TABLE 2

Polysomnography while using noninvasive ventilation and gas exchange parameters in the groups with obstruction with decreased central drive index (ODCDI) <5 and >5 h−1

ODCDI <5 h−1ODCDI >5 h−1p-value
Subjects273
TST min339.85±76.42364.80±95.610.610
Sleep latency min18.13±15.6718.26±21.010.989
Sleep efficiency index %68.83±12.1474.16±7.300.469
Arousal/awakening index h−119.31±18.2728.50±27.780.447
Sleep stage
 N1 %24.17±12.2621.40±13.230.719
 N2 %46.95±13.4249.03±3.090.795
 N3 %23.17±14.1428.50±16.290.552
 REM %5.67±5.511.03±0.110.001
TST90 %3.77±7.297.70±7.630.386
ODI h−16.79±12.5428.30±20.030.012
Minimum SpO2 %84.70±9.6681.00±7.210.528
Mean SpO2 %94.29±1.8993.33±1.150.401
ODCDI h−10.88±0.9912.99±5.770.028
pH7.42±0.027.42±0.020.865
PaO2 mmHg79.92±8.5769.66±10.010.062
PaCO2 mmHg42.37±4.2748.66±7.570.032
HCO3 mmol·L−127.48±2.2929.40±4.800.562

TST: total sleep time; REM: rapid eye movement; TST90: time spent with arterial oxygen saturation <90%; ODI: oxygen desaturation index; SpO2: arterial oxygen saturation measured by pulse oximetry; PaO2: arterial oxygen tension; PaCO2: arterial carbon dioxide tension; HCO3: bicarbonate.