The total group consisted of 100 patients (24 female, 76 male), 98% suffering from blunt and 2% from penetrating trauma. All patients were substantially injured (ISS: 34.0 ± 1.7). Of these, 30 patients with an ISS of 33.7 ± 1.6 developed secondary pulmonary complications. Seventy patients with an ISS of 34.1 ± 1.3 had no pulmonary complications. The AISchest was comparable in both groups (3.1 ± 0.2 in the ØPC group and 3.5 ± 0.2 in the PC group). Time on mechanical ventilation, length of stay in the ICU and hospital were significantly prolonged in the PC group. Additionally, more patients developed sepsis (P < 0.05), organ failure, and MOF in the PC group. In-hospital mortality was also increased. summarizes general patient characteristics and physiologic parameters in the study population. depicts the type, severity, and cause of injury.
Summary of patient characteristics and physiologic parameters in the investigated groups (ØPC: no pulmonary complications, PC: pulmonary complications and ctrl, data are presented as mean ± SEM unless otherwise stated).
Overview of type and mechanisms of injuries within the two investigated groups groups (ØPC: no pulmonary complications, PC: pulmonary complications and ctrl, data are presented as mean ± SEM).
shows the distribution of plasma LTB4 values in the first sample obtained in the ED and subsequent daily measurements for five consecutive days. Median concentrations (and IQR) of LTB4 in trauma patients on admission were significantly increased compared to healthy controls (106.1 (62–159)
pg/mL versus 58.4 (36–108)
< 0.05, ). The LTB4 levels on admission were also significantly elevated compared with levels at day 1 until day 5.
Summary of median (interquartile range) LTB4 (pg/mL) in multiply traumatized patients over a 5-day time course after admission (n = 100), and ctrl (n = 20). *P < 0.05 versus other groups.
To investigate the relation between the injury severity and LTB4 concentrations determined in the ED, the study population was subdivided into three groups: seriously injured patients (ISS: 16–24, n
= 17), seriously/severely injured patients (ISS: 25–39, n
= 54), and severely injured patients (ISS: ≥40, n
= 29). Plasma LTB4 concentrations in each group were markedly enhanced (112.8 (68–167)
pg/mL, 107.6 (48–164)
pg/mL, and 105.3 (62–148)
pg/mL, resp.) compared with healthy volunteers 58.4 (36–108)
pg/mL, but this tendency was not significant ().
Figure 2 Summary of median (interquartile range) LTB4 (pg/mL) in ED samples in different groups of patients based on the overall injury severity (a) and the severity of chest injury (b). (a) ISS: 16–24, n = 17, ISS: 25–39, n = 54, ISS: ≥40, (more ...)
The severity of chest trauma was assessed using the AIS chest scores. Patients without a relevant chest injury were graded as AISchest
≤ 2 (n
= 21). Patients with serious and serious/severe chest injury (AISchest
= 3 or 4) occurred most frequently (n
= 23, and n
= 49, resp.), whereas patients with an AISchest
= 5 occurred less often (n
= 7). Taken together, LTB4 levels were increased in all four trauma patient groups (AISchest
≤ 2: 113.9 (61–162), AISchest
= 3: 105.8 (47–200), AISchest
= 4: 107.7 (64–156), and AISchest
= 5: 94.9 (65–133)
pg/mL) compared with healthy volunteers, but this difference was not significant ().
However, comparing LTB4 levels taken in the ED of those patients who developed pulmonary complications (n
= 30) following injury with those patients who did not develop pulmonary complications (n
= 70) and healthy volunteers revealed a significant difference (127.8 (104–200) versus 95.6 (55–143) and 58.4 (36–108)
pg/mL, resp., P
< 0.05, Figures and ). Follow-up LTB4 levels (day 1–day 5) showed that increased LTB4 levels in the ED in patients with pulmonary complications diminished in a time-dependent manner (). This effect was irrespective of the patients ISS or AISchest
since subgroup analysis according to ISS or AISchest
revealed no differences in LTB4 levels.
Figure 3 Summary of median LTB4 (pg/mL) in two patient groups based on the development of pulmonary complications (ØPC: no pulmonary complications, n = 70, and PC: pulmonary complications, n = 30) and ctrl, n = 20, *P<0.05 versus other groups: (more ...)
Receiver operating characteristics (ROCs) analysis for LTB4 shows an optimal cutoff of 109.6
pg/mL with 72% specificity (95% CI: 0.61–0.81) and 67% sensitivity (95% CI: 0.49–0.84), for predicting pulmonary complications in a later posttraumatic course (). The area under the ROC curve is 0.73.
Figure 4 Receiver operating curve showing the optimal cutoff for LTB4 levels (109.6pg/mL in predicting the presence or absence of postinjury pulmonary complications with 72% specificity and 67% sensitivity).
Multiply traumatized patients with pulmonary complications needed significantly prolonged mechanical ventilation compared with patients without secondary pulmonary complications (18.4 ± 2.7 days versus 6.4 ± 0.8 days, resp., P < 0.05, ). The mean ICU stay of all patients was 12.8 ± 1.3 days. Patients with pulmonary complications had a mean ICU stay of 22.4 ± 3.1 days versus 8.9 ± 0.9 days in patients without pulmonary complications (P < 0.05, ). Patients with pulmonary complications also had significantly prolonged hospital stay compared with patients without pulmonary complications (32.5 ± 5.2 days versus 20.5 ± 1.7 days, resp., P < 0.05, ). Sixteen patients developed sepsis, of those 69% had pulmonary complications (). Eight patients suffered from organ failure, and 4 patients had MOF, of those 63% and 75%, respectively, had pulmonary complications (). The mortality rate was enhanced for patients with pulmonary complications (10%) compared with patients without pulmonary complications (4%, ).