Table 3.
Patient subgroups defined by different ranges of lung weightsa
| Patient subgroups | Atelectasis (≤ reference range) | Above reference range | Consolidation |
|---|---|---|---|
| Definition | Mlung ≤1,164 g | Mlung >1,164 g | Mlung >1,380 g |
| Number of patientsb | 46 (59%) | 32 (41%) | 17 (22%) |
| Median agec, yr | 45 (32 to 53) | 28 (17 to 46) | 21 (17 to 48) |
| Median PaO2/FiO2ns, mmHg | 184 (128 to 252) | 136 (78 to 238) | 132 (68 to 230) |
| Median Lung Injury Scoree | 2.3 (1.6 to 2.6) | 2.7 (2.3 to 3.3) | 3.0 (2.3 to 3.3) |
| Median Injury Severity Scorens | 34 (29 to 45) | 41 (28 to 50) | 36 (25 to 50) |
| Median AIS-T scoreb | 4 (4 to 4) | 4 (4 to 4) | 4 (4 to 4) |
| Median Thoracic Trauma Severity Scorens | 11 (8 to 14) | 12 (9 to 15) | 12 (11 to 15) |
| Median Glasgow Coma Scale scoree | 14 (10 to 15) | 6 (3 to 12) | 7 (3 to 15) |
| Median volume of intravenous fluids ns, ml | 2,000 (1,000 to 3,000) | 2,000 (1,500 to 2,875) | 2,500 (1,500 to 3,000) |
| Median time to CTns, min | 135 (90 to 220) | 112 (90 to 177) | 131 (103 to 227) |
| Median ventilator-free daysd | 19 (10 to 25) | 15 (0 to 19) | 15 (0 to 19) |
| Median ICU-free daysc | 14 (2 to 22) | 1 (0 to 13) | 5 (0 to 14) |
| Median Vlunge, ml | 2,832 (2,226 to 3,669) | 3,812 (3,134 to 4,696) | 3,696 (3,019 to 4,668) |
| Median Mlungb, g | 899 (787 to 1,048) | 1,398 (1,265 to 1,972) | 1,930 (1,461 to 2,065) |
| Median Mnone, % | 16 (10 to 25) | 34 (18 to 52) | 40 (33 to 57) |
aAll values are given as medians with interquartile ranges. Atelectasis, patients with lung weights (Mlung) within the reference interval (that is, 584 to 1,164 g) for normal Mlung; above reference, patients with Mlung values exceeding the upper limit of the reference interval (that is, 1,164 g); consolidation, patients with Mlung values exceeding the lower limit of the 95% confidence interval of the mean Mlung values reported for patients with acute lung injury (that is, 1,380 g [10]); PaO2/FiO2, ratio of arterial partial pressure of oxygen to fraction of inspired oxygen; AIS-T, Abbreviated Injury Scale of the Thorax; time to CT, interval between trauma and computed tomography (CT); ventilator-free days, number of days without mechanical ventilation within a period of 28 days; ICU, intensive care unit; ICU-free days, number of days without ICU treatment within a period of 28 days; Vlung, total lung volume; Mlung, total lung mass; Mnon, percentage mass of nonaerated lung compartment (percentage of Mlung value); ns, not significant. bNo statistical test performed. cP < 0.05, dP < 0.001 and eP < 0.01, respectively, for the Kruskal-Wallis test over all groups.