Parameter | SB | Li-NPPV | Hi-NPPV | p-value | ||
SB versus Li-NPPV | SB versus Hi-NPPV | Li-NPPV versus Hi-NPPV | ||||
fR breaths·min−1 | 24.8±8.4 | 21.3±6.3 | 22.9±3.3 | ns | ns | ns |
tI s | 1.25±0.3 | 1.1±0.19 | 0.74±0.1 | ns | <0.05 | <0.001 |
tE s | 1.46±0.75 | 1.98±0.77 | 1.93±0.34 | ns | ns | ns |
tI/ttot | 0.48±0.09 | 0.37±0.08 | 0.27±0.05 | <0.001 | <0.001 | <0.001 |
VT L | 0.4±0.1 | 0.56±0.11 | 0.67±0.13 | <0.001 | <0.001 | <0.001 |
VT/tI L·s−1 | 0.33±0.08 | 0.52±0.11 | 0.93±0.18 | <0.05 | <0.001 | <0.05 |
V′E L·min−1 | 9.6±3.5 | 11.7±2.3 | 15.2±2.0 | <0.01 | <0.001 | <0.001 |
Air leakage L·min−1 | 10.62±5.27 | 16.11±7.88 | <0.05 |
Data are presented as mean±sd, unless otherwise stated. SB: spontaneous breathing; Li: low-intensity; NPPV: noninvasive positive pressure ventilation; Hi: high-intensity; fR: respiratory frequency; tI: inspiratory time; tE: expiratory time; ttot: total time of respiratory cycle; VT: tidal volume; V′E: minute ventilation; ns: nonsignificant.