Antithrombin levels related to infections and outcome

Antithrombin (AT) was measured in the plasma of 59 trauma patients at Detroit Receiving Hospital from July 1987 through December 1992 to determine how well low AT levels correlated with the outcome and development of later infections. The average lowest AT measured was 74 +/- 14% (SD) (normal = 75 to 120%). The mean lowest AT of the 11 trauma patients who developed sepsis (45 +/- 13%) was significantly lower than that of the 15 who developed an infection without sepsis (66 +/- 12%) (p < 0.001) and of the 33 who did not develop an infection (87 +/- 15%) (p <0.001). No patient with an AT always > or = 70% became septic or died, and no patient with an AT always > or = 90% developed an infection. In the 33 patients who did not develop infections, the mean AT levels rose progressively from 75 +/- 17% during the first 48 hours after admission to 91 +/- 11% during the next 48 hours. In contrast, the mean AT levels in the 26 patients who later developed infections were significantly lower (48 +/- 24%) during the first 48 hours and 60 +/- 16% during the next 48 hours (p < 0.016 and p <0.001). Of 10 patients with an AT < 60% in the first 96 hours, 9 (90%) developed an infection later. Low levels of AT, thus, may be of help in predicting infection, outcome, or both in severely injured patients.