TY - JOUR T1 - Variability in AHI and mean pressure over time in OSA patients treated with APAP JF - European Respiratory Journal JO - Eur Respir J VL - 38 IS - Suppl 55 SP - p2208 AU - Sriram Chandramouli AU - Dorothy Price AU - Jennifer Furlong AU - Syed Huq AU - Justine Hadcroft Y1 - 2011/09/01 UR - http://erj.ersjournals.com/content/38/Suppl_55/p2208.abstract N2 - Background: In patients with obstructive sleep apnoea (OSA), studies have shown that automatic positive airway pressure (APAP) treatment is comparable to continuous positive airway pressure (CPAP) in its cost effectiveness and efficacy. Patients with OSA are treated with APAP devices in our hospital.Aims: Monitor changes in APAP and apnoea hypopnoea index (AHI) over a period of 3 monthsIdentify factors which affect changes in mean AHI and APAPMethods: Symptomatic OSA patients [Epworth sleep score (ESS) >10, AHI>10) were offered APAP therapy and monitored prospectively for 3 months.Data was downloaded at 2 weeks and 3 months and analyzed using paired t test and multiple regression.Results: APAP therapy was initiated in 26 patients (22 men) with a mean (SD) age of 51 (11.7) years. Mean AHI was 44.5 (25.5) and mean Epworth score was 12 (4.7).Changes in mean AHI and APAP are shown in the table.View this table:Table 1Multiple regression identified baseline AHI to be the only predictor of AHI change over 2 weeks and 3 months (p<0.0001) while a higher mean APAP at 3 months was also found to be significant (p<0.0003)Age, sex or body mass index did not affect changes in mean AHI or APAP.Conclusions: In our study,AHI was significantly reduced after 2 weeks' treatment with APAP and continued to fall at 3 months even though mean pressure did not change noticeably.AHI change is greatest in patients with a higher baseline AHI and is affected by mean pressure at 3 months.This implies the influence of other factors such as change in upper airway muscle dynamics.Larger studies are needed to elucidate this complex relationship. ER -