title: Continuous positive airway pressure in clinically stable patients with mild-to-moderate obesity hypoventilation syndrome and obstructive sleep apnoea.
abstract: OBJECTIVE
  The use of continuous positive airway pressure (CPAP) treatment in patients with obesity hypoventilation syndrome (OHS) and obstructive sleep apnoea (OSA) was evaluated, and factors that might predict CPAP treatment failure were determined.
  
  
  METHODS
  A sleep study was performed in 29 newly diagnosed, clinically stable OHS patients. CPAP treatment was commenced if the apnoea-hypopnoea index was >15. Lung function, night-time oximetry, blood adipokine and C-reactive protein levels were assessed prospectively on enrollment and after 3 months. Treatment failure at 3 months was defined as daytime arterial partial pressure of carbon dioxide (PaCO(2)) >45 mm Hg and/or oxygen saturation (SpO(2)) <90% for >30% of the night-time oximetry study.
  
  
  RESULTS
  All patients had severe OSA (median apnoea-hypopnoea index = 74.7 (62-100) with a nocturnal mean SpO(2) of 81.4 ± 7), and all patients were treated with CPAP. The percentage of time spent below 90% saturation improved from 8.4% (0.0-39.0%) to 0.3% (0.4-4.0%). Awake PaCO(2) decreased from 50 (47-53) mm Hg to 43 (40-45) mm Hg. Seven patients failed CPAP treatment after 3 months. PaCO(2) at 1 month and mean night-time SpO(2) during the first night of optimal CPAP were associated with treatment failure at 3 months (odds ratio 1.4 (1.03-1.98); P = 0.034 and 0.6 (0.34-0.93); P = 0.027).
  
  
  CONCLUSIONS
  CPAP treatment improves night-time oxygenation and daytime hypoventilation in selected clinically stable OHS patients who also have OSA. Patients with worse night-time saturation while on CPAP and higher daytime PaCO(2) at 1 month were more likely to fail CPAP treatment.
authors.affiliation: Department of Respiratory Medicine, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain; Respiratory Diseases Research Network (CibeRes), Universitat Autònoma de Barcelona, Barcelona, Spain; Department of Internal Medicine, School of Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain; Department of Respiratory Medicine, Hospital Universitari de Bellvitge, Hospitalet de LLobregat, Spain.
authors.forename: Neus
authors.initials: N
authors.lastname: Salord
authors.forename: Mercedes
authors.initials: M
authors.lastname: Mayos
authors.forename: Rosa Maria
authors.initials: RM
authors.lastname: Miralda
authors.forename: Ariadna
authors.initials: A
authors.lastname: Farré
authors.forename: Montserrat
authors.initials: M
authors.lastname: Carreras
authors.forename: Rosa
authors.initials: R
authors.lastname: Sust
authors.forename: Cristina
authors.initials: C
authors.lastname: Masuet-Aumatell
authors.forename: Jose
authors.initials: J
authors.lastname: Rodríguez
authors.forename: Antonio
authors.initials: A
authors.lastname: Pérez
mesh_terms: D054392:Adipokines / Q000378:metabolism; D000368:Aged; D002097:C-Reactive Protein / Q000378:metabolism; D002245:Carbon Dioxide / Q000378:metabolism; D045422:Continuous Positive Airway Pressure / Q000379:methods*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010845:Obesity Hypoventilation Syndrome / Q000378:metabolism / Q000628:therapy*; D010092:Oximetry; D010108:Oxyhemoglobins / Q000378:metabolism; D017286:Polysomnography; D011446:Prospective Studies; D012189:Retrospective Studies; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000378:metabolism / Q000628:therapy*; D016896:Treatment Outcome
chemical_list: D054392:Adipokines; D010108:Oxyhemoglobins; D002245:Carbon Dioxide; D002097:C-Reactive Protein
keywords: continuous positive airway pressure; night-time oxyhaemoglobin saturation; obesity; obesity hypoventilation syndrome; obstructive sleep apnoea syndrome