Table 2.
Polysomnographic and arterial blood gas variables in the study population
| Characteristics | Non-OSA | OSA | p value |
|---|---|---|---|
| AHI (n/h) | 4.10 (2.57) | 33.77 (20.47) | < 0.001 |
| ODI (n/h) | 5.63 (3.44) | 34.36 (20.47) | < 0.001 |
| ST90 (%) | 1.86 (2.64) | 23.62 (21.93) | < 0.001 |
| pH | 7.43 (0.02) | 7.43 (0.03) | 0.633 |
| PaO2 (mmHg) | 89.12 (15.80) | 78.20 (9.34) | 0.001 |
| PaCO2 (mmHg) | 39.38 (2.45) | 40.74 (3.08) | 0.109 |
| SO2 (%) | 96.53 (1.55) | 94.29 (9.30) | 0.358 |
| HCO3− (mEq/l) | 25.84 (1.07) | 29.08 (9.67) | 0.188 |
| ESS | 6.05 (2.74) | 12.70 (3.00) | < 0.001 |
| Mean oxygen saturation (%) | 94.95 (1.25) | 92.78 (3.17) | 0.002 |
| Sleep efficiency (%) | 85.90 (11.06) | 88.76 (8.81) | 0.22 |
| Supine position (%) | 82.08 (22.59) | 81.85 (25.16) | 0.97 |
Mean ± SD (Unpaired Student’s t test). Bold font indicates p < 0.05
AHI apnoea-hypopnoea index, ODI oxygen desaturation index, ESS Epworth sleepiness score, ST90 % of sleep time spent below 90% oxygen saturation, SD standard deviation