Residual sleep apnea on polysomnography after 3 months of CPAP therapy: Clinical implications, predictors and patterns

• Published in: Sleep medicine 2010-02, Vol.11 (2), p.119-125
• Main Authors: Mulgrew, Alan T, Lawati, Nabil Al, Ayas, Najib T, Fox, Nurit, Hamilton, Peter, Cortes, Lisa, Ryan, C. Frank
• Format: Article
• Language: English
• Subjects: Complex sleep apnea; Continuous Positive Airway Pressure; Female; Humans; Male; Middle Aged; Neurology; Obstructive sleep apnea; Periodic breathing; Polysomnography; Quality of Life; Randomized controlled trial; Residual sleep apnea; Respiration; ROC Curve; Severity of Illness Index; Sleep - physiology; Sleep Apnea, Obstructive - physiopathology; Sleep Apnea, Obstructive - therapy; Sleep Medicine; Sleep Stages - physiology; Statistics, Nonparametric; Treatment Failure; Treatment Outcome
• ISSN: 1389-9457; 1878-5506
• DOI: 10.1016/j.sleep.2009.05.017

Abstract Objective We sought to determine the clinical implications, predictors and patterns of residual sleep apnea on continuous positive airway pressure (CPAP) treatment in patients with moderate-to-severe obstructive sleep apnea (OSA). Methods We performed a post hoc secondary analysis of data from a previously reported randomized trial. Sleepy patients with a high risk of moderate-to-severe OSA identified by a diagnostic algorithm were randomly assigned to standard CPAP titration during polysomnography (PSG) or ambulatory titration using auto-CPAP and home sleep testing. We observed them for 3 months and measured apnea–hypopnea index (AHI) on CPAP, Epworth sleepiness scale (ESS), sleep apnea quality of life index (SAQLI), CPAP pressure and objective CPAP compliance. Results Sixty-one patients were randomized, 30 to the PSG group and 31 to the ambulatory group. Fifteen patients (25%) had residual sleep apnea (AHI >10/h on CPAP) with similar proportions in the PSG (7/30) and ambulatory (8/31) groups. Baseline variables including age, body mass index (BMI), ESS, SAQLI, respiratory disturbance index (RDI) and CPAP pressure did not differ between the groups. Outcomes including compliance were worse in patients with residual sleep apnea. Periodic breathing was prevalent among patients with residual sleep apnea. Conclusions Residual sleep apnea is common in patients with moderate-to-severe OSA, despite careful CPAP titration, and is associated with worse outcomes.