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With increasing prevalence of obesity, the substantial contribution of obesity hypoventilation syndrome (OHS) to morbidity and mortality is likely to increase. It is therefore crucial that the condition has a clear definition to allow timely identification of patients. OHS was first described as “Pickwickian syndrome” in the 1950s; in subsequent decades, case reports did not clearly delineate between patients suffering from OHS and those suffering from obstructive sleep apnoea. In 1999, the American Academy of Sleep Medicine published a guideline that delineated the cause of daytime hypercapnia as either predominantly upper airway or predominantly hypoventilation. This was the first formal definition of OHS as the presence of daytime alveolar hypoventilation (arterial carbon dioxide tension >45 mmHg) in patients with body mass index >30 kg·m−2 in the absence of other causes of hypoventilation. This definition is reflected in the most recent guidelines published on OHS. Recent developments in defining OHS include proposed classification systems of severity and demonstrating the value of using serum bicarbonate to exclude OHS in patients with a low index of suspicion. Educational aims To provide an overview of the historical basis of the definition of obesity hypoventilation syndrome. To explain the rationale for the current definition of obesity hypoventilation syndrome. To demonstrate areas that need further investigation in defining obesity hypoventilation syndrome., Obesity hypoventilation syndrome is defined as daytime alveolar hypoventilation in obese patients in the absence of other causes of hypoventilation. Classifications of severity are now needed to target treatment at the most appropriate individuals. https://bit.ly/3yLuiL9

Objective:To compare the clinical outcomes of HFNC with non-invasive ventilation(NIV) with auto-titrating EPAP for severe pneumonia patients with OHS(obesity hypoventilation syndrome). Methods:It was a prospective, randomized and controlled study. 60 severe pneumonia patients with OHS (27.3±8.9 yrs,BMI:40±8.9 kg/m2) were included, who had no a history of immunosuppressant therapy. Main criteria: 100＜PO2/FiO2＜300 mmHg; APACHE-Ⅱ:20-30. All subjects were randomly divided (1:1:1) into three groups: HFNC-group(Flow:50-60L/min,FiO2:40-60%); AVAPS- group (NIV with AVAPS mode, EPAP=8 cmH2O) and AVAPS-AE (average volume assured pressure support auto-titrating EPAP)group: AVAPS-AE mode, maximum EPAP=14cmH2O,minimum EPAP=4cmH2O. Results:Higher occurrence of ventilator-induced lung injury(VILI) and patient-ventilator asynchrony were observed in AVAPS-group than in other groups (pl0.001) .28-day mortality rates of 20.0%(n=4) in HFNC–group was significantly lower than in 45% (n=9) in “AVAPS-group and 30% (n=6) in AVAPS- AE group(pl0.05). There were no significant differences in changes of PO2/FiO2 between AVAPS-AE and AVAPS group(pg0.05). Degree of the comfortable during NIV in AVAPS-AE group were higher than in AVAPS group(pl0.05). Conclusions:Young OHS patients with severe pneumonia maybe could not benefit from noninvasive ventilation, either AVAPS or AVAPS-AE mode, and there were high mortality rate in both groups. HFNC seems to be superior to NIV in increasing VILI and 28-day mortality rate. AVAPS-AE mode could improve the patient’s comfort by auto-titrating EPAP level.

Background Obstructive sleep apnea (OSA) syndrome is strongly associated with obesity and inflammation. Adipose tissue is not simply an inactive storage depot for lipids but is also an active endocrine organ that plays a crucial role regarding endocrine, metabolic, and inflammatory signals of which leptin, ghrelin, adiponectin, and resistin play an important role in body homeostasis. So, we aimed to study leptin and ghrelin serum levels in OSA patients. Patients and methods The study included 15 healthy control participants and 30 patients diagnosed with OSA. All patients were subjected to history taking, clinical examination, routine laboratory investigations, and polysomnography. Manual analysis and scoring were performed using the criteria established by the American Academy of Sleep Medicine. Results Patient’s serum leptin ranged between 11.4 and 66.4 ng/ml with a mean±SD of 33.303±15.728 while in control participants it ranged between 0.5 and 34.7 ng/ml with a mean±SD of 10.467±10.339. Patient’s serum ghrelin ranged between 103.5 and 6673 pg/ml with a mean±SD of2034.527±1815.687 while in control participants it ranged between 976 and 2184 pg/ml with a mean±SD of 1682.467±334.064. Leptin levels were statistically significantly higher in obstructive sleep apnea syndrome (OSAH) patients versus control participants. Leptin levels statistically significantly correlated with some indices of obesity hypoventilation syndrome severity, that is, apnea–hypopnea index and desaturation index. Leptin levels statistically significantly correlated with a variety of anthropometric measurements, including BMI and neck circumference. Leptin levels statistically significantly correlated with serum triglyceride levels. Regression analysis showed that the best predicting variables for leptin levels were the lowest oxygen saturation, average SaO2, sleep time with oxygen saturation of less than 90% (t90%) and BMI. There was no statistically significant difference between the two studied groups regarding serum ghrelin levels and no statistically significant correlation was found between serum ghrelin and any parameter.

Rationale: Noninvasive ventilation (NIV) is an effective treatment in obesity hypoventilation syndrome (OHS) with severe obstructive sleep apnoea (OSA) but there is paucity of evidence in OHS patients without severe OSA phenotype. Methods: In this multicentre (16 sites in Spain), open-label parallel group clinical trial, we randomly assigned 98 stable ambulatory patients with untreated OHS and apnoea-hypopnoea index Results:49 patients were randomised in each group and 48 patients were analysed in each one of them. During a median [IQR] follow-up of 4.98 [2.98; 6.62] years, mean (SD) hospitalization days/year was 2.60 (5.31) in the control group and 2.71 (4.52) in the NIV group [adjusted rate ratio (95% CI) 1.07 (0.44; 2.59) (p = 0.882)]. Cardiovascular events occurred in 11 (23%) participants in the control group and 10 (21%) in the NIV group (hazard ratio (95% CI) 0.96 (0.40;2.30), p=0.927). Similar results were observed in the per-protocol analysis [rate ratio (95% CI) 1.21 (0.43;3.41) (p=0.717)]. Death occurred in 9 (19%) participants in both arms (adjusted hazard ratio (95% CI) 1.07 (0.41;2.82), p=0.893). Similar results were found in the per-protocol analysis [rate ratio (95% CI) 1.38 (0.50;3.79) (p=0.529)]. Conclusion: In stable ambulatory patients with OHS without severe OSA, NIV and lifestyle modification had similar long-term hospitalization days-year. Larger studies are necessary to better determine the long-term benefit of NIV in this subgroup of OHS.

Context: Continous positive airway pressure (CPAP) is the standard treatment for obstructive sleep apnea (OSA) and obesity hypoventilation syndrome (OHS). It9s effectiveness is limited due to suboptimal adherence and probably explained by differnte psycho-social features. Objective: Identify the relationship between psychological variables like locus of control, autoefficacy, negative affectivity (NA) and social inhibition (SI) with one-month CPAP use in patients with OSA & OHS. Methods: Through a prospective cohort, 40 patients with OSA or OHS virgin to CAP use were included. Previous to followup, patients completed 8 autoapplicable scales: DS-14 for type D personality, SEMSA for autoefficacy, MHLC for locus of control, BIS/BAS por activation/inhibition, mini-IPIP for personality traits, HADS, BDI-II and BAI for anxiety/depression. Patients were evaluated one month later for adherence to CPAP defined as percentage of use >4 hours ≥70% or with mean daily use in minutes (MDUM). Results: Every point in the NA subscale of DS-14 decreased in 11% the probabilities of adherence while every point in the SI subscale of DS-14 did so in 17%. MDUM decreased in 8.85min (CI95% -17.33/-0.36) for every point in NA and 11.92min (CI95% -22.1/-1.74) for every point increase in SI. Other scales and clinical variables did not predict treatment adherence. Conclusions: Designers of new interventions to enchance patients with AOS & SOH CPAP adherence should consider NA and SI as personality traits that influence patient outcomes.

Background: In patients with obesity hypoventilation syndrome (OHS), current monitoring of domiciliary non-invasive ventilation (NIV) relies on clinical outcomes, daytime arterial blood gases (ABG) and nocturnal pulse oximetry. Aim: To evaluate the usefulness of nocturnal transcutaneous capnography in assessing nocturnal hypoventilation when compared to routine exams. Methods: A monocentric prospective study was conducted from August 2018 to November 2019 in a university hospital centre in France. Thirty-two patients suffering from OHS treated with domiciliary NIV were included. Systematic nocturnal transcutaneous capnography was performed after at least 6 months of home ventilation. Results: Twenty-nine transcutaneous capnographies were analyzed. Main results are displayed in the Table. Eighteen tests showed nocturnal hypoventilation, even though the combination of ABG and nocturnal pulse oximetry revealed nocturnal hypoventilation in 9 cases only. Among the 19 patients with normal ABG and nocturnal pulse oximetry, 11 exhibited nocturnal hypoventilation on transcutaneous capnography. Only one patient reported symptoms. Conclusion: Based on these findings, we suggest that patients with OHS treated by home NIV should be systematically evaluated with additional transcutaneous capnography to detect nocturnal hypoventilation.

Rationale: Obesity hypoventilation syndrome (OHS) has been associated with cardiac dysfunction. However, randomized trials have assessing the impact of long-term noninvasive ventilation (NIV) or CPAP on cardiac structure and function assessed by echocardiography are lacking. Methods: In a pre-specified secondary analysis of the largest multicenter randomized controlled trial of OHS〔Pickwick project, n=221 patient with OHS and coexistent severe obstructive sleep apnea (OSA)〕, we compared the effectiveness of 3 years of NIV and CPAP on structural and functional echocardiographic changes. At baseline and annually during 3 sequential years patients underwent transthoracic two-dimensional and doppler echocardiography. Echocardiographers were blinded to the treatment allocation. Statistical analysis was performed using a linear mixed-effects model with a treatment group/repeated measures interaction to determine the differential effect between CPAP and NIV. Results:196 patients were analyzed, 102 treated with CPAP and 94 treated with NIV. Systolic pulmonary artery pressure decreased from 40.5±1.47 mmHg at baseline to 35.3±1.33 mmHg at 3 years with CPAP and from 41.5±1.56 mmHg to 35.5±1.42 with NIV (p Conclusion: In patients with OHS and concomitant severe OSA, long-term treatment with NIV and CPAP led to similar degrees of improvement in pulmonary hypertension and LVDF.

Background: Non-invasive ventilation (NIV) is widely considered during management of acute respiratory failure within obesity-hypoventilation syndrome(OHS) patients in ICU. Nevertheless, other management features remain debated. We aimed to describe ventilatory practices and outcome of SOH patients in intensive care unit. Methods: This was a retrospective study carried within a medical ICU in Abderrahmen Mami Hospital between January 2017 and September 2019. OHS Patients admitted in ICU were included. Ventilatory management and outcomes were collected. Results: We enrolled 55 patients. Mean age was 64±11 years and sex-ratio=1.04. At their basic state, patients had primarily chronic respiratory failure with mMRC dyspnoea stage of 2(47%) and 3(33%). At admission, 53(96%) patients had acute respiratory failure, 40(75%) were hypercapnic. At arterial blood gases, means pH, PaCO2 and PaO2/FiO2 were respectively 7.29±0.12; 63±23 mmHg and 182±95 mmHg. NIV was used as first-line ventilatory support in 43 subjects (78%) and was successful in 30(70%). PEP max setting was 10cmH2O and mean NIV duration was 4.5±3days. Invasive ventilation (n=25) was immediately necessary in 12 patients and secondary in the 13 others. Mechanical ventilation weaning was processed in 21 patients (38,2 %), it was simple (n=5), difficult (n=11) or prolonged (n=5). Extubation was scheduled in 8 cases and accidental in 4 cases. Mean length of stay was 12±11days. Overall mortality was 40%. It was 21 % in NIV success group, 67% within immediately intubated patients, and reached 85% in intubated patients after NIV failure. Conclusion: NIV success within OHS patients was 70%. Invasively ventilated patients had poor outcome.

Introduction: Noninvasive ventilation (NIV) is recommended in patients with obesity hypoventilation syndrome (OHS) with acute hypercapnic respiratory failure (AHRF). Left heart disease is frequently present in obese patients but its prognostic role in patients with OHS and AHRS is unknown. This study aimed to assess the impact of cardiac dysfunction on the outcome of acute NIV in this clinical setting. Methods: A prospective cohort study was undertaken in a respiratory intermediate care unit in an academic medical center between 2018 and 2019. Clinical characteristics, echocardiographic data (that defined left heart dysfunction), NT-pro BNP levels, hours of NIV during the first 72 hours (dNIV-72h) and other data were recorded. The main outcome was NIV failure. Secondary outcomes were NIV duration and length of hospital stay. Results: 33 patients (20 female, mean age 63 years) with OHS and AHRF were included. 26 patients (78%) had left heart dysfunction. NIV failure was 3.3%, mean LOS was 9 days, mean NIV duration was 5.5 days. The presence of left heart dysfunction increased both dNIV-72h (p Conclusion: NIV failure rate was not influenced by the presence of left heart dysfunction nor by the NT-pro BNP levels. Patients with left heart dysfunction required prolonged use of NIV.

Introduction: There is an ongoing debate about the best home ventilatory strategy in OHS. CPAP is a simpler approach than NIV. However, little is known about potential consequences of substitution by CPAP or NIV withdrawal in OHS patients previously treated with home NIV. Methods: Retrospective monocentric study that included all consecutive OHS patients withdrawn from home NIV between 2017 and 2018 in our centre. Success of NIV withdrawal was defined as a PaCO2 Results: Out of the 237 OHS patients who attended our outpatient NIV clinic, 27 (11%) were withdrawn from NIV. Patients were mainly female (n:14), had a mean age of 68±11 yrs and had been established on NIV for 1.1 yrs [0.7-3.2]. NIV was established following an acute respiratory failure for 9 (33%) patients. Before NIV withdrawal, 10 patients had a compliance >4hrs/day and diurnal PaCO2 was 5.5 kPa [4.9-6.0]. Reasons for NIV withdrawal were normocapnia (n:15), non-compliance to NIV (n:10), weight loss (n:2). Successful NIV withdrawal was obtained in 11 (41%) patients. Five patients had a relapse of hypercapnia at follow-up with a daytime PaCO2 increase of 0.64 kPa [0.38-0.75]. Five remained non-compliant to CPAP. Four died after NIV withdrawal with a median survival of 147 days [137-200]. One patient remained normocapnic but developed cardiac failure and preferred to go back on NIV. One patient remained to be evaluated. Conclusion: Home NIV withdrawal in OHS patients has a poor success rate. CPAP and NIV cannot be considered as comparable treatments for OHS.

Rationale: Obesity hypoventilation syndrome (OHS) is commonly treated with noninvasive ventilation (NIV) or CPAP. NIV is more complex and costly but provides ventilatory support. To date there have been no long-term or cost trials comparing these treatment modalities. Methods: We performed a large, randomized, multicenter, open-label controlled trial in Spain to compare the long-term effectiveness of NIV and CPAP using hospitalization days/year-patient as the primary end point. We carried out a simple cost analysis including effectiveness cost during 3 year of follow-up. We included the following cost groups: visits, adjustment of NIV, tests, medication, therapies and hospital resources utilization. A sensitivity analysis was conducted according to 3 different scenarios guided by the International Gross Domestic Product. Results: In total, 215 patients with untreated OHS and severe obstructive sleep apnea (OSA) were randomized to NIV or CPAP therapy and followed at least 3 years. The effectiveness was close between arms (mean difference NIV-CPAP: -0.19, 95% CI -1.13 to 0.75). The cost per patient/year was lower in the CPAP arm (1,898.2€; SD 1939.5) than the cost in the NIV arm (2,809.3€; SD 2901.6), mean difference -911.1€ (p Conclusions: In stable patients with OHS and severe OSA, despite NIV having a slight advantage in effectiveness, CPAP could be considered the first line of treatment due to its lower cost but, a case-by-case assessment is recommended to detect patients who would benefit from a switch to NIV.

Background: Active humidification is commonly suggested for long-term NIV. However its impacts on NIV compliance, quality of life (QoL) and NIV efficacy have not been assessed. Methods: Randomised controlled monocentric trial conducted between 05/2018 and 01/2019 that included all patients referred for home NIV initiation. Patients were randomised to have their NIV setup with a humidification device (HD group) or without (control group). Outcomes were assessed 2 months following NIV initiation. Results: Thirty-three patients were included in the trial. They had a mean age of 66±12 years. Underlying respiratory disease was: obesity hypoventilation syndrome (n:12), COPD (n:8), neuromuscular/chest-wall disease (n:8) and COPD-OSA (n:5). At baseline, there was no difference between both groups. Final assessments were available at follow-up: 14 in the HD group and 16 in the control group. At follow-up, compliance was: 5.7±3.3 in the HD group and 5.3±1.6hours/day in the control group (p:0.683). Improvement in QoL assessed by the Severe Respiratory Insufficiency questionnaire was: +5±24 in the HD group vs -11±22 in the control group (p:0.125). Improvement in daytime PaCO2 was: -0.36±0.87 in the HD group vs -0.02±0.68 kPa in the control group (p:0.260). Perceived mouth dryness assessed by visual analogue scale was: 6.1±2.7 out of 10 in the HD group and 6.3±3.1 in the control group (p:0.869). Conclusion: Active humidification does not improve compliance, efficacy of NIV nor QoL. These data need to be confirmed on a larger population.

Background: OHS and COPD are both common respiratory conditions that can lead to chronic hypercapnic respiratory failure with the need for domiciliary NIV. Variability of NIV practice is a known issue. The aim of this study was to investigate differences regarding baseline characteristics and adherence between both conditions. Method: A retrospective analysis of patients observed in our chronic respiratory failure clinic between 2016 and 2018 was performed. Patients with OHS and COPD were selected and compared regarding baseline characteristics and adherence at the first evaluation after NIV setup. Adherence to treatment was evaluated by the mean use hours per night. Results: 94 patients were included. 57 were OHS and 37 were COPD patients. Baseline characteristics according to each group are summarised in table 1. There were statistically significant differences between gender, prevalence of heart failure, BMI, EPAP and pCO2 value. A tendency to poor adherence in COPD patients was observed. Conclusion: The tendency to poor compliance to NIV of COPD patients may justify the higher pCO2 values found and contribute to the difficulty of demonstrating NIV benefits in these patients in several studies. New strategies to improve adherence should be researched.

Introduction: Patients on chronic noninvasive ventilation must adapt to NIV. Little is known how side effects and associated symptoms influence adherence to NIV. Methods: Consecutive patients at outpatient NIV clinic were included, with underlying diseases: obesity hypoventilation syndrome (OHS), kyphoscoliosis (KS) and COPD. Side effects and associated symptoms on NIV were recorded systematically with a questionnaire. Results: 231 patients (47% OHS, 9% KS, 44% COPD) were included, 66% men, age 64 ± 12 years. Of these, 85% were adherent to NIV, with no difference between disease groups. Patients reported nocturia (62%), insomnia (34%), mask leaks (27%), stomach distention (15%), skin issues (13%), deventilation dyspnea (11%), headache (8%), chest pain (4%). In multivariate analysis adjusted for sex, residual hypercapnia, insomnia, headaches, nocturia, mask leaks, deventilation dyspnea, chest pain, stomach distention, only deventilation dyspnea (OR 0.29, CI 0.088-0.94, p=0.039) was independently negatively associated with adherence. In the same model for each disease group, hypercapnia (OR 0.03, CI 0.002-0.41, p=0.009), insomnia (OR 0.014, CI 0.01-0.26, p Conclusions: Overall adherence to NIV was good. Deventilation dyspnea was associated with worse adherence. In the COPD group female sex was associated with worse adherence. In the OHS group, residual hypercapnia and insomnia were associated with worse and improvement of nocturia with good adherence.

Rationale: Obesity hypoventilation syndrome (OHS) is commonly treated with CPAP or noninvasive ventilation (NIV). NIV is more complex and costly but it provides ventilatory support. To date there have been no long-term trials comparing these treatment modalities. Methods: We performed a large, multicenter, open-label controlled trial in Spain to compare the long-term effectiveness of NIV and CPAP: respiratory function, Epworth sleepness scale (ESS), other clinical symptoms, blood pressure (BP) and health related quality of life (HRQL). The analysis was performed according to the intention-to-treat principle. Results: In total, 215 patients with untreated OHS and severe obstructive sleep apnea (OSH) were randomized to NIV or CPAP therapy and followed at least 3 years. PaCO2, bicarbonate and pH improved significantly with both treatments without group differences. FEV1 and FVC improved with positive airway pressure (PAP) but without significant group differences. The 6-MWD test did not improve with either PAP modality and there were no significant group differences. ESS and other clinical symptoms like dyspnea or unrefreshing sleep improved similarly with CPAP and NIV therapy. Both systolic and diastolic BP improved significantly with PAP but without group differences. HRQL tests (SF-36 physical and mental, FOSQ and VAWS) improved with PAP without any significant group differences. Conclusions: In stable patients with OHS and severe OSA, NIV and CPAP have similar long-term effectiveness improving respiratory function, symptoms, BP and HRQL. Given that CPAP has lower complexity and cost, CPAP may be the preferred treatment modality until more studies become available.

Background: Obstructive sleep apnea (OSA) is a widespread respiratory disorder and it is associated with cardiogical comorbidities. Galectin-3 is a seric protein used as biomarker of cardiac macrophages activation and it is upregulated in failing and remodelling hearts. Aims: To evaluate correlations between seric level of galectin-3 and nocturnal cardiorespiratory indices, such as Apnea-Hypopnea Index (AHI), Oxygen Desaturation Index (ODI), Total Sleep Time with oxyhemoglobin saturation Methods: We enrolled patients affected by OSA defined at our sleep center according to International Classification of Sleep Disorder Breathing III edition (Sateia MJ, Chest 2014;146(5):1387-1394). Patients affected by Overlap Syndrome (OSA-Chronic Obstructive Pulmonary Disease) and Obesity Hypoventilation Syndrome (OHS) were excluded. We evaluated linear correlation between hypnological parameters (AHI, ODI, TST90 and mean nocturnal SpO2) and seric level of Galectin-3. Statistical significance: p Results: 75 patients were eligible for the study. There was no correlation between AHI, ODI and seric level of galectin-3. A significant direct correlation was found between TST90 and Galectin-3 (p:0.00, r:0,360). Moreover, a significant negative correlation was found between mean nocturnal SpO2 and Galectin-3 (p:0.00, r:-0,356). Conclusions: In OSA patients, severity of nocturnal hypoxemia (TST90/mean nocturnal SpO2), rather than number of obstructive events for hour (AHI), could contribute to cardiac remodelling and therefore to the onset of cardiological comorbidities.

Introduction: Data from NIV built-in softwares are a cornerstone of NIV monitoring. However, little is known on the adequate management of such data. The aim of this study was to assess the impact of utilising telemonitored data in the long-term management of patients and its theoretical costs. Methods: We built a retrospective database that included 3-months daily NIV data of patients established on long-term NIV in Rouen. Data available were: underlying respiratory disease, daily compliance, leaks, tidal volume, respiratory rate (RR), residual apneic events, % of triggered breaths. 11 NIV experts independently proposed a management pathway of these data. For each alert, the expert proposed an action: telephone call, home visit or overnight oximetry. Each pathway was applied to the database. Results: Ninety-one patients were included. Underlying respiratory disease was: obesity hypoventilation syndrome (n:25), COPD (n:23), COPD-OSA (n:23), neuromuscular disease (n:13) and chest-wall disease (n:7). Expert pathways varied greatly regarding the parameters to monitor. Parameters most commonly included in alerts were: daily compliance (n:11), leaks (n:10), RR (n:7). The percentage of patients for which an action would have been triggered by expert pathway varied from 20 to 100% (p Conclusion: There is no established consensus on the management of telemonitored data of home NIV. Clinical benefit remains unclear and subsequent costs may be significant.

Introduction: Obesity hypoventilation syndrome (OHS) is defined as a combination of obesity (BMI ⩾30 kg·m−2) and daytime hypercapnia (PaCO2 ⩾45 mmHg). Nocturnal ventilation is usually use to treat the OHS but to date it still unclear if is better use CPAP or Bilevel. Aim: Compare the long-term (3-year) results obtained through ventilatory therapy with Bilevel or CPAP in terms of reduction of PaCO2, improvement of PaO2 and daytime sleepiness. Methods: 26 OHS (Age 54±11.8; BMI 47.16±7.1, PaCO2 52.45±5.2) were followed for 3 years after diagnosis and initiation of night-time ventilatory therapy. All subjects were first titrated with CPAP, if the results were not satisfactory (in term of reduction of AHI or T90) or the patients did not tolerate CPAP they were then treated with Bilevel, thus 16 patient received Bilevel and 10 CPAP. Once a year for three consecutive years have undergone pneumological examination, blood gas analysis, weight control and sleepiness. Results: In both groups a significant reduction in PaCO2 values was obtained (Bilevel 52.4±5.1 vs 44.5±2.9, p Conclusions: CPAP or Bilevel ventilation ensures improved gas exchange and daytime sleepiness in OHS patients, however a higher percentage of patients need Bilevel and they achieve better results in terms of PaCO2 reduction.

Introduction: Guidelines recommend that OHS patients are electively admitted to hospital for initiation of home NIV, but it is unknown whether OP setup is safe and as effective as IP setup. We hypothesised that OP NIV setup would be more cost-effective than IP NIV setup. Method: OHS patients were recruited to a multicentre international clinical trial. Patients were randomised to IP setup, using nurse-led overnight titration with standard fixed level NIV, or OP setup using an auto-titrating NIV device (AVAPS-AE, Philips, US). Primary outcome was cost-effectiveness difference at 3 months with carbon dioxide (PaCO2) embedded as an a priori non-inferiority clinical effectiveness safety outcome. Costs were converted to UK £ sterling 2017. Results: 82 patients were randomised (41 IP vs. 41 OP; 53 UK, 29 France). Baseline data were matched with age 59±14yrs, body mass index (BMI) 47±10kg/m2, PaCO2 6.8±0.6kPa and severe respiratory insufficiency questionnaire (SRI) 52±19. There was no difference at 3 months between OP vs. IP setup in additional quality adjusted life months (QALM), total cost, SRI or PaCO2 (non-inferior).[Table 1] Conclusion: OP NIV setup in OHS, using an auto-titrating device, has similar cost as IP setup using nurse-led overnight titration NIV. There was no difference in clinical effectiveness or safety between IP and OP setup.

Objective: To evaluate the role of noninvasive ventilation with AVAPS-AE mode in acute exacerbation of COPD patient with OHS. Methods: A randomized, prospective and controlled study. We included 66 patients: the majority(75.8%,n=50) is male; BMI:34.5±3.4kg/m2. Depending on ventilation mode, all subjects were divided(1:1:1) into 3 groups: S/T group, AVAPS group and AVAPS-AE group. Settings in 3 groups respectively: S/T mode(IPAP/EPAP:20/10cmH2O, TV depending on individual BMI); the similar parameters in AVAPS mode; AVAPS-AE mode(maximum EPAP=16cmH2O, minimum EPAP=6cmH2O). During NIV, degree of patients’ comfort was measured by VAS (Visual Analog Scale). Results: There was a higher VAS score of patients in AVAPS-AE group than others(p 0.05).48-hour intubation rate: 31.8%(n=7) in S/T group, 22.7%(n=5) in AVAPS group, 13.6%(n=3) in AVAPS-AE group respectively(p>0.05). Occurrence of patient-ventilator asynchrony in AVAPS group versus AVAPS-AE group:（45.4%(n=10) vs. 13.6%(n=3),p=0.021）. Conclusions: For AECOPD patients with OHS, AVAPS-AE mode could improve clinical symptoms quickly, especially in comfort of patients during NIV, we suggest that strategy for EPAP set in NIV should be a varying range rather than a fixed parameter, which maybe contribute to relieve dynamic hyperinflation of acute exacerbation of COPD patients with OHS.

Background: Patients on home continuous positive airway pressure (CPAP) or noninvasive ventilation (NIV) show large variability in compliance to treatment. Aim: To identify predictors of poor compliance, we evaluated compliance to treatment in patients with obstructive sleep apnea (OSA), obesity hypoventilation syndrome (OHS), and OSA-chronic obstructive pulmonary disease (COPD) overlap syndrome. Methods: We analyzed clinical and compliance data provided by a single home care provider, in 602 patients (n=442 OSA, males (M) 308; 38 OHS M=15, and 122 overlap M=111) on home CPAP/NIV in the province of Agrigento, Italy, after one year of treatment. The following variables were considered: age, body mass index (BMI), sex, diagnosis, type of prescribed ventilator, and common comorbidities. Results: Mean (±SD) age and BMI were: 64.6±11.9 yrs, and 34.4±7.3 kg/m2. CPAP was prescribed in 67.1%, AutoCPAP in 12.9%, Bilevel in 9.1%, and volume assured pressure support ventilation in 10.9% of the sample. Mean compliance to treatment was 4.7±2.7 h/day, with 64.3% of the patients showing good compliance (>4 h/night). Patients overestimated CPAP/NIV use by 0.5 h/night. Compliance was not affected by age, diagnosis, severity of sleep disordered breathing, type of ventilation or occurrence of comorbidities, with the exception of depression (p=0.05). BMI was higher in poorly compliant compared to compliant patients (p=0.02). When data were split by gender, compliance was OHS>OSAS>overlap in women (p 0.007); overlap>OSAS>OHS in men (p=0.013) Conclusions: A high degree of obesity and depression were associated with poor compliance to ventilatory treatment.

Introduction: The prevalence of obesity is continuously increasing worldwidely which increases the incidence of obesity hypoventilation syndrome (OHS) and its consequent mortality. Methods: We reviewed all OHS patients treated at our hospital between the years 2005-2016 for their therapy mode, and incidence of mortality. The control group consisted of randomly selected patients with obstructive sleep apnea (OSA) treated during the same period. Results: A total of 208 OHS patients and 236 OSA patients were studied. OHS patients were significantly older, heavier and percentage of women was higher than OSA patients, mean ± SD (56 ± 10 vs 52 ± 11 years; body mass index 46 ± 8 vs 32 ± 7 kg/m2; percentage of women 41 vs., 24 %) respectively. The mortality rate was significantly higher in OHS compared to OSA [x2 (1, n = 442) = 6.464, P = .008]. Conclusions: The mortality rate of obesity hypoventilation syndrome is significantly higher than that of obstructive sleep apnea. This implies attention to an early detection and treatment.

Background: The connection between obstructive sleep apnea and secondary erythrocytosis is controversial. We hypothesized that there could be a higher prevalence of erythrocytosis in patients with Obesity hypoventilation syndrome due to persistent hypoxemia. Methods: We undertook a retrospective, cross-sectional review of OHS patients forming part of an established cohort of “Non -invasive ventilation “patients at the Department of Sleep Medicine at the Royal Infirmary Medical Centre, Edinburgh (2004-2017). We obtained the relevant clinical data from patient9s records. Results: The cohort comprised 74 OHS patients. Overall there were 44 men (59.5 %) and 30 women (40.5%). The mean age at diagnosis was 54 yrs. (25-75 SD 10). The mean Haematocrit level for the group overall was 0.44, in men the mean Hct was 0.45 and 0.41 in women. Eleven patients had erythrocytosis (14.9%), seven were men and 4 were women. Thirteen patients (17.5%) died during follow- up (2004-2017). There was a statistically significant increase in risk of death in patients with higher and lower haematocrit levels compared to OHS patients with normal haematocrit. Conclusions: To our knowledge, this is the first study showing increased prevalence of erythrocytosis in OHS patients. We found a “U” shape correlation with mortality according to haematocrit levels.

Introduction: Epidemiology of home mechanical ventilation (HMV) and its changes is important to evaluate the situation of this therapy in a specific area. Methods: Prospective observational study to describe epidemiological changes of HMV in the health area of the University Hospital of Badajoz over three periods of time (A: Before 2008, B: Between 2008 and 2012 and C: From 2013 to the present). A comparative analysis was made between the three periods indicated. The patients were followed until June 2017. Results: We included 422 patients (53.1% women, mean age 65.8 ± 13.3 years). There was a significant increase in the number of patients since 2008 (A: 89, B: 163 and C: 170 patients) as well as in the age of onset of treatment (A: 18% > 75 vs. B: 26.4% and C: 33.5%, p = 0.027). The main diagnosis for the onset was obesity hypoventilation syndrome (55.1% vs 58.3% vs 57.6%). Presence of comorbidities and their number (> 3 comorbidities 41.6% vs 57.7% vs 64.1%, p = 0.002), presence of previous admissions and its number (1.7 ± 2.3 vs 1.6 ± 1.6 vs 2.4 ± 3.1, p = 0.005), increased with the time. We found changes in the situation at the beginning of HMV (Acute respiratory failure: 9% vs 20.9% vs 35%). We found a trend towards higher mortality among patients in the last period (Median survival A: 59 months [95% CI: 34.3-83.6] vs B: 54 months [95% CI: 37.1-70.8 ] vs C: 25 months [95% CI: 18.8-23.3], p = 0.13). Conclusions: We found a progressive increase in the number of patients who began HMV in our area. Changes in age, presence of comorbidities and previous situation at the beginning of the HMV show more "severe" patients in whom this procedure could have worse long-term results.

Introduction: Arterial blood gas (ABG) sampling is difficult in patients with obesity hypoventilation syndrome (OHS) and neuromuscular diseases (NMD). Our aim was to investigate the usability of venous blood gas (VBG) analysis, to replace ABG. Material and Methods: Study included stabilized OHS and NMD patients. ABG was taken from all of the cases in the room air and peripheral VBG samples were taken within 5 minutes after ABG analysis. Results: Totally 82 cases (female:33, male:49, mean age:46.9years) with OHS (n=36) and NMD (n=46) were included. For all patients, there was a moderate positive correlation between arterial and pH values (rs=0.590, p For NMD patienst; there was moderate positive correlation between arterial and venous pH and PCO2 values (rs=0.542, rs=0.540, p Conclusion: We found a relationship between ABG and VBG for the values of pH, PCO2 and HCO3. As a results, VBG values (pH, pCO2, HCO3) can be used safely during treatment and follow-up period of the patients with OHS and NMD, instead of ABG.

Background: Noninvasive ventilation (NIV) and continuous positive airway pressure (CPAP) are the habitual treatments for obesity hypoventilation syndrome (OHS). Despite differences in cost and complexity between them, there are no long-term effectiveness studies comparing both treatments. Objectives: We performed a large multicenter randomized open-labell controlled study to determine the comparative long-term effectiveness of NIV and CPAP using hospitalization days as the primary outcome measure. Methods: Sequentially screened OHS patients with severe sleep apnea were randomized into the above-mentioned arms for at least 3 years of follow-up. Hospital resources utilization, mortality, cardiovascular events incidence, dropouts, compliance and side effects were evaluated. Statistical analysis was performed using intention-to-treat protocol evaluating event/year per patient and incidence by negative binomial, logistic and Cox regressions models and survival analysis. A secundary analysis by compliance subgroups was performed. Results: 215 patients were randomized and 202 were available for primary analysis. The median follow-up was 5.42 years. The hospital days/year was 2.19±5.65 for CPAP and 1.44±3.07 for NIV (adjusted p=0.12). Other hospital resources utilization, cardiovascular events incidence, mortality, dropouts, compliance and side effects were similar between arms. The better compliance subgroup had lower hospital resources utilization and mortality regardless of the treatment used. Conclusion: NIV and CPAP have similar long-term effectiveness. Because CPAP has economical advantages and simplicity, CPAP should be the preferable treatment for OHS patients with severe OSA.

Introduction: Home NIV is used to treat chronic respiratory failure. However, side effects are rarely reported in clinical trials. Our aim was to report the incidence of side effects, their severity and consequences on quality of life (QoL) and compliance to NIV. Methods: Retrospective analysis including patients established on home NIV attending an outpatient NIV clinic from 05/2017 to 01/2018 in Rouen University Hospital. Eleven NIV side effects were systematically evaluated using a dedicated chart. Side effects were graded as follow: absent (0 point) to intolerable (4points). Score of all side effects was summed. All patients filled a Severe Respiratory Insufficiency questionnaire (SRI). Results: Out of 490 patients who attended our outpatient clinic, 437 (89%) completed their SRI and a NIV side-effect evaluation. Underlying respiratory disease: obesity hypoventilation syndrome (n :142,32%), COPD-OSA (n:96,22%), COPD (n:81,19%), neuromuscular disease (n:78,18%), chest wall disorder (n:29, 7%) and OSA (n :11,2%). Twenty (5%) patients did not report any side effect. Incidence of side effects are summarised in figure 1. NIV side effects score was 5 [IQ: 3 – 8] out of 44. Side effects score was inversely correlated to SRI score and to compliance to NIV: rho: -0.419 (p Side effects are frequent within home NIV users and impair QoL and compliance.

The number of patients treated with NIV at home for chronic respiratory failure (CRF) is steadily increasing. Historical indications for long-term NIV were unsettled by obesity hypoventilation syndrome (OHS) and chronic obstructive pulmonary disease (COPD) with controversial results. Ten years after the results of the last major cohorts, we investigated both health-related quality of life (HRQL) and survival of home ventilated patients in a French area. HRQL was assessed by 36-items Short-Form Health Survey (SF-36) at baseline and 12 months after NIV initiation. From September 2009 to December 2015, 451 patients were included in this prospective and multicenter cohort study. CRF resulted from: COPD (n=56), COPD and obesity (n=107), OHS (n=161), neuromuscular (NM) disease (n=35), amyotrophic lateral sclerosis (n=41), others (n=51). Median length of follow-up was 608±653 [0;2281] days. Overall survival at 4 years was 66%. NM patients had the best survival. No survival difference between OHS, COPD and COPD obese patients was found. In COPD patients, NIV did not improve subscales of SF-36 at 12 months. NIV increased all subscales and mental composite score in OHS patients, while 5 subscales were improved in COPD obese patients (p

Introduction: High-flow humidified (HFH) oxygen is used for the management of acute respiratory failure. HFH could be used in patients with chronic hypercapnic respiratory failure. The aim of this study was to assess the physiological effect of HFH air on patients with chronic hypercapnic failure secondary to obesity-hypoventilation syndrome (OHS). Methods: This was a physiological study enrolling patient with OHS established on long-term non-invasive ventilation. Trans-diaphragmatic pressure, diaphragmatic EMG and respiratory inductance plethysmography were recorded during self-ventilation, with HFH at a flow from 10 to 60L/min (10L/min steps). HFH was delivered using an Airvo2. Results: Nine patients with an age of 59±10years and a BMI of 49±10kg/m 2 were included. HFH significantly decreased diaphragmatic pressure time product (PTP), respiratory rate, minute ventilation and diaphragmatic EMG activity; it increased inspiratory and expiratory time (Figure 1). There was no significant change in comfort of breathing or breathlessness (Borg and visual analogue scale). TcCO 2 decreased from 6.6±1.0kPa whilst self-venting to 6.1±0.9kPa on HFH 60L/min (p:0.01). Conclusion: HFH improves respiratory mechanics and reduces neural respiratory drive of stable patients with OHS. Further studies are required to assess the clinical relevance of this physiological improvement.

Aims and objective: To determine the prognostic factors related to all-cause mortality of patients surviving their first acute hypercapnic respiratory failure (AHRF) episode treated with non-invasive mechanical ventilation (NIV). Methods: Observational study from January 2010 to January 2017, including patients treated with NIV whom survived their first AHRF episode. To determine the factors associated with all-cause mortality, a multivariate logistic regression model was performed after univariate analysis determined related variables along with others considered relevant by the investigators. Results: A total of 155 patients were treated with NIV, 78 men (50%) and mean age of 71.2±11.1 years. During follow-up, 84 (54%) deaths took place, and median survival was 33.7 months (IQR 11.1–49.0). The univariate analysis showed that age (OR 1.06; CI95% 1.02–1.09; p=0.001) and pulmonary hypertension (PH) prior to the AHRF episode (OR 4.33; CI95% 1.31–14.4; p=0.02) were related to mortality, while obesity hypoventilation syndrome (OHS) as main cause of the AHRF episode showed to be a protective factor (OR 0.32; CI95% 0.14–0.70; p=0.005). These results remained significant in the multivariate logistic regression model. Conclusions: While age and pulmonary hypertension prior to a first episode of AHRF which needed NIV were related to greater all-cause mortality, OHS presented as a protective factor.

Introduction: Patients with respiratory failure - Chronic Obstructive Pulmonary Disease, Obesity Hypoventilation Syndrome, or Neuromuscular Disease - are increasingly managed with non-invasive ventilation (NIV). There may be an advantage to an automatic adjustable EPAP (AutoEPAP) for managing the changing therapeutic requirements in these patients. Objective: To compare oxygen desaturation index (ODI) values following the use of AutoEPAP algorithm in comparison to manual EPAP on the Astral ventilator. Methods: This is a prospective, randomized, cross-over trial carried out at 6 sites in the United States. Randomized participants are representative of adult patients with respiratory failure, history of upper airway obstruction, and established on NIV therapy. Randomized participants complete two overnight polysomnography studies, one each using Astral with iVAPS manual EPAP and the other with Astral with iVAPS AutoEPAP. The results are expected March 2017. Results: There have been 37 of the total of 40 participants enrolled to date. The final results will present baseline characteristics, including age, gender, BMI, primary respiratory diagnosis and dependent/not dependent on ventilatory support. The primary endpoint is designed to show non inferiority of AutoEPAP versus manual EPAP. Secondary results (AHI, SpO2, transcutaneous CO2, sleep efficiency) will also be presented. No serious adverse events reported to date. Conclusions: This trial was designed to assess the functionality of an AutoEPAP algorithm for treating upper airway obstruction in patients with respiratory failure. The results of this study will provide valuable information regarding the titration of NIV in these patients.

There are no randomized controlled trials assessing the impact of noninvasive ventilation (NIV) and continuous positive airway pressure (CPAP) on cardiac function in obesity hypoventilation syndrome (OHS). Objective: To determine the efficacy of 2 months of NIV, CPAP or lifestyle modification (control) on echocardiographic changes. Method: OHS patients (n=302) were sequentially randomized by: 1) severe obstructive sleep apnea (OSA), into NIV, CPAP or control; 2) non-severe OSA, into NIV or control. ABG, spirometry, six-minute walk distance, Epworth sleepiness scale, polysomnography and transthoracic echocardiogram were evaluated. Results: We analyzed 2 groups: 1) with or without severe OSA and NIV or control treatments (entire OHS group; n=222); 2) with severe OSA and NIV, CPAP or control treatments (severe OSA subgroup; n=221). In the entire OHS group, NIV improved the left ventricular (LV) hypertrophy (mass index: -6.6 g/m2; 95%CI -11/-2.1 vs 3.6; 95%CI -1.1/8.3; adjusted p Conclusion: Medium-term NIV therapy is more effective than CPAP and lifestyle modification in improving PAP and LV hypertrophy in OHS

Background Obesity hypoventilation syndrome (OHS) is defined as hypoxemia with morning hypercapnia in obese patients;90% are associating OSA. The influence of gender in patients with OHS and OSA is insufficient described. Aims Retrospective study evaluating differences (clinical, paraclinical, sleep parameters) between women and men with OHS in a Romanian OSA cohort. Methods Among files of 100 OSA patients (2012-2015) we found 15 patients with OHS. Exclusion criteria: COPD, pulmonary fibrosis, kyphoscoliosis, neuromuscular disease. Demographics, diurnal arterial blood gases, spirometry, sleep study (diagnostic and under positive airway pressure (PAP) therapy) data were analyzed using SPSS 17. Results 67% (10) men, mean values: age 53.13+/-13.78 years, AHI 61.12+/-30.05/h (100% severe OSA), nocturnal SaO 2 68.84+/-12.44%; morning PO 2 46.53+/-8.10 mmHg, PCO 2 52.49+/-5.40mmHg, HCO 3 29.47+/-3.98 mmol/L; efficient PAP therapy in all patients. There were no significant differences between genders regarding comorbidities, symptoms, smoking status, Epworth score, OSA severity, mean PAPs values, body mass index and abdominal index, degree of ventilator restriction, morning PCO 2 and HCO 3 , mean hospitalization days. Men were younger (48.20+/-14.03 vs 63.0+/-6.2years, p=0.045), with longer time spent in bed (455.00+/-41.23 vs 295.33+/-107.07min, p=0.038). The morning PCO 2 at hospital discharged was still abnormal in men, and higher than in women (48.20+/-8.42 vs 37.94+/-6.65 mmHg, p=0.048). Conclusions Taking in account the fast and appropriate response to PAP therapy in women, we conclude that is a need for a better understanding of OHS underlying mechanism in respect to gender.

Aim of the study was to evaluate anthropometric, clinical and sleep characteristics of Obesity Hypoventilation Syndrome (OHS) patients, in comparison to obese eucapnic Obstructive Sleep Apnea Syndrome (OSAS) patients and controls. Methods Included were 942 consecutive subjects with BMI≥30kg/m 2 (69.9% males, age 54.9±11.9 years), examined with polysomnography (PSG), due to suspected OSAS. All had undergone pulmonary function testing and ABGs examination and had completed the Epworth Sleepiness Scale (ESS) and Athens Insomnia Scale (AIS) for sleepiness and insomnia assessment, respectively. They were categorized as follows: OHS patients (n=177), obese, eucapnic OSAS patients (AHI≥5/h, n=615), and obese controls with AHI Results OHS patients had the highest BMI (p 1, SpO 2 , PaO 2 , PaCO 2 and HCO 3 values in awake (p 2 and averSpO 2 during sleep were more impaired in OHS patients (p Conclusions OHS patients were more obese, differed significantly in several sleep characteristics and reported insomnia and daytime sleepiness more frequently, compared with obese OSAS patients and controls.

While obstructive sleep apnoea syndrome dominates discussion of the prevalence of sleep disordered breathing, nocturnal hypoventilation remains extremely prevalent in those with chronic ventilatory disorders and in the natural history of these conditions pre-dates the development of daytime ventilatory failure. In this review the clinical management of chronic hypoventilation in neuromuscular disease will be considered and then compared with that in obesity hypoventilation syndrome. In simple terms these conditions illustrate the polar opposite ends of the spectrum, as in neuromuscular disease the reduced capacity of the respiratory system is unable to withstand a normal respiratory load, and in obesity hypoventilation syndrome the normal capacity of the respiratory system is unable to tolerate a substantially increased ventilatory load.

Background: After 60 years of its first description in 1955, OHS remains a curiosity. Responsible for a large proportion of chronic respiratory failure, it is commonly diagnosed on the first hypercapnic acute exacerbation. It opposes diagnostic and therapeutic challenges to the clinician. Aim: To identify prognostic factors related to AE/OHS. To design an early goal-directed therapy algorithm for the management of AE/OHS. Methods: A retrospective study over a 13 years period (2002-2014). Were analyzed clinical, therapeutic and outcome characteristics. Univariate and multivariate analyses were performed to identify factors independently associated to ICU mortality. Results: One hundred patients were included. 50% of patients required immediate invasive mechanical ventilation. NIV was only possible in 44%, in whom 31.8% failed within 85.57±156,73hrs. 37% of patients required diuretics and 25% inotropic agents. Overall ICU mortality was 39%. Hypercapnic encephalopathy grade, NIV failure and use of inotropic agents were factors independently associated with mortality. Static and dynamic hypercapnic encephalopathy grade, diuretics and inotropic agents were integrated to design an early goal-directed therapy algorithm. Conclusion: This comprehensive study demonstrated a poor outcome of AE/OHS. This could be improved by the implementation of an early goal-directed therapy algorithm.

Introduction: The lower life expectancy in elderly patients (> 75 years) with chronic respiratory failure has been argued as possible limiting the use of Non-invasive domiciliary ventilation (NIDV). The aim of this study was to evaluate the outcome-including long term effects of NIDV- in our elderly patients. Methods: Prospective study of patients who started NIDV at 75 years of older. Data recorded included: demographic data, comorbidities, compliance, admissions and survival at the end of follow-up. Analysis of survival was undertaken using Kaplan-Meier method and Cox regression. Results: 82 patients were included (72% women, mean age: 79.9 ±3, 7 years). Diagnosis included: Obesity hypoventilation Syndrome (65,9 %) and restrictive diseases (17,1 %). Significants improvements were obtained in diurnal blood gases at discharge and in the follow-up as well as a significant decrease in the number of hospital admissions. The compliance at home was considered poor in 50 %. At the end of the follow-up the mortality was 63,4 %. The estimated survival at 1o year, 2 o year and 3 o year was 62 %, 53 % and 43 %, respectively. It was independently associated with: good compliance (OR: 0,46; CI 95 %: 0,24-0,87), restrictive disease (OR: 0,36; CI95 %: 0,16-0,82), EPAP level (OR: 1,6; CI 95 %: 1,1-2,3) and dyspnea level (mMRC) in the follow-up (OR 2,1; IC95 %: 1,2-3,6). Conclusions: 1.-In our experience, the results of the NIDV in elderly patients were satisfactory improving arterial blood gases and readmissions. 2. Global compliance was poor (50%). In spite of that, NIDV obtained long survival in these patients. 3. Survival was better in “good compliance” patients, in restrictive diseases and with less functional impairment.

Introduction: We hypothesized that airway resistance differs in obese subjects with or without ventilatory failure Methods: 73 morbidly obese subjects had measurements of both airways resistance and adiposity Results: All measures of airways resistance increased in the supine position: R5 (total airways resistance) by 37% (p

We manage patients on NIV with a diagnosis of obstructive sleep apnoea hypopnoea syndrome (OSAHS), obesity hypoventilation syndrome (OHS), and neuromuscular disorders (ND9s). In 2015 we initiated telemonitoring with NIV devices that facilitate efficacy data transfer to a secure website for those commenced on NIV for the first 30 days following initiation with the option for long term telemonitoring where this is thought to be appropriate. Aim: Explore potential benefits of telemonitoring in NIV users. Methods: Assess the impact of telemonitoring on service delivery and review the telemetry data in terms of adherence to therapy, mask fit and efficacy of NIV therapy. Results: 18 patients now commenced on NIV with telemetry data available. 6 have a diagnosis of ND9s; 3 with adherence of 5.5-9.5 hours/night and 3 with adherence of Conclusion: Where poor NIV adherence/high mask leaks are seen this prompts early telephone/clinic follow up. Our experience to date of those commenced on NIV telemonitoring is positive (with no adverse outcomes reported) and allows us to monitor the adherence/ efficacy data remotely and intervene where necessary. Our expereince of remote telemonitoring in NIV users so far is positive and propose that it may be advantageous for patients/clinicians and we are now planning a pilot randomised controlled trial in 2017 to explore this further.

Rationale: Patients need to acquire specific skills for the use of home NIV. No study as yet described the cognitive performance of patients at NIV setup. There is a lack of data of patients9 skills on their use of NIV. Aim: To assess the cognitive performance and patients9 skills at NIV setup and their consequences in adherence. Methods: Prospective audit conducted in Lane Fox Respiratory Unit, London from 02/2015 and 12/2015 including all patients admitted for home NIV setup and expected to be independent in its use. Assessments were: Montreal Cognitive Assessment (MOCA), Instrumental Activities of Daily Living (IADL), education level and visual analogue scales to assess patients own understanding and skills. They were performed at NIV setup and at 6 weeks follow-up. Results: 104 patients completed follow-up. Mean age was 62±15 years-old, mean BMI was 35±11kgm/ 2 . Underlying disease was obesity hypoventilation syndrome (n:37), COPD-OSA (n:28), neuromuscular/chest wall diseases (n:15), COPD (n:13), OSA (n:11). At baseline: MOCA was 22.3±0.5 and IADL was 5.7±2.2. 45 (43%) patients left school at 16 years-old. Patients9 understandings and self-perceived skills are summarised in figure 1. At follow-up, mean use of NIV was 4.5±3.4 hours/day and MOCA improved by 2 (p Conclusion: Patients admitted for NIV setup have low cognitive performance and independence level. NIV training should be adjusted to patient9s cognitive level.

Background: The incidence of obesity hypoventilation syndrome (OHS) may be increasing. Despite polysomnographics parameters and extensive NIV use in these patients, information about efficacy is limited. Aims and objectives: Evaluate the prevalence and typology of SBD in severe OHS patients. Evaluate compliance and side effects of at home NIV in these patients. Methods: Were included all consecutive patients admitted to ICU within 13 Years. Anthropometric, clinical, functional,ABGs data were collected and Epworth scale was measured. Respiratory polygraphy was performed at steady state. Compliance and observance to NIV were analyzed. Statistical analysis was performed for prevalence of SDB and NIV compliance was also analyzed. Results: We included 100 patients.50% of patients required immediate invasive mechanical ventilation. NIV was only possible in 44%. Overall ICU mortality was 39%. The patients are mostly old, female with morbid obesity. 61 patients improved and were directed to the respiratory department. Six patients died within a delay of 16,1±16,2months from ICU discharge. Only 24 patients were be reached for a respiratory polygraphy. All patients have an abnormal Epworth scale. The AHI average is 48±29/h and time spent with SpO2 Conclusion: This comprehensive study demonstrated a poor outcome of AE/OHS. We noted a high prevalence of OSA. Most of these patients are lost to follow.

Introduction: Obesity-related respiratory failure (ORRF) may occur as a result of obesity alone (obesity hypoventilation syndrome, OHS) or in combination with other problems, such as obstructive lung diseases (OLD). For patients with ORRF treated with NIV, it is unknown if the presence of OLD impacts patient outcome. Aims: To compare treatment outcomes in patients with ORRF according to the presence or absence of OLD. Methods: Retrospective study of consecutive patients with hypercapnic respiratory failure attributed to obesity who started home NIV (2006-2011) via a regional NIV service. Patients were identified via database and divided into group I (FEV1/VC > 0.7) and group II (FEV1/VC Results: Both groups were well matched (Table 1). 64% of patients in group II had severe OLD (FEV1 Conclusions: For patients with ORRF, the presence of obstructive lung disease does not exert an adverse impact on NIV compliance or survival.

Obesity hypoventilation Syndrome (OHS) is diagnosed only after eliminating chronic obstructive pulmonary disease (COPD)and any other diagnostic ethiologies. The similar versus nonsimilar clinical and inflammatory laboratory parameters of OHS patients with chronic respiratory insuffiency compared to COPD patients with obesity are quite restrictive. In our study the answer to the question whether there is any other common point except obesity between OHS with respiratory insufficency and COPD with obesity is tried to be found. Method: OHS withpatients with chronic respiratory insufficency and COPD patients with obesity referred and followed by our ICU out patient clinic between 2014-2015 were included in retrospective cohort study.Demographic characteristics, BMI arterial blood gas analysis, spirometry, blood panel, biochemical parameters, CRP, values are all recorded.The two group of patients were compared according to their recorded data. Findings: 365 OHS and 378 COPD patinets were included totally in our study data.Inflammatory markers were insignificantly higher.Laboratory results that significantly higher had no clinical importance.COPD patients with obesity had significantly higher PCO2 values and insignificantly higher HCO3 levels.Spirometry results of OHS patients were in restrictive pattern. Results: Clinical presentation of COPD patients with obesity versus OHS patients looks like more or less the same where as the spirometric pattern is obstructive in COPD but restrictive in OHS.Coexistence of hypercapnia in OHS patient means that there is another underlying ethio pathology other than an airway pathology.