NIV | Conventional therapy | p-value | |
Subjects n | 62 | 62 | |
Duration of mechanical ventilation days | 7.9±3.6 | 8.8±4.2 | 0.23 |
APACHE II at the time of extubation | 14.8±3.4 | 15.5±3.5 | 0.32 |
Physiological indices during spontaneous breathing trial | |||
Heart rate min-1 | 96.9±18.8 | 99.3±19.9 | 0.51 |
Respiratory rate min-1 | 23.7±4.3 | 22.6±4.7 | 0.43 |
fR/VT ratio min-1·L-1 | 74.6±11.6 | 71.5±13.7 | 0.16 |
Arterial pH | 7.39±0.05 | 7.4±0.06 | 0.58 |
Pa,CO2 mmHg | 47.1±8.9 | 44.8±7.7 | 0.13 |
Pa,O2 mmHg | 83±14 | 84±12 | 0.67 |
Pa,O2/FI,O2 | 215±38 | 221±41 | 0.38 |
Data are presented as mean±sd, unless otherwise stated. NIV: noninvasive ventilation; APACHE: Acute Physiology and Chronic Health Evaluation; fR/VT: ratio of respiratory frequency to tidal volume; Pa,CO2: carbon dioxide arterial tension; Pa,O2: oxygen arterial tension; FI,O2: inspiratory oxygen fraction. 1 mmHg = 0.133 kPa.