Heme/Onc Flashcards
What is the goal INR for a patient with a mechanical heart valve?
2.5-3.5
What initiates the intrinsic pathway? extrinsic pathway?
Intrinsic = collagen exposure following vascular trauma Extrinsic = endothelium produced TF
What causes the paradoxical hypercoagulability when taking warfarin?
This occurs at first b/c warfarin inhibits Protein C and S BEFORE it inhibits factors 2,7,9,10.
What is found in cryoprecipitate?
Factor VIII, fibrinogen mainly (this is why you choose cryo over FFP)
some factor XIII, vWF and fibronectin,
What is the tx for hemophilia?
Cryoprecipitate
DDAVP can also be used in mild hemophilia (helps the body produce more factor VIII)
What is the most common inherited bleeding disorder?
vWF deficiency. It is much milder than hemophilia and results from lack of VIII.
What drug worsens VWF disease? Why don’t you see petechiae with this disease?
ASA will worsen the bleeding. No petechiae b/c the platelet dysfunction is not that bad.
What will labs for VWD look like? Dx? Tx?
prolonged aPTT, prolonged bleeding time
Normal PT and platelet count
Dx = Ristocetin cofactor assay Tx = DDAVP
What is the MOA of clopidogrel and ticlopidine?
They block the ADP receptor, needed for platelet aggregation
What is the most common hereditary thrombotic disease? MOA?
factor V Leiden - a polymorphism that makes it resistant to inactivity by activated protein C (factor V is stuck in the “on-position” and makes a ton of activated thrombin (more clots.)
How long do you tx w warfarin for first thrombotic event? After doing heparin of course.
3-6 months
6-12 months for second event
lifelong for everything else
What is the difference in terms of labs between severe liver disease and DIC?
In DIC, the factor VIII is depressed.
What 5 characteristics/signs of TTP?
Low plts microangiopathic hemolytic anemia neuro changes (delirium, seizure, stroke) impaired renal function fever
What differentiates HUS from TTP?
HUS will have high Cr levels
HUS, TTP, and DIC are the only causes of microangiopathic hemolytic anemia
What tx is contraindicated in TTP? what tx should you use?
platelet transfustion - this will worsen the condition due to platelet aggregation and microvascular thrombosis.
Tx: steroids to bust the microthrombi, and plasma replacement/plasmapheresis
What are the labs in DIC and TTP?
DIC = low clotting factors, plts, fibrinogen. High PT, PTT, d-dimer, and fibrin split products
TTP: everything is normal except low plts.
What is the Tx for HUS?
Supportive. No Abx as this could delay toxin expulsion
What is the Tx for ITP?
Dont really have to treat acute/childhood forms as these remit spontaneously.
For Chronic form, use corticosteroids, IVIG, and splenectomy (last resort if CTSDs don’t work after 6 months.
What is a high retic count? What does it indicate?
> 2.5% is high, this indicates hemolysis/hemorrhage is occuring and BM is responding by making more RBCs
What are the 4 causes of microcytic anemia?
TICS
Thalassemia
Iron Def
Chronic Disease
Sideroblastic anemia
What Heme test is HIGHLY SPECIFIC for iron deficiency anemia?
Elevated RDW
What is the serious side effect that could occur with IV iron dextran administration?
Anaphylaxis
What are the lab differences between iron def anemia and anemia of chronic disease?
Fe Def = low serum iron and ferritin, high TIBC (transferrin) and transferrin R
CD = low serum iron and TIBC (transferrin), high ferritin, normal transferrin R
Both: low serum iron, normal TIBC (transferrin, ferritin, and transferrin R
Which class of drugs can cause megaloblastic anemia?
Chemotherapeutic drugs
What organism can cause an infection which causes B12 def anemia?
Diphyllobothrium Latum. its a tapeworm. It can cause neuro issues as well (b12 you know.)