EFFECTS OF ACCIDENTAL TRAUMA ON CYTOKINE AND ENDOTOXIN PRODUCTION

Objective: To determine the effects of accidental injury of varying se verity on interleukin (IL)-1alpha, IL-6, IL-8, tumor necrosis factor-a lpha (TNF-alpha), and endotoxin release. Design: Prospective, multi-un it, longitudinal study. Setting: Emergency Departments and intensive c are units of two university hospitals. Patients: Trauma patients after mild, moderate, and severe injury (Injury Severity Score of less-than -or-equal-to 10, 11 to 24, and greater-than-or-equal-to 25, respective ly). Interventions: None. Measurements and Main Results: Plasma cytoki ne and endotoxin concentrations were measured over a 5-day period, sta rting within 2 hrs of accidental injury. An enzyme-linked immunosorben t assay was used to determine plasma concentrations of IL-1alpha, EL-6 , IL-8, and TNF-alpha. Plasma endotoxin concentrations were measured u sing a chromogenic limulus amebocyte assay. Preresuscitation samples o btained immediately on arrival in the Emergency Department, and within 2 hrs of injury, demonstrated significant increases of IL-6 and IL-8 concentrations in the severe injury group, in contrast to minimal incr eases seen after mild or moderate injury. Analysis of serial postresus citation samples demonstrated rapid increases in IL-6 and IL-8 concent rations within 12 hrs of injury. IL-6 and IL-8 remained increased for 24 hrs after injury, then decreased markedly from their peak values du ring the next 24 hrs. Increased circulating concentrations of these cy tokines continued to be present for >5 days in the severely injured pa tients. IL-6 and IL-8 concentrations were only minimally increased in patients 8 and 24 hrs after moderate injury. Endotoxin and IL-1alpha w ere not found in any samples, including those samples obtained seriall y from severely injured patients. No patient at any time point had TNF -alpha concentrations of >35 pg/mL. Conclusions: These results demonst rate that severe injury produces rapid, large increases in circulating concentrations of IL-6 and IL-8 that may contribute to the frequent d evelopment of the adult respiratory distress syndrome and multiple org an system failure in this clinical setting.