title: Randomised short-term trial of high-span versus low-span APAP for treating sleep apnoea.
abstract: OBJECTIVE
  Auto-titrating continuous positive airway pressure (APAP) devices were developed to improve treatment efficacy and compliance in patients with obstructive sleep apnoea syndrome (OSAS). Since there are insufficient data on the optimal pressure range setting, we aimed to compare the adherence, efficacy and tolerability of treatment with high-span versus low-span APAP.
  
  
  METHODS
  Seventy-six newly diagnosed OSAS patients fulfilling the treatment criteria were randomised to receive high-span (HS, range 4-15cmH2O, n = 38) or low-span (LS, range 8-12cmH2O, n = 38) APAP. Patients were assessed at 1 and 3 months.
  
  
  RESULTS
  Median Epworth sleepiness scale (ESS) was 13 (IQR, 6-16) and median apnoea-hypopnoea index (AHI) was 35.9 (IQR, 27.6-56.3). There were no significant differences in baseline demographic and clinical characteristics between groups. Overall, no significant differences were found at the first month assessment. After 3 months of therapy, we found again no differences in residual AHI or ESS. However, the group HS proved less adherent than group LS, respectively, with median 87 % (IQR, 60.5-97.5) versus 94 % (IQR, 80.0-98.3) of the nights using ≥4 h (P = 0.014) and mean (±SD) usage 5.7 ± 1.6 versus 6.4 ± 1.2 h/night (P = 0.049). The group HS reported more frequently nasal congestion, excessive oronasal dryness and nocturnal awakenings of at least moderate intensity, the latter with statistical significance (P = 0.005).
  
  
  CONCLUSIONS
  Both pressure ranges appear to be equally effective to correct AHI and to improve symptoms. Though, patients with high-span APAP were less compliant to treatment, raising issues about the tolerability of wide pressure range settings of these devices.
authors.affiliation: Pulmonology Department, Centro Hospitalar de São João, Alameda Prof. Hernâni Monteiro, 4200-319, Porto, Portugal. helder.bastos@hsjoao.min-saude.pt.|Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Minho, Braga, Portugal. helder.bastos@hsjoao.min-saude.pt.|ICVS/3B's - PT Government Associate Laboratory, Braga, Guimarães, Portugal. helder.bastos@hsjoao.min-saude.pt.
authors.forename: Helder Novais
authors.initials: HN
authors.lastname: Bastos
authors.affiliation: Pulmonology Department, Centro Hospitalar de São João, Alameda Prof. Hernâni Monteiro, 4200-319, Porto, Portugal.
authors.forename: Ana Verónica
authors.initials: AV
authors.lastname: Cardoso
authors.affiliation: Pulmonology Department, Centro Hospitalar Gaia-Espinho, Vila Nova de Gaia, Portugal.
authors.forename: Ana Sofia
authors.initials: AS
authors.lastname: Castro
authors.affiliation: Pulmonology Department, Hospital Sousa Martins, Guarda, Portugal.
authors.forename: Rita
authors.initials: R
authors.lastname: Gomes
authors.affiliation: Pulmonology Department, Centro Hospitalar de São João, Alameda Prof. Hernâni Monteiro, 4200-319, Porto, Portugal.
authors.forename: Tiago
authors.initials: T
authors.lastname: Pinto
authors.affiliation: Pulmonology Department, Centro Hospitalar de São João, Alameda Prof. Hernâni Monteiro, 4200-319, Porto, Portugal.
authors.forename: Anabela
authors.initials: A
authors.lastname: Marinho
authors.affiliation: Pulmonology Department, Centro Hospitalar de São João, Alameda Prof. Hernâni Monteiro, 4200-319, Porto, Portugal.
authors.forename: Maria
authors.initials: M
authors.lastname: Sucena
authors.affiliation: Pulmonology Department, Centro Hospitalar de São João, Alameda Prof. Hernâni Monteiro, 4200-319, Porto, Portugal.
authors.forename: João
authors.initials: J
authors.lastname: Almeida
authors.affiliation: Pulmonology Department, Centro Hospitalar de São João, Alameda Prof. Hernâni Monteiro, 4200-319, Porto, Portugal.|Faculty of Medicine, University of Porto, Porto, Portugal.
authors.forename: Marta
authors.initials: M
authors.lastname: Drummond
authors.affiliation: Pulmonology Department, Centro Hospitalar de São João, Alameda Prof. Hernâni Monteiro, 4200-319, Porto, Portugal.|Faculty of Medicine, University of Porto, Porto, Portugal.|Linde AG, Linde Healthcare, Pullach, Germany.
authors.forename: João Carlos
authors.initials: JC
authors.lastname: Winck
mesh_terms: D000328:Adult; D000368:Aged; D045422:Continuous Positive Airway Pressure / Q000295:instrumentation / Q000379:methods*; D006970:Disorders of Excessive Somnolence / Q000175:diagnosis / Q000628:therapy; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance; D017286:Polysomnography; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis / Q000628:therapy*; D011795:Surveys and Questionnaires
keywords: Auto-titrating positive airway pressure; Obstructive sleep apnoea; Pressure range; Treatment compliance