Objective: To study the long term effects with CPAP in OSAS.
Methods: Eighteen patients with OSAS were treated by CPAP at home for 3 to 27 months from 1987 to 1995, comparing the parameters of polysomnography (PSG) before and after treatment.
Results: (1) all the symptoms of OSAS were improved; (2) The parameters of PSG showed that the longest apnea duration from 66 +/- 21s to 43 +/- 24s (P < 0.05); AHI from 66 +/- 16 to 28 +/- 20 n/hour (P < 0.001); The lowest SaO2 from 53% +/- 19% to 75% +/- 11% (P < 0.001); (3) Comparing the body weight and blood pressure, no significant difference was shown before and after treatment with CPAP, but the blood pressure of 6 (50%) OSAS patients with hypertension had decreased to normal range.
Conclusion: Long term treatment with CPAP in OSAS were effective, after which, the AHI, lowest level of hopoxemia, the longest apnea duration and the sympoms of OSAS were improved. The mechanism could be that the patents' breathing control were restored.