Spirometric and arterial blood gas measurements
| Eucapnic (n=83) | Hypercapnic (n=162) | |
|---|---|---|
| FEV1 (L) | 2.48±0.98 | 1.55±0.84* |
| FVC (L) | 2.92±1.12 | 1.84±0.97* |
| FEV1/FVC | 0.85±0.08 | 0.84±0.08 |
| FEV1% predicted | 77.6±23.1 | 58.5±44.6* |
| FVC % predicted | 74.7±21.8 | 56.9±36.6* |
| pH | 7.41±0.02 | 7.39±0.06* |
| PaO2 (kPa) | 9.86±1.49 | 8.15±1.36* |
| PaCO2 (kPa) | 5.43±0.38 | 7.19±0.9* |
| HCO3− (mmol/L1) | 25.5±1.9 | 31.8±3.6* |
| Base excess | 1.0±1.7 | 5.96±4.17* |
| Haematocrit (%) | 44.0±5.0 | 44.4±8.7 |
Values expressed as mean±SD.
*Significant difference compared with eucapnic group (p<0.001).
FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; HCO3−, arterial bicarbonate ion concentration; PaCO2, arterial partial pressure of carbon dioxide; PaO2, arterial partial pressure of oxygen.