Continuous Positive Airway Pressure Compliance Research Articles

Continuous positive airway pressure improved daytime sleepiness and memory function in patients with obstructive sleep apnea.

Obstructive sleep apnea (OSA) is a sleep disorder which results in daytime sleepiness and impaired memory function. The aim of this study was to investigate the effect of continuous positive airway pressure (CPAP) on daytime sleepiness and memory function in OSA patients. We also investigated whether CPAP compliance impacted the effect of this treatment. The nonrandomized, nonblinded clinical trial enrolled 66 patients with moderate-to-severe OSA subjects. All subjects completed a polysomnographic study, daytime sleepiness questionnaires (the Epworth Sleepiness Scale and the Pittsburgh Sleep Quality Index), and four memory function tests (working memory; processing speed [PS]; logical memory [LM]; face memory [FM]). Before CPAP treatment, no significant differences (P < 0.05) were noted in the demographic data, daytime sleepiness, or memory function between two groups (with/without CPAP). However, OSA patients treated with CPAP for 2 months showed significant improvements in daytime sleepiness, PS, mostly of LM, and FM comparing to 2 months ago. As compared to those who did not receive CPAP treatment, CPAP can improve only parts of LM (delayed LM [DLM] and LM percentage [LMP]). In addition, compared to control group, a significant improvement of daytime sleepiness and LM (LM learning, DLM, and LMP) in good compliance with CPAP treatment group and of DLM and LMP in the low compliance with CPAP treatment group was found. CPAP treatment for 2 months could improve some of LM in OSA patients, especially in patients exhibiting good CPAP compliance.

Surgical Treatment Options for Epiglottic Collapse in Adult Obstructive Sleep Apnoea: A Systematic Review.

The critical role of epiglottis in airway narrowing contributing to obstructive sleep apnoea (OSA) and continuous positive airway pressure (CPAP) intolerance has recently been revealed. This systematic review was conducted to evaluate available surgical treatment options for epiglottic collapse in adult patients with OSA. The Pubmed and Scopus databases were searched for relevant articles up to and including March 2022 and sixteen studies were selected. Overall, six different surgical techniques were described, including partial epiglottectomy, epiglottis stiffening operation, glossoepiglottopexy, supraglottoplasty, transoral robotic surgery, maxillomandibular advancement and hypoglossal nerve stimulation. All surgical methods were reported to be safe and effective in managing selected OSA patients with airway narrowing at the level of epiglottis. The surgical management of epiglottic collapse can improve OSA severity or even cure OSA, but can also improve CPAP compliance. The selection of the appropriate surgical technique should be part of an individualised, patient-specific therapeutic approach. However, there are not enough data to make definitive conclusions and additional high-quality studies are required.

P039 A novel mean disease alleviation outcome measure in the management of adult obstructive sleep apnoea

Abstract Introduction Current methods assessing device and surgical treatment efficacy for OSA, such as apnoea hypopnea index (AHI), do not factor in compliance. Clinical effectiveness may be better represented when long-term compliance is incorporated into a mean disease alleviation score (MDA). Here, MDA scores between surgery and device are compared in a high-volume adult OSA clinic. Methods Three hundred and forty-five patients seen over a 13-year period in a high-volume adult OSA clinic staffed by an experienced sleep-trained otolaryngologist and sleep physician were included. Patients were managed with device (Continuous Positive Airway Pressure (CPAP), Mandibular Advancement Splint (MAS) or underwent multilevel airway surgery. Mean disease alleviation was calculated as the product of therapeutic efficacy (change in AHI) and adjusted compliance. Surgical compliance was assumed as one hundred percent. Cardinality matching was utilised to account for differences in patient and disease factors between subgroups. Results Surgically treated patients demonstrated higher MDA than device users (67.3 ± 29.9% vs. 59.4 ± 31.1%, p=0.039), despite higher therapeutic efficacy seen in device users (85.0±24.4% vs. 67.0±29.9%, p&amp;lt;0.001). Surgical patients were younger, had lower comorbidity scores, lower BMI, and suffered worse daytime sleepiness than device users. Cardinality matching for these factors demonstrated similar mean MDA between groups (66% vs 58%, p=0.11). Device users had to utilise &amp;gt;8hrs per night of compliant use to reach a similar MDA to matched surgical patients. Discussion In Adult OSA patients with less-than-ideal CPAP compliance, multilevel airway surgery is an equivalent and effective alternative, based on novel MDA measures.

P002 CPAP therapy compliance and changes in cognitive function in patients with obstructive sleep apnoea

Abstract Aims Obstructive sleep apnoea (OSA) has been implicated in the pathophysiology of Alzheimer’s disease (AD). Intermittent hypoxia and arousals may contribute to mechanisms leading to accumulation of amyloid beta plaques and intraneuronal neurofibrillary tangles seen in AD. Treatment with Continuous Positive Airway Pressure (CPAP) improves symptoms and cardiovascular sequalae of OSA, and may also mitigate the progression of AD. We investigated, in patients with moderate to severe OSA, whether CPAP compliance altered cognitive test scores. Methods Cognitive testing with the Addenbrooke’s Cognitive Examination-Revised Version (ACE-R) was performed before commencing CPAP and repeated after 3 to 5 years. Student’s independent t-test was used to compare changes in ACE-R between compliant and non-complaint groups based on usage greater than 4 hours/day. Results 30 subjects, mean age 67 years (SD=6.4), had baseline ACE-R of 90 (SD=4.75). At follow up, treatment compliant subjects demonstrated improvement in cognitive test scores in the memory and visuospatial cognitive domains with a mean improvement in memory of 1.5 points p=0.01 95% CI [0.33, 2.67], and mean improvement in visuospatial cognition of 0.95 points p=0.01 95% CI [0.23, 1.7]. Scores for CPAP non-compliant subjects showed no significant difference over time. Conclusion Sustained use of CPAP over time results in a statistically significant improvement in ACE-R test scores, in the subdomains of memory and visuospatial cognition. However, the clinical significance of these findings is unclear and requires further research, as the scores remained in the normative range.

Impact of OSA treatment success on changes in hypertension and obesity: A retrospective cohort study

ObjectivePediatric obstructive sleep apnea (OSA) has been shown to lead to the development of chronic cardiometabolic conditions, including obesity and cardiovascular disease. We sought to describe the impact of the success of continuous positive airway pressure (CPAP) and surgery, common treatment options for pediatric OSA, on cardiometabolic conditions. MethodsA retrospective review of patients (≤18 years) diagnosed with OSA based on a polysomnogram at a tertiary care pediatric otolaryngology practice from 2015 to 2019 was conducted. Clinical data, including the systolic blood pressure (SBP) values, body mass index (BMI), overall apnea/hypopnea index (AHI) values, and CPAP compliance, were collected. Linear mixed-effects models were developed to observe the relationship between the clinical measurements of each comorbidity and OSA treatment modalities. Results414 patients were included. BMI and SBP measures were collected for 230 and 184 patients respectively. The difference-in-difference estimate for the SBP z-score percentile after successful treatment was −5.5 ± 2.1 percentile units per 100 days. The difference-in-difference estimate for SBP z-score percentile after successful CPAP treatment was −13.2 ± 5.1 percentile units per 100 days while the estimate after successful surgical treatment was −4.6 ± 2.4 percentile units per 100 days. No significant differences were found between clinical measures for obese patients in any treatment cohort. ConclusionsSuccessful OSA management was shown to have a positive impact on SBP in hypertensive patients and no impact on BMI in obese patients. In hypertensive patients, CPAP success tripled improvements in SBP z-score percentile compared to surgical treatment success.

The Role of Isolated Nasal Surgery in Obstructive Sleep Apnea Therapy-A Systematic Review.

Nasal obstruction is believed to play a significant role in the pathophysiology and management of obstructive sleep apnea (OSA). However, controversy remains about the ability of isolated nasal surgery to improve OSA. The objective of this systematic review is to give an updated overview of the literature on whether isolated nasal surgery can improve OSA subjectively (Epworth Sleepiness Scale (ESS)) and/or objectively (polysomnography (PSG)). Methods: A systematic review was performed searching the electronic databases PubMed, Embase.com (accessed on 20 June 2022) Cochrane Database of Systematic Reviews and Cochrane Central Register of Controlled Trials (CENTRAL) up to 20 June 2022. Eligible studies were reviewed for methodological quality using the NIH Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Results: Twenty-one studies met the inclusion criteria. The majority of the included studies reported no significant reduction in the apnea-hypopnea index (AHI) after isolated nasal surgery in patients with OSA. The meta-analysis suggests that the AHI slightly decreases after nasal surgery. The ESS was significantly lower after nasal surgery in eighteen studies. Conclusion: Based on the present analysis of objective outcomes, isolated nasal surgery did not improve the AHI significantly in the majority of the studies. The meta-analysis suggests a slight decrease in AHI after nasal surgery, but this reduction is not clinically relevant in terms of treatment success. Isolated nasal surgery should therefore not be recommended as a first-line treatment for OSA. Because of high study heterogeneity, these results should be interpreted with caution. Isolated nasal surgery can possibly improve OSA subjectively. Perhaps only OSA patients with complaints of nasal obstruction or OSA patients experiencing difficulty with continuous positive airway pressure (CPAP) compliance would benefit from isolated nasal surgery.

Differential effects of obstructive sleep apnea on the corneal subbasal nerve plexus and retinal nerve fiber layer.

PurposeObstructive sleep apnea (OSA) is an established independent risk factor for peripheral neuropathy. Macro and microvascular changes have been documented in OSA, including high levels of potent vasoconstrictors. In diabetes, vasoconstriction has been identified as an underlying risk factor for corneal neuropathy. This study sought to establish a potential relationship between OSA and corneal nerve morphology and sensitivity, and to determine whether changes in corneal nerves may be reflective of OSA severity.DesignSingle center cross-sectional study.MethodsSixty-seven patients were stratified into two groups: those with OSA and healthy controls. Groups were matched for age, sex, race, smoking, and dry eye status. Outcome measures included serologies, a dilated fundus exam, dry eye testing, anthropometric parameters, corneal sensitivity, subbasal nerve plexus morphology, retinal nerve fiber layer (RNFL) thickness, and the use of questionnaires to assess symptoms of dry eye disease, risk of OSA, and continuous positive airway pressure (CPAP) compliance.ResultsNo significant differences were observed in corneal nerve morphology, sensitivity, or the number of dendritic cells. In the OSA test group, RNFL thinning was noted in the superior and inferior regions of the optic disc and peripapillary region. A greater proportion of participants in the OSA group required a subsequent evaluation for glaucoma than in the control. In those with OSA, an increase in the apnea hypopnea index was associated with an increase in optic nerve cupping.ConclusionsOSA does not exert a robust effect on corneal nerves. OSA is however, associated with thinning of the RNFL. Participants with glaucomatous optic nerve changes and risk factors for OSA should be examined as uncontrolled OSA may exacerbate glaucoma progression.

Continuous positive airway pressure treatment of obstructive sleep apnea and hypertensive complications in high-risk pregnancy.

To evaluate whether or not continuous positive airway pressure (CPAP) treatment in pregnancies complicated by obstructive sleep apnea (OSA) is associated with a decrease in hypertensive disorders of pregnancy. This was a retrospective cohort study of perinatal outcomes in women who underwent objective OSA testing and treatment as part of routine clinical care during pregnancy. Where diagnostic criteria for OSA were reached (respiratory event index (REI) ≥ 5 events per hour), patients were offered CPAP therapy. Obstetrical outcomes were compared between the control group (no OSA), the group with untreated OSA (OSA diagnosed, not CPAP compliant), and the group with treated OSA (OSA diagnosed and CPAP compliant), with CPAP compliance defined as CPAP use ≥ 4h, 70% of the time or greater. A composite hypertension outcome combined diagnoses of gestational hypertension (gHTN) and preeclampsia (PreE) of any severity. The study comprised outcomes from 177 completed pregnancies. Our cohort was characterized by obesity, with average body mass indices > 35kg/m2, and average maternal age > 30years old. CPAP was initiated at an average gestational age of 23weeks (12.1-35.3weeks), and average CPAP use was 5.9h (4-8.5h). The composite hypertension outcome occurred in 43% of those without OSA (N = 77), 64% of those with untreated OSA (N = 77), and 57% of those with treated OSA, compliant with CPAP (N = 23) (p = 0.034). Real-world data in this small study suggest that CPAP therapy may modulate the increased risk of hypertensive complications in pregnancies complicated by OSA.

Holistic care for obstructive sleep apnea (OSA) with an emphasis on restoring nasal breathing: A review and perspective.

Obstructive sleep apnea (OSA) is characterized by partial or complete airway blockage during sleep. Nocturnal nasal obstruction usually leads to mouth breathing while sleeping, which worsens sleep apnea by aggravating tongue base and lateral pharyngeal wall collapse. The pathogenesis of OSA is multifactorial, and the precipitating factors vary significantly among individuals. Although continuous positive airway pressure (CPAP) is considered the first-line therapy for OSA, its adherence rate remains a challenge. Oral appliances are more suitable for simple snorers or patients with mild OSA. Maxillomandibular advancement (MMA) is highly effective for treating those with mandibular retrognathia and moderate-to-severe OSA. Intrapharyngeal surgeries yield favorable outcomes in patients with large tonsils and low tongue resting position (Friedman Stage I); however, their efficacy declines with time. Each therapy has its own strength and weakness; thus, the principle of multimodality treatment should be adopted. Nasal surgery plays an indispensable role in the holistic care for OSA. In addition to alleviating nasal congestion, nasal surgery significantly reduces snoring intensity and daytime sleepiness, which improves the quality of life of patients with OSA. Although it significantly reduces the respiratory disturbance index, its effect on the apnea-hypopnea index remains controversial. A combination of nasal surgery and multilevel pharyngeal surgery may result in better prognosis. Nasal surgery can significantly reduce the therapeutic pressure and improve the CPAP compliance of patients undergoing CPAP therapy. In conclusion, multimodality treatment and holistic care for OSA should involve nasal surgery for optimizing treatment outcomes.

0798 Detriggered - a case of tenosynovitis ameliorated by CPAP

Abstract Introduction The influence of sleep quality and pain is bidirectional (1). Sleep loss can induce hyperalgesia through upregulated inflammatory mediators such as IL-6 and TNF (2, 3). Obstructive sleep apnea (OSA) is characterized by obstructive respiratory events, hypoxemia, sleep fragmentation, and ultimately poor quality sleep. Here we present a case of how the treatment of OSA with continuous positive airway pressure (CPAP) mitigated hand inflammation and trigger finger symptoms. Report of Cases: A 60 year old male with prediabetes, hypertension, and BMI 30 presented to primary care with bilateral finger pain and stiffness. Hand orthopedics noted a tender left A1-pully 4th finger with 20 degree flexion contracture and a palpable right 3rd finger flexor tendon nodule causing definite triggering. He was diagnosed with trigger finger and initially treated with steroid injections and again 5 months later due to persistent symptoms. 10 months after the initial orthopedic visit, orthopedics planned for surgical intervention, but patient missed his surgery for unknown reasons. 7 months later, sleep medicine evaluated the patient for snoring and daytime fatigue. He underwent home sleep apnea testing which revealed a respiratory event index (REI) of 36.7 which necessitated CPAP therapy. Unfortunately, the patient was then lost to follow up in sleep medicine clinic. More than a year later, the patient showed to clinic and found to have 100% CPAP compliance with residual REI of 0.7. He enthusiastically noted improvement of daytime fatigue and trigger finger symptoms when using CPAP. When he would forget to use CPAP at night or during naps, he would wake up with returned finger pain and stiffness. Per patient, the symptoms would then resolve after re-initiation of CPAP. This consistent association of CPAP and finger symptom amelioration continued even 8 months later in most recent follow up. Conclusion To our knowledge, this is the first report of trigger finger symptoms improving with treatment of OSA. One hypothesis is that through improved sleep quality, there is a dampening of chondrocyte proliferation of the retinacular sheath and allowing unrestricted motion of the flexor tendon (4). More studies are needed to evaluate the musculoskeletal benefits of CPAP for OSA. Support (If Any) 1. Haack M. Scott Sutherlandj. Et al. Pain sensitivity and modulation in primary insomnia. Eur J Pain. 2012, 16: 522-533.2. Chhangani BS, Roehrs Ta et al. Pain sensitivity in sleepy pain-free normals. Sleep, 209, 32:1011-1017.3. Li, Joule Sarah Appleton. Association of Musculoskeletal Joint Pain with Obstructive Sleep Apena, Daytime Sleepiness, and Poor Sleep Quality in Men. Arthritis Care and Research Vol 69. No 5. May 2017.4. Makkouk Al Hasan et al. Trigger finger: etology, evaluation, and treatment. Curr Rev Musculoskeltal Med 2008. 1:92-96.

0840 Be Wary Of Adjustment Disorder with Anxiety In Patient With Insomnia And Discomfort With Positive Pressure Airway Therapy

Abstract Introduction Insomnia is a common complaint. When it occurs in the context of treatment with continuous positive airway pressure (CPAP), it can complicate treatment and lead to dissatisfaction with CPAP therapy. Adjustment disorder with anxiety (ADWA) is a condition that develops following an identifiable stressor and can be associated with insomnia. We describe a case of ADWA causing disrupted sleep and dissatisfaction with CPAP therapy. Report of Cases: The patient is an 80-year-old man with history of severe obstructive sleep apnea (OSA) and chronic obstructive lung disease, under stable management with CPAP. During a routine follow up visit, he reported the recent onset of frequent, and often prolonged, nocturnal awakenings associated with daytime sleepiness and fatigue. Insomnia was associated with discomfort with breathing, especially during exhalation, while using CPAP. His machine report indicated a significant decrement in compliance. Upon questioning, he reported that a few of his family members had died unexpectedly, following which he began to experience significant anxiety. His wife noted that he had become moody and irritable. On examination, the patient was visibly anxious; his speech was accelerated and animated, and he displayed psychomotor activation. Affect also displayed despondency. The patient was diagnosed with ADWA leading to insomnia and discomfort with CPAP use. He was prescribed buspirone 10 mg twice daily. On two week follow up patient reported no improvement in symptoms and was switched to escitalopram 10 mg daily. Following approximately three weeks, his clinical evaluation revealed significant improvement in mood; anxiety had dissipated, and sleep was more continuous with infrequent and brief awakenings. Daytime alertness had been restored. Of interest was the temporary return of anxiety and insomnia symptoms following the brief discontinuation of escitalopram because of hospitalization. Conclusion ADWA can occur in the setting of recent stressors and can result in sudden onset of insomnia, compromise CPAP adherence and decrease subjective benefit from PAP therapy. This case highlights the importance of questioning patients for the possibility of recent stressors and traumatic events when they develop difficulties with PAP use. These may indicate the presence of ADWA, whose management can restore CPAP compliance and improve sleep quality and daytime functioning. Support (If Any)

Telemonitoring for the Follow-Up of Obstructive Sleep Apnea Patients Treated with CPAP: Accuracy and Impact on Therapy.

Continuous positive airway pressure (CPAP) telemonitoring (TMg) has become widely implemented in routine clinical care. Objective measures of CPAP compliance, residual respiratory events, and leaks can be easily monitored, but limitations exist. This review aims to assess the role of TMg in CPAP-treated obstructive sleep apnea (OSA) patients. We report recent data related to the accuracy of parameters measured by CPAP and try to determine the role of TMg in CPAP treatment follow-up, from the perspective of both healthcare professionals and patients. Measurement and accuracy of CPAP-recorded data, clinical management of these data, and impacts of TMg on therapy are reviewed in light of the current literature. Moreover, the crucial questions of who and how to monitor are discussed. TMg is a useful tool to support, fine-tune, adapt, and control both CPAP efficacy and compliance in newly-diagnosed OSA patients. However, clinicians should be aware of the limits of the accuracy of CPAP devices to measure residual respiratory events and leaks and issues such as privacy and cost-effectiveness are still a matter of concern. The best methods to focus our efforts on the patients who need TMg support should be properly defined in future long-term studies.

Feasibility and Long-Term Compliance to Continuous Positive Airway Pressure Treatment in Adults With Down Syndrome, a Genetic Form of Alzheimer's Disease.

BackgroundDown syndrome (DS) is a genetic form of Alzheimer’s disease (AD) with a high prevalence of obstructive sleep apnea (OSA). These characteristics place the DS population as an optimal model to study the relationship between sleep and AD and to design clinical trials of preventive sleep therapies for AD. Regrettably, OSA treatment with continuous positive airway pressure (CPAP) is often neglected in adults with DS. In both clinical practice and research trials, it is usually presumed that these patients will not adapt to or tolerate the therapy.Study ObjectiveWe aimed to evaluate the feasibility and long-term CPAP compliance in this population and their capacity to be enrolled in CPAP research studies.MethodsWe prospectively compared the CPAP compliance of 17 OSA patients with DS and 19 age and sex matched OSA euploid patients. CPAP management and follow-up schedules were prescribed according to the habitual clinical practice. We compared group differences in tolerance, objective, and subjective hours of nightly CPAP usage at the 1st, 3rd, 6th, 12th, 24th, and 36th month visits. Good compliance was defined as at least 4 h use per night. We also investigated predictive factors of long-term CPAP compliance.ResultsThe percentage of DS subjects with good CPAP compliance (81.2 vs. 78.9%) and the objective CPAP use (5 vs. 6 h, p = 0.92) did not differ from the control group (CG). Subjective CPAP compliance was significantly higher in OSA patients with DS than in controls in all the follow-up visits (8 vs. 6.75 h, p = 0.001). The DS group had a significantly higher number of visits (9 vs. 5; p = 0.021) and mask changes (2.5 vs. 2; p = 0.05) than controls. Objective hours of CPAP use at the first follow-up visit predicted long-term CPAP compliance (p < 0.005).ConclusionCPAP treatment is feasible and has good long-term compliance in OSA patients with DS. It should be recommended to improve health and prevent comorbidities. The DS population is indeed suitable to participate in longitudinal preventive sleep clinical trials for AD.

Heart-Sparing Capability and Positional Reproducibility of Continuous Positive Airway Pressure in Left-Sided Breast Radiation Therapy

PurposeOur purpose was to investigate the interfraction and intrafraction reproducibility and practical applicability of continuous positive airway pressure (CPAP) for left breast volumetric modulated arc therapy (VMAT). Methods and MaterialsInterfraction reproducibility of the position of the heart was evaluated by measuring the heart-to-target distance on 20 planning computed tomography (CT) and 300 daily cone beam CT of 20 patients with left breast cancer treated with a 15-fraction VMAT. The dosimetric metrics of the whole heart and its substructures were compared between CPAP and free-breathing based VMAT plans. Intrafraction reproducibility was evaluated by measuring the motions of the breast target and diaphragm in 4-dimensional CT of 20 female patients with nonbreast cancer. Lastly, we analyzed the CPAP compliance data of 237 consecutive patients with left-sided breast cancer with and without internal mammary node irradiation (IMNI). ResultsThe heart position was reproducible as evidenced by an absolute average heart-to-target distance error of 2.0 ± 2.0 mm. Compared with free-breathing, CPAP significantly reduced the mean heart dose and the dose to the left ventricle and left anterior descending artery. The average intrafraction position variation of the breast target was 0.5 ± 0.5, 2.5 ± 2.0, and 1.8 ± 1.4 mm in the mediolateral, craniocaudal, and anteroposterior directions, respectively. CPAP was successfully applied in 221 patients (93%), with a mean heart dose of 1.6 ± 0.7 Gy (IMNI: 2.0 Gy and no IMNI: 1.1 Gy). ConclusionsCPAP has adequate heart-sparing capability and sufficient reproducibility in VMAT for left-sided breast cancer treatment, with a high compliance rate. Thus, CPAP is applicable in routine practice for left-sided breast cancer radiation therapy.

Continuous Positive Airway Pressure Compliance: Addressing the Elephant in the Room

Continuous Positive Airway Pressure Compliance: Addressing the Elephant in the Room

Surgical correction of nasal obstruction in obstructive sleep apnea improves CPAP outcomes and compliance.

Although continuous positive airway pressure (CPAP) therapy curtails most of the negative impacts of obstructive sleep apnea (OSA), its efficacy is limited by its low long-term adherence. Nasal obstruction contributes to OSA pathophysiology and necessitates high CPAP titration pressures which reduce CPAP compliance. This study aims at elucidating the outcomes of surgical correction of nasal obstruction in patients intolerant to CPAP therapy. Forty-nine patients with severe OSA intolerant to CPAP secondary to surgically correctable nasal obstruction were operated upon. Patients were evaluated preoperatively and at least 3months after the surgical intervention. Subjective assessment entailed the Nasal Obstruction Symptom Evaluation score (NOSE) and the Epworth Sleepiness Scale (ESS). Objectively the patients were assessed by acoustic rhinometry and standard polysomnography. Nasal surgical intervention resulted in an a statistically significant decrease in the mean NOSE score, ESS and optimal CPAP titration pressure. In addition, theminimalcross-sectional area (MCA1&2) increased significantly postoperatively. There was a positive correlation between the improvement in NOSE score as well as the MCA1& 2 and the postoperative decrease in CPAP titration pressure. Surgical correction of nasal obstruction improved CPAP outcomes and compliance in all patients. Nasal surgery in OSA objectively assessed by acoustic rhinometry improved nasal obstruction with a resultant decrease in the CPAP pressure requirements. Given that lower CPAP pressures improve adherence to CPAP therapy, surgical alleviation of nasal obstruction should be considered a crucial intervention in the management armamentarium of OSA.

Effect of Continuous Positive Airway Pressure on Lipid Profiles in Obstructive Sleep Apnea: A Meta-Analysis.

Background: Obstructive sleep apnea (OSA) is associated with dyslipidemia. However, the effects of continuous positive airway pressure (CPAP) treatment on lipid profiles are unclear. Methods: PubMed/Medline, Embase and Cochrane were searched up to July 2021. Randomized controlled trials (RCTs) of CPAP versus controls with ≥4 weeks treatment and reported pre- and post-intervention lipid profiles were included. Weighted mean difference (WMD) was used to assess the effect size. Meta-regression was used to explore the potential moderators of post-CPAP treatment changes in lipid profiles. Results: A total of 14 RCTs with 1792 subjects were included. CPAP treatment was associated with a significant decrease in total cholesterol compared to controls (WMD = −0.098 mmol/L, 95% CI = −0.169 to −0.027, p = 0.007, I2 = 0.0%). No significant changes in triglyceride, high-density lipoprotein nor low-density lipoprotein were observed after CPAP treatment (all p > 0.2). Furthermore, meta-regression models showed that age, gender, body mass index, daytime sleepiness, OSA severity, follow-up study duration, CPAP compliance nor patients with cardiometabolic disease did not moderate the effects of CPAP treatment on lipid profiles (all p > 0.05). Conclusions: CPAP treatment decreases total cholesterol at a small magnitude but has no effect on other markers of dyslipidemia in OSA patients. Future studies of CPAP therapy should target combined treatment strategies with lifestyle modifications and/or anti-hyperlipidemic medications in the primary as well as secondary cardiovascular prevention models.

Heart-Sparing Capability and Reproducibility of Continuous Positive Airway Pressure (CPAP) in Left-Sided Breast Radiation Therapy

<h3>Purpose/Objective(s)</h3> CPAP is a novel method to avoid heart radiation exposure during radiation therapy, recently proposed as an alternative to the current standard-of-care deep inspiration breath-hold technique. In this study, the heart dose, inter- and intrafraction motions in CPAP-based treatment were investigated. <h3>Materials/Methods</h3> A retrospective study on heart dose level and CPAP compliance included 237 left-sided breast cancer patients treated with CPAP-based VMAT in hypofractionation (with (n = 116) and without (n = 105) internal mammary node irradiation (IMNI)) between June 2020 and January 2021. During simulation, CT was obtained with free breathing (FB) and CPAP. For each treatment fraction, CBCT was acquired to confirm geometric accuracy within 3 mm tolerance. Two different datasets were used for reproducibility evaluations. Dataset 1: interfraction reproducibility was evaluated by measuring heart-to-PTV distance (MinHD), defined as the minimum distance between the line posteriorly tangential to the PTV and the heart, on 300 CBCT and 20 planning CT data of 20 women. Using dataset 1, heart-sparing effect was further explored by comparing dosimetric metrics of the whole heart and its substructures (e.g., atrium, ventricles, and vessels) between CPAP- and FB-based VMAT plans. Dataset 2: intrafraction reproducibility was evaluated in 20 women who were treated for different malignancies and underwent 4D CT with CPAP. <h3>Results</h3> Among 237 patients recruited, the CPAP compliance was 93% with a mean heart dose of 1.6 ± 0.7 Gy (no IMNI, 1.1 Gy; IMNI 2.0 Gy). The use of CPAP during treatment did not require additional time resource. The analysis of dataset 1 (i.e., total of 300 CBCT and 20 planning CT images) showed small variations of MinHD (0.6 ± 0.2 cm), demonstrating a reasonable agreement of the heart-to-PTV distance between the planning CT and CBCTs (MinHD difference < 0.2 cm, on average, for all patients). Compared with FB, the use of CPAP significantly reduced the mean heart dose (2.1 to 1.7 Gy), the mean dose to the left ventricle, the maximum dose to the left anterior descending artery, and the mean lung dose by 21%, 23%, 36%, and 23%, respectively. In dataset 2, the breast surface motion amplitude was 0.5 ± 0.5, 2.5 ± 2.0, and 1.8 ± 1.4 mm across the patients in the mediolateral, craniocaudal, and anteroposterior directions, respectively, and exceeded 5 mm for only two patients. <h3>Conclusion</h3> To the best of our knowledge, this is the first and largest study to evaluate the heart-sparing capability and reproducibility of CPAP-based VMAT for left-sided breast cancer treatment. A large population study confirmed a reasonably low irradiation to the heart with CPAP. This heart-sparing effect can be consistent across treatment fractions as demonstrated in sub-centimeter reproducibility of the heart position. For most of the women, the intrafraction breast motion with CPAP was minimal.

Association between septal deviation and OSA diagnoses: a nationwide 9-year follow-up cohort study.

Obstructive sleep apnea (OSA) is a multilevel problematic disease. Major septal deviation (SD) can lead to severe nasal congestion, which, in turn, can lead to sleep apnea. Although SD seems to be related to OSA, very few studies have quantitatively examined this relationship. In this study, we investigate this using a 9-year large-scale cohort study. The SD group was selected out of 1 million individuals randomly extracted by the National Health Insurance Service. The non-SD group was obtained through propensity score matching considering several variables. The primary end point was OSA diagnosis. The study (SD) group included 11,238 individuals and the non-SD group (control group) included 22,476 persons. The overall hazard ratio for OSA in the SD group was 4.39 (95% confidence interval [CI]: 3.56-5.42). In subgroup analysis, the hazard ratio for OSA of male individuals was 3.77 (95% CI: 2.83-5.03), high economic status was 1.27 (95% CI: 1.05-1.56), metropolitan area was 1.31 (95% CI: 1.07-1.62), young age was 0.79 (95% CI: 0.64-0.98), hypertension was 1.00 (95% CI: 0.37-2.7), and diabetes mellitus was 2.44 (95% CI: 1.15-5.21). In the SD group, the hazard ratio for OSA after septoplasty was 0.71 (95% CI: 0.54-0.94). From long-term follow-up, the prevalence of OSA was 4.39 times higher in the SD group compared with the control group. This phenomenon was more pronounced with increasing body mass index and decreased significantly after septoplasty. Yeom SW, Chung SK, Lee EJ, etal. Association between septal deviation and OSA diagnoses: a nationwide 9-year follow-up cohort study. J Clin Sleep Med. 2021;17(10):2099-2106.

430 Outcome of Sleep-Wake Pattern in Obstructive Sleep Apnea Patients after Positive Airway Pressure Therapy using Actigraphy

Abstract Introduction The initial phase of continuous positive airway pressure (CPAP) therapy in patients with obstructive sleep apnea (OSA) may affect sleep parameters and PAP compliance. Actigraphy is a validated method using accelerometer to objectively measure sleep parameters in patients with a range of sleep disorders, including OSA, particularly to follow-up after treatment. We compare sleep parameters from actigraphy, sleep log, sleep diary, Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI), heart rate and blood pressure in OSA patients before and after CPAP therapy for 1 week. Methods This pilot study have been prospectively performed at Central Chest Institute of Thailand (CCIT) since June to November 2020. Adult OSA patients, diagnosed by ICSD-3 criteria and achieved optimal or good CPAP pressure titration from split-night polysomnography (PSG), were informed and consent to wear actigraphy before and after CPAP therapy each for 1 week. Clinical and sleep parameters were recorded and analyzed using Wilcoxon matched-pair signed-rank and Mann Whitney U test. P-value &amp;lt; 0.05 was considered to have statistical significance. Results All 11 OSA patients participated in this study. Most patients were male (63.6%), hypertension (54.5%) and dyslipidemia (45.4%). Means of age, body mass index (BMI), ESS, PSQI, apnea hypopnea index (AHI), nadir SpO2, and CPAP usage were 45.5 ± 15.9 years, 29.1 ± 5.2 kg/m2, 10.8 ± 3.9, 7.7 ± 2.9, 65.2 ± 37.7 events/h, 82.3 ± 10.8 % and 9.5 ± 3.1 cmH2O, respectively. Comparing before and after 1-week CPAP therapy, an average number of wake bouts ((NWB), 48.4 vs 38 events, p=0.010), ESS (11 vs 9, p=0.035) and PSQI (8 vs 4, p=0.005) were significantly decrease. Additionally, when comparing between poor and good CPAP compliance group, NWB (55.1 vs 36.3 events, p=0.036) and the difference of wake after sleep onset (WASO, 10.5 vs -0.11 min, p=0.035) were significantly decrease. Conclusion OSA patients treated with CPAP for 1-week experienced marked improvement in sleepiness, sleep quality and nighttime awakening. Support (if any):