285b vW disease and platelets

Question 1

platelet disorders - symptoms?

Answer 1

mucous membrane bleeding - epistaxis, GI, petechiae

Question 2

platelet disorders - labs?

Answer 2

increased bleeding time, possible decreased platelet count

Question 3

Bernard-Soulier Syndrome - mechanism? labs?

Answer 3

low GpIb

low PC, increased BT

Question 4

Glanzmann thrombasthenia - mechanism? lab?

Answer 4

low GpIIb/IIIa

normal PC, increased BT

Question 5

ITP (immune thrombocytopenia) - mechanisms? labs?

Answer 5

splenic Abs –> GpIIb/IIIa –> Mo eat in spleen

acute - kids, viral; chronic - adults

low PC, increased BT, increased megakaryocytes in BM

Question 6

TTP (thrombotic thrombocytopenic purpura) - mechanism? labs? symptoms?

Answer 6

Ab –> ADAMSTS13 –> increased vWF multimers –> platelet adhesion/thrombus

low PC, high BT, schistocytes, high LDH

symptoms - fever, microangiopathic hemolytic anemia, renal and CNS issues (HUS = renal)

Question 7

vW disease - inheritance? mechanism? labs? Rx?

Answer 7

AD

low vWF –> low F VIII –> high PTT, bleeding (mild)

increased BT, ristocetin assay - low agglutination)

Rx - DDAVP

Question 8

DIC - mechanism? labs? causes? Rx?

Answer 8

widespread clotting –> low platelets –> bleeding

low OC, high BT, high PT, high PTT
schistocytes, high D-dimer, low fibrinogen

Sepsis, Trauma, OB (amniotic fluid has TT), Pancreatitis, Cancer, Transfusions

Question 9

what activates extrinsice pathway?

Answer 9

tissue factor in endothelium