Table 1:Chest wall motion and volume changes with and without NIV
| Variable | Supine without NIV | Supine with NIV | p-value |
| Vtcw (L) | 0.4 ± 0.2 | 0.6 ± 0.2 | 0.025 |
| Vtrcp% | 29 ± 15 | 32 ± 15 | 0.572 |
| Vtrca% | 13 ± 5 | 11 ± 6 | 0.180 |
| Vtab% | 58 ± 15 | 57 ± 18 | 0.830 |
| Veicw (L) | 18.9 ± 4 | 19.4 ± 3.9 | 0.008 |
| Veecw (L) | 18.5 ± 4 | 18.8 ± 4 | 0.019 |
| f (irpm) | 19 ± 9 | 21 ± 11 | 0.212 |
| VE (L/min) | 6.9 ± 2.5 | 10.7 ± 4 | 0.013 |