Comparison of the Thrombotest with the Modified Quick Test
Drug-Induced Hypoprothrombinemia Countered with Phytonadione
Forty-five patients, given anticoagulant therapy with prothrombinopenic drugs, were given 10 mg. of phytonadione intravenously. Thrombotest prothrombin times and modified Quick-test prothrombin times were compared as indices for measuring the resulting increase in prothrombin times. These increases were similar generally for both tests. The thrombotest times were lower, approximately 0.5 to 0.67 of the comparable Quick-test times, and on several occasions, grossly inaccurate results were found with the thrombotest. Blood samples stored for 24 hours in Lusteroid tubes lost a significant reproducibility of thrombotest time. Therapeutic thrombotest-time levels are inadequate for acceptable hypoprothrombinemia as judged by the Quick-test times.
- © 1963 American Heart Association, Inc.