Table 1.
Patient characteristics and demographic data at study entry
| Characteristic | |
| Age (years) | 67 ± 12 |
| Sex (male/female) | 24/16 |
| Etiology of acute respiratory failure (n) | |
| Postoperative | 20 |
| Pneumonia | 12 |
| Sepsis | 8 |
| Drug treatment | |
| Midazolam (n, mg/kg per h) | 40, 0.12 ± 0.03 |
| Sufentanil (n, mg/kg per h) | 40, 0.012 ± 0.003 |
| Ketamine (n, mg/kg per h) | 15, 1.5 ± 0.5 |
| Respirator therapy (CPPV, pressure controlled mode, by Evita*) | |
| Pmax (n, mbar) | 40, 26 ± 4 |
| PEEP (n, mbar) | 40, 10 ± 2 |
| FiO2 (n, %) | 40, 70 ± 16 |
| I:E (n, time ratio) | 40, 1:1 |
*Draeger Corp, Luebeck, Germany. CPPV, continuous positive pressure ventilation; Pmax, maximal airway pressure; PEEP, positive end-expiratory pressure; FiO2, fractional inspiratory oxygen concentration; I:E, inspiration to expiration time ratio.