Table 2 Baseline demographics of four groups of patients specified in our multivariable regression model
Characteristic | Low P/F and LTVV | High P/F and LTVV | Low P/F and HTVV | High P/F and HTVV | Overall p value |
|---|---|---|---|---|---|
n | 107 | 115 | 113 | 111 | – |
Age, years | 51.4 ± 14.3 | 48.8 ± 16.1 | 51.0 ± 16.8 | 51.4 ± 16.9 | 0.56 |
Female | 50 (47%) | 41 (36%) | 51 (45%) | 42 (38%) | 0.26 |
APACHE III | 88.3 ± 29.5 | 76.8 ± 28.0 | 87.3 ± 28.2 | 80.9 ± 26.6 | 0.006 |
Initial P/F ratio | 84.5 ± 20.8 | 183.9 ± 46.5 | 84.0 ± 19.9 | 175.3 ± 47.5 | < 0.001 |
Initial driving pressure | 14.9 ± 5.3 | 22.9 ± 7.0 | 16.9 ± 5.4 | 24.6 ± 6.6 | < 0.001 |
Mean PaO2 (mmHg) | 74.1 ± 18.2 | 83.5 ± 21.3 | 75.4 ± 11.7 | 83.0 ± 15.7 | < 0.001 |
Mean FiO2 (%) | 62.1 ± 15.3 | 49.0 ± 12.2 | 58.2 ± 14.0 | 47.6 ± 11.8 | < 0.001 |
Mean PEEP (cm H20) | 9.9 ± 2.8 | 7.7 ± 2.6 | 9.1 ± 3.2 | 7.2 ± 2.3 | < 0.001 |
Lowest systolic blood pressure | 87.6 ± 19.4 | 92.3 ± 19.3 | 87.7 ± 18.1 | 92.3 ± 17.4 | 0.07 |
Highest temperature | 38.6 ± 0.9 | 38.5 ± 0.8 | 38.5 ± 1.1 | 38.4 ± 0.83 | 0.33 |
Mean pH | 7.32 ± 0.53 | 7.24 ± 0.90 | 7.29 ± 0.79 | 7.30 ± 0.70 | 0.88 |
Platelet count | 161.0 ± 115.1 | 149.7 ± 115.5 | 162.8 ± 94.5 | 144.1 ± 100.7 | 0.51 |
Pneumonia | 49 (45.8%) | 29 (25.2%) | 53 (46.9%) | 39 (35.1%) | 0.002 |
Sepsis | 28 (26.1%) | 36 (31.3%) | 23 (20.3%) | 27 (24.3%) | 0.29 |
Aspiration | 15 (14.0%) | 17 (14.8%) | 17 (15.0%) | 14 (12.6%) | 0.95 |
Multiple transfusions | 4 (3.7%) | 1 (0.8%) | 3 (2.7%) | 9 (8.1%) | 0.03 |
Trauma | 3 (2.8%) | 23 (20.0%) | 4 (3.5%) | 14 (12.6%) | < 0.001 |
Other | 7 (6.5%) | 9 (7.8%) | 13 (8.8%) | 8 (7.2%) | 0.54 |
Days of NMB, median (25–75 IQR) | 0 (0–1) | 0 (0–0) | 0 (0–1) | 0 (0–1) | 0.62a |