Table 4 Main characteristics of 456 patients with ARDS—classification 24 h after initial ARDS diagnosis based on SpO2/FiO2 cutoff of 190 and PEEP cutoff of 10 cm H2O
Variables | Group I (N = 213) | Group II (N = 145) | Group III (N = 17) | Group IV (N = 81) | P value |
|---|---|---|---|---|---|
SpO2/FiO2 ≥ 190 and PEEP < 10 | SpO2/FiO2 ≥ 190 and PEEP ≥ 10 | SpO2/FiO2 < 190 and PEEP < 10 | SpO2/FiO2 < 190 and PEEP ≥ 10 | ||
APACHE IV score | 75 (60–93) | 84 (65–108) | 78 (65–112) | 86 (68–110) | 0.001 |
Age, years | 63 (53–73) | 60 (49–69) | 57 (42–70) | 59 (49–69) | 0.018 |
Female | 80 (37.6) | 61 (42.1) | 5 (29.4) | 26 (32.1) | 0.436 |
CCI 2 | 1 (0–3) | 1 (0–2) | 2 (0–3) | 1 (0–2) | 0.423 |
LIPS | 8 (6.5–9.5) | 9 (7.5–10.5) | 7 (6.5–8) | 9.5 (7.5–11.5) | < 0.001 |
Tidal volume, ml/kg | 6.4 (5.3–7.7) | 6.2 (5.2–7.5) | 7.2 (6.5–8.2) | 6.4 (5.6–7.4) | 0.166 |
FiO2, % | 40 (36–40) | 40 (40–50) | 60 (55–60) | 60 (55–65) | < 0.001 |
PEEP, cm H2O | 5 (5–8) | 12 (10–13) | 7 (5–8) | 14 (12–15) | < 0.001 |
Arterial pH | 7.4 (7.4–7.5) | 7.4 (7.3–7.4) | 7.4 (7.3–7.5) | 7.3 (7.3–7.4) | < 0.001 |
PaCO2, kPa | 5.3 (4.7–6.2) | 5.6 (4.9–6.2) | 5.6 (5–7) | 5.8 (5.1–6.6) | 0.018 |
Plasma lactate level, mmol/l | 2.4 (1.4–4.1) | 3.1 (1.7–6.2) | 1.6 (1.4–3.9) | 5.4 (2.6–10.9) | < 0.001 |
Respiratory rate | 22 (17–27) | 24 (17.2–30) | 22 (18–28) | 24 (16–34) | 0.183 |
PaO2/FiO2 | 207 (175–252) | 193 (167–226) | 128 (120–149) | 133 (105–153) | < 0.001 |
SpO2/FiO2 | 243 (231–265) | 232 (200–245) | 165 (154–170) | 158 (136–176) | < 0.001 |
Vasopressor use in first 24 h | 100 (47.0) | 102 (70.3) | 6 (35.3) | 67 (82.72) | < 0.001 |
ARDS class after 24 h | |||||
Mild ARDS | 122 (57.3) | 61 (42.1) | 0 0 | 5 (6.2) | < 0.001 |
Moderate ARDS | 91 (42.7) | 84 (57.9) | 15 (88.2) | 59 (72.8) | < 0.001 |
Severe ARDS | 0 0 | 0 0 | 2 (11.8) | 17 (21) | < 0.001 |
Cause of ARDS | |||||
Pulmonary | 156 (73.2) | 99 (68.3) | 12 (70.6) | 58 (71.6) | 0.509 |
Non-pulmonary | 67 (31.5) | 78 (53.8) | 5 (29.4) | 40 (49.4) | 0.426 |