Table 1 Patient demographic and clinical characteristics
Variable | Intubated patients (n = 113) | Non-intubated patients (n = 201) | p value |
|---|---|---|---|
Sex, male, n (%) | 68 (60.2) | 101 (50.2) | 0.091 |
Age (years), median [IQR] | 77 [67, 83] | 73 [65, 85] | 0.603 |
BMI (kg/m2), mean ± SD | 22.7 ± 5.5 | 22.9 ± 5.8 | 0.678 |
Charlson Comorbidity Index, median [IQR] | 3 [1, 5] | 3 [1, 5] | 0.968 |
Comorbidities, n (%) | |||
 COPD | 22 (19.5) | 42 (20.9) | 0.764 |
 Chronic renal disease stage 4 or 5 | 13 (11.5) | 37 (18.4) | 0.127 |
 History of myocardial infarction | 31 (27.4) | 47 (23.4) | 0.426 |
 Heart failure | 32 (28.3) | 71 (35.3) | 0.205 |
 History of a cerebrovascular event | 32 (28.3) | 54 (26.9) | 0.782 |
 Dementia | 18 (15.9) | 24 (11.9) | 0.320 |
 Post-COVID-19 status | 18 (15.9) | 25 (12.4) | 0.388 |
Vital signs | |||
 SBP, mmHg, mean ± SD | 126 ± 35 | 132 ± 34 | 0.137 |
 MAP, mmHg, mean ± SD | 88 ± 23 | 92 ± 22 | 0.072 |
 Hypotension (SBP ≤ 90 or MAP ≤ 65 mmHg), n (%) | 15 (13.3) | 24 (11.9) | 0.731 |
 Heart rate, bpm, mean ± SD | 102 ± 23 | 98 ± 23 | 0.216 |
 Respiratory rate, per minute, median [IQR] | 28 [24, 32] | 26 [24, 30] | 0.014 |
 Respiratory rate > 30 per minute, n (%) | 33 (29.2) | 42 (20.1) | 0.098 |
 SpO2, (%), median [IQR] | 94 [90, 98] | 96 [92, 99] | 0.006 |
 Glasgow Coma Scale score, median [IQR] | 15 [13, 15] | 15 [15] |  < 0.001 |
 Glasgow Coma Scale score < 15, n (%) | 41 (36.3) | 33 (16.4) | 0.002 |
Blood gas analysis | |||
 pH, mean ± SD | 7.37 ± 0.11 | 7.41 ± 0.08 | 0.001 |
 PaO2, mmHg, median [IQR] | 125 [84, 18] | 130 [82, 172] | 0.362 |
 PaCO2, mmHg, median [IQR] | 33 [27, 42] | 33 [29, 40] | 0.910 |
 PF ratio, mean ± SD | 377.77 ± 137.47 | 391.87 ± 135.20 | 0.379 |
 Bicarbonate, mEq/L, mean ± SD | 19.9 ± 6.1 | 21.6 ± 4.8 | 0.007 |
 Blood lactate, mmol/L, median [IQR] | 1.7 [0.8, 3.3] | 1.8 [1.0, 2.8] | 0.717 |
 Serum creatinine, mg/dL, median [IQR] | 1.18 [0.79, 1.72] | 1.14 [0.82, 1.82] | 0.848 |
 SOFA score, median [IQR] | 3 [2, 5] | 2 [1, 4] | 0.001 |
 Non-invasive respiratory support, n (%) | 88 (77.9) | 131 (65.2) | 0.019 |
Final diagnosis, n (%) | |||
 Respiratory infection | 63 (55.8) | 73 (36.3) | 0.001 |
 Sepsis | 76 (67.3) | 73 (36.3) |  < 0.001 |
 Acute exacerbation of COPD | 20 (17.7) | 37 (18.4) | 0.876 |
 Asthma attack | 4 (3.5) | 10 (5.0) | 0.555 |
 Cardiogenic pulmonary edema | 22 (19.5) | 61 (30.3) | 0.036 |
 COVID-19 pneumonia | 17 (15.0) | 7 (3.5) | 0.050 |
 Diaphragmatic excursion, cm, median [IQR] | 0.9 [0.76, 1.10] | 1.8 [1.30, 2.40] |  < 0.001 |