MHD: Clinical approach to bleeding patient Flashcards Preview

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Flashcards in MHD: Clinical approach to bleeding patient Deck (14):

What can we learn from a CBC with differential lab?

Platelet quantity
Look for involvement of other cell lines
Platelet appearance
Evidence of systemic disorder


What can we learn from PT and aPTT?

Are there abnormalities in coagulation system?
Will detect qualitiative AND quantitative disorders, but not differentiate the two
May differentiate which factor is culprit


What can we learn from a bleeding time test?

Gives info about platelet activation, but not used anymore today


Prolonged bleeding time with a normal platelet count suggests what type of disorder

Qualitative disorder: inherited (Glanzmann, Bernard-Soulier, storage pool disease, VWD)


Which receptors are affected in Glanzmann, Bernard-Soulier disorders?

Gp1b in BS
GpIIbIIIa in Glanzman


If VWD is suspected, what lab studies can be done to confirm the suspicion?

VWF antigen to see if patient has any VWF
vWF:ristocetin activity to see if VWF works
FVIII clotting activity to see if VIII is affected
VW multimers looks at VWF structure


How are factor VIII levels related to VWD?

VWF is a carrier for FVIII, so in the absence of VWF, the half life of FVIII is decreased and levels will be lower than normal


What lab tests differentiated hemophilia A from VWD?

Ristocetin activity: normal in HemA, low in VWD
vWF:Ag: normal in HemA, low/normal in VWD


What causes a prolonged PT?

Liver disease
Warfarin therapy
Factor VII deficiency


What causes a prolonged PTT?

Heparin theapy
Deficiency/inhibition of VIII, IX, XI, XII
Lupus anticoagulant


What causes both a prolonged PT and PTT?

Heparin/Warfarin high doses
Vit K deficiency
Liver disease


What is the utility of a mixing study?

To differentiate between a clotting factor deficiency and an inhibitor of the clotting factor function
Mix patient plasma with normal plasma, will clot if problem was a deficiency, but will not clot if problem was inhibitor


What are the most common inherited coagulation defects?

X-linked: Hemophilia A (VIII) and Hemophilia B (IX)


How can you confirm normal platelet production?

Bone marrow aspirate showing megakaryocytic hyperplasia