wk 6 Flashcards
(59 cards)
What is the difference between bleeding and thrombosis?
Bleeding = hypocoagulable, Thrombosis = hypercoagulable.
What is the role of fibrin in clotting?
Fibrin stabilizes the platelet plug. Thrombin converts fibrinogen to fibrin.
What is the earliest response to vascular injury?
Vasospasm.
What does von Willebrand Factor (VWF) do?
VWF helps with platelet adhesion.
What test is associated with the intrinsic pathway? What factors are involved?
aPTT (table tennis indoors). Factors: 12, 11, 9, 8 (especially 8 and 9).
What causes a prolonged PTT?
Deficiency of factors 8, 9, 11, 12, VWF, heparin, or direct factor Xa inhibitors.
What test is associated with the extrinsic pathway? What factors are involved?
PT (tennis outdoors). Factors: 7 (primary), and 3.
What causes a prolonged PT?
Factor 7 deficiency, mild vitamin K deficiency, liver disease, DIC, or warfarin use.
What factors are involved in the common pathway?
Factors 10, 5, 2, 1, and 13.
What causes deficiencies in the common pathway?
Deficiencies of prothrombin, fibrinogen, factor 5, factor 10, liver disease, DIC, severe vitamin K deficiency, or supratherapeutic anticoagulation doses.
What factors are vitamin K-dependent, and where are they synthesized?
Factors 2, 7, 9, and 10. They are synthesized in the liver.
What does a mixing study differentiate between?
Factor deficiencies and factor inhibitors.
○ Take patients plasma and pooled normal plasma
○ If clotting test normalizes = Factor deficiency
○ If clotting test does not normalize = Factor inhibitor
How does a mixing study work?
Mix patient plasma with pooled normal plasma: - Normalizes = Factor deficiency. - Does not normalize = Factor inhibitor.
What causes hemophilia?
Inherited hemorrhagic disorder caused by deficiency of factors 8, 9, or 11.
What is the inheritance pattern for Hemophilia A and B?
X-linked recessive. Females with a single mutated gene are generally asymptomatic.
- 1/3 happen spontaneously
What happens if a father has hemophilia and the mother does not carry the gene?
Each son has a 0% chance of having hemophilia. Each daughter has a 100% chance of being a carrier.
What happens if the mother carries the hemophilia gene?
50/50 chance for sons and daughters to inherit or not, depending on the X chromosome they receive.
What are the inheritance odds if both parents have hemophilia?
100%
What is Hemophilia A?
X-linked, Factor 8 deficiency, most common hemophilia.
What is Hemophilia B, and what is it also called?
Factor 9 deficiency, 10% of cases, milder than Hemophilia A. Also called Christmas disease.
What is Hemophilia C, and who is it common in?
Factor 11 deficiency (Rosenthal syndrome), autosomal recessive. Common among Ashkenazi Jews.
What are the shared signs and symptoms of hemophilia?
Bleeding into joints/muscles, bruises easily, prolonged bleeding after surgery/injury, frequent nosebleeds, blood in urine.
PTT: prolonged
PT: normal
What is compartment syndrome, and what causes it?
Complication of bleeding into muscles, causing pressure on arteries/nerves. Symptoms: weakness, pallor, swelling, numbness, severe pain, paralysis.
How are Hemophilia A and B treated?
Hemophilia A:
- recombinant factor VIII, cryo
- mild = DDVAP (stimulate vWF release from storage sites in endothelial cells and stabilize factor VIII) -> only lasts 6-8 hrs
Hemophila B:
- recombinant factor IX, FFP
- NO DDVAP