Table 2.
Baseline characteristics of patients with acute respiratory failure stratified by etiology
| Variable | COPD (n = 24) | Others (n = 39) | Total (n = 63) | P value |
|---|---|---|---|---|
| Age (years) | 56 (11.8) | 39.3 (16.1) | 45.7 (16.6) | 0.0001 |
| Female gender, No. (%) | 9 (37.5) | 14 (35.9) | 23 (36.5) | 0.9 |
| BMI (kg/m2) | 21.7 (4.7) | 25.4 (6.9) | 24 (6.4) | 0.02 |
| Presence of other co-morbid illness, No. (%) | 18 (75) | 27 (69.2) | 45 (71.4) | 0.08 |
| APACHE II scores | 21.7 (4.8) | 16.7 (4.8) | 18.6 (5.4) | 0.0001 |
| Respiratory rate (breaths/min) | 34.1 (7.4) | 38.2 (7.8) | 36.7 (7.9) | 0.04 |
| Heart rate (beats/min) | 116.8 (16.9) | 114.4 (19.3) | 115.3 (18.3) | 0.35 |
| pH | 7.27 (0.07) | 7.36 (0.12) | 7.33 (0.11) | 0.002 |
| PaO2/FiO2 | 198.9 (33) | 149 (58.3) | 168.2 (55.4) | 0.001 |
| PaCO2 (mm Hg) | 73.1 (24.3) | 43.3 (16.1) | 54.6 (24.3) | 0.0001 |
Abbreviations: BMI, body mass index; COPD, chronic obstructive pulmonary disease; FiO2, fraction of inspired oxygen concentration; PaCO2, partial pressure of carbon dioxide in arterial blood; PaO2, partial pressure of oxygen in the arterial blood.