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108 Cards in this Set
- Front
- Back
What are the four major systems involved in maintaining hemostasis?
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vascular system
platelets Coagulation Fibrinolysis |
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What does bleeding from arterioles and venules produce?
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petechiae
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what does bleeding from veins produce?
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ecchymosis
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How does the vascular system maintain hemostasis?
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Prevents bleeding by vasoconstriction, diversoin of blood away from damaged area, contact activation of platelets, activation of coag system
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How dod platelets maintain hemostasis?
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The have dense granules of ADP, attract other platelets to site of injury and form platelet plug. Activation of PF3 facilitates thrombin formation by int. coag system
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What does aspirin do?
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Inhibits cyclooxygenase, which blocks the formation of prostaglandins, thus preventing platelet aggregation
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Where are Coag factors produced?
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All produced in liver, except for factor VIII, which is produced by platelets
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What stabilizes the platelet plug?
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Fibrinogen (factor I), it is the end stage of both the int and ext coag cascades
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What 2 factors cannot be quantified?
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III (tissue factor/ thromboplastin)
XIII (fibrin-stabilizing factor) |
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What type of factors does the PT test?
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Extrinsic factors, vit K dependent
I, II, V, VII, X |
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What is the antidote for excessive warfarin therapy?
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vitamin K
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What tube is PT drawn in?
What is ratio? |
blue tube with Na citrate
ration should be 4.5/.5 |
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What may prolong the PT?
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Alcohol, diarrhea, malabsorption, ASa, allopurinol
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What may shorten PT?
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diet high in fat or green leafy vegetables, benadryl, ocp's
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Who is on Warfarin therapy?
Contraindicated? |
pts s/p hip/knee replacements, afib, PE, DVT, TIAs
Contraind in pregnancy, use heparin |
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What's the INR
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International Normalized Ratio - standardizes PT results
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Normal ther. range of INR
For mech heart valve |
2-3
3-4.5 |
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What is PTT?
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Partial thromboplastin time
measures intrinsic coag system: 1,2,5,8,9,10,11,12 |
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When is PTT used?
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To measure heparin therapy
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What does heparin do?
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inactivates prothrombin (2) and prevents formation of thromboplastin
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When should PTT be drawn when monitering heparin therapy?
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30-60 minutes before next dose
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How can hep effects be reversed?
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protamine sulfate
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What is normal PTT?
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30-45 secs
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What is APTT
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more sensitive version of PTT, activators are added to reagents. NOrmal is 21-35 secs
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What is Bleeding Time an indicator of?
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platelet function
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What is heparin?
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high molecular wt compound taht is an anti-thrombin III antagonist. It accelerates the binding of antithrombin III to thrombin.
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What is in vivo half life of heparin?
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90 minutes
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When is FSP increased?
What is replacing it? |
DIC, DVT, MI, PE, hepatic dysfunction
Replased by D-dimer |
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How are d-dimer fragments produced?
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Fibrin acted on by plasmin
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When do you see decreased levels of fibrinogen (I)
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malnourished, liver disease, comsumptive coagulopathies, large volume transfusions
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What meds change levels of fibrinogen?
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increase:estrogen, OCP
decrease: depakote, androgens, dilantin |
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Thrombin Time
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Normal 10-14 secs
Thrombin acts on fibrinogen conversion to fibrin aids in eval of long ptt detects presence of hep, decreased fibrinogen |
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Congenital anti-thrombin III deficiency results in?
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disorder that predisposes patient to thrombosis
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Hypercoagulable states are associated with?
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malignancies (trousseau's)
pregnancy, nephritic syndrome, ocps, pure estrogen, ulcer. colitis, crohn's, intravascular devices |
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Gen characteristics of bleeding disorders
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excessive or repetitive bleeding or bleeding at unusual sites
may be congenital or acquired |
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Congenital bleeding disorders involve defects related to?
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vascular integrity,plt function, coagulation or fibrinolytic systems
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Acquired bleeding disorders usually involve?
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more than 1 system. eg: Kidneys, collagen vascular, immune.
May be drug induced, neoplasm, malabsorption or OB complications |
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What lab tests are done to look for bleeding disorders?
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CBC with diff, plt count, bleeding time,pt,ptt,thrombin time
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Thrombocytopenia
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decreased number of plts, may be 2ry to impaired production, increased destruction, sequestration or diluted
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What med should be avoided in thrombocytopenia, why?
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Aspirin, becauses is is a platelet antagonist
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Idiopathic thrombocytopenia purpura - acute, found most common in?
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Children, associated with preceding URI
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signs and symps of ITP, acute
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acute onset of petechiae and purpura on skin and mucus membranes
Labs: dec plts, eosinophilia, mild leukocytosis |
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prognosis and tmt of acute ITP
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usually resolves spontaneously, may require corticosteroids or splenectomy
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Chronic ITP - who gets it?
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occurs at any age, women are more common, other autoimmune diseases common often present
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signs and symps of chronic ITP
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usually asymptomatic, may have petechiae
Labs: low plt count, but not as low as acute |
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Tmt of chronic ITP
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corticosteroids, IV gamma globulin, immunosuppressive agents, occasionally splenectomy
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DIC
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Desseminated Intravascular Coagulation, a type of plt consumption syndrome
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Plt consumption syndromes, what happens?
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widespread deposit of thrombi in the microcirculation of all organs
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How is DIC initiated?
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tissue thromboplastin stimulates extrinsic cascade, sources of tp: hemolyzed rbcs, placental, neoplastic and traumitized tissue
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Labs in DIC
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prolonged pt, ptt, thrombin time, increased FDP, decreased plts and fibrinogen, schistocytes seen on peripheral smear, elevated d-dimer, prolonged clot retraction
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When should PTT be drawn when monitering heparin therapy?
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30-60 minutes before next dose
|
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How can hep effects be reversed?
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protamine sulfate
|
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What is normal PTT?
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30-45 secs
|
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What is APTT
|
more sensitive version of PTT, activators are added to reagents. NOrmal is 21-35 secs
|
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What is Bleeding Time an indicator of?
|
platelet function
|
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What is heparin?
|
high molecular wt compound taht is an anti-thrombin III antagonist. It accelerates the binding of antithrombin III to thrombin.
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What is in vivo half life of heparin?
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90 minutes
|
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When is FSP increased?
What is replacing it? |
DIC, DVT, MI, PE, hepatic dysfunction
Replased by D-dimer |
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How are d-dimer fragments produced?
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Fibrin acted on by plasmin
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When do you see decreased levels of fibrinogen (I)
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malnourished, liver disease, comsumptive coagulopathies, large volume transfusions
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What drugs cause increased fibrinogen?
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estrogen, bcp
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What drugs cause decreased fibrinogen?
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depakote, androgens, dilantin
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What does thrombin do?
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Thrombin acts on fibrinogen conversion to fibrin.
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Normal thrombin time
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10 -14 secs
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When is thrombin time used?
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Used to detect presence of heparin, decreased fibrinogen, aids in evaluation of prolonged PTT.
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Congenital antithrombin III deficiency results in?
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disorder that predisposes pt to thrombosis
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Protein S and Protein K
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Vit K dependent factors important in anticoagulation
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Hypercoagulable states are associated with?
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malignancy (Trousseau’s syndrome), pregnancy, nephritic syndrome, OCPs, pure estrogen, ulcerative colitis, Crohn's, intravascular devices
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General characteristics of bleeding disorders
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involves excessive or repetitive bleeding or bleeding at unusual sites
may be congenital or acquired |
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Congenital bleeding disorders are related to defects in?
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vascular integrity, platelet function, coagulation, or fibrinolytic systems.
|
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Acquired bleeding disorders usually involve?
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more than one system-eg. kidneys, collagen vascular, immune system-may be drug-induced, secondary to neoplasm, malabsorption, or OB complications
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Lab test for bleeding disorders
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cbc with diff, plt count, bleeding time, pt, ptt, thrombin time
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Thrombocytopenia
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dec. plts, may be 2dary to impaired production, inc destruction, sequestration or dilution
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Why should asa be avoided in thrombocytopenia?
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its is a plt antagonist
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Acute Idiopathic thrombocytopenia purpura, who gets it?
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usually children, after viral URI
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acute ITP, signs and symps
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acute onset of petechiae and purpura on skin and mucus membranes
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acute ITP labs
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decreased platelets (10-20,000), eosinophilia, mild leukocytosis
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acute ITP tmt
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usually resolves spontaneously, may require corticosteroids or splenectomy
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Chronic ITP, who gets it?
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may occur at any age, is more common in women, other autoimmune diseases are often present
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Chronic ITP, signs and symps
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patients are generally asymptomatic, may have petechiae
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Labs for chronic ITP
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platelet count is low at 25-75,000
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tmt of chronic ITP
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corticosteroids, IV gamma globulin, immunosuppressive agents, and occasionally splenectomy
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Platelet consumption syndromes
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widespread deposition of thrombi in microcirculation of all organs
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DIC
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Desseminated Intrinsic Coagulopathy, type of plt cons syndrome
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Key symptom of DIC
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BLEEDING
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Effects of DIC
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prolonged PT, PTT, and Thrombin times, increased FDP, decreased platelets and fibrinogen, schistocytes seen on peripheral smear, elevated D-dimers, prolonged clot retraction
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tmt of DIC
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treat underlying cause
FFP, cryoprecipitate |
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Thrombotic thromobocytopenia purpura, who gets it?
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Rare, can be fatal, seen in women who are previously healthy
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Signs and symps of ttp?
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severe thrombocytopenia with purpura, hemolytic anemia, fever, abnormal neurological signs, and renal dysfunction. Negative Coomb’s.
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tmt of ttp
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corticosteroids, plasmapherisis, ffp
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Hemolytic Uremic Syndrome
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often found in children. Identical to ttp, but only in kidney. Same tmt as ttp, better prognosis
Ass. w/ E.Coli 0157:H7 |
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HELLP
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Hemolysis, Elevated Liver enzymes, Low Platelets
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Signs and symps of HELLP
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Pregnancy: htn, proteinuria, renal dysfunction (preeclampsia) to cerebral edema and seizures (eclampsia)
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? cause of HELLP
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abnormal prostaglandin metabolism
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How is HELLP reversed
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Delivery
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Most common cause of acquired plt dysfunction
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asa and NSAID use
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hemophilia A, aka
who gets it? |
Factor VIII deficiency, classic hemophilia
hereditary, x-linked rec. |
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signs and symps
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mild to severe, post surg/trauma bleeding, hemarthroses, epistaxis, intracranial bleeds, hematemesis, melena, gingival bleeds
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Lab studies for hemophilia A
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prolonged ptt, normal pt, normal bleeding time, normal plt. Factor VIII and VIIIc activity are reduced, while factor VIII antigen is normal
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Tmt for hemophilia A
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ffp, cryoprecipitate given pre surgery, precedures.
desmopressin DDAVP may elevate factor VIII levels |
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Hemophilia B
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Factor IX deficiency, aka christmas disease
similar to A but less frequent |
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VonWillebrand's Disease
Who gets it? |
Congenital, autosomal dominant, equall affects men or women, occurs in 6 major types
|
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VonWillebrand's
signs and symps |
Nasal, sinus, vaginal, and GI mucus membrane bleeds, spontaneous hemarthroses and soft tissue bleeds are less common
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VonWillebrand's, Lab studies
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prolonged bleeding times and decreased levels of factor VIII
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VonWillebrand's Tmt
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FFP, cryoprecipitate, or desmopressin.
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Vitamin K deficiencies
General |
Most common acquired coagulopathy. May be due to malnutrition, malabsorption, drugs
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Vit K deficiencies - Labs
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PT/PTT are prolonged, normal bleeding time, liver enzymes may be elevated, levels of vitamin K and factors II, VII, IX, and X are decreased
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Tmt of Vit K deficiencies
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vitamin K restores factor production, hemorrhage is treated with FFP
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