Baseline characteristics of the patients
| Overall population | |
| Demographic characteristics | |
| Age, years | 62±16 |
| Male sex, n (%) | 178 (68%) |
| Weight, kg | 74±17 |
| Height, m | 1.69±0.09 |
| Vital signs | |
| Systolic blood pressure, mm Hg | 129±22 |
| Diastolic blood pressure, mm Hg | 70±15 |
| Mean blood pressure, mm Hg | 87+16 |
| Heart rate, beats/min | 105±20 |
| Temperature, °C | 37.9±0.9 |
| Respiratory rate, breaths/min | 33±7 |
| Oxygen flow, L/min | 14±2 |
| Bilateral infiltrates on chest X-ray, n (%) | 209 (80%) |
| Arterial blood gases | |
| pH, units | 7.43±0.06 |
| PaO2, mm Hg | 87±32 |
| PaCO2, mm Hg | 35±6 |
| FiO2 | |
| Measured FiO2, % | 65±13 |
| Estimated FiO2 | |
| 3%-formula, % | 62±6 |
| 4%-formula, % | 75±8 |
| Table, % | 95±0 |
FiO2, fraction of inspired oxygen; PaO2, partial pressure of arterial oxygen.