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IM - PLATELET DISORDERS---DISORDERS OF COAGULATION

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tonystep1's version from 2017-08-02 05:47

PLATELET DISORDERS CLINICAL FEATURES

Question Answer
Thrombocytopenial. Cutaneous bleeding: petechiae (most common in dependent areas) , ecchymoses at sites of minor trauma 2. Mucosal bleeding: epistaxis, menorrhagia, hemoptysis, bleeding in GI and genitourinary tracts 3. Excessive bleeding after procedures or surgery 4. Intracranial hemorrhage and heavy GI bleeding can be life-threatening and occur when platelet levels are severely low. 5 . Unlike coagulation disorders (e.g. , hemophilia) , heavy bleeding into tissues and joints (hemarthroses, hematomas) is not seen in thrombocytopenia
Immune Thrombocytopenic Purpura UTP)l . Petechiae and ecchymoses on the skin 2. Bleeding of the mucous membranes 3. No splenomegaly
Thrombotic Thrombocytopenic Purpura (TTP)l. Hemolytic anemia (microangiopathic) 2. Thrombocytopenia 3. Acute renal failure (mild) 4. Fever 5. Fluctuating, transient neurologic signs-can range from mental status change to hemiplegia
Bernard·Soulier SyndromeAutosomal recessive disease // On peripheral blood smear, platelets are abnormally large. // Platelet count is mildly low. // Disorder of platelet adhesion (to subendothelium) due to deficiency of platelet glycoglycoprotein GPib-IX
Glanzmann's ThrombastheniaAutosomal recessive disease // Bleeding time is prolonged // Platelet count is normal // Disorder of platelet aggregation due to deficiency in platelet glycoprotein GPIIb-Illa
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PLATELET DISORDERS DIAGNOSIS

Question Answer
Thrombocytopenial. CBC-platelet count 2. Bleeding time, prothrombin time (PT), partial thromboplastin time (PTT) 3. To determine the cause of thrombocytopenia, the following may be helpful: examination of peripheral blood smear, bone marrow biopsy.
Immune Thrombocytopenic Purpura ITP)l. The platelet count is frequently less than 20,000. The remainder of the blood count is normal (unless significant bleeding has occurred, in which case the Hb!Hct is decreased and the reticulocyte count is increased) . 2. Peripheral smear shows decreased platelets. 3. Bone marrow aspiration shows increased megakaryocytes. 4. There is an increased amount of platelet-associated IgG.
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DISORDERS OF COAGULATION CLINICAL FEATURES

Question Answer
von Willebrand's Disease (vWD)Autosomal dominant////// l. Cutaneous and mucosal bleeding-epistaxis, easy bruising, excessive bleeding from scratches and cuts, gingival bleeding 2. Menorrhagia (affects more than 50% of women with vWD) 3. GI bleeding is possible
Hemophilia AX-linked recessive disorder /// Caused by deficiency or defect of factor VIII coagulant protein /// 1. . Hemarthrosis a. Knees are the most common site, but any joint can be involved. b. Progressive joint destruction can occur secondary to recurrent hemarthroses.2. Intracranial bleeding 3. Intramuscular hematomas 4. Retroperitoneal hematomas 5. Hematuria or hemospermia
Hemophilia BX-linked recessive disorder ///Caused by deficiency of factor IX/// 1. . Hemarthrosis a. Knees are the most common site, but any joint can be involved. b. Progressive joint destruction can occur secondary to recurrent hemarthroses.2. Intracranial bleeding 3. Intramuscular hematomas 4. Retroperitoneal hematomas 5. Hematuria or hemospermia
Disseminated Intravascular Coagulation (DIC)Most common in critically ill patients (in ICU) /// l. Bleeding tendency (more common in acute cases) a. Superficial hemorrhage (ecchymoses, petechiae, purpura) b. Bleeding from GI tract, urinary tract, gingival or oral mucosa c. Oozing from sites of procedures, incisions, and so on Thrombosis-occurs most often in chronic cases. End-organ infarction may develop; all tissues are at risk, especially the CNS and kidney
Vitamin K DeficiencySeveral clotting factors depend on vitamin K as a cofactor in their synthesis by the liver (factors II, VII, IX, and X; protein C and S). /// l. Hemorrhage-Serious bleeding can develop. PT is initially prolonged (factor VII has the shortest half-life) . PTT prolongation follows (as other factors diminish)
Coagulopathy of Liver DiseaseAll clotting factors are produced by the liver (except vWF ) Abnormal bleeding-GI bleeding is the most common, primarily due to varices secondary to portal hypertension, but exacerbated by the coagulopathy.// Prolonged PT and PIT (especially PT)
Inherited Hypercoagulable Statesl. Venous thromboembolism (deep venous thrombosis [DVT] and pulmonary embolism [PE ] ) are the most common sequelae. Such hypercoagulable disorders are usually not diagnosed until the patient has had several episodes of DVT or PE.
Causes of Inherited Hypercoagulable StatesAntithrombin (AT) Ill deficiency // Antiphospholipid antibody syndrome // Protein C deficiency // Protein S deficiency // Factor V Leiden (activated protein C resistance) // Prothrombin gene mutation // Hyperhomocystinemia
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Laboratory Findings for Bleeding Disorders

Question Answer
NL Platelet Count // NL Bleeding Time // NL PT // Prolonged PTTHemophilia
NL Platelet Count // Increased Bleeding Time // NL PT // Prolonged PTTvWD
Decreased Platelet Count // Increased Bleeding Time // NL PT // NL PTTITP or TTP
Decreased Platelet Count // Decreased Bleeding Time // Decreased PT // Decreased PTTDIC
NL or Decreased Platelet Count // NL Bleeding Time // NL PT // Prolonged PTTHeparin
NL Platelet Count // NL Bleeding Time // Prolonged PT // NL PTTWarfarin
NL Platelet Count // NL Bleeding Time // Prolonged PT // Prolonged PTTLiver Disease
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TREATMENT FOR BLEEDING DISORDERS

Question Answer
von Willebrand's Disease (vWD) Type Il. DDAVP (desmopressin)-induces endothelial cells to secrete vWF /// Factor VIII concentrates (containing high-molecular-weight vWF) a. Give to all patients with vWD (any type) after major trauma or during surgery
von Willebrand's Disease (vWD) Type II or III Factor VIII concentrates (containing high-molecular-weight vWF) // Recommended for type 3 vWD (and type 2 patients not responsive to DDAVP)
von Willebrand's Disease (vWD) precautionsCryoprecipitate is not recommended as treatment for vWD because it carries the risk of viral transmission /// Avoid aspirin/NSAIDs (exacerbate bleeding tendency) .
Hemophilia A Acute hemarthrosisa. Analgesia (codeine with or without acetaminophen) // b. Immobilization of the joint, ice packs, non-weight-bearing
Hemophilia AClotting factor replacement // Factor VIII concentrate is the mainstay of therapy (both plasma-derived and recombinant factor VIII are available)-for acute bleeding episodes and before surgery or dental work // DDAVP for mild disease
Hemophilia BTreatment involves administration of factor IX concentrates
Disseminated Intravascular Coagulation (DIC)l. Management of the condition that precipitated DIC // Supportive measures may be indicated if severe hemorrhage is present (these are only temporizing measures) -- a. FFP replaces all the clotting factors. b. Platelet transfusions c. Cryoprecipitate replaces clotting factors and fibrinogen d. Low doses of heparin (IV or SC) inhibit clotting and can prevent consumption of clotting factors. The use of heparin is controversial Other supportive measures include oxygen and IV fluids. Maintain BP and renal perfusion.
Vitamin K Deficiencyl. Vitamin K replacement (oral or subcutaneous)-It may take a few days for PT to return to normal // If bleeding is severe and emergency treatment is necessary; FFP should be transfused
Coagulopathy of Liver DiseaseI. FFP (contains all clotting factors)-if PT or PIT is prolonged or if bleeding is present // Vitamin K in certain cases (cholestasis) // Platelet transfusion-if thrombocytopenia is present // Cryoprecipitate-if there is a deficiency of fibrinogen
Inherited Hypercoagulable StatesStandard treatment for DVT or PE as in patients without primary hypercoagulable states // Patients with any of these disorders who have had two or more thromboembolic events should be permanently anticoagulated with warfarin.
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ANTICOAGULATION

Question Answer
Heparin Mechanism of actionl. Potentiates the action of antithrombin to primarily inhibit clotting factors Ila and Xa 2. Prolongs PTT
Heparin Indications for usel . Venous thromboembolism: DVT, PE 2. Acute coronary syndromes: unstable angina, myocardial infarction 3. Low-dose standard heparin or LMWH for DVT prophylaxis 4. Atrial fibrillation in acute setting 5. After vascular bypass grafting
Heparin Adverse effectsl . Bleeding 2. Heparin-induced thrombocytopenia (HIT)-lower incidence with LMWHs 3. Possible osteoporosis-lower incidence with LMWHs 4. Transient alopecia 5. Rebound hypercoagulability after removal due to depression of AT III
Contraindications to heparin1. Previous HIT 2. Active bleeding, G I bleeding, intracranial bleeding 3. Hemophilia, thrombocytopenia 4. Severe HTN 5. Recent surgery on eyes, spine, brain
Reversing the effects of heparin and LMWHsOne can give protamine sulfate to reverse the effects of heparin if necessary
Low-Molecular-Weight Heparin ILMWH) Mechanism of actionLMWHs mostly inhibit factor Xa (equivalent inhibition of factor Xa as standard heparin) , but have less inhibition of factor Ila (thrombin) and platelet aggregation
Warfarin Mechanism of actionl. A vitamin K antagonist-leads to a decrease in vitamin K-dependent clotting factors (II, VII, IX, X) and proteins C and S 2. Causes prolongation of PT (and increase in INR)
Warfarin Indications for usesame as heparin but used for long-term anticoagulation
Warfarin Adverse effectsl . Hemorrhage 2. Skin necrosis is a rare but serious complication. It is caused by rapid decrease in protein C (a vitamin K-dependent inhibitor of factors Va and VIlla). 3 . Teratogenic-avoid during pregnancy! 4. Should not be given to alcoholics or to any patient who is prone to frequent falls because an intracranial bleed in a patient on warfarin can be catastrophic
Warfarin Reversing the effects of warfarinl. Discontinue warfarin and administer vitamin K . 2 . The half-life of warfarin is much longer than that of heparin it takes 5 days to correct the effects of warfarin on stopping the medication. Vitamin K infusion corrects an abnormal PT within 4 to 10 hours if the patient has normal liver function. 3. Giving vitamin K makes it difficult to return the patient to therapeutic INR levels if anticoagulation is to be continued.
if severe bleeding occurs (for patients on either warfarin or heparin)Administer FFP
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