RT Journal Article SR Electronic T1 Long term effects of compliance with positive airway pressure (PAP) therapy in patients with obesity hypoventilation syndrome (OHS) JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP PA3427 DO 10.1183/13993003.congress-2016.PA3427 VO 48 IS suppl 60 A1 Izolde Bouloukaki A1 Charalampos Mermigkis A1 Charalampos Protopapadakis A1 Nikolaos Tzanakis A1 Stylianos Michelakis A1 Eleni Mauroudi A1 Violeta Moniaki A1 Dimitrios Georgopoulos A1 Sophia Schiza YR 2016 UL http://erj.ersjournals.com/content/48/suppl_60/PA3427.abstract AB Background: There is limited data concerning long-term effects of positive airway pressure (PAP) therapy on survival and functional status in patients with obesity hypoventilation syndrome (OHS).Aims: To assess the role of different levels of compliance and long-term effects of PAP therapy on gas exchange, sleepiness, quality of life, depression and death rate in patients with OHS.Methods: Two hundred fifty two OHS patients, newly diagnosed, who have been recommended PAP therapy, were followed up for a minimum of 2 years. Arterial blood samples were taken for gas level measurements with patients awake, for more than 4 h since wakening.The hours/day and percentage of days PAP was used were monitored. Epworth sleepiness scale (ESS), quality of life (Short Form 36-SF-36) and Beck Depression Inventory (BDI) were recorded together with the death rate before and at the end of the follow up period.Results: At the end of thefollow-up period (mean duration, 50 months), PaO2 had increased from baseline (p<0.001), and both PaCO2 and HCO3−had decreased (p<0.001). PAP therapy also significantly improved ESS (p<0.001), BDI (p<0.001) and SF-36(p<0.001) scores. During follow-up, 11 patients died (2 due to progressionof respiratory failure). Patients who used PAP therapy for > 6 hours/day had a considerably greater improvement in blood gases and questionnaires scores than less adherent patients.Conclusions: Increased hours of use and long-term therapy with PAP are effective in the treatment of patients with OHS. Clinicians should encourage adherence to PAP therapy in order to provide a significant improvement in clinical status and gas exchange in these patients.