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BackgroundNon-invasive ventilation (NIV) is an effective form of treatment in patients with obesity hypoventilation syndrome (OHS) who have concomitant severe obstructive sleep apnoea (OSA). However, there is a paucity of evidence on the efficacy of NIV in patients with OHS without severe OSA. We performed a multicentre randomised clinical trial to determine the comparative efficacy of NIV versus lifestyle modification (control group) using daytime arterial carbon dioxide tension (PaCO2) as the main outcome measure.MethodsBetween May 2009 and December 2014 we sequentially screened patients with OHS without severe OSA. Participants were randomised to NIV versus lifestyle modification and were followed for 2 months. Arterial blood gas parameters, clinical symptoms, health-related quality of life assessments, polysomnography, spirometry, 6-min walk distance test, blood pressure measurements and healthcare resource utilisation were evaluated. Statistical analysis was performed using intention-to-treat analysis.ResultsA total of 365 patients were screened of whom 58 were excluded. Severe OSA was present in 221 and the remaining 86 patients without severe OSA were randomised. NIV led to a significantly larger improvement in PaCO2 of −6 (95% CI −7.7 to −4.2) mm Hg versus −2.8 (95% CI −4.3 to −1.3) mm Hg, (p<0.001) and serum bicarbonate of −3.4 (95% CI −4.5 to −2.3) versus −1 (95% CI −1.7 to −0.2 95% CI)  mmol/L (p<0.001). PaCO2 change adjusted for NIV compliance did not further improve the inter-group statistical significance. Sleepiness, some health-related quality of life assessments and polysomnographic parameters improved significantly more with NIV than with lifestyle modification. Additionally, there was a tendency towards lower healthcare resource utilisation in the NIV group.ConclusionsNIV is more effective than lifestyle modification in improving daytime PaCO2, sleepiness and polysomnographic parameters. Long-term prospective studies are necessary to determine whether NIV reduces healthcare resource utilisation, cardiovascular events and mortality.Trial registration numberNCT01405976; results.

Cough can be impaired in ALS. This can result in peak cough flows (PCFs) too low for an adequate airway clearance (<270 l/mn). There are several cough assistance techniques that aim at a better elimination of airway secretions, but which are effective, especially in bulbar patients, is not known. We designed the present investigation to compare the PCFs produced by a range of manual and mechanical techniques in patients with ALS, in non-bulbar but also in bulbar patients. In the whole study population, PCFs ranged from 84 (35-118) l/mn for the spontaneous cough manoeuvre to 488 (243-605) l/min for the in/exsufflator (p = 0.0005). In the bulbar group, these values were 42 (35-130) l/min versus 436 (244-630) l/min, respectively (p = 0.008), and 89 (40-106) l/min versus 491 (192-580) l/min, respectively, in the non-bulbar group (p = 0.019). There was no statistically significant difference between the bulbar and the non-bulbar groups. The in/exsufflator was not always the best tool. We conclude that capacity of coughing efforts to produce efficient peak cough flows can be dramatically improved with different tools, even in patients with very severe bulbar symptoms and that it appears useful to test an array of techniques to optimally tailor cough improvement techniques to individual patients.

The aim of this study to evaluate the efficacy of a home-based programme on clinical response, continuous positive airway pressure (CPAP) compliance and cost in a population of high pre-test probability of suffering obstructive sleep apnoea syndrome (OSAS).Patients were randomised into the following three groups. Group A: home respiratory polygraphy (RP) and home follow-up; group B: hospital polysomnography and hospital followup; and group C: home RP and hospital follow-up. Evaluation during 6 months included Epworth Sleepiness Scale (ESS), Functional Outcomes Sleep Questionnaire (FOSQ), and daily activity and symptom questionnaires. Compliance was assessed by memory cards (group A) and using an hourly counter (groups B and C).66 patients were included (22 per branch), 83% were males, aged mean¡SD 52¡10 yrs, body mass index 34¡7kg?m -2 , apnoea/hypopnoea index 43¡20 h -1 , CPAP pressure 8¡2 cmH 2 O, with no between-group differences. Clinical response showed an ESS of mean¡SD 15¡3 to 6¡4, a FOSQ of 16¡3 to 18¡2, symptoms of 43¡7 to 25¡7, and activity of 37¡11 to 25¡8. At the end of the study, compliance was: group A 73%, group B 68% and group C 57%. The cost per patient was: group A J590¡43, group B J894¡11 and group C J644¡93 (p,0.001).In conclusion, patients with a high initial probability of having OSAS can be diagnosed and treated in a home setting, with a high level of CPAP compliance and lower cost than using either a hospital-based approach or home RP/hospital follow-up.

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