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M6 13-005
Exam 14: Coagulation D/O
Term | Definition |
---|---|
Hemostasis | a body process that arrests the flow of blood and prevents hemorrhage. |
Preventing hemorrhage consists of three actions | a vessel spasm, followed by a platelet plug formation and lastly a clot formation. |
The clotting cascade is stimulated after | damage to a blood vessel or massive tissue damage and exists to maintain circulating blood in the vessels after an injury. |
Three steps of hemostasis | Vessel spasm. Platelet plug. Clotting cascade. |
Vessel spasm | Contraction of blood vessel immediately after damage to control the loss of blood. Effect lasts for about 30 minutes. |
Platelet plug | Platelets become activated (become sticky), clump together and adhere to the damaged blood vessel. Controls blood loss if vessel break is small. |
Clotting cascade | Damage to blood vessels or tissue causes the release of substances that activate the clotting cascade. Prothrombin is converted to thrombin. Thrombin degrades fibrinogen into fibrin. Fibrin threads maintain the stability of a clot. |
Thrombocytopenia | Platelet disorder exhibiting a deficiency of the number of circulating platelets or change in the function of platelets which alters the process of coagulation. |
Normal Platelet Count | Normal is 150,000 to 450,000/mm3 |
Thrombocytopenia: Platelets | platelets is reduced below 100,000/mm3 |
Thrombocytopenia: Causes | Decreased production. Decreased platelet survival. Altered platelet function/↑ platelet consumption. Platelet sequestration can occur in the spleen. Thrombocytopenia purpura. |
Thrombocytopenia: Decreased production from | a) Aplastic anemia. b) Leukemia. c) Tumors and chemotherapy. |
Thrombocytopenia: Decreased platelet survival | a) Antibody destruction. b) Infection or viral invasion. |
thrombocytopenia purpura | a) Usually idiopathic, called ITP. b) Acute form is found most commonly in children. c) Chronic form is found in all ages, but most commonly in women. d) May be drug induced. |
Thrombocytopenia: Clinical manifestation | (a) Petechiae- occur only in platelet disorder. (b) Ecchymoses. (c) Severity correlates with the platelet count. (d) Significant bleeding can occur with platelet count < 20,000/mm3. (e) Spontaneous bleeding can occur with platelet count < 5,000/m |
Thrombocytopenia: Subjective data | 1) Recent viral infection. 2) Current use of medications. 3) Extent of alcohol ingestion. 4) History of bleeding tendencies. |
Thrombocytopenia: Objective Data | 1) Petechiae and ecchymoses. 2) Epistaxis and gingival bleeding. 3) Signs of increased intracranial pressure caused by cerebral hemorrhage. |
Thrombocytopenia: CBC shows | shows decreased platelets |
Thrombocytopenia: Peripheral blood smear | to identify abnormalities in all cell lines. |
Thrombocytopenia: Bone marrow aspiration | identify presence of immature platelets or primary bone marrow abnormality (neoplastic invasion, aplastic anemia). |
Thrombocytopenia: Medical Management | Corticosteroid therapy. Intravenous gamma globulin or immunosuppressive drugs. Transfusion of platelets with bleeding. Plasmapheresis. Splenectomy with chronic condition. |
Plasmapheresis | removes antibodies (which degrade platelets) produced by the autoimmune process. |
Hemophilia | a hereditary clotting factor defect characterized by a decrease/lack of clotting factors. |
Hemophilia A | the most common type (85% of cases)- Antihemophilic factor VIII is absent. Factor VIII is essential for conversion of prothrombin to thrombin. |
Hemophilia B (Christmas Disease) | deficiency of factor IX-results in a lack of thromboplastin. |
Hemophilia: Clinical Manifestations | Internal or external hemorrhage with large ecchymoses into tissues- muscles show deformity and joints become ankylosed (immobile). Hemathrosis. Pain, erythema & fever w/ hemarthrosis. Excessive bleed from small cuts and small dental procedures. |
Hemarthrosis | bleeding into joints- hallmark of severe disease). |
Hemophilia: Subjective data | 1) Patient and family history of ecchymoses and hemorrhage. 2) Pain associated with joint movement. |
Hemophilia: Objective data | 1) Presence of blood in subcutaneous tissues, urine, or stool. 2) Edematous or immobile joints. |
Hemophilia: Diagnostic Tests | Deficiency or absence of factors VIII and/or IX. Serum blood tests reveal a normal PLT count, PT and INR. Partial thromboplastin time (PTT) is prolonged. Hemoglobin/hematocrit may be normal or decreased dependent on bleeding. |
Hemophilia: Transfusion and administration of factors VIII and IX. | 1) Prophylactic or to control hemorrhage. 2) Concern over viral transmission (i.e. HIV) with blood products. 3) Now using recombinant (genetically engineered) Factor VIII. |
Disseminated Intravascular Coagulation (DIC) | Grave coagulopathy resulting from the over stimulation of clotting and anti-clotting processes in response to disease or injury. Mortality reaches 80-90%. |
Disseminated Intravascular Coagulation: Part of the process | Secondary process resulting in the over stimulation of normal clotting (thrombosis) and anticlotting (fibrinolysis) processes due to a primary medical process (i.e. sepsis). |
Disseminated Intravascular Coagulation: Clot Formation | Massive stimulation of the clotting cascade results in the formation of clots in the microvasculature. Clotting factors are depleted during wide spread clotting within microvasculature, thrombosis where not needed, & clots can't form where needed. |
Causes of DIC: Obstetrical | Abruptio placenta, acute fatty liver of pregnancy, amniotic fluid embolism, hydatidiform mole, retained dead fetus, retained placenta and toxemia. |
Causes of DIC: Neoplastic | Acute leukemias, adenocarcinomas, carcinomas, pheochromocytoma (tumor of the adrenal glands), polycythemia vera, and sarcomas. |
Causes of DIC: Hematological | Blood transfusion reactions, sickle cell crisis, thalassemia major. Commonly found in infants (anemia, fever, failure to thrive, and splenomegaly). |
Causes of DIC: Trauma | Fat emboli, burns, heat stroke, snake bite, multiple injury, and transplant surgeries. |
Causes of DIC: Other | Acute infection process/sepsis, anaphylaxis, cirrhosis, glomerulonephritis, hepatitis, purpura, shock, systemic lupus erythematosus, ASA poisoning. |
DIC: Clinical Manifestations | Bleeding is noted from 3 unrelated sites (may be occult or profuse). -Mucous membranes. -Venipunctures. -GI and urinary tract. -Orifices. -Lungs, resulting in hemoptysis and dyspnea. -Diaphoresis with cold and mottled digits. |
DIC: Subjective Data | 1) Bleeding complaints (mucous membranes, hematuria, melena, and hemoptysis). 2) Indications of end organ damage (i.e. dyspnea, chest pain, decreased urine output). 3) Complaints of bone and joint pain. 4) Complaint of visual changes. |
DIC: Objective Data | Occult blood or obvious bleeding. Purpura on chest & ABD Petechiae of skin & mucosa. GI bleeding, ABD tenderness. Hematuria. Pulmonary embolism, pulmonary edema. Hypotension, tachycardia, decreased peripheral pulses. |
DIC: Diagnostic Tests | (a) DIC panel- shows prolonged PT/PTT, positive D-dimer (b) Decreased fibrinogen and decreased clotting factors. |
DIC: Medical Management | Correct underlying cause. Volume replacement. Vitamin K. Heparin Therapy. Aminocapaproic acid. Anti-thrombin III |
DIC: Vitamin K | Promotes liver synthesis of clotting factors. |
DIC: Heparin Therapy | Low dose (<500 units/hour), though controversial, prevents thrombosis. |
DIC: Aminocaproic Acid | Fibrinolysis inhibitor |
DIC: Anti-thrombin III | Thrombosis inhibitor |
Medications that may have a thrombocytopenic effect | Aspirin. Digitalis derivatives. Furosemide. NSAIDs. Oral hypoglycemics. Penicillins. Quinidine. Rifampicin. Sulfonamides. Thiazides. Rantitidine. |
von Willebrand's Disease | inherited bleeding disorder characterized by abnormally slow coagulation of blood and spontaneous episodes of GI bleeding, epistaxis, and gingival bleeding caused by a mild deficiency of factor VIII. |
von Willebrand's Disease: Common occurrence | It is common during post partum periods, as menorrhagia, and after surgery or trauma. |
von Willebrand's Disease: Treatment | (1) Cryoprecipitate transfusion containing factors VIII, recombinant factor VIII, fibrinogen and/or fresh plasma. (2) Desmopressin (DDAVP) is becoming the treatment choice of mild hemophilia. |