Hematology Pimp Session. 1. What is the sequence of the intrinsic pathway of coagulation?.
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1. What is the sequence of the intrinsic pathway of coagulation?
Prekallikrein+ HMW kininogen + factor XII + exposed collagen → activates Factor XI → activates Factor IX +Factor VIII → activates Factor X + Factor V → converts prothrombin (Factor II) to thrombin → thrombin converts fibrinogen to fibrin
2. What is the sequence of the extrinsic pathway of coagulation?
Factor VII + tissue factor → activates Factor X +Factor V → converts prothrombin to thrombin → thrombin converts fibrinogen to fibrin
3. Which factors are known as the labile factors (i.e. activity lost in stored blood)?
Factors V and VIII
4. Which factor has the shortest half-life?
5. What are the Vitamin K dependent factors?
Factors II, VII, IX, and X and proteins C and S
6. Which factor is the convergence point for both the extrinsic and intrinsic pathways of coagulation?
7. PT measures the function of which factors?
Factors II, V, VII, and X and fibrinogen
8. PTT measures the function of which factors?
Factors II, V, VIII, IX, X, XI, and XII and fibrinogen
9. What 2 electrolytes are required for the formation of a platelet plug?
Calcium and Magnesium
10. What is the sequence of physiologic reactions that mediate hemostasis following vascular injury?
2. Platelet activation/adherence/aggregation
3. Thrombin generation
11. Uremia leads to a downregulation of?
GpIb, GpIIb/IIIA, and vWF
12. What is the treatment of choice for uremic coagulopathy?
13. Which drug can be given to help correct platelet dysfunction from uremia, bypass, or ASA?
14. DDAVP and conjugated estrogens stimulate the release of?
Factor VII and vWF
15. What platelet count is needed before surgery?
16. What platelet count is associated w/ spontaneous bleeding?
17. What platelet count suggests the prophylactic transfusion of platelets?
18. What is Virchow’s triad?
Stasis, endothelial injury, and hypercoagulability
19. What is the most common cause of acquired hypercoagulability?
20. What is the most common inherited hypercoagulablestate?
Factor V Leiden
21. What is the treatment for hyperhomocysteinemia?
Vitamin B-12 and folate
22. Name the prothrombin gene defect causing spontaneous venous thrombosis?
Prothrombingene defect G20210A
23. What is the normal life of a platelet?
24. What electrolyte is most likely to fall after the infusion of stored blood?
Ionized calcium (citrate in stored blood binds serum calcium)
25. How long can PRBCs be stored?
~ 42 days or 6 weeks
26. What is the most common blood product to contain bacterial contamination?
Platelets (stored at room temperature)
27. What type of bacteria is usually found in contaminated platelets?
28. What is the most common bacteria found w/ blood product contamination?
Gram negative rods (E. coli)
29. Who would you transfuse with leukocyte reduced packed red blood cells?
Patients with multiple reactions despite premedication with antipyretics, patients needing long term platelet support, and transplant candidates in order to prevent formation of HLA antibodies
30. What are the indications for blood transfusion?
Hgb< 10 w/ h/o CAD/COPD, Healthy symptomatic pt. w/ Hgb < 7, acute blood loss
31. What is the approximate formula to convert Hct to Hgb?
Hct/ 3 = Hgb
32. 1 U PRBC should increase the Hgb and Hct by this much?
Should increase Hgb by 1 g/dL and Hct by ~3-4%
33. What happens during a type and screen?
Patient's blood is screened for antibodies and blood type is determined
34. What happens during a type and cross?
Pts. blood is sent to the blood bank and cross-matched for specific donor units for possible transfusion
35. What fluid cannot be infused with PRBC and why?
Lactated Ringer's; Calcium in LR may result in coagulation w/in IV line
36. Most common cause of transfusion hemolysis?
Clerical error leading to ABO incompatibility
37. What is the treatment for transfusion hemolysis?
Stop transfusion; fluids; Lasix; alkalinize urine w/ bicarbonate; pressors as needed
38. How long does it take for Vitamin K to take effect?
39. How long does it take for FFP to work?
40. How long do the effects of FFP last?
41. What does cryoprecipitate contain?
vWF, Factor VIII, and fibrinogen
42. What does FFP contain?
All factors including labile Factors V and VIII, AT-III, protein C and S
43. What is the best method for detecting pts. at risk for bleeding?
A complete history and physical exam
44. What is the most common congenital bleeding disorder?
Von Willebrand's disease
45. What factor is deficient in hemophilia A?
46. What is the preoperative treatment for hemophilia A?
Factor VIII infusion to 100% normal preoperative levels
47. What factor is deficient in Hemophilia B?
48. What is the treatment for hemarthrosis in a pt. w/ hemophilia A?
Initial therapy includes Factor VIII, joint rest, cold packs (3-5 days) and a compression dressing (3-5 days); Followed by active range of motion exercised 24 hrs. after Factor VIII therapy.
49. What receptor deficiency is found in Glanzmann's thrombocytopenia?
GpIIb/IIIareceptor deficiency; platelets can not bind to each other
50. What receptor deficiency is found in Bernard Soulier disease?
GpIbreceptor deficiency; platelets can not bind to collagen
51. What are the desired platelet counts and Hct for a pt. with polycythemia vera before an elective operation?
Plt< 400,000/mL and Hct < 48%
52. What protein does Heparin bind to for its anti-coagulation effects?
Anti-thrombin III; Heparin-antithrombin III complex then binds factor IX, X, XI
53. What is the half-life of heparin?
54. What is the dose of protamine to reverse 100 U or 1 mg of heparin?
55. What signs will you see in a protamine reaction?
Bradycardia, hypotension, and decreased heart function
56. How does warfarin induced skin necrosis occur?
Protein C and S have a shorter half life than Factors II, VII, IX, and X. Coumadin leads to a decrease in Protein C and S before the other factors leading to a hypercoagulable state
57. Pts. with this deficiency are at increased risk for Warfarin induced skin necrosis?
Protein C deficiency
58. What is the desired activated clotting time for routine anticoagulation?
59. What is the desired activated clotting time for cardiopulmonary bypass?
60. What INR is a contraindication to intramuscular injection?
INR > 1.5
61. What are the absolute contraindications to the use of thrombolytics?
Recent CVA (<2 months), intracranial pathology, and active internal bleeding
62. What are the indications for an IVC filter?
Pts. who have undergone a pulmonary embolectomy, pts. with documented PE while anticoagulated, pts. with free floating femoral, ileofemoral, IVC DVT, pts. with contraindication to anticoagulation, and pts. at high risk for DVT (head injured/orthopedic injured on prolonged bed rest)"
63. What is Argatroban?
A synthetic direct thrombin inhibitor derived from L-arginine
64. What is Hirudin?
An irreversible direct thrombin inhibitor derived from leeches
65. What is Ancrod?
Malayan pit viper venom that stimulates tPA release