CPAP frequently leaves residual sleep apnea according to article in Sleep Medicine. (Sleep Med. 2010 Feb;11(2):119-25. Epub 2010

The biggest problem with CPAP is that it is rejected by the majority of patients. This new article points to the additional problem of residual sleep apnea not treated by CPAP. Outcomes were worse when patients had residual apnea and compliance with CPAP use decreased.

From abstract (below):
"Residual sleep apnea on polysomnography after 3 months of CPAP therapy: clinical implications, predictors and patterns." is a new article by Mulgrew AT, Lawati NA, Ayas NT, Fox N, Hamilton P, Cortes L, Ryan CF. They reported the following 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."

Periodic Breathing or Cheyne Stokes breathing was prevelant among patients with residual sleep apnea. This can sometimes be do to over-titration of CPAP that decreases Carbon dioxide levels. This leads to a decreased drive to breath and cantral sleep apnea.

Oral appliances are an alternative to CPAP that is much more comfortable for the patient but also does not treat central sleep apnea or periodic breathing. There is much higher compliance with oral appliances leading to beter overall treatment for many patients. Information about oral appliances is available at www.ihatecpap.com

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