Combinations of Oral Appliance and CPAP for Patients With Severe Obstructive Sleep Apnea Untolerate High-pressure CPAP

This is a prospective study in a tertiary teaching hospital, National Taiwan University Hospital. Patients are eligible with age ≧ 20 years old, severe OSA \[apnea-hyponea index (AHI) \>= 30/hr\] who could not tolerate CPAP pressure \>15 cmH2O, determined by manual titration (first titration) and willing to use OA. The study designed was found out the patients with severe OSA (AHI \>= 30/hr ). With first titration, the investigators excluded the severe OSA patients using CPAP (CPAP pressure \< 15 cmH2O) and could tolerate CPAP. Those patients who could not tolerance CPAP high pressure setting started a three-month oral appliance trial. Then, the investigators repeated the full-channel polysomnography (PSG) with second titration on those with residual AHI ≧ 10/hr while patients were on OA. Therefore, those patients treated with combinations of OA and CPAP for three months and then repeated the PSG. The washout period in each therapy was two weeks. The total follow-up period is about 6 months after enrolled. The investigators collected the demographic data from medical records and PSG data, including age, gender, body mass index (BMI), CPAP titration, AHI, total sleep time, oxygen desaturation, and arousal index…et al. Our primary end point is the changes in AHI compared with combination therapy, and OA use. The secondary end points are the difference in titrated CPAP pressure, BMI, blood pressure, and daytime sleepiness compared with combination therapy and OA use. Statistics analysis Data are presented as mean ± standard deviation (SD). Continuous variables were tested by paired Student's t test in group comparisons. Statistical significance was assumed when a null hypothesis could be rejected at p\<0.05. The investigators compared the difference between combination therapy, OA, and baseline by ANOVA, repeated measure. Statistical analysis was done using the SPSS 22.0 for Windows.