Objective: The adult respiratory distress syndrome (ARDS) is a frequent complication after severe accidental trauma. This study examines the hypothesis that increased systemic concentrations of proinflammatory cytokines, endotoxin, or complement fragments may predict the development of ARDS.
Design: Prospective, observational study.
Setting: Two Level I university trauma centers.
Patients: Fifteen severely injured patients (Injury Severity Score of > or = 25).
Interventions: Standard emergency department, operating room, and intensive care unit management.
Measurements and main results: Plasma samples were obtained at 4-hr intervals from the time of injury and were assayed for concentrations of endotoxin, tumor necrosis factor-alpha, interleukin (IL)-1 beta, IL-6, IL-8, and complement fragments C3a and C4a. Hemodynamic and oxygen metabolism variables also were measured at 4-hr intervals after injury. Seven patients developed ARDS and eight patients did not. The PaO2/FIO2 ratio was significantly decreased in the patients with ARDS compared with non-ARDS patients as early as 4 hrs postinjury, and remained significantly decreased throughout the initial 24 hrs after severe accidental injury. Plasma IL-8, IL-6, C3a, and C4a concentrations were markedly increased starting in the immediate postinjury period in both ARDS and non-ARDS patients, but no significant differences were found between the two groups until 16 hrs after injury when plasma IL-8, C3a, and C4a concentrations became significantly higher in the ARDS group. Neither the ARDS nor non-ARDS patients showed the presence of circulating IL-1 beta, TNF-alpha, or endotoxin at any postinjury time point.
Conclusions: These results demonstrate that measurements of plasma concentrations of proinflammatory cytokines, endotoxin, or complement fragments are not helpful in predicting the development of ARDS after severe accidental injury.