Auto-titrating Positive Airway Pressure Research Articles

Real-world data on polysomnography- and patient-reported outcomes in hypoglossal nerve stimulation and auto-titrating positive airway pressure therapy for obstructive sleep apnea

BackgroundFew data are available comparing first-line positive airway pressure (PAP) therapy of obstructive sleep apnea (OSA), especially auto-adjusting PAP (aPAP), with second-line hypoglossal nerve stimulation (HGNS) therapy. The aim of this study was to directly compare these therapeutic options by standard polysomnography (PSG)-related parameters and patient-reported outcomes in comparable groups. Methods20 patients (aged 57.30 ± 8.56 years; 6 female) were included in the HGNS and 35 patients (aged 56.83 ± 9.20 years; 9 female) were included in the aPAP group. In both groups participants had to fit the current guideline criteria for HGNS treatment. Groups were compared by analysis of covariance (ANCOVA) using inverse propensity score weighting. ResultsPropensity scores did not differ between groups. Pre-therapeutic AHI (HGNS: 40.22 ± 12.78/h; aPAP: 39.23 ± 12.33/h) and ODI (HGNS: 37.9 ± 14.7/h, aPAP: 34.58 ± 14.74/h) were comparable between the groups. After 413.6 ± 116.66 days (HGNS) and 162.09 ± 140.58 days (aPAP) of treatment AHI (HGNS: 30.22 ± 17.65/h, aPAP group: 4.71 ± 3.42/h; p < 0.001) was significantly higher in the HGNS group compared to the aPAP group. However, epworth sleepiness scale (ESS) was post-interventionally significantly lower in the HGNS group compared to the aPAP group (pretherapeutic: HGNS: 13.32 ± 5.81 points, aPAP: 9.09 ± 4.71 points; posttherapeutic: HGNS: 7.17 ± 5.06 points; aPAP: 8.38 ± 5.41 points; p < 0.01). ConclusionThese are novel real-world data. More research on the key parameters regarding titration of the HGNS neurostimulation parameter tuning and on the impact of factors influencing HGNS adherence is needed.

1045 Resolution of Sexsomnia with Positive Airway Pressure

Abstract Introduction Sexsomnia is an infrequently encountered non-rapid eye movement (NREM) arousal disorder that can overlap with obstructive sleep apnea (OSA). Treatment of underlying OSA has been reported to resolve sexsomnia episodes. Report of case(s) A 26-year-old overweight man was referred to our Sleep Disorders Center for evaluation of possible “REM sleep behavior disorder.” The patient’s wife reported that he would fondle her breasts while he slept. Episodes began 6 months prior to his referral and occurred once every 1-2 months. During episodes, the patient did not get out of bed. He did not recall the events and denied dream recall. The patient had an infant at home with resultant sleep deprivation. He slept between 5-7 hours a night and stated episodes were more common with decreased total sleep time. Additionally, he reported recent increase in stressors after moving in with his in-laws. On evaluation, patient endorsed bruxism for which he wore a mouth guard. He reported history of sleepwalking in elementary school. He denied excessive daytime sleepiness, snoring, witnessed apneas, gasping arousals, morning headaches, unrefreshing sleep, insomnia, or substance use. He was advised to increase total sleep time and pursue a baseline polysomnogram to evaluate for sleep-disordered breathing. The polysomnogram demonstrated moderate OSA (apnea/hypopnea index of 17). Excessive arousals out of N3 sleep were not reported. He was initiated on auto-titrating positive airway pressure (APAP) and maintained moderate adherence for 2 months. At his follow-up visit, he reported no further episodes of nocturnal fondling after PAP initiation despite persistent sleep deprivation and home stressors. Conclusion This case highlights the importance of screening for sleep-disordered breathing which can coexist with NREM parasomnias such as sexsomnia. Even in patients without clear symptoms of sleep-disordered breathing, the evaluation, diagnosis, and treatment of possible OSA could decrease the frequency of sexsomnia episodes. Although this case study was mainly limited by short follow-up duration, the patient’s resolution of sexsomnia in that time demonstrates the importance of treatment of concurrent sleep-related breathing disorders. Support (if any) None.

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

BackgroundObstructive 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.MethodsWe 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 ge 60 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.ResultsOf 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.ConclusionsWe 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 registrationThis trial was retrospectively registered in clinicaltrials.gov NCT02954224 on 03/11/2016.

Patients with Epiglottic Collapse Are Less Adherent to Autotitrating Positive Airway Pressure Therapy for Obstructive Sleep Apnea.

Rationale: The anatomic orientation of the epiglottis is such that it points in the opposite direction to inspiratory flow, thereby potentially making positive airway pressure (PAP) treatment challenging in patients with epiglottic collapse. However, no previous studies have analyzed PAP adherence in these patients. Objectives: This study aimed to analyze adherence to autotitrating PAP (APAP) treatment in patients with epiglottic collapse. Methods: We performed an age- and sex-matched case-control study. On the basis of their overnight level-I polysomnogram, patients were prescribed APAP in a tertiary hospital between July 2018 and March 2019. The site of airway collapse was diagnosed with drug-induced sleep endoscopy. Demographic factors, sleep questionnaire, polysomnography, and APAP usage statistics were analyzed. Results: Eighteen patients with epiglottic collapse (epi-group) and 36 without epiglottic collapse (control group) were analyzed. We found that 22.8% of patients in the epi-group terminated APAP within 2 weeks, whereas only 2.8% of patients in the control group terminated APAP within 2 weeks (P = 0.048). The percentage of days with usage over 4 hours was significantly lower in the epi-group (64.6% vs. 75.6%; P = 0.008). In addition, the adherence failure rate was 66.7% in the epi-group and 33.3% in the control group (P = 0.039). Patients with epiglottic collapse were also found to have lower body mass index, which is an unfavorable predictor of APAP adherence. Conclusions: This study suggests that patients with epiglottic collapse have a higher APAP adherence failure rate than patients without epiglottic collapse. Thus, patients with epiglottic collapse should be followed closely during treatment, and alternative therapies should probably be considered for these patients.

0846 Severe OSA in a 17yr old patient with Prader Willi Syndrome and poorly controlled Diabetes Mellitus

Abstract Introduction Prader Willi Syndrome (PWS), while rare, is the most common genetic cause of obesity. It is caused by a functional loss of paternally expressed genes from chromosomal region 15q11-13. PWS is characterized by short stature, neurodevelopmental delay, obsessive-compulsive behaviors, hypothalamic dysfunction, and hyperphagia, associated with an aberrant satiety response and elevated levels of ghrelin. Excessive daytime sleepiness (EDS) and sleep-disordered breathing (SDB), including obstructive sleep apnea (OSA) and central sleep apnea, are common. Report of Cases: A 17-year-old male, with PWS, morbid obesity, autism, and diabetes mellitus (DM) type-2 was referred for evaluation of snoring and EDS (Epworth Sleepiness Score 16). He had recently been admitted with diabetic ketoacidosis associated with binge eating. He had no prior sleep testing. He denied sleep paralysis, hypnagogic/hypnopompic hallucinations, and cataplexy. He had a body mass index of 54 kg/m2 with short stature (1.6m). On exam, he had a Mallampati score of 4 and 1+ tonsils. A recent echocardiogram was normal. Polysomnography showed sleep latency of 10 mins, apnea-hypopnea index (AHI) of 148/hr, nadir oxygen saturation of 73%, with 45% of total sleep time &amp;lt; 90%. Hypoventilation was not present. He was prescribed auto-titrating positive airway pressure (PAP) therapy. His mother was instructed to start locking access to food again. He was treated with insulin and metformin, with a plan to start on a glucagon-like peptide-1 (GLP-1) agonist. He had been on growth hormone (GH) previously, but in the context of his other morbidities, it was not reinitiated. Conclusion It is critical to screen and monitor patients with PWS for OSA, as SDB occurs in almost 70%. While PAP therapy may improve OSA, there is often residual EDS (likely due to underlying hypothalamic dysfunction), and alerting agents may be needed. GH can be considered for short stature but is contraindicated in patients with morbid obesity, untreated severe OSA, and uncontrolled diabetes. Management of diabetes, obesity, and hyperphagia in patients with PWS is challenging. Supervision and strict limitation of food intake using physical barriers are important. While data are limited, GLP-1 agonists may provide potential benefits for weight, glycemic, and appetite control in patients with PWS. Support (If Any)

Factors associated with treatment outcomes after use of auto-titrating CPAP therapy in adults with obstructive sleep apnea.

To determine factors that are associated with OSA therapy outcomes with auto-titrating positive airway pressure (APAP). We sequentially grouped patients from a retrospective cohort based on APAP efficacy (sufficiently vs. insufficiently treated; insufficiently treatment defined as residual AHI of ≥ 5), therapy adherence (adherent vs. non-adherent, non-adherence defined as < 70% usage for ≥ 4h/night), and therapy outcomes (optimal vs. non-optimal and non-optimal outcomes defined as non-adherent and/or insufficiently treated). We subsequently compared each group. The insufficiently treated were older (68.4 ± 12.5 vs. 60.4 ± 13.1years, p < 0.01) and had lower BMI (31.9 ± 6.3 vs. 37.9 ± 9.1kg/m2, p < 0.01). They had higher baseline central apnea indices (CAI), longer leaks, higher peak pressures, and were less compliant. The non-adherent were younger (61.1 ± 12.6 vs. 65.5 ± 13.2years, p = 0.03) and comprised more females (56.1 vs. 43.9%, p = 0.04). The leak duration per usage hour was higher in the non-compliant (median: 1.5; IQR 7.9 vs. median: 0.3; IQR 1.9min/h; p < 0.01). The non-optimally treated had lower BMI, longer leaks, and less nightly usage. Multivariate analyses showed that leak duration was the common factor associated with treatment effectiveness and optimal therapy outcomes. Various demographic and clinical factors were associated with treatment efficacy and adherence. However, leak duration was the common factor related to treatment efficacy and overall optimal therapy outcomes.

Outcomes of Pediatric Titration Sleep Studies Following Empirical Use of Positive Airway Pressure and the Effect on Adherence to Therapy.

Obstructive sleep apnea (OSA) is diagnosed through polysomnography (PSG) testing and commonly treated with positive airway pressure (PAP). The initial recommended treatment for pediatric OSA is adenotonsillectomy, but when this is contraindicated or ineffective, PAP is the next option. Children followed in our pediatric sleep disorders center who are diagnosed with OSA and meet criteria for therapy are empirically prescribed a PAP device, usually auto-titrating PAP (APAP), to avoid delays in therapy. Titration PSG is performed later to assess adequacy of settings. The aims of this study were to determine how often PSG titration results in changes to empirically prescribed PAP and to assess adherence to therapy before and after PSG titration. A retrospective medical records review was completed for children diagnosed with OSA, prescribed PAP, and had a titration PSG within a 5-y consecutive period of 2008-2012. Demographic data, type of device, pressure settings, and adherence downloads were reviewed. Adherence was assessed before and after titration overall and compared for those who did and did not have therapy changes following titration. The study included 121 participants. Median age at the time of the diagnostic PSG was 11 (interquartile range [IQR] 8-14) y. Most (106, 88%) were initially prescribed APAP. Median length of time between initial and follow-up PSG was 6.4 (IQR 4.4-10.1) months. The majority (94, 78%) had therapy changes following titration. Overall, adherence percentage > 4 h per night was not significantly increased post titration (P = .47). There were no statistically significant differences in adherence between those who had therapy changes and those who did not (P = .26). Titration studies resulted in therapy modifications for most children. Adherence was not increased following the titration PSG. Changes in therapy did not result in increased adherence. Titration PSGs may optimize empirically prescribed settings.

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

ABSTRACTObjective:Obstructive sleep apnea (OSA) is a common disorder associated with a significant economic burden. Continuous positive airway pressure (CPAP) and auto-titrating positive airway pressure (APAP) are recognized therapeutic options in patients with OSA, although treatment costs are higher with APAP. We conducted a study aimed at evaluating the effectiveness and potential cost savings resulting from the implementation of a protocol guiding the transition to CPAP in OSA patients previously treated with APAP. Methods:This prospective study included patients with OSA under APAP who were followed up at the Sleep Medicine outpatient clinic of a tertiary referral hospital between January 2019 and January 2021. Treatment was switched to CPAP in patients who met the following criteria: satisfactory adaptation and adherence to APAP, residual apnea-hypopnea index (AHI) of < 5/hour, and no relevant air leaks. APAP and CPAP outcomes were compared and an estimate of the savings obtained by the transition from APAP to CPAP was calculated. Results:Ninety-three patients were included in the study. APAP and CPAP were both effective in correcting obstructive events and improving daytime sleepiness. No significant differences were found regarding treatment adherence and tolerance between both PAP modalities. The selection of fixed-pressure CPAP through 90th or 95th percentile APAP pressure proved to be effective and an alternative strategy to titration polysomnography. At the end of this two-year study, the transition from APAP to CPAP enabled savings of at least 10,353€. Conclusion:The transition from APAP to CPAP may be an effective, well-tolerated, safe, and cost-saving strategy in patients with OSA.

Auto-titrating versus fixed-EPAP intelligent volume-assured pressure support (iVAPS) ventilation in patients with COPD and hypercapnic respiratory failure.

Intelligent volume-assured pressure support (iVAPS) is a new noninvasive ventilation (NIV) mode that can automatically adjust pressure support to deliver effective ventilation. Our aim was to compare treatment efficacy and level of satisfaction between auto-titrating expiratory positive airway pressure (auto-EPAP) and fixed expiratory positive airway pressure (fixed-EPAP) during iVAPS treatment in stable hypercapnic chronic obstructive pulmonary disease (COPD) patients. In this prospective single-blinded, randomized study, 50 patients with chronic stable hypercapnia (COPD) who met the study criteria were randomized into a group I treated with auto-EPAP and a group II who received fixed-EPAP during iVAPS treatment for 5 consecutive days. The patients' characteristics, arterial blood gases, and lung function test were recorded. Numeric rating scale (NRS), dyspnea and comfort scale were obtained. The study subjects were evaluated and followed up after initiating therapy for 5 consecutive days. Outcome measures were recorded at baseline (T0) and after three (T1) and five (T2) days of each consecutive period All parameters were collected and statistically analyzed. No significant differences were found regarding age, sex, or BMI between the both groups. It was noted that daytime PaCO2 decreased significantly over the follow-up period in the group I patients treated with auto-EPAP as compared with fixed-EPAP. Regarding the patient comfort and dyspnea during iVAPS treatment, dyspnea sensation was significantly lower with auto-EPAP 7.9 ± 1.8 (T0) vs 3.5 ± 1.1 (T2), p = 0.001 and fixed-EPAP 7.7 ± 1.9 (T0) vs 3.4 ± 1.6 (T2), p = 0.001, but no significance was reached between the both groups. However, auto-EPAP demonstrated significant improvement in comfort when compared with fixed-EPAP modality. However, the overall satisfaction of the patients receiving auto-EPAP modality was significantly increased. Mean tidal volume tended to be higher in auto-EPAP 698 ± 213 mL compared with 628 ± 178 mL in fixed-EPAP (p = 0.001). The air leak was significantly lower in auto-adjusting mode (2.5 ± 1.3 vs 3.7 ± 2.2 L/ min) in fixed-EPAP modality. Auto-titrating NIV mode may provide additional benefit in decreasing PaCO2 more efficiently and improve patient comfort and satisfaction.

Analysis of risk factors for air leakage in auto-titrating positive airway pressure users: a single-center study.

Because air leakage from masks is known as a common cause of low adherence to continuous positive airway pressure therapy, we analyzed the risk factors for air leakage related to parameters associated with auto-titrating positive airway pressure, polysomnography, InBody Test, and rhinomanometry. Usage data and medical records of 120 auto-titrating positive airway pressure users were reviewed retrospectively. All patients used a nasal or pillow mask and were carefully monitored at scheduled follow-ups. Use of a pillow mask, sex (male), age, and abdominal fat percentage were significantly associated with high average air leakage. The higher the auto-titrating positive airway pressure average and mean pressure, the more likely patients exhibited high rates of air leakage. The percentage of patients with high average air leakage increased over time (up to 6 months of follow-up). Older male patients using a pillow mask and those with a high abdominal fat percentage and high auto-titrating positive airway pressure may require close follow-up and continuous monitoring for air leakage. Because air leakage from a mask can change over time, mask-sealing capacity should be reassessed and masks should be changed regularly. Kang YJ, Cho J-H, Park C-S. Analysis of risk factors for air leakage in auto-titrating positive airway pressure users: a single-center study. J Clin Sleep Med. 2022;18(1):75-88.

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

Attended manual continuous positive airway pressure (CPAP) titration is the standard practice for determining optimal positive airway pressures for obstructive sleep apnea (OSA) treatment. However, an unattended single night auto-titrating positive airway pressure (APAP) titration is an alternative. The goal of this study was to determine whether therapeutic CPAP pressures determined during manual titrations are higher than APAP-generated surrogate pressures. We conducted a retrospective review of 165 adults with uncomplicated OSA who had full/split-night manual CPAP titrations prior to commencing treatment with APAP. Demographic and clinical data including 30-day APAP compliance data were obtained. We compared the recommended CPAP pressure from manual titrations with the 90th/95th percentile pressure generated from APAP usage over 30 days. The recommended CPAP pressures during the manual titrations were higher than the 90th/95th percentile pressures generated from APAP (11.4 ± 3.4 vs 10.3 ± 2.4 cmH2O; P = .000). Almost half the group (41.9%) had their manually derived titration pressure at least 1.5 cm above the 90th/95th percentile pressure. In multivariate analyses, body mass index was the only variable that predicted higher manual titration pressures. Notably, the average residual apnea-hypopnea index on 30-day APAP data was less than the average residual apnea-hypopnea index observed at the recommended pressure during the manual titration (5.0 ± 4.3 vs 7.2 ± 8.5; P = .006). Manual CPAP titrations may overestimate pressure requirements, particularly in patients with higher body mass index, and may not be necessary in managing patients with uncomplicated OSA. APAP appears to be at least as effective as single-pressure CPAP, while delivering lower positive airway pressure. Fashanu OS, Budhiraja R, Batool-Anwar S, Quan SF. Titration studies overestimate continuous positive airway pressure requirements in uncomplicated obstructive sleep apnea. J Clin Sleep Med. 2021;17(9):1859-1863.

458 The effect of cardioversion therapy for atrial fibrillation on AHI in obstructive sleep apnea patients

Abstract Introduction Sleep apnea (SA) is known to be associated with development of atrial fibrillation (AF), and therapy ameliorates this risk. Case reports and small series raise the possibility of a bidirectional effect of AF on SA burden. We hypothesize that SA control, demonstrated either by residual apnea-hypopnea index (AHI) or pressure during positive airway pressure (PAP) therapy, improves after successful cardioversion. Methods The cohort included VA patients with SA on PAP therapy who underwent successful outpatient direct-current AF cardioversion. Only patients with good adherence in the peri-procedural period, defined as use most days in the week before and after procedure, were included in the study (n=17). We compared AHI prior to and after cardioversion using the sign test since values were not normally distributed. Since most participants were on auto-titrating PAP, the sign test was also used to compare mean pressure difference in the 7 days before and after the procedure. Results There was no statistical difference when comparing AHI before and after AF cardioversion therapy (AHI change = -0.45, 95% CI = [-0.94, 0.17]) There was also no difference between mean pressure used for PAP therapy before and after therapy (pressure change = 0.05, 95% CI = [-0.1, 0.33]). Conclusion This small study did not find an association between successful AF cardioversion and PAP residual AHI or pressure (for auto-titrating machines). A larger cohort may have improved power to detect subtle effects of AF therapy on SA burden. Support (if any) This study was supported by the Career Development Award IK2CX001882 from the United States (U.S.) Department of Veterans Affairs Clinical Sciences Research and Development Service.

795 Real World Challenges and Barriers for Positive Airway Pressure Therapy Use in Acute Ischemic Stroke Patients

Abstract Introduction Untreated obstructive sleep apnea (OSA) in patients with acute ischemic stroke (AIS) increases morbidity and mortality post-stroke. However, diagnosing and treating OSA in AIS is challenging. As such, we aimed to determine the feasibility of portable monitoring (PM) for diagnosis and positive airway pressure (PAP) therapy for treatment of OSA in an inpatient stroke population. Methods We recruited inpatients with AIS from the Cleveland Clinic. Those who consented underwent PM; participants with a respiratory event (REI) ≥10 were offered auto-titrating positive airway pressure therapy (APAP). Ease-of-use questionnaires were completed. We summarized categorical variables using n(%) and continuous variables using mean±SD or median [IQR]. Results 27 participants (age 59.8±11.8, 51.9% female, 51.9% African American, BMI 33.3±11.4) enrolled. The study ended early due to Medicare contracting that forced most patients to complete stroke rehabilitation outside the Cleveland Clinic health system. 69.6% had large vessel occlusions and 52% had moderate/severity disability (Modified Rankin score ≥2). PM was attempted in 23 participants and successful in 19. Nursing and patients rated the PM device as highly easy to use. 11 of 14 patients who had an REI ≥10 consented to APAP titration, but only 5 continued APAP after discharge. Four patients who initially said APAP was easy to use noted that their stroke interfered with their APAP use at home. Conclusion This study demonstrates the challenges in the assessment and treatment of OSA in an acute ischemic stroke population, highlighting the necessity for further research into timely and feasible screening and treatment. Support (if any) ResMed

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

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. Between January 2015 and December 2017, 50 participants were enrolledwho were diagnosed with OSA and prescribed auto-titration PAP (APAP) devices. TheRIs 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 polysomnographicdata. 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, oxygensaturation, and respiratory distress indices of diagnostic polysomnographic factors. 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.

Optimal pressure in obstructive sleep apnea: auto-titrating positive airway pressure versus predictive equations

Background The prescription of equation-based predicted pressure (Ppred) using mathematical equations has been proposed as a practical strategy for the determination of effective positive airway pressure (PAP). This study aimed at comparing the differences between therapeutic pressures obtained by auto-titrating positive airway pressure (APAP) and 10 predictive mathematical equations among Egyptian patients with obstructive sleep apnea (OSA). Patients and methods A retrospective cross-sectional study included 25 PAP-naive patients (23 males and two females) with polysomnographically confirmed OSA. The 95th percentile pressure (P95) of an APAP device during an attended successful titration study was selected as the effective reference PAP, against which PPred calculated from ten predictive equations was compared. Results Among the 25 patients included, four patients had mild, eight had moderate, whereas the remaining 13 patients had severe OSA. The mean P95 was higher than all predictive equations. A total of 24 (96%) of the 25 included patients experienced acceptable air leak during APAP titration. P95 correlated significantly and positively with pressures calculated by most of predictive equations except for those of equations 2, 6, and 7. Comparison between P95 and Ppred showed nonsignificant statistical difference for pressure calculated by Series equation, whereas Ppred of other equations were significantly lower than P95. Mean pressure difference between P95 and Ppred was around three in most of the equations with Series equation carrying the least mean pressure difference (0.7 cmH2O). Conclusion P95 is higher than Ppred, yet Series equation was the closest to P95. The utility of predictive equations for determining effective PAP level can serve a beneficial role during titration studies and can be used with caution as a practical alternative for PAP titration.

Comparison of 3‐months treatment adherence and estimating residual apnea hypopnea index between home versus in‐laboratory auto‐titrating positive airway pressure titration

We aimed to assess the accuracy of home titration in estimating apnea hypopnea index (AHI) and optimal pressure values and to compare improvements in subjective daytime sleepiness, sleep quality and quality of life, along with 3-months treatment adherence of patients that received at-home versus in-laboratory auto-titrating positive airway pressure (APAP) titration. In patients with a diagnosis of obstructive sleep apnea syndrome (OSAS), a study arm of laboratory attended APAP titration was compared with a study arm of home titration using an APAP device for three days. Subjective questionnaires were evaluated before and after 3 months of treatment. Fifty-three patients with newly diagnosed OSAS were enrolled. There was a significant positive correlation between PSG AHI and APAP AHI (rs =0.43, P=0.003) and the fixed pressure for the APAP arm was positively correlated with the APAP PSG arm of the study (rs =0.71, P<0.001). When the Bland-Altman graphs were compared, it was seen that the measurements obtained by the APAP AHI method were 0.3 units higher than the PSG AHI measurements, and that the mean of the measurement differences between the two methods was not different than 0 (P [H0 : Mean=0]=0.551). After 3 months of treatment, average nightly use was slightly higher in the APAP arm (P=0.387). The results indicate that both titration methods were not clinically inferior in terms of a fixed optimal pressure, residual events, 3-months treatment adherence and change in subjective sleepiness, sleep quality and quality of life after treatment.

Baseline Lighter Sleep and Lower Saturation Are Associated With Improved Sleepiness and Adherence on Continuous Rather Than Autotitrating Positive Airway Pressure.

The objective was to test whether there were better outcomes on switching from autotitrating positive airway pressure (APAP) to continuous positive airway pressure (CPAP) in a clinic sample of patients with obstructive sleep apnea (OSA). Patients prescribed APAP in 2015-2016 and belonging to a subset characterized by side effects, or suboptimal response or adherence, were advised a switch to CPAP following a CPAP titration polysomnography. The main analysis was for improvement (after switch from APAP to CPAP) in (1) sleepiness, wakefulness inability, and fatigue, using change from baseline in the Sleepiness-Wakefulness Inability and Fatigue Test (delta SWIFT), and Epworth Sleepiness Scale (delta ESS), and (2) adherence using percentage of days with ≥4-hour use and whether there was ≥4-hour use on ≥70% days. To determine possible predictors for switching, additional analysis was performed for differences at baseline between patients switching and those staying on APAP. A total of 148 patients were switched from APAP to CPAP and had greater improvement in delta SWIFT (5.2 vs 4.1, P = .004), greater improvement in delta ESS (3.6 vs 2.9, P = .011), and better adherence (79.4% vs 74.3%, P = .006) on CPAP than on APAP. More patients were adherent on CPAP than on APAP (83.1% vs 68.9%, P = .006). Patients switching had higher baseline arousal index and stage N1 sleep, and lower nadir oxygen saturation, than 96 patients not switching. Thus, there is a subset of patients with better outcomes after switching to CPAP than on APAP. Patients with baseline lighter sleep (indicated by more arousals and stage N1), or greater desaturation, may be more likely to do better on CPAP than on APAP. CPAP may be the preferable treatment in a significant subset of patients. If APAP is used first anyway, side effects, or suboptimal response or adherence, should lead to consideration of switching to CPAP based on a CPAP titration polysomnography.

Evolution and Predictive Factors of Improvement of Obstructive Sleep Apnea in an Obese Population After Bariatric Surgery.

Our objectives were to determine in an obese population (body mass index > 35 kg/m²) the number of patients, after gastric bypass (GBP), who no longer met French Ministry of Health criteria for utilizing positive airway pressure (PAP), and the predictive factors of obstructive sleep apnea (OSA) improvement. Between June 2012 and August 2014 we diagnosed OSA in 129 incident patients requiring PAP therapy before GBP. A postoperative sleep recording was undertaken for 44 of these patients after a weight loss of at least 10%. Most of the patients showed severe OSA with a mean [standard deviation] apnea-hypopnea index (AHI) of 52.8 [23.8] events/h. The body mass index was 46.1 [5.1] kg/m². All the patients were treated via PAP and most of them via auto-titrating PAP with a range of 4-16 cmH₂O. Following the GBP, in 31 patients (70.5%) OSA was improved, allowing PAP to be stopped (AHI < 15 events/h). The Epworth Sleepiness Scale score, the modified Medical Research Council dyspnea scale, the loudness of snoring, and sleep structure were improved. AHI was decreased by a mean of 40.9 [22.4] events/h (P < .001). In a multivariate logistic regression model, age (P = .018) and sleep oxygen desaturation index (P = .049) appeared to predict improvement of OSA. After GBP, 70.5% of the patients no longer met French Ministry of Health criteria for utilizing PAP, allowing discontinuation of this treatment. At diagnosis, a younger age and a less severe sleep oxygen desaturation were predictive factors of this improvement.

0529 Better Adherence and Less Sleepiness- Wakefulness Inability and Fatigue on Continuous Positive Airway Pressure (CPAP) than on Auto-titrating Positive Airway Pressure (APAP) in a Large Clinic Sample

0529 Better Adherence and Less Sleepiness- Wakefulness Inability and Fatigue on Continuous Positive Airway Pressure (CPAP) than on Auto-titrating Positive Airway Pressure (APAP) in a Large Clinic Sample

A randomised crossover trial comparing nasal masks with oronasal masks: No differences in therapeutic pressures or residual apnea-hypopnea indices.

In treating obstructive sleep apnea (OSA), the use of oronasal masks with continuous positive airway pressure (CPAP) has been reported to increase pressure levels and reduce compliance. These reports come mostly from large observational studies. In this study, we examined the impact that oronasal masks have on 95th centile pressures, the residual apnea-hypopnea index (AHI) and compliance compared with nasal masks. A randomised crossover design was implemented. Participants already established on CPAP were randomly allocated to a nasal mask or oronasal mask with auto-titrating positive airway pressure (APAP) for 2weeks. Participants then crossed over to use the alternate mask for another 2weeks. Seventy-one participants were recruited but only 60 completed the trial. There were no differences in median 95th centile pressure (nasal, 11.5cm H2 O; oronasal, 11.7cm H2 O; p=0.115), median residual AHI (nasal, 4.9 events/hr; oronasal, 5.3 events/hr; p=0.234) or median compliance (nasal, 7.3hr/night; oronasal, 7.3hr/night; p=0.961). Only four patients had 95th centile pressures that were at least 1.5cm H2 O greater with oronasal masks. Oronasal masks do not systematically increase therapeutic CPAP requirements. Rather, a small subset of patients display significant differences in CPAP levels.