a random effect model, and heterogeneity was tested by χ(2) and presented as I(2) statistics.

RESULTS

Seven studies met the inclusion criteria, for a total of 803 patients with obstructive sleep apnea (OSA). We compared 2 outcomes: AHI (320 opioid users and 483 non-users) and 790 patients with CAI (315 opioid users and 475 non-users). The absolute effect size for opioid use was a small increased in apnea measured by AHI = 0.25 (95% CI: 0.02-0.49) and a medium for CAI = 0.45 (95% CI: 0.27-0.63). Effect consistency across studies was calculated, showing moderate heterogeneity at I(2) = 59% and 29% for AHI and CAI, respectively.

CONCLUSIONS

The meta-analysis results suggest that long-term opioid use in OSA patients has a medium effect on central sleep apnea.

IGF-1: a potential biomarker for efficacy of sleep improvement with automatic airway pressure therapy for obstructive sleep apnea?

BACKGROUND

Positive airway pressure (PAP) reverses obstructive sleep apnea (OSA)-related hypoxia and restores slow wave sleep (SWS). Insulin-like growth factor 1 (IGF-1) is a neuropeptide that facilitates the repair of neurons from hypoxia and improves sleep regulation. IGF-1 concentrations are lower in OSA, and likely increase following PAP treatment; however, this relationship has not yet been determined in a younger cohort of OSA patients.

METHODS

This was a prospective, observational pilot study of 58 young men, who were diagnosed with OSA and provided PAP as an intervention. Adherence to PAP treatment over 3 months was objectively measured, as well as changes in the apnea-hypopnea index (AHI). Serum concentrations of IGF-1and C-reactive protein (CRP) were measured and correlated with PAP adherence.

RESULTS

IGF-1 concentrations at baseline were similar between PAP adherent 55.5 ± 34.4 ng/ml and PAP nonadherent participants 61.2 ± 27.1 ng/ml (p = 0.4), with the overall mean IGF-1 concentration of 59.0 ± 29.9 ng/ml. At follow-up, adherent participants had concentrations of IGF-1 that were significantly higher 128 ± 59.5 ng/ml compared to nonadherent participants 86.0 ± 47.4 ng/ml (p < 0.01). Increases in IGF-1 concentrations were significantly associated with reductions in AHI (Spearman's rho = -0.409, p = 0.015). Conversely, CRP concentrations did not differ between baseline and follow-up measurements in either group.

CONCLUSIONS

Adherence to PAP treatment leads to significant increases in IGF-1 concentrations in young men with OSA. While an objective measure of adherence exists, PAP usage does not allow for measure of sleep improvement. IGF-1 may serve as a potential biomarker for the efficacy of PAP therapy on improved sleep.

Optimal level of continuous positive airway pressure: auto-adjusting titration versus titration with a predictive equation

OBJECTIVES

The aims of the present study were twofold. We sought to compare two methods of titrating the level of continuous positive airway pressure (CPAP) - auto-adjusting titration and titration using a predictive equation - with full-night manual titration used as the benchmark. We also investigated the reliability of the two methods in patients with obstructive sleep apnea syndrome (OSAS).

METHODS

Twenty consecutive adult patients with OSAS who had successful, full-night manual and auto-adjusting CPAP titration participated in this study. The titration pressure level was calculated with a previously developed predictive equation based on body mass index and apnea-hypopnea index.

RESULTS

The mean titration pressure levels obtained with the manual, auto-adjusting, and predictive equation methods were 9.0 +/- 3.6, 9.4 +/- 3.0, and 8.1 +/- 1.6 cm H2O,respectively. There was a significant difference in the concordance within the range of +/- 2 cm H2O (p = 0.019) between both the auto-adjusting titration and the titration using the predictive equation compared to the full-night manual titration. However, there was no significant difference in the concordance within the range of +/- 1 cm H2O (p > 0.999).

CONCLUSIONS

When compared to full-night manual titration as the standard method, auto-adjusting titration appears to be more reliable than using a predictive equation for determining the optimal CPAP level in patients with OSAS.

Does home sleep testing impair continuous positive airway pressure adherence in patients with obstructive sleep apnea?

BACKGROUND

The increasing recognition of obstructive sleep apnea (OSA) and demand for polysomnography has created a need for home sleep testing (HST) using unattended diagnostic and titration studies. Although these studies increase access to care and reduce cost, the limited interaction with sleep laboratories may negatively affect positive airway pressure (PAP) adherence. We sought to determine the difference in PAP use between HST and traditional in-laboratory studies.

METHODS

This observational cohort study included 210 patients with OSA classified into three equal groups. Following preestablished guidelines, group 1 underwent unattended, type III home diagnostic and unattended home auto-adjustable PAP (APAP) titrations; group 2 underwent in-laboratory, type I diagnostic and continuous PAP titration studies; group 3 underwent type I diagnostic and APAP titration studies. Group 1 was primarily managed and educated in a primary care clinic, whereas groups 2 and 3 received extensive education in an academic sleep medicine center. Objective measures of PAP use during the first 4 to 6 weeks of therapy were compared between groups.

RESULTS

Type of study and location of care did not affect PAP adherence. PAP was used for 70%, 73%, and 72% of nights in groups 1, 2, and 3, respectively (P = .94). Mean hours of nightly use (4.4 ± 2.0 h, 4.7 ± 1.5 h, and 4.6 ± 1.5 h; P = .98) was also similar. Regular use was observed in 54%, 51%, and 50% of subjects (P = .84). Discontinuation rates were similar between groups.

CONCLUSIONS

PAP usage did not differ between those undergoing HST vs in-laboratory studies. HST offers a more accessible and cost-effective alternative without compromising therapeutic adherence.

Optimal continuous positive airway pressure level in korean patients with obstructive sleep apnea syndrome

Objectives

The aim of this study was to investigate optimal continuous positive airway pressure (CPAP) level, to examine the factors affecting optimal CPAP level, and to develop a predictive equation for optimal CPAP level in Korean patients with obstructive sleep apnea syndrome (OSAS).

Methods

A total of 202 patients with OSAS who underwent successful manual titration for CPAP treatment were included in this study. Correlations between the optimal CPAP level and baseline data including anthropometric and polysomnographic variables were analyzed. A predictive equation for optimal CPAP level was developed based on anthropometric and polysomonographic data.

Results

The mean optimal CPAP level in 202 patients with OSAS was 7.8±2.3 cm H₂O. The mean optimal CPAP level in the mild, moderate, and severe OSAS groups was 6.0±1.3, 7.4±1.9, and 9.1±2.1 cm H₂O, respectively. The apneahypopnea index (AHI) (r=0.595, P<0.001), arousal index (r=0.542, P<0.001), minimal SaO₂ (r=-0.502, P<0.001), body mass index (BMI) (r=0.494, P<0.001), neck circumference (r=0.265, P<0.001), and age (r=-0.164, P=0.019) were significantly correlated with optimal CPAP level. The best predictive equation according to stepwise multiple linear regression analysis was: Optimal CPAP level (cm H₂O)=0.681+(0.205×BMI)+(0.040×AHI). Forty-two percent of the variance in the optimal CPAP level was explained by this equation (R²=0.42, P<0.001).

Conclusion

A predictive equation for optimal CPAP level in Korean patients with OSAS was developed using AHI and BMI, which can be easily measured during the diagnostic process.

Initial adherence to autotitrating positive airway pressure therapy: influence of upper airway narrowing

Objectives

There is still debate concerning the reason for the high initial failure rate of positive airway pressure (PAP) treatment. The objective of this study is to investigate the factors of the initial adherence to PAP, with an emphasis on the role of upper airway narrowing.

Methods

The patients were divided into two groups according to the continuation of therapy within the first three months of treatment. The demographic and polysomnographic findings, the minimal nasal cross sectional area (MCA), the degree of palatine tonsilar hypertrophy (PTH) and the modified Mallampati grade of the oropharynx inlet (Orophx) were compared between the study groups.

Results

Among 36 patients, 23 continued the auto-adjusting positive airway pressure (APAP) therapy (the adherent group) and 13 discontinued APAP within three months (the non-adherent group). The apnea-hypopnea index (AHI) was significantly higher in the adherent group than in the non-adherent group (P<0.001). The AHI distributions of the two groups are extremely different. Thirteen of the 23 patients in the adherent group had an AHI of more than 60/hr, while none of the patients in the non-adherent group had an AHI of more than 60/hr. In the patients with an AHI from 15 to 60/hr, the MCA at the wide side of the nasal cavity and the sum of the MCAs of both sides were significantly larger in the adherent group than those values in the non-adherent group (P=0.004). The PTH and the Orophx were not significantly different between the two groups.

Conclusion

AHI is a definite significant factor of adherence to APAP therapy. The dimension of the nasal cavity has an influence on initial APAP adherence in the patients who have a not too high level of AHI.