Table 1.
General information of 229 patients who met the altitude-P/F-corrected criteria.
| Mild | Moderate | Severe | P values | |
|---|---|---|---|---|
| No(%) | 107(46.72%) | 84(36.68%) | 38(16.59%) | |
| Age (years, ± SD) | 50.45 ± 15.40 | 56.85 ± 16.83 | 59.05 ± 14.64 | 0.290 |
| Male (n,%) | 74(69.16%) | 55(65.47%) | 26(68.42%) | 0.859 |
| Source of ICU entry (n,%) | ||||
| Surgery | 39(36.45%) | 40(47.62%) | 10(26.32%) | 0.064 |
| Internal medicine | 10(9.35%) | 10(11.90%) | 12(31.58%) | 0.003 |
| Emergency | 58(54.21%) | 34(40.47%) | 16(42.11%) | 0.134 |
| ARDS risk factors (n,%) | ||||
| Pneumonia | 16(14.95%) | 18(21.43%) | 8(21.05%) | 0.463 |
| Infection | 37(34.58%) | 35(41.67%) | 11(28.95%) | 0.355 |
| Aspiration | 15(14.02%) | 12(14.29%) | 5(13.16%) | 0.986 |
| Trauma | 22(20.56%) | 15(17.86%) | 4(10.53%) | 0.383 |
| Basic diseases (n,%) | ||||
| Hypertension | 33(30.84%) | 27(32.14%) | 8(21.05%) | 0.434 |
| Diabetes mellitus | 15(14.02%) | 15(17.86%) | 1(2.63%) | 0.073 |
| Chronic pulmonary disease | 14(13.08%) | 21(25.00%) | 6(15.79%) | 0.096 |
| Chronic cardiac insufficiency | 25(23.36%) | 25(29.76%) | 9(23.68%) | 0.574 |
| Chronic renal dysfunction | 19(17.76%) | 15(17.86%) | 2(5.26%) | 0.153 |
| Chronic liver dysfunction | 29(27.10%) | 17(20.24%) | 2(5.26%) | 0.017 |
| APACHE II score ( ± SD) | 12.45 ± 5.11 | 13.24 ± 5.28 | 17.55 ± 5.52 | <0.001 |
| PaO2/FiO2 ( ± SD) | 183.49 ± 20.04 | 118.15 ± 20.97 | 52.31 ± 12.39 | <0.001 |
| pH ( ± SD) | 7.37 ± 0.31 | 7.29 ± 0.81 | 7.37 ± 0.11 | 0.572 |
| PaCO2(mmHg, ± SD) | 36.52 ± 18.21 | 41.17 ± 18.26 | 42.10 ± 12.03 | 0.098 |
| PaO2(mmHg, ± SD) | 82.25 ± 35.70 | 66.2 ± 22.92 | 43.86 ± 14.28 | <0.001 |
| FiO2(%, ± SD) | 63.92 ± 22.37 | 71.87 ± 21.41 | 89.47 ± 15.93 | <0.001 |
| PEEP (cmH2O, ± SD) | 5.11 ± 0.86 | 5.36 ± 1.59 | 5.26 ± 0.86 | 0.358 |
| Lac (mmol/L, median IQR) | 1.90(1.30–3.40) | 2.40(1.40–4.85) | 3.30(2.05–5.63) | 0.030 |
APACHE II, Acute Physiology and Chronic Health Evaluation II; PaO2, partial pressure of arterial oxygen; FiO2, fraction of inspired oxygen; PaO2, arterial oxygen partial pressure; PaCO2, arterial carbon dioxide partial pressure; FiO2, fraction of inspired oxygen; PEEP, positive end-expiratory pressure; Lac, lactic acid; IQR, Inter Quartile Range.