Resting pulmonary function data breathing room air or heliox
| Room air | Heliox | |
| FEV1 L | 1.41±0.58 | 1.58±0.68* |
| FVC L | 2.87±0.87 | 2.96±0.95 |
| FEV1/FVC % | 47.8±8.1 | 52.0±10.97* |
| PEFR L·s−1 | 6.40±2.64 | 7.94±3.38* |
| V′E L·min−1 | 14.8±5.25 | 13.88±5.44 |
| VT L | 0.90±0.38 | 0.79±0.36 |
| fR breaths·min−1 | 17.2±3.7 | 18.1±3.6 |
| EELV % TLC | 65.8±8.2 | 63.3±7.9 |
| EILV %TLC | 78.4±7.3 | 74.3±7.2 |
Data are presented as mean±sd. FEV1: forced expiratory volume in one second; FVC: forced vital capacity; PEFR: peak expiratory flow rate; V′E: minute ventilation; VT: tidal volume; fR: respiratory frequency; EELV: end-expiratory lung volume; TLC: total lung capacity; EILV: end-inspiratory lung volume. *: p<0.05.