First day dynamic changes in antithrombin III activity after supplementation have a predictive value in critically ill patients.

To evaluate the changes in the antithrombin III (antithrombin) values after initial supplementation to predict outcome in critically ill patients, we conducted a retrospective study. All consecutive patients admitted to the intensive care unit (ICU) and treated with antithrombin were enrolled in the study. Initial doses of 1,500 IU or 30 IU/kg antithrombin concentrates were administered over an hour. The clinical backgrounds of the patients were collected from computer-based records. Serial data of antithrombin were collected from the first day of administration (Day 0) to days 1-4. The patients were subdivided into two groups based on whether they demonstrated an increased antithrombin activity of more than 60% on the first day after the initial supplementation (responders) or not (nonresponders). Four hundred thirty-five patients were enrolled in the present study. Two hundred eighty-eight patients could achieve an antithrombin activity of more than 60%. The outcome was significantly different between the two groups. A logistic regression analysis revealed the day 1 antithrombin level and an initial increase of less than 60% after supplementation to be independently associated with ICU mortality. We also found a significant increase in the platelet counts and fibrinogen levels, and a decrease in the disseminated intravascular coagulation (DIC) scores for the responders. In conclusion, our findings demonstrated the first-day dynamic change in antithrombin activity, and not the basal level, to be able to predict critically ill patient death. This dynamic change was associated with an improvement in the platelet counts, fibrinogen levels, and the DIC score.