Table 1—

Baseline characteristics of the study patients at the time of randomisation in the emergency dept and causes of acute respiratory failure

CharacteristicsPatients receiving
Bi-level NPPVPlacebo
Subjects n1010
Age yrs71±976±7
History of previous intubation10
History of respiratory disease85
Smoking history84
Admission diagnosis
 APO3 (30)5 (50)
 COPD7 (70)5 (50)
Clinical conditions
 Symptoms <24 h57
 Symptoms >24 h53
 Duration of dyspnoea h22.5±3018.1±13
 VAS patient8.5±1.558.3±1.71
 VAS nurse8±1.158.1±1.91
 VAS investigator7.95±1.67.9±1.91
 Moderate dyspnoea21
 Major/severe dyspnoea89
 Abnormality on ECG99
 Abnormal radiograph1010
  • 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)