Baseline characteristics of the study patients at the time of randomisation in the emergency dept and causes of acute respiratory failure
| Characteristics | Patients receiving | |
| Bi-level NPPV | Placebo | |
| Subjects n | 10 | 10 |
| Age yrs | 71±9 | 76±7 |
| M:F | 7:3 | 4:6 |
| History of previous intubation | 1 | 0 |
| History of respiratory disease | 8 | 5 |
| Smoking history | 8 | 4 |
| Admission diagnosis | ||
| APO | 3 (30) | 5 (50) |
| COPD | 7 (70) | 5 (50) |
| Clinical conditions | ||
| Symptoms <24 h | 5 | 7 |
| Symptoms >24 h | 5 | 3 |
| Duration of dyspnoea h | 22.5±30 | 18.1±13 |
| VAS patient | 8.5±1.55 | 8.3±1.71 |
| VAS nurse | 8±1.15 | 8.1±1.91 |
| VAS investigator | 7.95±1.6 | 7.9±1.91 |
| Moderate dyspnoea | 2 | 1 |
| Major/severe dyspnoea | 8 | 9 |
| Palor/cyanosis | 10 | 10 |
| Sweating | 9 | 4 |
| Agitation | 0 | 3 |
| Abnormality on ECG | 9 | 9 |
| Abnormal radiograph | 10 | 10 |
Data are presented as mean±sd, n or n (%), unless otherwise stated
APO: acute pulmonary oedema
COPD: chronic obstructive pulmonary disease
ECG: electrocardiogram
NPPV: noninvasive positive-pressure ventilation
VAS: visual analog scale (0: normal breathing–10: unbearable dyspnoea)