The Role of Obstructive Sleep Apnea in Hypercapnic Respiratory Failure Identified in Critical Care, Inpatient, and Outpatient Settings

An emerging body of literature describes the prevalence and consequences of hypercapnic respiratory failure. While device qualifications, documentation practices, and previously performed clinical studies often encourage conceptualizing patients as having a single "cause" of hypercapnia, many patients encountered in practice have several contributing conditions. Physiologic and epidemiologic data suggest that sleep-disordered breathing-particularly obstructive sleep apnea (OSA)-often contributes to the development of hypercapnia. In this review, the authors summarize the frequency of contributing conditions to hypercapnic respiratory failure among patients identified in critical care, emergency, and inpatient settings with an aim toward understanding the contribution of OSA to the development of hypercapnia.

Contribution of Obstructive Sleep Apnea to Asthmatic Airway Inflammation and Impact of Its Treatment on the Course of Asthma

Asthma and obstructive sleep apnea (OSA) are very common respiratory disorders in the general population. Beyond their high prevalence, shared risk factors, and genetic linkages, bidirectional relationships between asthma and OSA exist, each disorder affecting the other's presence and severity. The author reviews here some of the salient links between constituents of the alternative overlap syndrome, that is, OSA comorbid with asthma, with an emphasis on the effects of OSA or its treatment on inflammation in asthma. In the directional relationship from OSA toward asthma, beyond direct influences, multiple factors and comorbidities seem to contribute.

Impact of PAP on the gut microbiome in OSA: A pilot study

OBJECTIVE/BACKGROUND

Microbes within the gastrointestinal tract have emerged as modulators of the host's health. Obstructive sleep apnea (OSA) is characterized by intermittent partial, or complete, airway closure during sleep and is associated with increased risk of non-communicable diseases as well as dysbiosis of the gut microbiome. Thus, we investigated if improving nocturnal airway patency via positive airway pressure (PAP) therapy improves gut microbial diversity in recently diagnosed patients with moderate-to-severe OSA (apnea-hypopnea index ≥15.0 events/hr).

PATIENTS/METHODS

Eight subjects (3 F, 56±9yrs, 33.5 ± 7.7 kg/m2, 45.0 ± 38.4 events/hr) provided stool samples before, and two months after, PAP therapy (mean adherence of 95 ± 6%, residual apnea-hypopnea index of 4.7 ± 4.6 events/hr).

RESULTS

While the Shannon diversity index tended to increase following PAP (3.96 ± 0.52 to 4.18 ± 0.56, p = 0.08), there were no changes in the Observed (1,088 ± 237 to 1,136 ± 289, p = 0.28) nor Inverse-Simpson (22.4 ± 12.99 to 26.6 ± 18.23, p = 0.28) alpha diversity indices. There were also no changes in beta diversity assessed using the Bray-Curtis (p = 0.98), Jaccard (p = 0.99), WUniFrac (p = 0.98), GUniFrac (p = 0.98), or UniFrac (p = 0.98) methods. No changes in differential abundance taxa were found using a false discovery rate threshold of <0.20.

CONCLUSIONS

Our data are the first to report that PAP therapy may not offset, or reverse, gut dysbiosis in patients with OSA. Accordingly, interventions which improve gut microbial health should be explored as potential adjunctive treatment options in patients with OSA to reduce their risk of developing non-communicable diseases.

Effectiveness of remote monitoring in improving CPAP compliance and the impact of preexisting organisation of standard care: a randomised controlled trial

PURPOSE   : Continuous positive airway pressure (CPAP) is often the treatment of choice for obstructive sleep apnea (OSA). Short-term adherence and early perceived benefits are the best predictors of long-term adherence. The aim of this study was to determine the effect of telemonitoring in the first period of treatment with CPAP (auto-titrating PAP) on compliance and the long-term outcome.

METHODS

Patients aged between 18-75 years old with symptomatic severe OSA (apnea-hypopnea index (AHI) ≥ 30) requiring CPAP therapy were included in this single-blind, single-centre, randomised, controlled trial. They were divided into 2 groups (telemonitored standard clinical care versus standard clinical care without telemonitoring).

RESULTS

A total of 230 patients (115 patients/group) were included (mean age 54 ± 16.6 years, BMI 32.6 ± 5.4 kg/m2, ESS 13.1 ± 6.2, AHI 47.5 ± 14.8/hr). At week 10 compliance was similar in both groups (telemonitoring vs control 6:27 and 6:35 h, respectively, p = 0.57), as were AHI (2.4; 2.4/hr, p = 0.89) and ESS (5.8; 4.9, p = 0.22). The number of contacts of a patient with a healthcare professional was significantly higher during the follow-up from week 3 until week 10 (0.25; 0.13, p = 0.03). The number of patients who could be evaluated after 1 year was equally distributed in both groups (104; 104, p = 1.00), as were compliance (6:43; 6:49 h, p = 0.59) and residual AHI (1.9; 2.2/hr, p = 0.41).

CONCLUSIONS

In patients with severe OSA with standard intensive follow-up during the initial weeks of CPAP therapy and good compliance, telemonitoring did not improve CPAP compliance nor the clinical outcome in the short or long term. The practical consequences can be highly relevant for patients and healthcare professionals.

The association between the effective apnea-hypopnea index and blood pressure reduction efficacy following CPAP/oxygen treatment

BACKGROUND

The effect of sleep apnea treatment on reducing cardiovascular disease risk remains inconclusive. This study aims to assess if the effective apnea hypopnea index (eAHI), a measure of residual sleep apnea burden post-treatment, is a factor in determining blood pressure (BP) response to continuous positive airway pressure therapy. The eAHI integrates time on therapy, residual apnea, and % of sleep time untreated.

METHODS

A secondary analysis of the Heart Biomarker Evaluation in Apnea Treatment (HeartBEAT) study, a randomized, controlled, parallel group assessment of continuous positive airway pressure (CPAP), oxygen and sleep hygiene. The Delta-AHI (▲AHI) was defined as the difference between baseline AHI and effective AHI at 12 weeks. Logistic and linear regression models estimated the predictors for nocturnal systolic BP change following sleep apnea therapy.

RESULTS

One hundred and sixty-nine subjects with a mean age of 62.82 ± 6.99 years were included in the final analysis. Fifty subjects had ▲AHI ≤8/hour of sleep and 119 subjects were higher. After adjustment, baseline mean nighttime systolic blood pressure (OR 1.036, 95% CI 1.015-1.058, p: 0.001) and ▲AHI ≥8/hour (OR 2.406, 95% CI 1.116-5.185, p:0.025) were independent predictors for mean nighttime systolic blood pressure change >3 mm Hg. The higher effective AHI was negatively related with BNP (β: -2.564, SE: 1.167, p: 0.029) and positively related with troponin change (β: 0.703, SE: 0.256, p: 0.007).

CONCLUSION

The ▲AHI was an independent predictor of the blood pressure response to sleep apnea treatment.

REGISTER NUMBER

NCT01086800.

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

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

The effects of social support and support types on continuous positive airway pressure use after 1month of therapy among adults with obstructive sleep apnea

BACKGROUND

The relationship between perceived social support and continuous positive airway pressure remains understudied among individuals with obstructive sleep apnea. The aim of this prospective cohort study was to determine if baseline perceived social support and subtypes predict regular continuous positive airway pressure use after 1month of therapy.

METHODS

Adults with obstructive sleep apnea initiating continuous positive airway pressure therapy were recruited from sleep clinics in New York City. Demographics, medical history, and comorbidities were obtained from patient interview and review of medical records. Objective continuous positive airway pressure adherence data was collected at the first clinical follow-up.

RESULTS

Seventy-five participants (32% female; non-Hispanic Black 41%; mean age of 56 ± 14years) provided data. In adjusted analyses, poorer levels of overall social support, and subtypes including informational/emotional support, and positive social interactions were associated with lower continuous positive airway pressure use at 1month. Relative to patients reporting higher levels of support, participants endorsing lower levels of overall social support, positive social interaction and emotional/informational support had 1.6 hours (95% CI: 0.5,2.7, hours; p = .007), 1.3 hours (95% CI: 0.2,2.4; p = .026), and 1.2 hours (95% CI: 0.05,2.4; p = .041) lower mean daily continuous positive airway pressure use at 1month, respectively.

CONCLUSION

Focusing on social support overall and positive social interaction particularly, could be an effective approach to improve continuous positive airway pressure adherence in patients at risk of suboptimal adherence.

Positive airway pressure therapy compliance in patients with comorbid insomnia and sleep apnea (COMISA)

Objectives

This study aimed to compare positive airway pressure (PAP) therapy compliance between patients with comorbid insomnia and sleep apnea (COMISA) and those with obstructive sleep apnea (OSA) alone, while assessing the influence of insomnia clinic visits on PAP compliance.

Methods

Patients diagnosed with OSA and initiated on PAP therapy between January 2012 and December 2021 were included. The COMISA group (n = 43) comprised patients with insomnia, while the control group (n = 86) consisted of OSA patients without insomnia, matched 1:2 based on age and sex. COMISA patients were further categorized into Group A (n = 20) with at least two insomnia clinic visits and Group B (n = 23) with minimal or no visits. PAP compliance was evaluated for each group at 3 and 9 months.

Results

No significant differences were observed in PAP compliance between COMISA patients and OSA patients without insomnia. Within the COMISA group, the impact of insomnia clinic visits on PAP compliance was not significant. No significant difference was observed in the daily PAP usage between the two groups at 3 months (265.5 ± 145.9 min in Group A vs. 236.3 ± 152.3 min in Group B, p = 0.760) or 9 months (213.4 ± 155.3 min in Group A vs. 166.3 ± 158.3 min in Group B, p = 0.538). Percentages of PAP users and nights with PAP use exceeding 4 hours also showed no significant differences at both intervals.

Conclusion

This study demonstrated no significant disparity in PAP compliance between the COMISA and control groups at either 3 or 9 months. Furthermore, insomnia clinic visits did not significantly impact PAP compliance in COMISA patients during the 3- and 9-month intervals.

Prevalence and predictors of sleep bruxism in patients with obstructive sleep apnea and the effect of positive airway pressure treatment

BACKGROUND

Sleep bruxism (SB) is often found to co-exist with obstructive sleep apnea (OSA). However, there are no data on prevalence and risk factors of SB in patients with OSA patients regarding the effect of optimal positive airway pressure (PAP).

OBJECTIVE

This study aimed to study prevalence and risk factors of SB in OSA and to compare SB episodes during pre-treatment versus during optimal PAP therapy.

METHODS

This investigation was a retrospective study including randomly selected patients with OSA who underwent split-night polysomnography. Data were collected from August 2021 to October 2022. Clinical demographic data and SB data were analyzed. The association between SB episodes and obstructive respiratory events were manually reviewed. If most of the SB episodes were observed within 5 s following obstructive respiratory events, SB was defined as SB associated with OSA. Comparison of SB index (SBI) was made between baseline portion of the study versus during optimal PAP.

RESULTS

Among 100 patients enrolled, mean age was 50.8 ± 16.7 years and 73 subject (73%) were male. Mean respiratory disturbance index (RDI) and mean nadir oxygen saturation were 52.4 ± 33.4 and 79.3 ± 11.2% respectively. During the baseline portion of the study, 49 patients (49%) had SB and 31 patients (31%) had severe SB (SBI ≥ 4). Sleep bruxism associated with OSA was observed in 73.5% of all SB. The risk factor for SB was endorsement of nocturnal tooth grinding (odds ratio (OR) 5.69, 95%CI 1.74-18.58). Risk factors for severe bruxism were male sex (OR 4.01, 95%CI 1.02-15.88) and endorsement of nocturnal tooth grinding (OR 9.63, 95%CI 2.54-36.42). Risk factors for SB associated with OSA were non-supine RDI (OR 1.02, 95%CI 1.001-1.034) and endorsement of nocturnal tooth grinding (OR 5.4, 95%CI 1.22-23.93). In SB group, when comparison was made between baseline portion and during optimal PAP, significant reduction of SBI was observed (5.5 (3.2, 9.3) vs. 0 (0, 2.1), p < 0.001). Median difference of SBI between baseline portion and during optimal PAP was 4.4 (2.0, 8.3) (p < 0.001).

CONCLUSIONS

In this group of patients with OSA, almost half was observed to have SB in which the majority were associated with OSA. Optimal PAP resulted in a significant reduction in SB episodes. In addition to endorsement of nocturnal tooth grinding, non-supine RDI was observed to be a potential risk factor for SB associated with OSA.

Sleep breathing disorder frequency, risk factors, and treatment among adults with cystic fibrosis

BACKGROUND

Our understanding of the epidemiology of sleep breathing disorders among adults with cystic fibrosis (CF) is limited. Our purpose was to describe the frequency, risk factors and treatment of sleep breathing disorders among adults with CF.

METHODS

This was a retrospective analysis of linked data from laboratory-based diagnostic polysomnography (PSG) undertaken at St. Michael's Hospital (Toronto, Canada) and the Canadian CF Registry. Adults (≥19 years old) with CF that underwent a diagnostic PSG at St. Michael's Hospital between 2002 and 2021 were included. Sleep breathing disorder frequency, risk factors, and treatment were described, using descriptive statistics and logistic regression.

RESULTS

There were 42 patients included (33.3 % women and median age at diagnostic PSG was 34.7 years). Obstructive sleep apnea [OSA] was the most commonly observed sleep breathing disorder (found in 64.3 %), followed by sustained nocturnal hypoxemia (16.7 %), and sleep hypoventilation (9.5 %). Only 41 % of individuals with an elevated total apnea-hypopnea index were receiving positive airway pressure [PAP] therapy. Corticosteroid use (either oral or inhaled) was the only factor with a significant positive association with presence of any sleep breathing disorder (odds ratio 5.00, 95 % confidence interval 1.28-22.78).

CONCLUSIONS

Among adults with CF, OSA occurs more commonly than previously appreciated and the majority of sleep breathing disorders were not being treated with PAP or supplemental oxygen. Management of sleep breathing disorders among adults with CF reflects a potentially important care gap, but further research is needed to determine the health impacts of treating sleep breathing disorders in CF.

Improving adherence to PAP therapy: A brief PAP coaching intervention for health care providers

Objectives

To evaluate a training program for non-specialist health care providers in a brief coaching intervention to improve positive airway pressure (PAP) usage in Veterans with sleep apnea.

Methods

We conducted a national webinar training designed for non-specialist providers to implement a brief telephone coaching intervention to improve PAP adherence. The curriculum was crafted by experts in sleep medicine and behavioral sleep medicine based on principles of PAP desensitization. Providers who participated in this training were asked to complete evaluations at 30 days and 1 year.

Results

Provider surveys indicated that most respondents had incorporated the intervention into their clinical practice and felt comfortable counseling patients about sleep apnea and adherence to PAP. Provider feedback suggested that future training programs should include refresher trainings, more training on PAP equipment specifics, and facilitated collaboration with local sleep medicine staff.

Conclusions

This pilot training program demonstrated that a webinar format was a feasible method to increase training in PAP adherence among non-specialist health care providers.

Innovation

Non-specialists can be trained as PAP coaches in webinar format, improving patients' access to effective strategies and support to be successful with PAP therapy.

Current treatment strategies in managing side effects associated with domiciliary positive airway pressure (PAP) therapy for patients with sleep disordered breathing: A systematic review and meta-analysis

Sleep disordered breathing is commonly treated with positive airway pressure therapy. Positive airway pressure therapy is delivered via a tight-fitting mask with common side effects including: leak, ineffective treatment, residual sleep disordered breathing, eye irritation, nasal congestion, pressure ulcers and poor concordance with therapy. This systematic review and meta-analysis aimed to identify the effectiveness of current treatment strategies for managing side effects associated with positive airway pressure therapy. Five databases were searched and 10,809 articles were screened, with 36 articles included in the review. Studies investigated: dressings, nasal spray/douche, chin straps, heated humidification and interfaces. No intervention either improved or detrimentally affected: positive airway pressure concordance, Epworth Sleepiness Score, residual apnoea hypopnea index or interface leak. The review was limited by study heterogeneity, particularly for outcome measures. Additionally, patient demographics were not reported, making it difficult to apply the findings to a broad clinical population. This review highlights the paucity of evidence supporting treatment strategies to manage side effects of positive airway pressure therapy.

Impact of treating obesity hypoventilation syndrome on body mass index

STUDY OBJECTIVES

To evaluate the impact of positive airway pressure (PAP) therapy on body mass index (BMI) in patients with obesity hypoventilation syndrome (OHS) associated with obstructive sleep apnea (OSA).

METHODS

A systematic review using the following terms: "obesity hypoventilation syndrome" AND "treatment" AND "randomized" using Cochrane Central Register of Controlled Trials, Medline and Web of Science was performed from the first data available until February 10, 2023. The inclusion criteria were: (1) original article; (2) adult OHS with concomitant OSA (apnea-hypopnea index or AHI ≥5 events/h); (3) randomized trial with PAP arm and standard care (control); (4) BMI evaluation at baseline and after the first months. We performed an individual participant data meta-analysis of randomized controlled trials.

RESULTS

Our initial search retrieved 32 articles and 3 randomized studies fulfilled study criteria and were included in the final analysis, leading to a total of 342 participants. Patients were predominantly females (62%) and had OHS associated with at least mild OSA. As compared to baseline, a decrease in BMI was observed at study endpoint but this difference was not different intergroups (-0.50 ± 1.49 and -0.50 ±1.83, in control and PAP groups respectively (p=0.939)). Weight change was not associate with PAP adherence, OSA severity or use of supplemental oxygen.

CONCLUSIONS

In contrast to treatment of eucapnic OSA with PAP that is associated with weight gain, treatment of OSA+OHS patients with or without PAP is associated with weight loss. Future studies are necessary to elucidate the mechanism by which weight loss occurs.

Potential health risks of sound abatement material in positive airway pressure devices for sleep breathing disorders: a summary of studies to date

PURPOSE

The potential carcinogenic and airway irritation risks of polyester-based polyurethane (PE-PUR) contained in sound-absorbing foam in positive airway pressure (PAP) devices have raised many concerns. We summarize the currently available studies to assess the potential health risks of PE-PUR.

METHODS

We searched Pubmed and Web of Science for studies on the safety of PAP devices containing PE-PUF and performed a systematic analysis of the cancer risk.

RESULTS

PE-PUR did not increase the cancer risk (OR: 1.08, 95% CI: 0.99-1.17, I2 = 0%). Patients in the group of PE-PUR devices had increased airway irritation, and they had higher rates of using short-acting beta-agonists and oral corticosteroids (SABA: 9.4% vs. 8.8%, p = 0.047; OCS: 19.7% vs. 17.3%, p < 0.001).

CONCLUSION

The application of PE-PUF can increase airway irritation, but there is no evidence for its potential carcinogenicity.

Adherence to positive airway pressure therapy initiated in the early subacute phase of ischemic stroke: a PRESS study follow-up

BACKGROUND

Sleep-disordered breathing (SDB) is frequent in stroke patients and negatively affects stroke outcomes. Positive airway pressure (PAP) is the standard first-line treatment for patients with moderate-to-severe SDB. Despite a strong link between PAP adherence and therapeutic response, rates of post-stroke PAP adherence remain underexplored. Our study aimed to determine PAP adherence in patients undergoing comprehensive sleep apnea assessment and in-lab PAP titration in the early subacute phase of stroke.

METHODS

In-hospital screening pulse oximetry was performed in consecutive patients with imaging-confirmed acute ischemic stroke. Subjects with desaturation index ≥ 15.3/h were selected as PAP candidates, and polysomnography was recommended. In a sleep laboratory setting, subjects underwent a diagnostic night followed by a titration night, and PAP therapy was initiated in subjects with apnea-hypopnea index ≥ 15/h. Adherence to PAP therapy was assessed at a 6-month follow-up visit.

RESULTS

Of 225 consecutive patients with acute ischemic stroke, 116 were PAP candidates and 52 were able to undergo polysomnography. PAP therapy was initiated in 35 subjects. At a 6-month follow-up visit, out of 34 stroke survivors, PAP adherence (PAP use of > 4 h per night) was present in 47%. Except for the significantly lower minimal nocturnal O2 saturation determined from the polysomnography (74.6 ± 11.7% vs. 81.8 ± 5.2%, p = 0.025), no other significant difference in characteristics of the groups with PAP adherence and PAP non-adherence was found.

CONCLUSIONS

Less than half of the stroke subjects remained adherent to PAP therapy at 6 months post-PAP initiation. Special attention to support adaptation and adherence to PAP treatment is needed in this group of patients.

Caregiver experiences helping children with Down syndrome use positive airway pressure to treat obstructive sleep apnea

BACKGROUND/OBJECTIVE

While positive airway pressure (PAP) is an efficacious intervention for the treatment of obstructive sleep apnea syndrome (OSAS) in children with Down syndrome (DS), implementation and consistent use can be difficult. Caregiver perspectives and experiences using PAP are described with the aim of informing clinical practice.

METHODS

Qualitative semi-structured phone interviews were conducted with 40 caregivers (i.e., mothers) of children with DS and OSAS treated with PAP for at least 6 months. Content analysis was used to identify themes associated with adherence and non-adherence.

RESULTS

Respondents indicated variability in caregiver experience with the adoption of PAP and observed benefits of PAP. Varied experiences were attributed to several themes including accessing supplies, interactions with the medical team and equipment company, and patients' unique needs and behaviors, including the child's willingness and ability to adapt to PAP, sensory sensitivities, keeping the mask on all night, and differences in daytime behavior. Many families reported that desensitization with a reward system and trust within the caregiver-patient relationship were helpful. Caregiver suggestions for improving PAP adherence for families of children with DS included improving communication with the medical team and medical equipment company, emphasizing patience, using visual supports, and social support and education for extended family.

CONCLUSIONS

Although family experiences varied, several actionable strategies by both the medical team and families emerged for improving the experience of and adherence to PAP in children with DS.

[Modeling the noninvasive bi-level positive airway pressure ventilation therapy system and simulated application]

Without artificial airway though oral, nasal or airway incision, the bi-level positive airway pressure (Bi-PAP) has been widely employed for respiratory patients. In an effort to investigate the therapeutic effects and measures for the respiratory patients under the noninvasive Bi-PAP ventilation, a therapy system model was designed for virtual ventilation experiments. In this system model, it includes a sub-model of noninvasive Bi-PAP respirator, a sub-model of respiratory patient, and a sub-model of the breath circuit and mask. And based on the Matlab Simulink, a simulation platform for the noninvasive Bi-PAP therapy system was developed to conduct the virtual experiments in simulated respiratory patient with no spontaneous breathing (NSB), chronic obstructive pulmonary disease (COPD) and acute respiratory distress syndrome (ARDS). The simulated outputs such as the respiratory flows, pressures, volumes, etc, were collected and compared to the outputs which were obtained in the physical experiments with the active servo lung. By statistically analyzed with SPSS, the results demonstrated that there was no significant difference ( P > 0.1) and was in high similarity ( R > 0.7) between the data collected in simulations and physical experiments. The therapy system model of noninvasive Bi-PAP is probably applied for simulating the practical clinical experiment, and maybe conveniently applied to study the technology of noninvasive Bi-PAP for clinicians.

Acute and long-term effects of acetazolamide in presumed high loop gain sleep apnea

BACKGROUND

The acute effect during positive pressure titration and long term efficacy of acetazolamide (AZT) in high loop gain sleep apnea (HLGSA) is inadequately assessed. We predicted that AZT may improve HLGSA in both conditions.

METHODS

A retrospective analysis of polysomnograms from patients with presumed HLGSA and residual respiratory instability administered AZT (125 or 250 mg) about 3 h into an initially drug-free positive pressure titration. A responder was defined as ≥ 50% reduction of the apnea hypopnea index(AHI 3% or arousal) before and after AZT. A multivariable logistic regression model estimated responder predictors. Long term efficacy of AZT was assessed by comparing both auto-machine (aREI_FLOW) and manually scored respiratory events (sREI_FLOW) extracted from the ventilator, prior to and after 3 months of AZT, in a subset.

RESULTS

Of the 231 participants (median age of 61[51-68] years) and 184 (80%) males in the acute effect testing: 77 and 154 patients were given 125 mg and 250 mg AZT. Compared to PAP alone, PAP plus AZT was associated with a lower breathing related arousal index (8 [3-16] vs. 5 [2-10], p < 0.001), and AHI3% (19 [7-37] vs. 11 [5-21], p < 0.001); 98 patients were responders. The non-rapid eye movement sleep (NREM) AHI3% (OR 1.031, 95%CI [1.016-1.046], p < 0.001) was a strong predictor for responder status with AZT exposure. In the 109 participants with 3-month data, both aREI_FLOW and sREI_FLOWwere significantly reduced after AZT.

CONCLUSIONS

AZT acutely and chronically reduced residual sleep apnea in presumed HLGSA; NREM AHI3% is a response predictor. AZT was well tolerated and beneficial for at least 3 months.

Effects of heated humidification on positive airway pressure side effects in patients with obstructive sleep apnoea: a meta-analysis

PURPOSE

An earlier study found that heated humidification reduced the side effects of positive airway pressure (PAP) in patients with obstructive sleep apnoea (OSA). However, other studies disagreed with this finding. Therefore, we evaluated the relationship between heated humidification and the side effects of PAP in patients with OSA.

METHODS

According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, six databases were searched for relevant randomised controlled trials (RCTs) performed from January 1999 to June 2021.

RESULTS

From 1012 retrieved articles, we identified 9 eligible RCTs. Compared to the control group, the heated humidification group reported improvements in dry nose (pooled standardised mean difference [SMD] =  - 0.70, 95% confidence interval [CI] =  - 0.96 to - 0.45, I² = 0%, p < 0.00001), blocked nose (SMD =  - 0.47, 95%CI - 0.69 to - 0.25, I² = 36%, p < 0.0001), runny nose (SMD =  - 0.22, 95%CI - 0.44 to 0, I² = 0%, p = 0.05), dry mouth (SMD =  - 0.62, 95%CI - 0.87 to - 0.37, I² = 0%, p < 0.00001), and dry throat (SMD =  - 0.61, 95%CI - 0.90 to - 0.33, I² = 41%, p < 0.0001), but did not enhance positive airway pressure adherence (pooled mean difference [MD] = 0.24, 95% CI - 0.10 to 0.58, I² = 0%, p = 0.17).

CONCLUSIONS

Heated humidification improved some PAP side effects in patients with OSA but did not increase PAP adherence. Additional large-scale multi-centre RCTs are needed to verify the long-term effects.

Relationship between level CPAP titration, anthropometric variables, and drug-induced sleep endoscopy DISE

INTRODUCTION

Subjects with palatal obstruction alone vs. multilevel obstruction on DISE had better outcomes after palate surgery. We asked ourselves if the therapeutic level positive airway pressure (PAP) titration could predict the level of airway obstruction and its complexity.

PURPOSE

The aim of this study was to identify possible relationships between therapeutic level of positive airway pressure initial titration and levels of collapse in drug-induced sleep endoscopy (DISE). A secondary objective was to establish the relationship the other variables and DISE.

METHODS

We analyzed retrospective clinical histories between March 2020 to March 2022 of 37 patients with polysomnography or cardiorespiratory polygraphy studies and PAP initial titration who were taken to drug-induced sleep endoscopy. Sleep study data, anthropometric variables, and patterns of airway collapse during DISE were analyzed with PAP initial titration levels.

RESULTS

Most of the patients with complex collapse had concentric velum collapse (p < 0.006). A significant association was found between the apnea-hypopnea index (AHI) and oropharyngeal collapse; (p < 0.0030) and finally we demonstrated relationship between neck circumference and gender with epiglottis collapse (p < 0.046), (p < 0.037), respectively.

CONCLUSIONS

Our findings show a strong relationship between that complex collapses and concentric velum collapse; patients with greater oropharyngeal collapse have a higher mean AHI. Patients without epiglottic collapse have a higher mean neck circumference. An association between mean pressure initial titration and complex collapse could not be established.

Investigating changes in cognition associated with the use of CPAP in cognitive impairment and dementia: A retrospective study

STUDY OBJECTIVES

To characterize the impact of CPAP use on cognition in a clinical cohort with obstructive sleep apnea (OSA) and cognitive impairment due to neurodegenerative or vascular etiologies after controlling for baseline sleepiness.

METHODS

We retrospectively analyzed data from 171 patients with cognitive impairment and an OSA diagnosis confirmed with in-laboratory polysomnography or home sleep apnea testing (mean age 69.8 ± 10.6; 66% male) who were eligible to use CPAP. Baseline and follow-up Epworth Sleepiness Score (ESS), Montreal Cognitive Assessment (MoCA), and Mini-Mental Status Examination (MMSE) were obtained from clinical and research visits conducted before and after CPAP initiation. Good CPAP adherence was defined as CPAP use ≥4 h/night, for 7 days/week at follow-up. Associations between CPAP adherence and follow-up cognitive scores were analyzed using multivariable linear mixed-effects models.

RESULTS

After adjusting for age, sex, body mass index, baseline ESS, duration of CPAP therapy, relevant comorbidities and the random effect of research study cohort, good CPAP adherence (compared to poor CPAP adherence or no use of CPAP) for a duration of 2-12 months was associated with a 2.3-point (1.2-3.3 95% CI) higher follow-up MoCA score (p < 0.001) and a 1.2-point (0.3-2.3 95% CI) higher follow-up MMSE score (p = 0.01).

CONCLUSIONS

In patients with OSA and cognitive impairment due to a neurodegenerative or vascular etiology, use of CPAP is associated with improved cognitive outcomes. The findings of this study may aid in motivating patients to use CPAP and support future randomized controlled trials in this area.

Sleep testing during the pandemic

BACKGROUND

The COVID-19 pandemic disrupted the U.S. healthcare system, reducing the capacity available for unrelated conditions, such as sleep disordered breathing, and increasing concerns about the safety of in-lab testing. This study characterizes how the pandemic impacted the assessment of sleep disordered breathing and use of associated services.

METHODS

Sleep testing claims occurring between January 2019 and June 2021 were extracted from the database of a national healthcare organization. Utilization was trended. Logistic regressions were run to assess the association between quarter of initial testing, whether testing was followed by treatment, and whether testing was followed by a clinical visit with a diagnosis related to sleep apnea, after controlling for patient-related factors. A Cox proportional hazards model assessed factors influencing time to treatment. Finally, a logistic regression assessed factors influencing the finality of home-based testing.

RESULTS

In Q2 2021, home-based testing utilization was 134% of its initial level, while in-lab and split night testing were both at 61% of initial levels. Patients receiving initial home-based testing did not significantly differ in their likelihood of treatment, but were significantly less likely to have a clinical visit for sleep apnea (P < 0.01). Patients initially tested in 2021 were treated significantly more quickly than those initially tested in Q1 2019. Home-based testing occurring in Q4 2019 or later was significantly more likely to be definitive than home-based testing occurring Q1 2019.

CONCLUSIONS

Home-based sleep testing increased significantly and durably in 2020, and was associated with faster time to treatment than initial in-lab testing.

The prevention of delirium in elderly surgical patients with obstructive sleep apnea (PODESA): a randomized controlled trial

BACKGROUND

Obstructive sleep apnea (OSA) is associated with neurocognitive impairment - a known risk factor for postoperative delirium. However, it is unclear whether OSA increases the risk of postoperative delirium and whether treatment is protective. The objectives of this study were to identify OSA with a home sleep apnea test (HSAT) and to determine whether auto-titrating positive airway pressure (APAP) reduces postoperative delirium in older adults with newly diagnosed OSA undergoing elective hip or knee arthroplasty.

METHODS

We conducted a multi-centre, randomized controlled trial at three academic hospitals in Canada. Research ethics board approval was obtained from the participating sites and informed consent was obtained from participants. Inclusion criteria were patients who were [Formula: see text]0 years and scheduled for elective hip or knee replacement. Patients with a STOP-Bang score of ≥ 3 had a HSAT. Patients were defined as having OSA if the apnea-hypopnea index was ≥ 10/h. These patients were randomized 1:1 to either: 1) APAP for 72 h postoperatively or until discharge, or 2) routine care after surgery. The primary outcome was postoperative delirium, assessed twice daily with the Confusion Assessment Method for 72 h or until discharge or by chart review. The secondary outcome measures included length of stay, and perioperative complications occurring within 30 days after surgery.

RESULTS

Of 549 recruited patients, 474 completed a HSAT. A total of 234 patients with newly diagnosed OSA were randomized. The mean age was 68.2 (6.2) years and 58.6% were male. Analysis was performed on 220 patients. In total, 2.7% (6/220) patients developed delirium after surgery: 4.4% (5/114) patients in the routine care group, and 0.9% (1/106) patients in the treatment group (P = 0.21). The mean length of stay for the APAP vs. the routine care group was 2.9 (2.9) days vs. 3.5 (4.5) days (P = 0.24). On postoperative night 1, 53.5% of patients used APAP for 4 h/night or more, this decreased to 43.5% on night 2, and 24.6% on night 3. There was no difference in intraoperative and postoperative complications between the two groups.

CONCLUSIONS

We had an unexpectedly low rate of postoperative delirium thus we were unable to determine if postoperative delirium was reduced in older adults with newly diagnosed OSA receiving APAP vs. those who did not receive APAP after elective knee or hip arthroplasty.

TRIAL REGISTRATION

This trial was retrospectively registered in clinicaltrials.gov NCT02954224 on 03/11/2016.

The Effect of Bilevel Positive Airway Pressure on Voice Quality

OBJECTIVES

Inflammation of the upper airways, thickening of the lateral pharyngeal walls, elongation of the soft palate and uvula, hypertrophy of the tonsils and base of the tongue can be seen in obstructive sleep apnea syndrome patients. Changes in these structures may affect articulation and phonation, negatively affecting the quality of the voice. Positive airway pressure (PAP) treatment reduces the volume of the root of the tongue, dissolves the edema in the upper respiratory tract, increases the posterior pharyngeal area, and positively changes the quality of the voice.

METHODS

A total of 151 people, 50 control group, and 101 patients, were included in the study between December 2020 and December 2021. The patient group was divided into two groups as continuous positive airway pressure (CPAP) and bilevel positive airway pressure (BPAP) users. All voice recordings were made in the control group and the patient group before and 3 months after CPAP and BPAP treatment, and were evaluated with the Praat (Paul, 2001) voice analysis program. The fundamental frequency of the sound (F0), frequency perturbation (jitter), amplitude perturbation (shimmer), noise-to-harmonic ratio (NHR) values were evaluated in the patient and control groups, and they were compared with each other before and after the treatment in the CPAP and BPAP groups.

RESULTS

Before and after PAP treatment; the changes in F0, Jitter, Shimmer, and NHR in the CPAP and BPAP group were statistically significant (P < 0.05). While the F0 change before and after PAP treatment was the most in the CPAP group, the jitter, shimmer and NHR changes were the most in the BPAP group.

CONCLUSIONS

Regular 3-month PAP treatment positively affects F0, jitter, shimmer and NHR values. The greatest F0 change is in the use of CPAP, the improvement in jitter, shimmer and NHR is the most in the use of BPAP.

Effect of positive airway pressure therapy of obstructive sleep apnea on circulating Angiopoietin-2

BACKGROUND

Obstructive sleep apnea (OSA) has been identified as a possible contributor to interstitial lung disease. While positive airway pressure (PAP) is effective therapy for OSA, it causes large increases in lung volumes during the night that are potentially deleterious, analogous to ventilator-induced lung injury, although this has not been previously studied. The goal of this study was to assess the impact of PAP therapy on four biomarkers of alveolar epithelial and endothelial injury and extracellular matrix remodeling in patients with OSA.

METHODS

In 82 patients with moderate to severe OSA who were adherent to PAP therapy, surfactant protein D, osteopontin, angiopoietin-2, and matrix metalloprotease-7 were measured by ELISA in serum samples collected before and 3- to 6-months after initiation of PAP therapy.

RESULTS

An increase in angiopoietin-2 level of 0.28 ng/mL following PAP therapy was observed (p = 0.007). This finding was replicated in an independent sample of OSA patients. No significant change was detected in surfactant protein D, osteopontin, or matrix metalloprotease-7.

CONCLUSIONS

This finding raises concern for a possible adverse impact of PAP therapy on vascular endothelium.

Barriers to positive airway pressure adherence among veterans with sleep apnea: a mixed methods study

Rates of adherence to positive airway pressure (PAP) for sleep apnea are suboptimal. Though previous studies have identified individual factors associated with PAP nonadherence, few projects have investigated a wide range of possible barriers directly from the patient perspective. We examined the range of factors that patients identify as barriers to optimal use of PAP as well as the solutions most commonly offered by providers. We employed a mixed methods design including semistructured interviews and medical record review at a US Department of Veterans Affairs Medical Center. Thirty patients identified as nonadherent to PAP participated. Patients were asked to report on current sleep problems, reasons for nonadherence, and solutions proposed by providers. Chart review was used to identify untreated apnea severity, Epworth Sleepiness Scale score, therapy hours, and residual apnea severity. Patients described physical and psychological barriers to adherent use at approximately equal rates: Mask leaks and dry throat/nose were common physical barriers, and anxiety/claustrophobia and worsening insomnia were common psychological barriers. Untreated apnea severity, residual apnea severity, and daytime sleepiness were not associated with therapy hours. Solutions offered by providers most frequently addressed physical barriers, and solutions to psychological barriers were rarely proposed. The most common solution offered by providers was trying different masks. We recommend individualized assessment of each patient's barriers to use as well as increased involvement of behavioral health providers in sleep medicine clinics.

Abnormal Sleep-Related Breathing Related to Heart Failure

Sleep-disordered breathing (SDB) is highly prevalent in patients with heart failure (HF). Untreated obstructive sleep apnea (OSA) and central sleep apnea (CSA) in patients with HF are associated with worse outcomes. Detailed sleep history along with polysomnography (PSG) should be conducted if SDB is suspected in patients with HF. First line of treatment is the optimization of medical therapy for HF and if symptoms persist despite optimization of the treatment, positive airway pressure (PAP) therapy will be started to treat SDB. At present, there is limited evidence to prescribe any drugs for treating CSA in patients with HF. There is limited evidence for the efficacy of continuous positive airway pressure (CPAP) or adaptive servo-ventilation (ASV) in improving mortality in patients with heart failure with reduced ejection fraction (HFrEF). There is a need to perform well-designed studies to identify different phenotypes of CSA/OSA in patients with HF and to determine which phenotype responds to which therapy. Results of ongoing trials, ADVENT-HF, and LOFT-HF are eagerly awaited to shed more light on the management of CSA in patients with HF. Until then the management of SDB in patients with HF is limited due to the lack of evidence and guidance for treating SDB in patients with HF.

Sleep Apnea and Cardiovascular Disease

PURPOSE OF REVIEW

Obstructive sleep apnea (OSA) is associated with incident coronary and cerebral vascular disease. The mechanisms underlying this association are thought to include increased sympathetic nervous system activity, oxidative stress, and systemic inflammation, with these effects mediated in part by elevated blood pressure and impaired glucose metabolism. In observational studies, OSA treatment with positive airway pressure (PAP) is associated with a reduction in cardiovascular disease risk. The aim of this review is to evaluate evidence from recent clinical trials that tested the impact of OSA treatment on major cardiovascular disease outcomes.

RECENT FINDINGS

Multicenter randomized trials have demonstrated a significant, albeit modest, reduction in blood pressure with OSA treatment. Treatment of OSA has generally not demonstrated improvement in type 2 diabetes mellitus, although limited evidence suggests that treatment may be effective in the prediabetic period. However, recent randomized trials of PAP treatment for OSA failed to demonstrate a reduction in incident or recurrent cardiovascular disease events. This may reflect the enrollment of a mostly non-sleepy study sample, as recent evidence suggests that sleepiness is a predictor of adverse cardiovascular outcomes from OSA. PAP treatment of OSA lowers blood pressure and may improve glucose metabolism; however, randomized clinical trials do not indicate a reduction in cardiovascular risk with treatment of minimally symptomatic OSA patients.

Treatment of Sleep Apnea with Positive Airway Pressure and Its Association with Diastolic Dysfunction: A Systematic Review and Meta-Analysis

BACKGROUND

This meta-analysis assessed the effect of long-term (>6 weeks) noninvasive positive airway pressure (PAP) on diastolic function in patients with obstructive sleep apnea (OSA).

METHODS

We searched the databases for randomized clinical trials including Ovid MEDLINE, Ovid Embase Scopus, Web of Science, Google Scholar, and EBSCO CINAHL from inception up to December 20, 2019. The search was not restricted to time, publication status, or language. Two independent investigators screened the studies and extracted the data, in duplicate. Risk of bias was assessed using Cochrane collaboration tools.

RESULTS

A total of 2,753 abstracts were resulted from literature search. A total of 9 randomized clinical trials assessing the effect of long-term (>6 weeks) PAP on diastolic function in patients with OSA including 833 participants were included. The following echo parameters were found in treated patients: a decrease in deceleration time (-39.49 ms CI [-57.24, -21.74]; p = 0.000), isovolumic relaxation time (-9.32 ms CI [-17.08, -1.57]; p = 0.02), and the ratio of early mitral inflow velocity to mitral annular early diastolic velocity (-1.38 CI [-2.6, -0.16]; p = 0.03). However, changes in left-atrial volume index and the ratio of early to late mitral inflow velocities were not statistically different. The risk of bias was mild to moderate among the studies.

CONCLUSION

Our results suggest that chronic treatment of moderate to severe OSA with noninvasive PAP is associated with improvement in echocardiographic findings of diastolic dysfunction.

Prognostic effect of sleep-disordered breathing on hospitalized patients following acute heart failure

BACKGROUND

Identifying patients at risk for poor clinical outcomes following acute heart failure (AHF) is essential. However, data regarding the prognostic effect of sleep-disordered breathing (SDB) and treatment with positive airway pressure (PAP) on clinical outcomes of hospitalized patients following AHF is lacking.

OBJECTIVES

This study investigated the prognostic effect of SDB, PAP treatment, and compliance with PAP treatment on patient clinical outcomes. Polysomnography was performed in hospitalized patients whose left ventricular ejection fraction was < 50%. Patients were divided into groups based on whether SDB was defined as an apnea-hypopnea index ≥ 15 and if they had received PAP treatment. Furthermore, patients with SDB and PAP were subdivided into more and less compliant groups. We assessed the incidences of deaths and rehospitalizations due to heart failure.

RESULTS

Overall, 241 patients were enrolled; 73% had SDB and 29% were initiated on PAP treatment. At a median follow-up of 1.7 years, 74 clinical events (32 deaths, 42 rehospitalizations) occurred. In the multivariable analysis, compared with the non-SDB group, SDB without PAP treatment was associated with an increased risk of clinical outcomes (hazard ratio [HR] 1.79, P = 0.049), whereas SDB with PAP treatment was not (HR 0.78, P = 0.582). Among patients with PAP treatment, a more compliant group was also inversely associated with clinical events (HR 0.11, P = 0.012).

CONCLUSIONS

In hospitalized patients with AHF, untreated SDB was associated with worse clinical outcomes that might be reversible by PAP treatment. However, this potential may be suppressed in less compliant patients.

Physiological Responses and Perceived Comfort to High Flow Nasal Cannula Therapy in Awake Adults: Effects of Flow Magnitude and Temperature

Clinical use of heated, high flow nasal cannula (HFNC) for non-invasive respiratory support is increasing and may have a therapeutic role in stabilizing the upper airway in obstructive sleep apnea (OSA). However, physiological mechanisms by which HFNC therapy may improve upper-airway function and effects of different temperature modes are unclear. Accordingly, this study aimed to determine effects of incremental flows and temperature modes (heated and non-heated) of HFNC on upper airway muscle activity (genioglossus), pharyngeal airway pressure, breathing parameters and perceived comfort. Six participants (2 females, aged 35±14 years) were studied during wakefulness in supine position and received HFNC at variable flows (0-60 L/min) during heated (37ºC) and non-heated (21ºC) modes. Breathing parameters via calibrated Respitrace inductance bands (chest and abdomen), upper-airway pressures via airway transducers, and genioglossus muscle activity via intra-muscular bipolar fine wire electrodes were measured. Comfort levels during HFNC were quantified using a visual analogue scale. Increasing HFNC flows did not increase genioglossus muscle activation despite increased negative epiglottic pressure swings (p=0.009). HFNC provided ~7cmH₂O positive airway pressure at 60 L/min in non-heated and heated modes. In addition, increasing the magnitude of HFNC flow reduced breathing frequency (p=0.045), increased expiratory time (p=0.040), increased peak inspiratory flow (p=0.002), and increased discomfort (p=0.004). Greater discomfort occurred at higher flows in non-heated versus heated mode (p=0.034). These findings provide novel insight into key physiological changes that occur with HFNC for respiratory support and indicate the primary mechanism for improved upper-airway stability is positive airway pressure, not increased pharyngeal muscle activity.

Is kidney a new organ target in patients with obstructive sleep apnea? Research priorities in a rapidly evolving field

The bidirectional relationship between sleep disordered breathing and chronic kidney disease (CKD) has recently gained a lot of interest. Several lines of evidence suggest the high prevalence of coexistent obstructive sleep apnea (OSA) in patients with CKD and end-stage renal disease (ESRD). In addition, OSA seems to result in loss of kidney function in some patients, especially in those with cardio-metabolic comorbidities. Treatment of CKD/ESRD and OSA can alter the natural history of each other; still better phenotyping with selection of appropriate treatment approaches is urgently needed. The aim of this narrative review is to provide an update of recent studies on epidemiological associations, pathophysiological interactions, and management of patients with OSA and CKD or ESRD.

Rapid eye movement related obstructive sleep apnea: Where do we stand?

Rapid eye movement (REM) related obstructive sleep apnea (OSA) is defined by the presence of episodes of apnea or hypopnea predominantly or exclusively during REM sleep. Epidemiology of this disorder shows a complex interaction with age, sex, and body mass index. The prevalence is variable and depends on the criteria used to define this disorder. Moreover, the clinical significance of this entity remains poorly defined. However, episodes of apnea or hypopnea encountered during REM sleep are longer and are associated with a more profound drop in oxygen saturation than non-REM sleep. Likewise, this disorder may be independently associated with hypertension and poor glycemic control. More importantly, positive airway pressure therapy as currently prescribed may not treat the majority of apnea episodes during REM sleep. The treatment is further complicated by the different definitions used for the diagnosis of this disorder and the lack of consensus if patients with this diagnosis should be treated if their overall apnea-hypopnea index does not meet the threshold for the clinical diagnosis of OSA. The definition and treatment used for the diagnosis and management of REM-related OSA needs to be standardized. Moreover, a consensus needs to be developed as to whether patients with this disorder should be treated if their overall apnea-hypopnea index does not meet the threshold for the clinical diagnosis of OSA. Further investigation may help answer if this disorder is independently associated with neurocognitive and cardiometabolic adverse outcomes and help guide the therapeutic approach.

Low arousal threshold is associated with unfavorable shift of PAP compliance over time in patients with OSA

PURPOSE

To determine the predictive factors of initial and long-term adherence to positive airway pressure (PAP) therapy and factors leading to an unfavorable shift of PAP compliance.

METHODS

This follow-up study was comprised of newly diagnosed patients with obstructive sleep apnea (OSA) amenable to PAP therapy from January 2017 to April 2019. Information on basic demographics, comorbidities, and sleep-related symptoms were collected. PAP adherence data were collected at the end of the first week and the third month.

RESULTS

Of 166 patients enrolled, data from 142 (86%) were in the final analysis. Overall PAP usage was worse at 3 months declining from the first week. After adjusting for age and gender, multinomial logistic regression analysis showed that a small number of sleep-related symptoms (OR, 0.69; 95% CI, 0.52-0.91) and low arousal threshold (ArTH) (OR, 4.44; 95% CI, 1.52-12.98) were associated with higher odds of noncompliance. Low ArTH (OR, 2.87; 95% CI, 1.09-7.57) and lower body mass index (BMI) (OR, 0.88; 95% CI, 0.78-0.99) increased the risk of compliance-to-noncompliance shift. Sixty-two patients with polysomnography were analyzed separately. After adjustment for age and gender, poor sleep efficiency (OR, 0.80; 95% CI, 0.68-0.94) was associated with higher odds of consistent noncompliance. Low ArTH (OR, 15.36; 95% CI, 1.44-164.24) increased the risk of compliance-to-noncompliance shift in this subgroup.

CONCLUSIONS

Lower BMI and low ArTH were associated with an unfavorable shift of PAP compliance over time in patients with OSA, which was different from the predictors of consistent PAP noncompliance of patients with OSA.

Positive airway pressure therapy for chronic pain in patients with obstructive sleep apnea-a systematic review

PURPOSE

Obstructive sleep apnea (OSA) is prevalent in patients with chronic non-cancer pain. OSA may lead to low sleep quality and an increase in pain sensitivity. Patients reporting greater sleep impairment tend to experience higher pain intensity and vice versa. Positive airway pressure (PAP) is the current gold standard treatment for OSA. This review aims to evaluate the efficacy of PAP therapy in patients with comorbid chronic pain and OSA in influencing pain outcomes like pain intensity, tolerance, threshold, and sensitivity.

METHODS

We performed a systematic literature search for studies published after 1990, utilizing the following databases: Medline, Medline In-Process/ePubs, Embase, Cochrane CENTRAL, and the Cochrane Database of Systematic Reviews. Search terms included "chronic pain," "sleep disorders," and "positive airway pressure."

RESULTS

Of 1982 initial studies, ten studies met the study inclusion criteria. Seven of these studies examined the effect of PAP therapy on chronic pain, of which five demonstrated improved pain outcomes, specifically, headache pain. The effect of PAP therapy on chronic non-headache pain was found to be inconclusive. When examining the three studies that did not involve chronic pain patients, PAP therapy effectively increased pain threshold and tolerance in two studies (p = 0.03 and p = 0.01).

CONCLUSION

An association exists between PAP therapy and decreased chronic headache outcomes in patients with OSA. Additionally, research shows that PAP therapy may increase pain tolerance and threshold. Future high-quality evidence is required to further investigate the association between PAP and non-headache chronic pain.

Impact of the sleep apnea management group clinic on positive airway pressure adherence

Background

Positive airway pressure (PAP) adherence is critical for managing obstructive sleep apnea (OSA). We postulate that group-based Sleep Apnea Management (SAM) clinic, which harnesses the benefits of providing mutual support as well as facilitates access to system-based resources and education, will confer improvements in PAP adherence.

Methods

Data from SAM clinic attendees from January 2017 to June 2018 were retrospectively analyzed. Adherence data at SAM baseline visit and 1-3 months follow-up were collected. Average PAP usage from all-days and days used were analyzed along with demographics, co-morbidities, and Epworth Sleepiness Scale. Adherence was defined as >4 hours a night for ≥70% of nights over a 30-day period. Key structural elements of the SAM group clinic model were co-presence of the OSA care team members and peer group support. Key efficiency elements were group education and the prompt-to-patient multidisciplinary troubleshooting adherence barriers.

Results

Of 110 SAM clinic attendees, average age was 60.9±12.7 years, 53% were men, and 46% Caucasian. At baseline, the mean for average-all-days usage was 4.2 hours, mean average-days-used usage was 5.2 hours, and mean percentage-of-days usage ≥4 hours was 57%. At follow-up, the mean average-all-days usage increased 1.2 hours (p<0.001), mean average-days-used usage increased 0.8 hours (p<0.001), and the mean percentage-of-days with usage ≥4 hours increased 16% (p<0.001). At baseline, 46% of patients met criteria for adherence, which increased to 66% at follow-up.

Conclusion

In this study, after the SAM clinic, all PAP adherence parameters improved significantly. This observational study serves as a proof of concept study for future trials pertaining to group clinic in managing PAP adherence in OSA.

Transvenous phrenic nerve stimulation improves central sleep apnea, sleep quality, and quality of life regardless of prior positive airway pressure treatment

STUDY OBJECTIVE

Positive airway pressure (PAP) therapy for central sleep apnea (CSA) is often poorly tolerated, ineffective, or contraindicated. Transvenous phrenic nerve stimulation (TPNS) offers an alternative, although its impact on previously PAP-treated patients with CSA has not been examined.

METHODS

TPNS responses among PAP-naïve and prior PAP-treated patients from the remedē^® System Pivotal Trial were assessed. Of 151, 56 (37%) used PAP therapy before enrolling in the trial. Patients were implanted with a TPNS device and randomized to either active or deferred (control) therapy for 6 months before therapy activation. Apnea-hypopnea index (AHI) and patient-reported outcomes (PRO) were assessed at baseline, and 6 and 12 months following active therapy.

RESULTS

Patients had moderate-severe CSA at baseline, which was of greater severity and more symptomatic in the PAP-treated vs. PAP-naïve group (median AHI 52/h vs. 38, central apnea index (CAI) 32/h vs. 18, Epworth Sleepiness Scale 13 vs. 10, fatigue severity scale 5.2 vs. 4.5). Twelve months of TPNS decreased AHI to <20/h and CAI to ≤2/h. Both groups showed reductions in daytime sleepiness and fatigue, improved well-being by patient global assessment, and high therapeutic acceptance with 98% and 94% of PAP-treated and PAP-naïve patients indicating they would undergo the implant again. Stimulation produced discomfort in approximately one-third of patients, yet <5% of prior PAP-treated participants discontinued therapy.

CONCLUSION

Polysomnographic and clinical responses to TPNS were comparable in PAP-naïve and prior PAP-treated CSA patients. TPNS is a viable therapy across a broad spectrum of CSA patients.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT01816776; March 22, 2013.

Olfactory function in patients with obstructive sleep apnea and the effect of positive airway pressure treatment: a systematic review and meta-analysis

OBJECTIVES

To investigate olfactory function (OF) in patients with obstructive sleep apnea (OSA) and evaluate whether or not the use of positive airway pressure (PAP) treatment has an impact on olfactory performance.

METHODS

All studies published in English that gave satisfactory data regarding the assessment of OF in patients with OSA were included in this review. First, a baseline assessment of OF in patients with OSA who had not received any treatment was examined. Second, the effect of PAP therapy on OF was assessed to be able to make before and after comparisons. The primary outcome of this study was the threshold-discrimination identification (TDI) scores, obtained from the Sniffin' Sticks test.

RESULTS

The database search identified 552 articles. According to the exclusion criteria, 11 studies involving 557 patients diagnosed with OSA were included in this meta-analysis. The general rate of olfactory dysfunction was 73% (95% CI: 56.481-87.057) among the patients with OSA. The patients with OSA had lower TDI scores compared to the control group and the difference was statistically significant (p < 0.001). PAP treatment significantly improved the TDI scores in patients with OSA (p < 0.001). There was a significant negative correlation between the severity of apnea-hypopnea index and TDI scores (p = 0.001, z = -3.377, r = -0.438) and between age and TDI scores (p = 0.007, z = -2.695, r = -0.236).

CONCLUSION

This meta-analysis demonstrates that OSA impairs OF, while PAP treatment can reverse the olfactory performance of patients with OSA.

The impact of national health insurance on the compliance of positive airway pressure therapy in patients with obstructive sleep apnea

Objectives

Compliance with positive airway pressure (PAP) in patients with obstructive sleep apnea (OSA) directly affects its treatment efficacy. Since July 2018, polysomnography and PAP therapy have been covered by the national health insurance (NHI), which has reduced the price barrier and promoted PAP therapy in Korea. This study aimed to compare changes in PAP compliance before and after NHI implementation.

Methods

This study is a retrospective analysis in a tertiary hospital setting in Korea. From 2011 to 2019, patients with OSA (apnea-hypopnea index≥5) treated using a PAP device for ≥ 1 month were included. They were allocated to the pre-insurance (PI) (having started PAP before July 2018) and NHI groups (having received a PAP reimbursement by the NHI service). We collected and analyzed medical records and PAP use information for between-group comparisons of compliance. We defined compliance as (A) percentage of usage days, (B) percentage of days with usage for ≥ 4 night hours, and (C) average daily usage hours.

Results

We included 146 and 100 patients in the PI and NHI groups, respectively. Automatic positive airway pressure (APAP) mode and NHI were independent predictors of compliance B at the 3- and 9-month follow-up points. The NHI group showed significantly higher compliance A at 3, but not 9 months. For compliance B, the NHI group showed significantly higher compliance than the PI group at 1 month and 3 months, but not at 9 months. Compared with the PI group, the NHI group showed significantly higher compliance C only at 3 months.

Conclusion

The NHI has positively affected PAP therapy in patients with OSA. Insurance policy may affect compliance within the first 3 months.

Adherence to Sleep Therapies in Children and Adolescents

Improved recognition of obstructive sleep apnea (OSA) in children has led many to identify effective strategies to treat pediatric OSA. Positive airway pressure (PAP) therapy in children, which has been shown to resolve OSA, is highly contingent on adequate adherence. In pediatrics, adherence is complex, related largely to the influence of age. Consequently, reported adherence rates in children are often lower than adults. Notwithstanding, studies have identified significant risk factors, some modifiable, and several intervention strategies that may improve pediatric adherence. Close follow-up, including use of cloud-based monitoring, of children using PAP therapy may optimize adherence further.

Socioeconomic Disparities in Positive Airway Pressure Adherence: An Integrative Review

Nonadherence with positive airway pressure (PAP) therapy impedes the effectiveness of treatment and increases risk of mortality. Disparities in PAP adherence as a function of socioeconomic status (SES) are not well understood. A literature search identified 16 original publications meeting inclusion criteria that described effects of SES factors on objective PAP adherence; 69% of these articles found evidence of lower adherence as a function of SES. This integrative review provides a structured summary of the findings, highlights factors that may contribute to disparities among adult PAP users, and identifies future directions to improve equity in the management of OSA.

Considering the Role of Adherence in New and Emerging Sleep Treatments

There are several novel and emerging treatments for obstructive sleep apnea (OSA), including new devices and pharmacotherapies. Long-term efficacy and adherence data for these interventions in the sleep context are lacking. Future studies exploring the long-term adherence and efficacy in novel and emerging treatments of OSA are required to fully understand the place of these treatments in treatment hierarchies. Such research also should aim to evaluate the use of these novel therapies in real-world clinical settings, because many of the studies performed to date have been done under closely monitored research populations and relatively small sample sizes.

What is a Clinically Meaningful Target for Positive Airway Pressure Adherence?

Although good adherence to continuous positive airway pressure (PAP) traditionally is defined as greater than or equal to 4 hours/night, the origins and rationale for this remain unclear. Research studies report variation in optimal duration of PAP adherence, depending on outcome of interest. Evidence demonstrates benefit with PAP for daytime sleepiness, quality of life, neurocognitive outcomes, depression, and hypertension, predominantly in symptomatic, moderate-severe obstructive sleep apnea. Recent randomized controlled trials, however, have failed to demonstrate a reduction in cardiovascular and mortality risks. This review explores the question of what can be considered a clinically meaningful outcome for PAP adherence.

Validating respiratory index of auto-titrating positive airway pressure device with polysomnography

PURPOSE

Positive airway pressure (PAP) devices have been widely used as the first line of treatment in obstructive sleep apnea (OSA). Most advanced PAP devices support the estimation of respiratory index (RI) using the patient's mask airflow. In addition to the compliance factor for PAP device use, which is important for monitoring patient sleep health, RI is also becoming important for monitoring. However, there are few reports that validate RI of a PAP device with polysomnography.

METHODS

Between January 2015 and December 2017, 50 participants were enrolled who were diagnosed with OSA and prescribed auto-titration PAP (APAP) devices. The RIs of participants were measured at night using APAP devices, concurrently with electroencephalography, respiratory inductance plethysmography sensors, and other polysomnographic sensors in a sleep laboratory. The respiratory-related data of APAP were prospectively analyzed with the manually scored polysomnographic data.

RESULTS

The apnea-hypopnea index and apnea index showed a statistically close relationship between the auto-scored respiratory data from the APAP device and the manually scored respiratory data from polysomnographic sensors. Obstructive apnea and central apnea indices showed relatively low correlations. The differences between the auto-scored RI and manually scored RI were influenced by BMI, waist circumference, weight, oxygen saturation, and respiratory distress indices of diagnostic polysomnographic factors.

CONCLUSIONS

The RIs of APAP devices have a tendency to be underestimated or mismatched when compared with polysomnography. Sleep specialists are advised to consider additional anthropometric and diagnostic factors to account for these differences during PAP treatment.

Rationale and design of the Hyperglycemic Profiles in Obstructive Sleep Apnea (HYPNOS) trial

The Hyperglycemic Profiles in Obstructive Sleep Apnea (HYPNOS) randomized clinical trial was conducted in adults with type 2 diabetes and moderate-to-severe obstructive sleep apnea (OSA) to determine whether treatment with positive airway pressure (PAP) therapy is associated with improvements in glycemic measures. Participants were randomly assigned to PAP therapy with lifestyle counseling or lifestyle counseling alone. While observational and experimental evidence indicate that intermittent hypoxemia and recurrent arousals in OSA may alter glucose metabolism and worsen glycemic measures, the effect of treating OSA with PAP therapy on these measures in type 2 diabetes is uncertain. Adequately powered randomized clinical trials have yet to be performed to demonstrate whether PAP therapy for OSA in patients with type 2 diabetes can improve glycemic measures. The HYPNOS trial was designed to determine whether PAP therapy for OSA in patients with type 2 diabetes over 3 months leads to improvements in glycemic measures including glycemic variability (standard deviation) based on Dexcom G4 Platinum continuous glucose monitoring. Secondary objectives were to assess the effects of PAP therapy for OSA on measures of: (1) glycemic variability based on Abbott Freestyle Pro Libre continuous glucose monitoring; (2) point-of-care hemoglobin A1c (HbA1c); (3) degree of post-prandial hyperglycemia as determined by 7-point self-monitoring of blood glucose; (4) clinic and ambulatory blood pressure; and (5) endothelial function. The HYPNOS trial was designed to address gaps in our understanding of the effects of PAP therapy on glucose metabolism in adults with type 2 diabetes and moderate-to-severe OSA. Trial Registration: ClinicalTrials.gov Identifier NCT02454153.

Perioperative Care and Medication-related Hypoventilation

Cumulative evidence supports the association of adverse postoperative outcomes with obstructive sleep apnea (OSA) and obesity hypoventilation syndrome (OHS). Although current guidelines recommend preoperative screening for OSA and OHS, the best perioperative management pathways remain unknown. Interventions attempting to prevent complications in the postoperative period largely are consensus based and focused on enhanced monitoring, conservative measures, and specific OSA therapies, such as positive airway pressure. Until further research is available to improve the quality and strength of these recommendations, patients with known or suspected OSA and OHS should be considered at higher risk for perioperative cardiopulmonary complications.

Treatment of Obstructive Sleep Apnea: Achieving Adherence to Positive Airway Pressure Treatment and Dealing with Complications

Obstructive sleep apnea is a common and treatable condition, but therapeutic adherence is limited by numerous factors. Despite advances in positive airway pressure (PAP) technology and a multitude of effective pharmacologic and behavioral therapeutic interventions to overcome the most common barriers to PAP, adherence has not increased significantly over the past 30 years. This review aims to identify the most important factors that impact adherence, common barriers to treatment, and evidence-based treatment strategies to maximize the effectiveness of PAP treatment. Complications of PAP treatment and mitigation techniques are also discussed.

Findings of routine nocturnal polysomnography in children with Down syndrome: a retrospective cohort study

STUDY OBJECTIVE

Children with Down syndrome (DS) are at risk for sleep disorders including; obstructive sleep apnea (OSA). Although OSA is diagnosed by polysomnography (PSG), the practicality of PSG in DS is questionable. Further, OSA treatment efficacy in DS is largely unknown given the challenges of PSG. Our aims were to review (i) the feasibility of PSG, and (ii) the efficacy (improvement in obstructive apnea hypopnea index (OAHI)) of OSA treatment using follow-up PSG in DS.

METHODS

Retrospective review of patients aged <21 years with DS who underwent PSG from October 2016 to June 2019. Successful PSG was determined using total sleep time (TST). PSG following treatment with adenotonsillectomy (AT) or positive airway pressure (PAP) was evaluated and compared to pre-treatment.

RESULTS

Among 248 patients with DS, only 11(4.4%) had unsuccessful PSG (TST<1h). Of the 237 successful studies (age: 7.9 ± 0.3y), average TST and sleep efficiency was 5.6 ± 0.1h and 79.5 ± 1.3%. 41 had post-AT PSG and 11(27%) achieved OSA cure (OAHI<2) with all demonstrating improved SE (p = 0.01) and OAHI (p = 0.0003). Multivariate analysis revealed only age was predictive (p = 0.003) of residual OSA post-AT. Of 24 children who underwent PAP titration, 20(83%) tolerated titration with improved OAHI (p = 0.01), however, no significant improvements in SE were observed.

CONCLUSIONS

In a large cohort of DS children, PSG was well tolerated. Following AT or PAP therapy, post treatment PSG confirmed efficacy, although residual OSA was identified. PSG is thus both feasible and useful in identifying OSA, OSA treatment response and should guide in decision making in children with DS.

Low arousal threshold is associated with unfavorable shift of PAP compliance over time in patients with OSA

PURPOSE

To determine the predictive factors of initial and long-term adherence to positive airway pressure (PAP) therapy and factors leading to an unfavorable shift of PAP compliance.

METHODS

This follow-up study was comprised of newly diagnosed patients with obstructive sleep apnea (OSA) amenable to PAP therapy from January 2017 to April 2019. Information on basic demographics, comorbidities, and sleep-related symptoms were collected. PAP adherence data were collected at the end of the first week and the third month.

RESULTS

Of 166 patients enrolled, data from 142 (86%) were in the final analysis. Overall PAP usage was worse at 3 months declining from the first week. After adjusting for age and gender, multinomial logistic regression analysis showed that a small number of sleep-related symptoms (OR, 0.69; 95% CI, 0.52-0.91) and low arousal threshold (ArTH) (OR, 4.44; 95% CI, 1.52-12.98) were associated with higher odds of noncompliance. Low ArTH (OR, 2.87; 95% CI, 1.09-7.57) and lower body mass index (BMI) (OR, 0.88; 95% CI, 0.78-0.99) increased the risk of compliance-to-noncompliance shift. Sixty-two patients with polysomnography were analyzed separately. After adjustment for age and gender, poor sleep efficiency (OR, 0.80; 95% CI, 0.68-0.94) was associated with higher odds of consistent noncompliance. Low ArTH (OR, 15.36; 95% CI, 1.44-164.24) increased the risk of compliance-to-noncompliance shift in this subgroup.

CONCLUSIONS

Lower BMI and low ArTH were associated with an unfavorable shift of PAP compliance over time in patients with OSA, which was different from the predictors of consistent PAP noncompliance of patients with OSA.