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Hematology Emergencies. Jack Lazerson, M.D. Professor Emeritus Department of Pediatrics University of Nevada School of Medicine. Clinical emergencies : diagnosis and treatment. The following is an outline, for discussion purposes, that
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Hematology Emergencies Jack Lazerson, M.D. Professor Emeritus Department of Pediatrics University of Nevada School of Medicine
Clinical emergencies: diagnosis and treatment The following is an outline, for discussion purposes, that will deal with common problems presenting to the physician as “medical emergency issues”. A. chief complaint: 1. “bruising for past 24-48 hours” 2. “epistaxsis that won’t stop” 3. “bleeding from ______” e.g. hematuria, melena, hematochiza (4. “circumcision bleeding”)
1. Clinical history including family history a. Onset and duration of symptom b. Other symptoms/illnesses and medications 2. Physical examination a. Type and area of hemorrhagic lesion(s) b. Other physical findings
3. Minimum laboratory evaluation a. Primary mechanism - PFA 100 or Simplate II Bleeding Time Platelet Count /MPV/Blood Smear b. Secondary mechanism - aPTT/PT/TT (with 1:1 correction study if test abnormal)
Mechanism - current concepts (cell-based model) a. Intiation b. Amplification (Priming) c. Propagation - (“classic” model”) a. Primary -platelet/vessel wall interation b. Secondary -fibrin clot formation c. “Tertiary” - fibrin stabilization d. “Quatinery” - Fibrinolysis
Note that these tests are screening tests and with the history and physical examination can provide the physician with a presumptive diagnosis in order to allow for initial treatment, if necessary, before a definitive diagnosis can be established.
Common Disorders 1. I.T.P. 2. Thrombocytopenia (non immune) 3. Thrombopathies 4. von Willebrand’s Disease 5. Coagulation Factor Deficiencies 6. Thrombosis
Common Disorders and Treatment 1. I.T.P. a. Steroids b. I.V. Gamma Globulin c. Anti-D d. Rituxomab e. Anit-CD40 ligand
2. Thrombocytopenia (non-immune) a. platelets b. factor VIIa c. other (E-ACA) 3. Thrombopathies a. platelets b. cryoprecipitate c. DDAVP (Stimate) d. estrogens
4. von Willebrand’s Disorder a. Cryoprecipitate b. Factor concentrate (Humate P) c. DDAVP (Stimate)
5. Coagulation Factor Deficiencies a. Plasma b. Cryoprecipitate c. Factor concentrates (VIII, IX, VIIa)
Thrombosis 1. Risk Factors: Epidemiological - Aging Surgery Oral contraceptives (Others, including cancer, pregnancy, etc. Genetic Predisposition - heterozygote homozygote
2. Mechanism of Inhibitors: Vessel wall Platelet Procoagulants Fibrinolytic “Other”
3. Laboratory Assays: Protein based DNA based Thrombomodulin - Heparans Prostacyclin - Nitrous Oxide Platelet Glycoproteins Factor V Leiden (APC Resistance) Prothrombin 20210A Mutation Tissue Factor Pathway Inhibitor Antithrombin 3 Protein C/S Fibrinogen Plasminogen Plasminogen Activator Inhibitor 1 Homocysteine Antiphospholipid Antibodies (L.A. & A.C.L.A.) Procoagulants
4. Treatment: Anticoagulants Heparin - unfractionated vs low molecular weight Coumadin “Others” - direct antithrombin inhibitors e.g. hiruidin, agatroban Antiplatelet agents Aspirin Clopidogrel Monoclonal antibodies Folic acid
Advances in Blood Component Therapy Jack Lazerson, M.D. Professor Emeritus Department of Pediatrics University of Nevada School of Medicine
Anemia Chief complaint: 1. “looks pale” 2. “breathing hard” The minimum evaluation includes the history and physical examination and baseline laboratory studies. The CBC must include an absolute reticulocyte count and peripheral blood smear. The focused question is whether one needs to transfuse and therefore what are the indications for transfusion in an anemic patient?
Transfusion of red blood cells should be reserved for the following: 1. Acute blood loss with impending hypotension 2. To prevent or reverse tissue hypoxia (increase organ perfusion) (3. Anticipation of progressive anemia) Note that there is no arbitrary level of hemoglobin or hematocrit as an indication for transfusion. Packed red blood cells are the product of choice with the notation that CMV negative, washed, leukoreduced and irradiated cells may be indicated.
Red Blood Cell Transfusions 1. Indications Acute Blood Loss Chronic Transfusion Theory 2. Packed Red Blood Cells Leukoreduction of RBCs Irradiation of RBCs
Erythropoietin Stimulates a. proliferation b. differentiation Requires adequate iron intake and stores
Chief complaint: 1. “bruising for past 24-48 hours” 2. “epistaxsis that won’t stop” 3. “bleeding from ______” e.g. hematuria, melena, hematochiza
3. Minimum laboratory evaluation a. Primary mechanism - PFA 100 or Simplate II Bleeding Time Platelet Count /MPV/Blood Smear b. Secondary mechanism - aPTT/PT/TT (with 1:1 correction study if test abnormal)
Platelet Transfusions 1. Indications 2. Dosage 1 unit/10 kgm
Thrombocytopenia (non-immune) a. platelets b. factor VIIa c. other (E-ACA) Thrombopathies a. platelets b. cryoprecipitate c. DDAVP (Stimate) d. estrogens
Blood Coagulation Factors 1. Plasma 2. Factor VIII 3. Factor IX 4. vW Factor 5. Factor VIIa
von Willebrand’s Disorder a. Cryoprecipitate b. Factor concentrate (Humate P) c. DDAVP (Stimate)
VIDEO Part I
Apheresis 1. Manual 2. Automated a. Continuous b. Discontinuous