INFLUENCE OF CORRECTION OF FLOW LIMITATION ON CONTINUOUS POSITIVE AIRWAY PRESSURE EFFICIENCY IN SLEEP APNOEA HYPOPNOEA SYNDROME/

We evaluated the efficiency of two different treatment procedures with continuous positive airway pressure (CPAP) on sleep, nocturnal breath ing characteristics and daytime vigilance in 18 newly diagnosed patien ts with untreated sleep apnoea/hypopnoea syndrome (SAHS) randomly allo cated to two different groups. In group T, the positive pressure (PP) level was set to suppress Bow limitation (PFL), while in group II the PP was set at a level that eliminated only apnoea/hypopnoea and snorin g (PAHS). At the end of a 3 week period of home CPAP therapy, a follow -up sleep study, vigilance and cognitive tests were made. Overall, PFL was significantly higher than PAHS values (PFL: 10.4+/-2.6 cmH(2)O; P AHS: 8.9+/-2.6 cmH(2)O; p<0.01, mean+/-SD). We found no difference in sleep quality nocturnal saturation and apnoea/hypopnoea index, or in d aytime vigilance tests be: tween the two groups at the end of the trea tment period. However, there was a significantly greater scattering in the changes of sleep latency in group II than in group I. This was as sociated with a significant difference in the daily duration of nasal CPAP use between the two groups (group I: 7.29+/-0.95 h.day(-1);( )gro up II: 6.01+/-0.94 h.day(-1); p=0.01) and with a positive correlation between final maintenance of wakefulness test values and the duration of CPAP use (p<0.05; r=0.55). These results tend to show that correcti ng flow limitation is associated with a higher observance and a more i mportant efficiency in normalizing daytime vigilance than with convent ional nasal continuous positive airway pressure.