Criteria for extubation failure
| fR >25 breaths·min−1 for 2 h |
| fC >140 beats·min−1 or sustained increase or decrease of >20% |
| Clinical signs of respiratory muscle fatigue or increased work of breathing |
| Sa,O2 <90%; Pa,O2 <80 mmHg on FI,O2 ≥0.50 |
| Hypercapnia (Pa,CO2 >45 mmHg or ≥20% from pre-extubation), pH <7.33 |
fR: respiratory frequency; fC: cardiac frequency; Sa,O2: arterial oxygen saturation; Pa,O2: arterial oxygen tension; FI,O2: inspiratory oxygen fraction; Pa,CO2: arterial carbon dioxide tension. 1 mmHg = 0.133 kPa.