Table 2. Baseline characteristics of the cohort based on outcome (COT failure).
COPD: chronic obstructive pulmonary disease, GCS: Glasgow coma scale, BP: blood pressure, MAP: mean arterial pressure, SpO2: peripheral oxygen saturation, ABG: arterial blood gas, Δ (A-a) O2: alveolar-arterial oxygen gradient
| Variable | COT succeeded (n = 36) | COT failed (n = 65) | p-value |
| Age, years | 69.6 ± 16.9 | 75.1 ± 15.1 | 0.130 |
| Gender, n (%) | 0.603 | ||
| Male | 18 (17.8) | 36 (35.6) | |
| Female | 18 (17.8) | 29 (28.7) | |
| Comorbidities, n (%) | |||
| Hypertension | 19 (18.8) | 40 (39.6) | 0.392 |
| COPD | 7 (6.9) | 18 (17.8) | 0.358 |
| Clinical features, n (%) | |||
| Shortness of breath | 19 (18.8) | 44 (43.6) | 0.138 |
| Cough | 21 (20.8) | 30 (29.7) | 0.241 |
| GCS < 15 | 8 (7.9) | 13 (12.9) | 0.792 |
| Vital signs, mean ± SD | |||
| Systolic BP, mmHg | 121.6 ± 17.2 | 121.5 ± 20.5 | 0.829 |
| Diastolic BP, mmHg | 73.3 ± 12.1 | 70 ± 11.3 | 0.293 |
| MAP, mmHg | 89.4 ± 12.4 | 87.1 ± 12.8 | 0.456 |
| Heart rate, beats/min | 83.6 ± 15.4 | 90.6 ± 18.5 | 0.064 |
| Respiratory rate, breaths/min | 21.4 ± 6.5 | 24.8 ± 7 | 0.023 |
| SpO2, % | 94.1 ± 4 | 91.5 ± 5 | 0.004 |
| Body temperature, °C | 37.2 ± 0.8 | 37.7 ± 1 | 0.019 |
| ABG analysis, mean ± SD | |||
| pH | 7.5 ± 0.1 | 7.5 ± 0.1 | 0.525 |
| PaCO2, mmHg | 33.2 ± 6.6 | 31.4 ± 5.6 | 0.168 |
| PaO2, mmHg | 60.6 ± 8.3 | 54.8 ± 10.6 | 0.002 |
| HCO3-, mmol/L | 24.2 ± 2.9 | 23.3 ± 3.6 | 0.181 |
| Lactate, mmol/L | 1.1 ± 0.5 | 1.4 ± 0.7 | 0.004 |
| P/F ratio | 288.6 ± 39.6 | 255.9 ± 51.5 | 0.001 |
| Δ (A-a) O2 | 48.3 ± 9.3 | 56.5 ± 12.4 | <0.001 |
| ROX index | 22.7 ± 8 | 18.9 ± 6.1 | 0.009 |