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    1. Morey A. Blinder, MD Division of Hematology Division of Laboratory Medicine

    2. Objectives Clinical aspects of bleeding Hematologic disorders causing bleeding Coagulation factor disorders Platelet disorders Approach to acquired bleeding disorders Hemostasis in liver disease Surgical patients Warfarin toxicity Approach to laboratory abnormalities Diagnosis and management of thrombocytopenia Drugs and blood products used for bleeding

    3. Objectives - I Clinical aspects of bleeding

    4. Clinical Features of Bleeding Disorders

    5. Petechiae

    6. Ecchymoses

    7. Objectives - II Hematologic disorders causing bleeding Coagulation factor disorders Platelet disorders

    8. Coagulation factor disorders Inherited bleeding disorders Hemophilia A and B vonWillebrands disease Other factor deficiencies Acquired bleeding disorders Liver disease Vitamin K deficiency/warfarin overdose DIC

    9. Hemophilia A and B

    10. Hemophilia Clinical manifestations (hemophilia A & B are indistinguishable) Hemarthrosis (most common) Fixed joints Soft tissue hematomas (e.g., muscle) Muscle atrophy Shortened tendons Other sites of bleeding Urinary tract CNS, neck (may be life-threatening) Prolonged bleeding after surgery or dental extractions

    11. Hemarthrosis (acute)

    12. Treatment of hemophilia A Intermediate purity plasma products Virucidally treated May contain von Willebrand factor High purity (monoclonal) plasma products Virucidally treated No functional von Willebrand factor Recombinant factor VIII Virus free/No apparent risk No functional von Willebrand factor

    13. Dosing guidelines for hemophilia A Mild bleeding Target: 30% dosing q8-12h; 1-2 days (15U/kg) Hemarthrosis, oropharyngeal or dental, epistaxis, hematuria Major bleeding Target: 80-100% q8-12h; 7-14 days (50U/kg) CNS trauma, hemorrhage, lumbar puncture Surgery Retroperitoneal hemorrhage GI bleeding Adjunctive therapy ?-aminocaproic acid (Amicar) or DDAVP (for mild disease only)

    15. Complications of therapy Formation of inhibitors (antibodies) 10-15% of severe hemophilia A patients 1-2% of severe hemophilia B patients Viral infections Hepatitis B Human parvovirus Hepatitis C Hepatitis A HIV Other

    16. Viral infections in hemophiliacs

    17. Treatment of hemophilia B Agent High purity factor IX Recombinant human factor IX Dose Initial dose: 100U/kg Subsequent: 50U/kg every 24 hours

    18. von Willebrand Disease: Clinical Features von Willebrand factor Synthesis in endothelium and megakaryocytes Forms large multimer Carrier of factor VIII Anchors platelets to subendothelium Bridge between platelets Inheritance - autosomal dominant Incidence - 1/10,000 Clinical features - mucocutaneous bleeding

    19. Laboratory evaluation of von Willebrand disease Classification Type 1 Partial quantitative deficiency Type 2 Qualitative deficiency Type 3 Total quantitative deficiency Diagnostic tests:

    20. Treatment of von Willebrand Disease Cryoprecipitate Source of fibrinogen, factor VIII and VWF Only plasma fraction that consistently contains VWF multimers DDAVP (deamino-8-arginine vasopressin) ? plasma VWF levels by stimulating secretion from endothelium Duration of response is variable Not generally used in type 2 disease Dosage 0.3 µg/kg q 12 hr IV Factor VIII concentrate (Intermediate purity) Virally inactivated product

    21. Vitamin K deficiency Source of vitamin K Green vegetables Synthesized by intestinal flora Required for synthesis Factors II, VII, IX ,X Protein C and S Causes of deficiency Malnutrition Biliary obstruction Malabsorption Antibiotic therapy Treatment Vitamin K Fresh frozen plasma

    22. Common clinical conditions associated withDisseminated Intravascular Coagulation Sepsis Trauma Head injury Fat embolism Malignancy Obstetrical complications Amniotic fluid embolism Abruptio placentae Vascular disorders Reaction to toxin (e.g. snake venom, drugs) Immunologic disorders Severe allergic reaction Transplant rejection

    23. Disseminated Intravascular Coagulation (DIC)Mechanism

    24. Pathogenesis of DIC

    25. Disseminated Intravascular CoagulationTreatment approaches Treatment of underlying disorder Anticoagulation with heparin Platelet transfusion Fresh frozen plasma Coagulation inhibitor concentrate (ATIII)

    26. Classification of platelet disorders Quantitative disorders Abnormal distribution Dilution effect Decreased production Increased destruction Qualitative disorders Inherited disorders (rare) Acquired disorders Medications Chronic renal failure Cardiopulmonary bypass

    27. Thrombocytopenia

    28. Features of Acute and Chronic ITP

    29. Incidence of adult ITP increases with age

    30. Initial Treatment of ITP

    31. Summary of case seriesAdults with ITP

    32. Long-term morbidity and mortalityin adults with ITP 134 patients with severe ITP studied for mean of 10.5 yrs CR and PR patients (85%) No increased mortality compared to control population Non-responders/maintenance therapy Increased morbidity due to ITP-related hospitalizations Increased mortality related equally to bleeding and infection

    33. Objectives - III Approach to acquired bleeding disorders Hemostasis in liver disease Surgical patients Warfarin toxicity

    34. Liver Disease and Hemostasis Decreased synthesis of II, VII, IX, X, XI, and fibrinogen Dietary Vitamin K deficiency (Inadequate intake or malabsortion) Dysfibrinogenemia Enhanced fibrinolysis (Decreased alpha-2-antiplasmin) DIC Thrombocytoepnia due to hypersplenism

    35. Management of Hemostatic Defects in Liver Disease Treatment for prolonged PT/PTT Vitamin K 10 mg SQ x 3 days - usually ineffective Fresh-frozen plasma infusion 25-30% of plasma volume (1200-1500 ml) immediate but temporary effect Treatment for low fibrinogen Cryoprecipitate (1 unit/10kg body weight) Treatment for DIC (Elevated D-dimer, low factor VIII, thrombocytopenia Replacement therapy

    36. Vitamin K deficiency due to warfarin overdoseManaging high INR values

    37. Vitamin K deficiency due to warfarin overdoseManaging high INR values in bleeding patients

    38. Approach to Post-operative bleeding Is the bleeding local or due to a hemostatic failure? Local: Single site of bleeding usually rapid with minimal coagulation test abnormalities Hemostatic failure: Multiple site or unusual pattern with abnormal coagulation tests Evaluate for causes of peri-operative hemostatic failure Preexisting abnormality Special cases (e.g. Cardiopulmonmary bypass) Diagnosis of hemostatic failure Review pre-operative testing Obtain updated testing

    39. Objectives - IV Approach to laboratory abnormalities Diagnosis and management of thrombocytopenia

    40. Laboratory Evaluation of BleedingOverview CBC and smear Platelet count Thrombocytopenia RBC and platelet morphology TTP, DIC, etc. Coagulation Prothrombin time Extrinsic/common pathways Partial thromboplastin time Intrinsic/common pathways Coagulation factor assays Specific factor deficiencies 50:50 mix Inhibitors (e.g., antibodies) Fibrinogen assay Decreased fibrinogen Thrombin time Qualitative/quantitative fibrinogen defects FDPs or D-dimer Fibrinolysis (DIC) Platelet function von Willebrand factor vWD Bleeding time In vivo test (non-specific) Platelet function analyzer (PFA) Qualitative platelet disorders and vWD Platelet function tests Qualitative platelet disorders

    41. Coagulation cascade KEY POINT: The efficacy/safety ratio for currently available therapies is less than satisfactory due to their ill-defined, multitargeted activity. New antithrombotic strategies are needed that offer an improved efficacy/safety profile compared with existing antithrombotic agents.1,2 Currently available antithrombotic agents include the heparins (UFH and Enoxaparin), vitamin K antagonists (warfarin), and direct thrombin inhibitors (hirudins).3–6 The most widely used agents, heparins and vitamin K antagonists, have a range of actions on various components of the coagulation cascade. This contributes to the unpredictable clinical responses associated with these agents.3–5 Other limitations of currently available antithrombotics include3–7 High incidence of serious adverse effects, particularly bleeding complications Routine monitoring of coagulation markers may be needed and represents a substantial burden in terms of time and costs Narrow therapeutic margin Limited effectiveness in preventing VTE Factor Xa inhibitors are a novel class of antithrombotic agents designed to selectively target only 1 core step in the coagulation cascade, leading to potent and targeted effectiveness.8 KEY POINT: The efficacy/safety ratio for currently available therapies is less than satisfactory due to their ill-defined, multitargeted activity. New antithrombotic strategies are needed that offer an improved efficacy/safety profile compared with existing antithrombotic agents.1,2 Currently available antithrombotic agents include the heparins (UFH and Enoxaparin), vitamin K antagonists (warfarin), and direct thrombin inhibitors (hirudins).3–6 The most widely used agents, heparins and vitamin K antagonists, have a range of actions on various components of the coagulation cascade. This contributes to the unpredictable clinical responses associated with these agents.3–5 Other limitations of currently available antithrombotics include3–7 High incidence of serious adverse effects, particularly bleeding complications Routine monitoring of coagulation markers may be needed and represents a substantial burden in terms of time and costs Narrow therapeutic margin Limited effectiveness in preventing VTE Factor Xa inhibitors are a novel class of antithrombotic agents designed to selectively target only 1 core step in the coagulation cascade, leading to potent and targeted effectiveness.8

    42. Laboratory Evaluation of the Coagulation Pathways

    43. Pre-analytic errors Problems with blue-top tube Partial fill tubes Vacuum leak and citrate evaporation Problems with phlebotomy Heparin contamination Wrong label Slow fill Underfill Vigorous shaking Biological effects Hct =55 or =15 Lipemia, hyperbilirubinemia, hemolysis Laboratory errors Delay in testing Prolonged incubation at 37°C Freeze/thaw deterioration

    44. Initial Evaluation of a Bleeding Patient - 1

    45. Initial Evaluation of a Bleeding Patient - 2

    46. Initial Evaluation of a Bleeding Patient - 3

    47. Initial Evaluation of a Bleeding Patient - 4

    48. Coagulation factor deficienciesSummary Sex-linked recessive ? Factors VIII and IX deficiencies cause bleeding Prolonged PTT; PT normal Autosomal recessive (rare) ? Factors II, V, VII, X, XI, fibrinogen deficiencies cause bleeding Prolonged PT and/or PTT ? Factor XIII deficiency is associated with bleeding and impaired wound healing PT/ PTT normal; clot solubility abnormal ? Factor XII, prekallikrein, HMWK deficiencies do not cause bleeding

    49. Thrombin Time Bypasses factors II-XII Measures rate of fibrinogen conversion to fibrin Procedure: Add thrombin with patient plasma Measure time to clot Variables: Source and quantity of thrombin

    50. Causes of prolonged Thrombin Time Heparin Hypofibrinogenemia Dysfibrinogenemia Elevated FDPs or paraprotein Thrombin inhibitors (Hirudin) Thrombin antibodies

    51. Classification of thrombocytopenia Associated with bleeding Immune-mediated thrombocytopenia (ITP) Most others Associated with thrombosis Thrombotic thrombocytopenic purpura Heparin-associated thrombocytopenia Trousseau’s syndrome DIC

    52. Approach to the thrombocytopenic patient History Is the patient bleeding? Are there symptoms of a secondary illness? (neoplasm, infection, autoimmune disease) Is there a history of medications, alcohol use, or recent transfusion? Are there risk factors for HIV infection? Is there a family history of thrombocytopenia? Do the sites of bleeding suggest a platelet defect? Assess the number and function of platelets CBC with peripheral smear Bleeding time or platelet aggregation study

    54. Bleeding time and bleeding 5-10% of patients have a prolonged bleeding time Most of the prolonged bleeding times are due to aspirin or drug ingestion Prolonged bleeding time does not predict excess surgical blood loss Not recommended for routine testing in preoperative patients

    55. Objectives - V Drugs and blood products used for bleeding

    56. Treatment Approaches tothe Bleeding Patient Red blood cells Platelet transfusions Fresh frozen plasma Cryoprecipitate Amicar DDAVP Recombinant Human factor VIIa

    57. RBC transfusion therapyIndications Improve oxygen carrying capacity of blood Bleeding Chronic anemia that is symptomatic Peri-operative management

    58. Red blood cell transfusionsSpecial preparation

    59. Red blood cell transfusionsAdverse reactions

    60. Red blood cell transfusionsAdverse reactions

    61. Transfusion-transmitted disease

    62. Platelet transfusions Source Platelet concentrate (Random donor) Pheresis platelets (Single donor) Target level Bone marrow suppressed patient (>10-20,000/µl) Bleeding/surgical patient (>50,000/µl)

    63. Platelet transfusions - complications Transfusion reactions Higher incidence than in RBC transfusions Related to length of storage/leukocytes/RBC mismatch Bacterial contamination Platelet transfusion refractoriness Alloimmune destruction of platelets (HLA antigens) Non-immune refractoriness Microangiopathic hemolytic anemia Coagulopathy Splenic sequestration Fever and infection Medications (Amphotericin, vancomycin, ATG, Interferons)

    64. Fresh frozen plasma Content - plasma (decreased factor V and VIII) Indications Multiple coagulation deficiencies (liver disease, trauma) DIC Warfarin reversal Coagulation deficiency (factor XI or VII) Dose (225 ml/unit) 10-15 ml/kg Note Viral screened product ABO compatible

    65. Cryoprecipitate Prepared from FFP Content Factor VIII, von Willebrand factor, fibrinogen Indications Fibrinogen deficiency Uremia von Willebrand disease Dose (1 unit = 1 bag) 1-2 units/10 kg body weight

    66. Hemostatic drugsAminocaproic acid (Amicar) Mechanism Prevent activation plaminogen -> plasmin Dose 50mg/kg po or IV q 4 hr Uses Primary menorrhagia Oral bleeding Bleeding in patients with thrombocytopenia Blood loss during cardiac surgery Side effects GI toxicity Thrombi formation

    67. Hemostatic drugsDesmopressin (DDAVP) Mechanism Increased release of VWF from endothelium Dose 0.3µg/kg IV q12 hrs 150mg intranasal q12hrs Uses Most patients with von Willebrand disease Mild hemophilia A Side effects Facial flushing and headache Water retention and hyponatremia

    68. Recombinant human factor VIIa (rhVIIa; Novoseven) Mechanism Direct activation of common pathway Use Factor VIII inhibitors Bleeding with other clotting disorders Warfarin overdose with bleeding CNS bleeding with or without warfarin Dose 90 µg/kg IV q 2 hr “Adjust as clinically indicated” Cost (70 kg person) - $1 per µg ~$5,000/dose or $60,000/day

    69. Approach to bleeding disordersSummary Identify and correct any specific defect of hemostasis Laboratory testing is almost always needed to establish the cause of bleeding Screening tests (PT,PTT, platelet count) will often allow placement into one of the broad categories Specialized testing is usually necessary to establish a specific diagnosis Use non-transfusional drugs whenever possible RBC transfusions for surgical procedures or large blood loss