Introduction The administration of antithrombin III (ATIII) is useful in patients with congenital deficiency, but evidence for the other therapeutic indications of this drug is still uncertain. In Italy, the use of ATIII is very common in intensive care units (ICUs). For this reason we undertook an observational study to determine the pattern of use of ATIII in ICUs and to assess the outcome of patients given this treatment.

      Methods
      From 20 May to 20 July 2001 all consecutive patients admitted to ICUs in 20 Italian hospitals and treated with ATIII were enrolled. The following information was recorded from each patient: congenital deficiency, indication for use of ATIII, daily dose and duration of ATIII treatment, outcome of hospitalization (alive or dead). The outcome data of our observational study were compared with those reported in previously published randomized controlled trials (RCTs).


      Results
      Two hundred and sixteen patients were enrolled in the study. The clinical indications for using ATIII were sepsis (25.9%), disseminated intravascular coagulation (23.1%), and other clinical conditions (46.8%). At the end of the study, 65.3% of the patients were alive, 24.5% died and 10.2% were still in the hospital. Among the patients with sepsis (n = 56), 19 died during the observation period (33.9%; 95% confidence interval 22.1–47.5%).


      Discussion
      Our study described the pattern of use of ATIII in Italian hospitals and provided information on the outcome of the subgroup treated with sepsis. A meta-analysis of current data from RCTs, together with our findings, indicates that there is no sound basis for using this drug in ICU patients with sepsis.