Substitution therapy with an antithrombin III concentrate in shock and DIC.

In 15 patients admitted to the Intensive Care Unit for shock and with signs of DIC, Antithrombin III (AT III) was substituted. Immediately after the first blood sampling, 1,000 units of AT III was given. This was followed by 500 units AT III after 24 h and after 48 h. A continuous dose of heparin of between 250 and 500 I.U./h was simultaneously given. The following results were obtained: The activity of AT III on admission of 63 +/- 19% increased to 83 +/- 17% 30 min after the initial substitution. There was a clear difference between the recovery of the substituted AT III in acute DIC and in patients in a steady state. AT III recovered in circulation was 47 +/- 15% in the former group but 83 +/- 16% in the latter cases. One unit of AT III per kg body weight increased AT III activity in circulation by 1% in acute DIC but by 1.8% in a steady state. The average half life of the substituted AT III was 4.4 +/- 1.6 h in acute DIC and was 20.2 +/- 4.1 h when the patients were in a steady state.