Serum CRP and IL-6 levels after trauma: Not predictive of septic complications in 31 patients

We studied 31 blunt trauma victims, Injury Severity Score (ISS) mean 14 (9-57), for the pattern of release of C-reactive protein (CRP) and cytokine interleukin-6 (IL-6). Blood samples were taken on admission (within 6 hours of injury), as well as at 24 hours, and 3, 5 and 7 days. Serum CRP and IL-6 were measured by ELISA. Subsequent surgical events and sepsis were noted. Serum IL-6 levels on admission were considerably higher (median 135 pg mL-1) than our laboratory reference range (< 5 pg mL-1), slowly returning towards reference values during the study. Serum CRP levels were similar to laboratory normal values on admission (median 8.5 mg L-1 vs 7.5 mg L-1), reaching peak values (median 110 mg L-1) after 3 days. There was a correlation between IL-6 release and ISS but not between CRP and ISS. Patients undergoing surgery showed further increases in IL-6 and CRP levels postoperatively. Of 24 surgical patients, 9 developed postoperative sepsis. In blunt trauma patients, early assessment of the markers CRP or IL-6 were not useful for the diagnosis of sepsis. Levels of CRP following accidental or surgical trauma should be assessed with caution.