Measures of Clotting Cascade



- See: clotting cascade

- Prothrombin Time (PT) 11.5-13.5 sec
    - PT is used to evaluate extrinsic clotting mechanism: I, II, V, VII, X;
    - Prolonged:
         - coumadin;
         - vit K deficiency;
         - fat malabsorption
         - liver dz

- Partial Thromboplastin TIME (PTT) 27-38 sec;
    - tests intrinsic & common coag pathways (XII, XI, IX, VIII, X, V, II);
    - prolonged: heparin and any defect in the intrinsic clotting mechanism hemophilia A & B and lupus anticoagulant



In vivo study of bleeding time and arterial hemorrhage in hypothermic versus normothermic animals.

Effect of laboratory variation in the prothrombin-time ratio on the results of oral anticoagulant therapy.



Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Thursday, September 6, 2012 10:20 am