Clinical assessment and subjective indices | Agitation and anxiety |
| Depressed mental status |
| Diaphoresis |
| Cyanosis |
| Evidence of increasing effort |
| Increased accessory muscle activity |
| Facial signs of distress |
| Dyspnoea |
Objective measurements | Pa,O2 ≤50–60 mmHg on FI,O2 ≥0.5 or Sa,O2 <90% |
| Pa,CO2 >50 mmHg or an increase in Pa,CO2 >8 mmHg |
| pH <7.32 or a decrease in pH ≥0.07 pH units |
| fR/VT >105 breaths·min−1·L−1 |
| fR >35 breaths·min−1 or increased by ≥50% |
| fC >140 beats·min−1 or increased by ≥20% |
| Systolic BP >180 mmHg or increased by ≥20% |
| Systolic BP <90 mmHg |
| Cardiac arrhythmias |