Disorders of hemostasis


 * Haemostasis – stoppage of bleeding, takes place at three levels:
 * primary hemostasis – vessel vasoconstriction, platelet aggregation and platelet degranulation,
 * secondary hemostasis – hemocoagulation,
 * fibrinolysis – dissolution of the thrombus.
 * Disorders of hemostasis are the result of an imbalance between pro- and anti-coagulation factors, they can be twofold:
 * hemorrhagic diatheses - bleeding,
 * thromboembolic disease – thrombophilic conditions (Thrombosis and Embolism).

Hemorrhagic diatheses

 * Disorders of primary hemostasis ,
 * Vasculopathy (vasculitis, congenital connective tissue disorders, vitamin C deficiency)
 * Thrombocytopenia (autoimmune – ITP, TTP, with hypersplenism)
 * Thrombocytopathy.
 * Disorders of secondary hemostasis
 * congenital (lack of one factor) – hemofilie A (VIII), hemofilie B (IX),
 * afibrinogenemia,
 * acquired (mostly several coagulation factors are missing) – Vitamin K, Liver insufficiency.

Thrombophilic conditions

 * Congenital – defective hemocoagulation or fibrinolytic factors
 * Leiden Mutation (factor V mutation),
 * factor II mutation,
 * deficiency of antithrombin III, proteins C and S, Hyperhomocysteinemia.
 * Acquired – ( Virchow's trias ), these are actually risk factors for phlebothrombosis:
 * stasis (postoperative period, postpartum period, pregnancy),vascular wall damage (injuries, burns, varicosities, Sepsis, post-thrombotic syndromes),
 * blood abnormalities (pregnancy, oral contraceptives, malignancies,Nephrotic syndrome,trauma, burns, infections),
 * the main risk factors are age (over 40) and gender (women – estrogens, contraceptives), as well as smoking and Obesity.

Hemocoagulation examination

 * INR (formerly Quick, PT) - external system, to control warfarinization, norm 0.8-1.2.
 * APTT – internal system, for checking heparinization, standard 30–45 s.
 * TT thrombin time) – the last phase of coagulation (thrombin catalyzing the conversion of fibrinogen to fibrin), the norm is 10–20 s.
 * Euglobulin fibrinolysis – dissolution of fibrin clot in euglobulin plasma, standard 120–240 min.
 * FDP, D-dimers .
 * Fibrinogen – norm 2–4 g/l.

Overview of antithrombotic treatment

 * Anticoagulants – act against the formation of a thrombus,
 * direct (they inactivate the coagulation factors present) heparin (UFH), LMWH
 * indirect (acts against the synthesis of coagulation factors)- warfarin, ethyl biscum acetate (Pelentan),
 * Fibrinolytics – they dissolve an already formed thrombus - both venous and arterial
 * streptokinase, urokinase,
 * rt-PA (alteplase)... "Actilyse"
 * Antiaggregant - acts against the aggregation of platelets (prevention of the formation of a platelet thrombus - mainly as a prevention of arterial thrombosis, not as a prevention of deep vein thrombosis)
 * ASA, dipyridamole, ticlopidine, clopidogrel, abciximab, pentoxifylline.

Antidote

 * Protamine - the antidote of heparin.
 * Vitamin K –antidote to coumarin derivatives (warfarin).
 * Aprotinin, aminocaproic acid – an antidote to fibrinolytics.

related articles

 * Bleeding conditions (pediatrics) • Hemorrhagic diatheses (pathology) • Hereditary coagulopathy • Acquired coagulopathy • Thrombocytopathy
 * Hemostasis • Hemocoagulation • Examination of blood coagulation • Examination of bleeding