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20 Cards in this Set
- Front
- Back
What are the final two enzymatic conversions of the clotting cascade?
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Prothrombin to thrombin
Eibrinogen to fibrin |
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What is the first reaction in clot dissolution?
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Conversion of plasminogen to plasmin
Plasmin then dissolves fibrin clot |
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Heparin binds to what substance?
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Antithrombin Ill
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Once bound, heparin inhibits what two factors?
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Activated factor ll (lla)
Activated factor X (Xa) |
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What is the general threshold for platelet transfusion?
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Transfuse if platelets <5000
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Duplex ultrasound is 90% sensitive for what type of clot?
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Deep venous thrombosis (DVT) proximal to the trifurcation
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What type of ultrasound has the highest sensitivity?
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Color
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What is the risk of a fatal pulmonary embolism (PE) after arthroplasty if no prophylaxis is administered?
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0.1 to 0.5% after total hip or total knee arthroplasty
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How does the risk of a fatal postoperative PE change with prophylaxis?
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Reduced by one half
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Is prophylaxis against DVT necessary after spine surgery?
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Generally not; only SCDs (sequential compression devices) are used
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Other than direct venous compression, by what mechanism are 5CDs thought to also work?
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Enhance endogenous fibrinolytic activity
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What type of spine surgery is associated with an increased risk of DVT?
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Combined anterior/posterior fusions
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What is the threshold hemoglobin value below which there is an increased risk of needing a postoperative transfusion?
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Hemoglobin <13
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What is the association between transfusion and the postoperative infection rate?
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Transfusions increase the risk of postoperative infection
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What ticntranfusion technique achieves transfusion rates equivalent to chose with autologous donation?
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Normovolemic dilution
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For which viral infection is blood not routinely screened?
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Cytomegalovirus (CMV)
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What blood product should be administered for a low intraoperative fibrin value?
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Cryoprecipitate
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Following tourniquet use electromyograph (EMG)abnormalities can be detected in what percentage of postoperative patients?
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70%
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After 90 minutes of tourniquet use, how long should the tourniquet be deflated to achieve equilibrium?
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5 minutes
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How about after 3 hours of tourniquet use?
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Deflate for 15 minutes before reinflating
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