The Australasian Reference Thromboplastin: I. A study in bleeding patients

Area of Science:

• Hematology
• Pharmacology

Background:

• Long-term warfarin therapy requires careful monitoring to prevent bleeding.
• Assessing coagulation status is vital for managing oral anticoagulation.
• Hemorrhagic complications are a significant concern in patients on warfarin.

Purpose of the Study:

• To evaluate the effectiveness of different thromboplastin reagents in monitoring warfarin therapy.
• To identify reliable indicators for predicting bleeding in patients receiving warfarin.
• To assess the correlation between coagulation test results and bleeding events.

Main Methods:

• Patients on long-term warfarin therapy were divided into bleeding (n=17) and non-bleeding (n=13) groups.
• Coagulation tests performed included prothrombin time, activated partial thromboplastin time, thrombin time, and skin bleeding time.
• Assays for factors II, VII, IX, and X, platelet count, and liver function tests were conducted.
• Three thromboplastic reagents, including Australasian Reference Thromboplastin and rabbit brain thromboplastin, were used for comparison.

Main Results:

• Australasian Reference Thromboplastin demonstrated higher sensitivity to warfarin-induced coagulation defects compared to rabbit brain thromboplastin.
• Factor II levels, measured by the one-stage method, served as a valuable independent indicator of anticoagulation intensity.
• Factor II levels showed a strong correlation with the occurrence of bleeding events.

Conclusions:

• Australasian Reference Thromboplastin is more effective in detecting warfarin's anticoagulant effects, aiding in the prevention of hemorrhagic complications.
• Monitoring Factor II levels is a reliable method for assessing oral anticoagulation intensity and predicting bleeding risk.
• Optimized monitoring strategies can enhance patient safety during long-term warfarin treatment.