The effect of major surgery, low doses of heparin and thromboembolism on plasma antithrombin. Comparison of immediate thrombin inhibiting capacity and the antithrombin III content

Development and Clinical Use of Automated Synthetic Substrate Methods for the Evaluation of Coagulation and Fibrinolysis

“…A synthetic substrate assay for AT III was first reported by Blömback et al 13 in 1974 using a chromogenic substrate for thrombin, S-2160. In 1975, Bergström and Lahnborg 11 developed an automated test using S-2160 and the LKB 8600 reaction rate analyzer. 0degard and Abildgaard 52 reported an antifactor Xa assay with heparin included in the test and measurement of residual Factor Xa with a sensitive Factor Xa substrate, S-2222.…”

Photometric Assay of Antithrombin III with a Chromogenic Substrate

“…The usefulness of the chromogenic substrate S-2160 for the assay of anti thrombin III could be demonstrated recently by various authors [3][4][5]12]. There were, however, considerable differences in the methods which also resulted in differences of reproducibility.…”

“…It was, therefore, obvious to use S-2160 for determinations of thrombin activity and thrombin inhibition by antithrombins. Such experiments were done by various authors [3][4][5]12]. In the methods applied there is, however, considerable difference in the con centration of thrombin, the quantity of plasma for the test, the mode of defibrination and the question of the addition of heparin.…”

Disseminated Intravascular Coagulation: Evaluation of Therapeutic Approaches

“…It must be recognized, however, that in vivo action of heparin also depends on the availability of antithrombin III. This may be decreased in several clinical conditions, such as septicemia, pancreatitis, metastatic carcinoma, acute hepatic failure, liver cirrhosis, and also may be progressively consumed during DIC [8,31,35,73,104]. Heparin may furthermore be neutralized by the release of platelet factor 4 from platelets disintegrating during DIC [101,159].…”

“…In view of these observations it seems difficult to accurately predict the dose of heparin required to manage an individual patient with acute DIC. There is, of course, the possibility that relatively small doses of heparin can control intravascular clotting by inhibition of factor X a [8,161].…”