Positive Airway Pressure Titration Research Articles

Physiologic and anatomic determinants of hyoid motion during drug-induced sleep endoscopy.

To examine factors accounting for differences in hyoid motion during obstructive breathing events amongst obstructive sleep apnea (OSA) patients. This was a prospective cohort study from June 2022 to October 2022. Patients with OSA undergoing evaluation for PAP alternative therapies with drug-induced sleep endoscopy with positive airway pressure titration (DISE-PAP). All patients underwent DISE-PAP and concurrent hyoid-focused ultrasound. DISE-PAP enabled measurement of airway physiology (flow, respiratory effort) and airway collapsibility (pharyngeal opening pressure, PhOP). Hyoid-ultrasound enabled hyoid bone movement during obstructive breathing. Respiratory effort was measured using a retro-epiglottic pressure-sensitive catheter. Hyoid position was measured using a standardized, awake, CT protocol. Regression analyses adjusted for age, race, sex, and BMI were performed to associate indices of respiratory effort and CT data with hyoid motion. On average, the 26 patients in this cohort were older (63.9 ± 10.5years), male (69%), overweight (29.6 ± 3.99kg/m2), and with moderate-to-severe OSA (26.8 ± 10.4 events/hour). Greater respiratory effort was associated with increased hyoid motion (β [95% CI] = 0.034 [0.016,0.052], standardized β = 0.261,p = 0.0003). Higher hyoid position was associated with greater hyoid displacement (β [95% CI] = -0.20 [-0.38,-0.01], Standardized β = -0.57, p = 0.036). Our data demonstrate that greater respiratory effort, higher hyoid position, and higher airway collapsibility, but not airflow, are associated with greater hyoid motion during obstructive breathing in DISE. These findings suggest that downward hyoid movement represents a compensatory response to upper airway obstruction. Further studies should investigate the vectors of hyoid motion to better understand its role in sleep-related airway collapse.

The Repeatability of Pharyngeal Opening Pressure Under Drug-Induced Sleep Endoscopy.

Pharyngeal opening pressure (PhOP) is a measure of upper airway collapsibility that can be obtained during drug-induced sleep endoscopy (DISE) using a continuous positive airway pressure (CPAP) titration. However, the stability of PhOP over the course of sedation during DISE remains unclear. This study aims to compare repeat measures of PhOP over the course of DISE. Single arm prospective study. Single tertiary care institution. Patients had 2 CPAP titrations while undergoing DISE. Collected data included patient demographics, PhOP, patient sedation index (PSI), and duration of and between CPAP titrations. t Tests, test-retest coefficient analysis, and repeated measures correlation were performed. Twenty-five patients completed the study between 2022 and 2023 with 22 patients having sedation depth (PSI) recording. Most were male (76%), obese (average body mass index: 30.24 kg/m2), with severe obstructive sleep apnea (average apnea-hypopnea index: 39.8 events/hr). Test-retest analysis showed good-excellent correlation between PhOP values (intraclass correlation coefficient = 0.892, P < .0001, n = 25). Average time between CPAP titrations was 15 minutes to 6 seconds. Over that time, PhOP increased by an average of 0.72 cmH2O (P = .06, n = 25) and PSI decreased by 9.5 units (P = .01, n = 22). Repeated measures correlation showed a weak negative correlation between PhOP and PSI (r = -.45, P = .03, n = 22). The results showed repeatability of PhOP values over the course of DISE. When adjusted for sedation depth (PSI), deeper sedation was weakly associated with greater PHOP. However, the magnitude of this change was small and we conclude that PhOP remains relatively stable over the course of DISE (Effects of Lung Volume on Upper Airway Patency During DISE [DISE-Pulm], NCT05350332, clinicaltrials.gov).

Association Between Soft Tissue Measures From Computed Tomography and Upper Airway Collapsibility on Drug-Induced Sleep Endoscopy.

Positive airway pressure (PAP) titration during drug-induced sleep endoscopy (DISE) provides objective measures of upper airway collapsibility. While skeletal measurements relate to collapsibility measures on DISE, the influence of soft tissue dimensions on upper airway collapsibility is not known. We analyzed the relationship of measures of upper airway soft tissue volumes, specifically soft palate, pharyngeal lateral walls, and tongue, with metrics of collapsibility. Cross-sectional analysis from a prospective cohort. Academic medical center. Patients seeking PAP alternative therapies for obstructive sleep apnea (OSA) underwent standardized supine computed tomography (CT) acquisition and DISE protocols. The CT analysis primarily focused on soft tissue volumes and, secondarily, on airway and skeletal volumetric measures. DISE with PAP administration (DISE-PAP) enabled the determination of the pressure at which inspiratory airflow first commenced (pharyngeal critical pressure, PcritA) and the pressure at which inspiratory flow limitation was abolished (pharyngeal opening pressure, PhOP). Both unadjusted and adjusted correlation analyses were performed to understand the relationship between upper airway anatomy and either PcritA or PhOP. One hundred thirty-nine subjects completed both CT and DISE-PAP. On average, patients were male (70.5%), white (84.2%), middle-aged (56.6 ± 13.5 years), and overweight (29.6 ± 4.7 kg/m2), with moderate-severe apnea-hypopnea index (29.7 ± 21.3 events/h). Adjusted for age, sex, body mass index, and skeletal volumes, soft palate, and lateral pharyngeal wall volumes were not associated with PhOP or PcritA, but a larger tongue was associated with more positive PhOP (⍴ = 0.20, P = .02), and more positive PcritA (⍴ = 0.16, P = .07). Exploratory analyses revealed smaller minimum cross-sectional retropalatal area and intramandibular volume were also associated with increased collapsibility measures. After controlling for clinical factors and skeletal volume, greater tongue volume was associated with more severe collapsibility during DISE. These results, in concert with previous work, suggest that greater tongue volume in a smaller skeletal dimensions contribute to the severity of airway collapsibility, a key driver of OSA pathogenesis.

An Alternative In-Home Protocol to Diagnose and Treat Obstructive Sleep Apnea

Abstract Objective Obstructive sleep apnea (OSA) is a major public health problem of pandemic proportions. In-laboratory OSA diagnosis and continuous positive airway pressure (CPAP) titration are insufficient, considering the number of patients affected. Finding alternative ways to diagnose and treat OSA is mandatory, especially in this era of the coronavirus disease 2019 (COVID-19) pandemic. The present study aims to describe an alternative in-home protocol to diagnose and treat OSA. Materials and Methods We enrolled consecutive patients aged ≥ 18 years with moderate/severe OSA, who underwent in-home type-III polysomnography and home-based titration with automatic CPAP, coupled with an oximetry sensor for 3 consecutive nights. Patients were remotely monitored for 90 days to evaluate CPAP compliance and the use of an engagement tool was encouraged. Results We included 86 participants. The median time until the diagnosis was of one day. The mean time from the baseline visit until the acquisition and initiation of the CPAP therapy was of 33 (range: 17 to 52) days. Telemonitoring ensured good compliance in the first 30 (79.2%), 60 (76.3%) and 90 (74.3%) days, with an average daily use of 6.2 ± 1.4 h, 6.0 ± 1.4 h, and 6.0 ± 1.3 h respectively. About 1/3 of the patients used the engagement tool, and CPAP compliance was significantly higher among these patients compared with those who did not used the tool: 89.9% versus 73.5% (p &lt; 0.002), 87.9% versus 70% (p &lt; 0.003), and 86.6% versus 67.6% (p &lt; 0.001) at 30, 60, and 90 days respectively. Conclusion We demonstrated that an alternative in-home protocol to diagnose and treat OSA is effective, ensuring good CPAP compliance after 90 days. Telemonitoring and engagement tools could be strategies to improve CPAP compliance.

The prevalence and polysomnographic characteristics of treatment-emergent central sleep apnea with obstructive sleep apnea.

To investigate the prevalence of treatment-emergent central sleep apnea (TECSA) in individuals with obstructive sleep apnea syndrome (OSAS) during continuous positive airway pressure (CPAP) titration and assess their polysomnographic characteristics. A total of 116 patients with OSAS who underwent full-night CPAP titration at the Sleep Laboratory of Adana City Research and Education Hospital from September 2017 to January 2018 were recruited for the study. The patients' polysomnographic data related to respiratory events and sleep stages were reviewed in a retrospective manner. While on CPAP titration, 20 of the 116 patients developed central sleep apnea (CSA). The prevalence of TECSA in the patients with OSAS was 17.2%, being separately determined as 16.3% and 2.2% for the male and female patients, respectively. In the baseline PSG, the groups did not statistically significantly differ in relation to the apnea hypopnea index (AHI), central apnea index (CAI), arousal index (AI), or oxygen desaturation index (ODI). However, the TECSA group had a significantly higher mean oxygen saturation value compared to the non-TECSA group (p = 0.01). The total AHI, CAI, and AI values of the TECSA group were significantly higher during the whole CPAP titration compared to the non-TECSA group. No significant difference was observed in the comparison of the two groups in relation to the titration pressure and ODI. TECSA is a phenomenon that can occur with obstructive sleep apnea treatment and mostly regress spontaneously following appropriate CPAP treatment. TECSA is observed at different rates of prevalence. In this study, the prevalence of TECSA was higher than previously reported.

Profile of Sleep-related Breathing Disorders in Chronic Obstructive Pulmonary Disease-obstructive Sleep Apnea Overlap Syndrome

Introduction: Overlap syndrome (OS) is defined by the combined occurrence of obstructive sleep apnea (OSA) and chronic obstructive pulmonary disease (COPD). Sleep-related breathing disorders (SRBDs) in OS can also manifest with central sleep apnea (CSA) and hypoventilation; besides OSA. Methods: This study was carried out to evaluate various SRBD in OS and its therapeutic implications patients having postbronchodilator obstruction in spirometry with respiratory symptoms were classified as COPD. Those found to have an apnea–hypopnea Index (AHI) &gt;5/h in polysomnography (PSG) were diagnosed as OS. All 37 patients diagnosed as OS underwent a subsequent positive airway pressure (PAP) titration. Results: On the evaluation of the SRBD, over half (51%) of the patients had OSA with no hypoventilation. More than one-third of the patients (35%) had associated hypoventilation with OSA, three patients had hypercapnic CSA, and two patients had hypocapnic CSA with Cheyne–Stokes breathing (CSA-CSB). The OSA group was easily titrated and corrected by CPAP therapy. OSA with hypoventilation group had underlying COPD with severe obstruction requiring bilevel PAP titration. Patients with CSA-CSB were elderly hypertensive patients with congestive heart failure who were corrected by PAP and optimization of cardiac medications. Patients with hypoventilation and hypercapnic CSA were most difficult to titrate and needed a backup rate along with PAP therapy for correction. On classifying patients on the basis of severity of OSA and COPD, there was no correlation found between AHI and forced expiratory volume 1 (FEV1). Patients with mild COPD with severe OSA were easily titrated with CPAP with a mean pressure of 8 cm H2 0. The most challenging cases were with severe COPD with severe OSA who required high pressures in both exhalation PAP and inspiratory PAP titration; two of such patients required backup rate by spontaneous/timed mode of PAP therapy. Conclusions: There are many profiles of SRBD in OS, and a detailed in-hospital PSG with a PAP titration can help in effectively managing the patients.

Cumulative brain desaturation: Time to consider brain derived parameters to measure daytime sleepiness in obstructive sleep apnea

Objective/Background: The change in cerebral hemodynamics induced by sleep apneas and hypopneas may contribute to the daytime sleepiness in patients with obstructive sleep apnea (OSA). However, previous studies failed to discovery their relationship. We propose and test a new parameter, the cumulative brain oxygen desaturation, which may contribute to OSA patient's daytime sleepiness. Patients/methods22 patients with severe OSA (apnea-hypopnea index (AHI) at diagnosis [mean ± standard deviation, std.]: 52.1 ± 21.6/h, median: 45.1/h, interquartile range: 34.4–60.2/h) were monitored by polysomnography during routine continuous positive airway pressure titration. The reductions of brain tissue oxygen saturation (StO2) in all respiratory events at baseline sleep were measured by frequency-domain near-infrared spectroscopy (NIRS). The cumulative brain desaturation was calculated as AHI times the mean StO2 desaturation (i.e., AHI×ΔStO2‾). Similarly, cumulative peripheral desaturation was also calculated, i.e., AHI×ΔSpO2‾ where ΔSpO2‾ was the mean reduction of peripheral arterial oxygen saturation (SpO2). The correlations between Epworth sleepiness scale (ESS) and AHI, ΔStO2‾, AHI×ΔStO2‾, and AHI×ΔSpO2‾ were tested, respectively. Linear regression was applied to predict ESS using AHI×ΔStO2‾ and AHI×ΔSpO2‾, with age and BMI as covariates. ResultsESS significantly correlates to the cumulative brain desaturation (Pearson's correlation coefficient: 0.68, p = 0.00056), not the other parameters. Regression analysis only finds significant association between ESS and the cumulative cerebral desaturation (p = 0.00195) but not the cumulative peripheral desaturation (p = 0.71). ConclusionsThe cumulative brain oxygen desaturation, which comprehensively combines total sleep time, the frequency of apnea and hypopnea events, and the severity of cerebral oxygen desaturation, is a new indicator for daytime sleepiness in severe OSA.

Airway Collapsibility during Drug-Induced Sleep Endoscopy Relates with Clinical Features of Obstructive Sleep Apnea.

Increased pharyngeal collapsibility leads to obstructive sleep apnea (OSA). Positive airway pressure titration during drug-induced sleep endoscopy (DISE-PAP) provides objective collapsibility metrics, the pharyngeal opening pressure (PhOP), and active pharyngeal critical pressure (PcritA ). We examined the interrelationships between risk factors of OSA, airway collapsibility measures, and clinical manifestations of the disease. This is a cross-sectional analysis of consecutive OSA patients undergoing DISE-PAP. Nasal PAP was increased stepwise until inspiratory flow limitation was abolished, signifying PhOP. PcritA was derived from the resulting titration pressure-flow relationships. Clinical data including demographics, anthropometrics, sleep studies, and patient-symptom questionnaires were obtained from the electronic medical record. Multivariate regression was used to evaluate the relationship between risk factors, airway collapsibility, and clinical data. On average, the 164 patients meeting inclusion criteria were middle-aged (54.2 ± 14.7 years), overweight/obese (BMI 29.9 ± 4.5 kg/m2 ), male (72.6%), White (79.3%) and had severe OSA (AHI 32.0 ± 20.5 events/hour). Mean PhOP was 7.5 ± 3.3 cm H2 O and mean PcritA was 0.80 ± 3.70 cm H2 O. Younger age (Standardized β = -0.191, p = 0.015) and higher BMI (Standardized β = 0.176, p = 0.028) were associated with higher PhOP, but not PcritA . PhOP and PcritA were both associated with AHI, supine AHI, and SpO2 nadir. Higher PhOP was associated with higher snoring scores (Standardized β = 0.246, p = 0.008), but not other patient-reported outcomes. Objective assessment of passive and active airway mechanics during DISE relates with clinical risk factors for OSA. Quantitative measures of collapsibility provide accessible and meaningful data, enhancing the standard sleep surgery evaluation. 4 Laryngoscope, 134:1978-1985, 2024.

Accuracy of positive airway pressure titration through telemonitoring of auto-adjusting positive airway pressure device connected to a pulse oximetry in patients with obstructive sleep apnea.

In COVID-19 era, all forms of access of patients to the sleep units should be reduced as much as possible when implementing telemedicine. In the field of obstructive sleep apnea (OSA) therapy with positive airway pressure (PAP) devices, telemedicine includes the use of built-in software (BIS) and storage of PAPs and remote-controlled data (BISrc data) that are processed and transmitted daily to sleep units. We compared two methods of evaluating the final residual severity of OSA patients in home PAP titration: BISrc data versus nocturnal portable multichannel monitoring (PM) data in PAP (reference method) and to verify whether the efficacy PAP therapy guided by BISrc data was clinically adequate. We conducted a real-life prospective study in newly diagnosed patients with OSA. Patients used an auto-adjusting positive airway pressure (AirSense 10 ResMed) with a pulse oximeter that allows daily transfer of BISrc data (apnea hypopnea index [AHI] and SaO2 ) and remote changes in ventilator setting. Once the PAP titration was completed, the pressure value or ranges were kept constant for 3 days and home PM was repeated. There were 41 patients with moderate to severe OSA who completed the study. When considering AHI only, the diagnostic accuracy of BISrc on the third day was equal to 97.5%; when considering AHI > 10/h, ODI > 10/h, and SaO2 < 90%, the diagnostic accuracy slightly decreased to 90.2%. In clinical practice, the two measurement methods are equivalent. The use of BISrc data for home titration would reduce the access to sleep units. We urge that widespread use of BISrc be promoted in the current practice of management of OSA.

The Application of Ultrasound to Quantify Hyoid Motion During Drug-Induced Sleep Endoscopy.

The significance of hyoid dynamics in OSA pathophysiology remains unclear. Drug-induced sleep endoscopy (DISE) is often used for evaluating patients intolerant to positive airway pressure (PAP) therapy. We performed DISE with concurrent hyoid-focused ultrasonography to quantify hyoid dynamics during obstructive and non-obstructive breathing. A cross-sectional analysis from a prospective cohort of patients undergoing DISE with PAP titration (DISE-PAP) and hyoid-focused ultrasound was conducted. Hyoid ultrasound was performed during obstructive breathing, and non-obstructive breathing after PAP administration. Motion was quantified by generating displacement curves based on echo-tracking hyoid movement. The image analysis protocol for quantifying hyoid displacement was performed independently by two researchers, and reliability of measures was assessed. Univariate and multivariate regressions were performed for various clinical data and hyoid displacement during obstructive breathing. Twenty patients met inclusion criteria. On average, the cohort was male (75%), elderly (65.9 ± 10 years), overweight (29.3 ± 3.99 kg/m2 ), and with moderate-to-severe OSA (29.3 ± 12.5 events/h). Mean hyoid displacement during obstructive breathing was 5.81 mm (±3.48). In all patients, hyoid displacement decreased after PAP administration (-3.94 mm [95% CI: -5.10, -2.78]; p < 0.0001). Inter-rater reliability for measures of hyoid displacement was excellent. After multivariate regression, hyoid displacement at baseline was associated with higher AHI (β [95% CI] = 0.18 [0.03, 0.33], p = 0.020). During DISE, hyoid displacement is greater during obstructive breathing with significant variability amongst patients. Further, these ultrasonographic measurements had excellent intra- and inter-rater reliability. Additional, larger studies are needed to understand contributors to hyoid mobility. 4 Laryngoscope, 133:3221-3227, 2023.

Respiratory infection risk in positive airway pressure therapy users: a retrospective cohort study.

Concerns regarding the risk of positive airway pressure (PAP)-associated respiratory infection (RI) have shaped consumer views toward PAP device use and maintenance. However, data regarding temporal associations between PAP use and risk for RIs are limited. The purpose of the present study was to examine longitudinal associations between PAP use and risk of clinically significant RIs in a cohort of patients with obstructive sleep apnea. The frequency of clinically reported respiratory RIs pre- and post-PAP use were compared in a sample of 482 adult patients with obstructive sleep apnea who underwent PAP titration at a large academic sleep center between 2011 and 2014. RIs were identified by clinical record review beginning two years before and ending two years after the participants' PAP titration. Presence of longitudinal standard PAP data download reports identified PAP users from nonusers. PAP adherence was defined as at least 4 hours of use per day, five days per week for at least 70% of days. Poisson regression models, adjusted for age, sex, body mass index, and the number of pre-PAP use RIs were utilized to examine associations between PAP use and subsequent RIs. Poisson regression models adjusted for age, sex, body mass index, and the number of pre-PAP use RIs did not show associations between PAP therapy use and rate of post-PAP use RIs (rate ratio = 1.27, 95% confidence interval: 0.86-1.86). A sensitivity analysis that included only PAP users with difference in PAP adherence showed similar results (rate ratio = 0.65, 95% confidence interval: 0.32-1.30). Among adults with obstructive sleep apnea, we did not find evidence for association between PAP use/adherence and increased RI frequency. These data offer new information that could assuage patients with obstructive sleep apnea who are considering PAP deferral based on RI concerns. Gavidia R, Shieu MM, Dunietz GL, Braley TJ. Respiratory infection risk in positive airway pressure therapy users: a retrospective cohort study. J Clin Sleep Med. 2023;19(10):1769-1773.

0475 Optimal Thresholds for Split-Night Polysomnography with Transitions in Laboratory Hypopnea Scoring Criteria

Abstract Introduction Performance of split-night polysomnography, the application and titration of positive airway pressure (PAP) therapy after an initial diagnostic interval, is a common practice in clinical sleep medicine. There is no currently recommended apnea-hypopnea index (AHI) threshold at which PAP should be applied during polysomnography. Differences in American Academy of Sleep Medicine (AASM) and Centers for Medicare and Medicaid Services (CMS) hypopnea scoring criteria and limitations on real-time hypopnea classification complicates identification of an optimal split-night threshold. Of particular concern is that patients may be “split” under AASM hypopnea rules but have insufficiently severe sleep disordered breathing under CMS rules to be diagnosed or treated appropriately. This study aimed to clarify optimal AHI thresholds for split night polysomnography in the context of a laboratory-wide transition from CMS to AASM hypopnea scoring criteria. Methods Effective October 1, 2021, our laboratory transitioned solely to scoring AASM-defined hypopneas, with additional post hoc identification of CMS hypopneas for reporting purposes. With this change, the split-night threshold was changed from 15 to 30/hr. All diagnostic polysomnograms (without PAP therapy) performed on adult patients through October 31, 2022, were retrospectively analyzed to clarify the effect of changing hypopnea scoring criteria in this context. Results 634 diagnostic polysomnograms were analyzed. An AHI threshold of 15/hr (using AASM hypopnea criteria) in the first two hours of sleep with at least 3 hours of time remaining for PAP titration would have resulted in 96 additional patients receiving treatment with PAP therapy. Among these, only one (1.04%) had CMS AHI below 5/hr. Sixty-eight of these patients had CMS AHI 5-15/hr during the first two hours of sleep. Among these, only eight patients did not have an additional comorbidity or symptom profile under CMS guidelines making them eligible for PAP therapy, however, none had CMS AHI &amp;gt;15/hr when the full night of sleep was analyzed. Conclusion Our study suggests there is little need to raise the split-night threshold when transitioning from CMS to AASM hypopnea criteria, and doing so substantially reduces the number of patients treated with PAP therapy in the sleep laboratory. Support (if any) None

The accuracy and difference of scoring rules and methods to score respiratory event-related leg movements in obstructive sleep apnea patients

ObjectiveTo compare manual scoring: 1) to the American Academy of Sleep Medicine (AASM) auto-scoring rules. 2) to the AASM and World Association of Sleep Medicine (WASM) rules, and evaluate the accuracy of the AASM and WASM for respiratory event-related limb movements (RRLM) in diagnostic and continuous positive airway pressure (CPAP) titration polysomnography (PSG). MethodsWe retrospectively, re-scored diagnostic and CPAP titration PSGs of 16 patients with obstructive sleep apnea (OSA), using manual re-scoring by the AASM (mAASM) and WASM (mWASM) criteria for RRLM, periodic limb movements during sleep (PLMS), and limb movements (LM), which were compared to auto-scoring by the AASM (aAASM). ResultsIn diagnostic PSG, significant differences were found in LMs (p < 0.05), RRLM (p = 0.009) and the mean duration of PLMS sequences (p = 0.013). In CPAP titration PSG, there was a significant difference in RRLM (p = 0.008) and PLMS with arousal index (p = 0.036). aAASM underestimated LM and RRLM, especially in severe OSA. Changes in RRLM and PLMS with arousal index between diagnostic and titration PSG were significantly different between aAASM and mAASM, but there was no significant difference between scoring by mAASM and mWASM. The ratio of PLMS and RRLM changes between diagnostic and CPAP titration PSG was 0.257 in mAASM and 0.293 in mWASM. ConclusionsIn addition to the overestimation of RRLM by mAASM compared to aAASM, mAASM may also be more sensitive than aAASM in detecting RRLM changes in the titration PSG. Despite intuitive differences in the definition of RRLM between AASM and WASM rules, RRLM results between mAASM and mWASM were not significant and about 30% of RRLMs might be scored as PLMS by both scoring rules.

0937 Developing a Protocol for Abbreviated Daytime Sleep Studies for Positive Airway Pressure Acclimation

Abstract Introduction During the COVID pandemic, there was a decrease in the number of in lab positive airway pressure titration studies as well as in person DME company guided mask fittings due to COVID related restrictions. We wanted to assess the utility of daytime abbreviated sleep studies for PAP acclimation and mask fitting on patient compliance to therapy. Methods We assessed patients that were seen consecutively in our sleep lab for abbreviated sleep studies for positive airway pressure acclimation and mask fittings. Compliance rates 30 days prior to encounters were compared to compliance rates over the 30 days after the PAP acclimation and mask fitting took place. Results We found that the majority of patients that did undergo an encounter had improvement in their compliance rates. Despite this, we recognized that there was a lack of uniformity in the patient encounter as well as documentation as there was no formal protocol in place for physicians and sleep technicians to follow during these encounters. We sought to developed a new protocol that would allow for more uniform encounters and optimized patient care as well as clear and concise documentation of the encounter. Conclusion It is reassuring to see that daytime abbreviated PAP acclimation and mask fitting sessions do seem to improve compliance to therapy, but we recognize that the development of a new protocol is important to determine the clinical significance of this finding. This new protocol will allow us to improve the quality of care delivered to patients during in laboratory daytime abbreviated PAP acclimation and mask fitting sessions. With a new protocol in place we can reduce variables during the encounter and it will hopefully serve as a better platform to analyze how these sessions impact overall patient compliance to PAP therapy. Support (if any)

1018 Finally Awake: Treatment of Severe REM-Isolated Obstructive Sleep Apnea

Abstract Introduction Obstructive sleep apnea (OSA) is typically treated with positive airway pressure (PAP) therapy in symptomatic patients with ≥ 5 obstructive respiratory events (apneas, hypopneas or respiratory effort related arousals) per hour of sleep. In this case, we present a patient with severe OSA isolated to REM sleep who demonstrated significant symptomatic improvement on PAP therapy, despite an overall apnea-hypopnea index (AHI) of less than 5 events/hour. Report of case(s) A 73-year-old obese male with history of SVT, hypertension, and diabetes presented with symptoms of snoring, witnessed apneas, non-restorative sleep, restless sleep, excessive daytime sleepiness, and fatigue. A baseline polysomnogram (PSG) demonstrated severe OSA exclusively in REM sleep (overall AHI 2.9, REM AHI of 37.3, minimum SpO2 of 84%). A subsequent PAP titration study tested CPAP 5-17 and BPAP 19/15 cm of water but was unable to identify an effective pressure during REM sleep. Pressures as low as CPAP 5 cm of water appeared effective in NREM sleep. Ultimately, as the patient was unwilling to undergo a re-titration study, empiric treatment with auto-BPAP (min EPAP 5, max IPAP 25, PS 4) was initiated. With excellent adherence to BPAP therapy, the patient experienced profound symptomatic benefit, with resolution of daytime symptoms, less restlessness during sleep, and more restorative sleep. Conclusion This case highlights a gap, and potential pitfall, in current practice. Our patient 1) did not meet the overall AHI criteria for diagnosis of OSA yet had typical symptoms and high pretest probability for OSA; 2) had a PSG which showed severe OSA exclusively during REM sleep; and 3) experienced resolution of symptoms with PAP therapy. Presently, there is no consensus on whether REM-dependent OSA should be treated if the overall AHI is &amp;lt; 5 events/hour. In fact, there is no standardized definition for REM-dependent OSA. This patient with cardiovascular risk factors was able to receive PAP therapy through the Veterans’ Affairs, and access to PAP therapy changed the Veteran’s quality of life dramatically. Obtaining a PAP device for this patient through private payors would have been nearly impossible. More research is needed to understand the clinical implications of this condition. Support (if any)

Factors Associated with the Underestimation of Manual CPAP Titration Pressure.

During the SARS-CoV-2 pandemic, the use of in-laboratory positive airway pressure (PAP) titration studies was not routinely suggested. PAP pressure prediction calculations are emerging as alternative methods for the treatment of these patients. The underestimation of PAP titration pressure usually leads to unsatisfactory results for PAP therapy. This study aimed to evaluate the factors associated with the underestimation of PAP titration pressure when using PAP pressure prediction equations. Estimated PAP pressure formulas based on body mass index (BMI) and apnea-hypopnea index (AHI) were chosen to validate the accuracy of equations in the successful prediction of titration pressure. Among 341 adult patients diagnosed with obstructive sleep apnea (OSA) by overnight polysomnography (PSG) and who received overnight PAP titration in order to select a successful pressure, the mean age of the total subjects was 55.4 years old and 78.9% of patients were male. The average BMI and AHI scores were 27.1 ± 4.8 and 37 ± 21.7, respectively. After multivariate stepwise regression analysis, the odds ratio of participants with a pretitration AHI was 1.017 (95% CI: 1.005-1.030). Only the severity of OSA was significantly different between the underestimated group and the adequately assessed group. In conclusion, a high AHI, but not BMI, is associated with an underestimated CPAP titration pressure in adult patients with OSA.

Evaluation of polysomnography findings in children with genetic skeletal disorders.

Children with genetic skeletal disorders have variable conditions that can lead to sleep-disordered breathing, and polysomnography is the gold standard for diagnosing this condition. We aimed to review polysomnography findings, to assess the severity of sleep apnea, and to investigate the clinical variables predictive of sleep-disordered breathing in these patients. We retrospectively collected the medical records of patients with genetic skeletal disorders who underwent polysomnography for 5 years. Twenty-seven children with various genetic skeletal disorders, including achondroplasia (14), Crouzon syndrome (3), acromesomelic dysplasia Maroteaux type (3), Apert syndrome (2), osteopetrosis (1), Jeune dysplasia (1), Desbuquois dysplasia (1), acrodysostosis (1), and spondyloepiphyseal dysplasia (1) were enrolled. The median age at the first polysomnography was 58 (1st-3rd quartile: 31-113) months. The overall sleep-disordered breathing results were: 19 (70.3%) had obstructive sleep apneas (OSA) (4 mild, 6 moderate, 9 severe), 2 (7.4%) had central apneas, 4 (14.8%) had nocturnal hypoventilation. There was a significant correlation between non-ambulatory status with both total AHI and OSA (p < 0.001, rho: -0.66/p = 0.04, rho: 0.38, respectively). Nine patients received positive airway pressure titration, and the oAHI values of all returned to the normal range. These patients were started with positive airway pressure treatment. Our cohort showed that the majority of the patients with skeletal dysplasia had sleep apnea syndrome characterised mainly by OSA, highlighting the importance of polysomnography screening for sleep disorders. Positive airway pressure therapy represents an effective treatment for sleep-disordered breathing in those patients.

Sleep medicine practices in pediatric patients during the COVID-19 pandemic

Objectives: The COVID-19 pandemic required precautions for infection control in sleep centers. Our aim was to assess the impact of the COVID-19 pandemic on sleep medicine practices. Methods: Data of patients undergoing polysomnography and positive airway pressure titration studies prior to (2019) and during the pandemic (2020) were analyzed. In addition, the effect of taking appropriate precautions and performing SARS-CoV-2 polymerase chain reaction testing on the safety of sleep medicine practices was investigated. Results: The median age of the patients who underwent sleep studies (polysomnography + positive airway pressure titration studies) in 2019 was 7 (2.5-11.5) years (164 male, 147 female), whilst it was 9 (4-12) years (127 male, 84 female) in 2020. During the outbreak, the frequency of sleep studies increased from 3% (311 tests/10068 total number of outpatient visits in 2019) to 3.7% (211 tests/5666 in 2020). In contrast, the frequency of positive airway pressure titration studies declined from 31.8% (99 positive airway pressure titration studies/311 sleep studies) to 21.8% (46 positive airway pressure titration studies/211 sleep studies) in 2020 compared to 2019. Down syndrome was found to be the most common indication both in 2019 (20.9% of all tests) and 2020 (13.7%). Conclusions: Polysomnographies were performed at a high rate despite the pandemic. However, positive airway pressure titration studies were avoided except for urgent indications because of the potential for aerosolization. In this study, it was shown that sleep studies can be performed safely when necessary precautions are taken.

Transverse Maxillary Deficiency Predicts Increased Upper Airway Collapsibility during Drug-Induced Sleep Endoscopy.

To examine the relationship between craniofacial skeletal anatomy and objective measures of pharyngeal collapse obtained during drug-induced sleep endoscopy. We hypothesized that transverse maxillary deficiency and an increased pharyngeal length will be associated with higher levels of pharyngeal collapsibility. Cross-sectional analysis in a prospective cohort. University Hospital. A cross-sectional analysis was conducted in a cohort of consecutive patients from the positive airway pressure(PAP) alternatives clinic who underwent computed tomography (CT) analysis and drug-induced sleep endoscopy for characterization of upper airway collapsibility. PAP titration was used to determine pharyngeal critical pressure (PCRIT ) and pharyngeal opening pressure (PhOP). CT metrics included: Transverse maxillary dimensions (interpremolar and intermolar distances) and pharyngeal length (posterior nasal spine to hyoid distance). The cohort (n = 103) of severe obstructive sleep apnea (Apnea and Hipopnea Index 32.1 ± 21.3 events/h) was predominantly male (71.8%), Caucasian (81.6%), middle-aged (54.4 ± 14.3 years), and obese (body mass index[BMI] = 30.0 ± 4.9 kg/m2 ). Reduced transverse maxillary dimensions were associated with higher PCRIT (intermolar distance: β [95% confidence interval, CI] = -.25 [-0.14, -0.36] cmH2 O/mm; p = .03) and PhOP (Interpremolar distance: β = -.25 [-0.14, -0.36] cmH2 O/mm; p = .02). Longer pharyngeal length was also associated with higher PCRIT (β = .11 [0.08, 0.14] cmH2 O/mm, p = .04) and PhOP (β [95% CI] = .06 [0.03, 0.09] cmH2 O/mm, p = .04). These associations persisted after adjustments for sex, age, height, and BMI. Our results further the concept that skeletal restriction in the transverse dimension and hyoid descent areassociated with elevations in pharyngeal collapsibility during sleep, suggesting a role of transverse deficiency in the pathogenesis of airway obstruction.

Documentation of polysomnographic and home sleep apnea test interpretations: room for improvement?

Obstructive sleep apnea (OSA), a heterogeneous disorder with many different presentations, is diagnosed with sleep studies. In standard clinical practice, test data are reviewed and scored, and interpretations are documented. Little standardization exists regarding what should be included in interpretations. We aimed to determine how consistently the documented interpretation included references to study quality parameters and accepted disease phenotypes. This study was performed at a single academic center in January 2021. From the literature, we formulated a list of test and titration quality criteria and OSA phenotypes that should be reflected in study interpretations, including total recording time, total sleep time, positionality, and supine rapid eye movement (REM) sleep during titration. We retrospectively reviewed the documentation of sleep studies to determine how often these factors were reflected in interpretation reports or clinical notes. Of 134 patients in the study, 81 were diagnosed with OSA. A finding of inadequate total recording time during polysomnography or total sleep time on home sleep apnea testing was most often not documented. Positionality of OSA was not documented in 33% of applicable studies. The absence of supine REM sleep during positive airway pressure titration was not mentioned in 15% of interpretations. The documentation of quality concerns and clinically important OSA phenotypes in interpretations was inconsistent. Documentation of meaningful test quality information and sleep apnea phenotypes might be improved with report standardization or by developing enhanced data displays. Herberts MB, Morgenthaler TI. Documentation of polysomnographic and home sleep apnea test interpretations: room for improvement? J Clin Sleep Med. 2023;19(6):1043-1049.