Platelet Disorders Flashcards
What two drugs are most commonly causing ITP?
Quinine or quinidine
What family of drugs can also cause ITP acutely and give an example?
2b3a inhibitors like abciximab
What are the 3 clinical settings we see ITP?
Response to a drug, within another disease, and idiopathic
3 clinical diseases where we might see low platelet?
HIV, LUPUS, and in older patients, lymphoproliferative malignancy
2 clinical symptoms of ITP and what makes for a more probable diagnosis? What should blood smear show and bone marrow aspirate?
Petechial rash and easy bruising.
ITP is more probable in an isolated setting. Everything else should be normal. Maybe a little anemia with larger blood loss that is secondary.
Blood smear shows decreased platelets and can be large. Bone marrow should show increased megakaryocytes.
2 first line treatments for ITP and 2 second line treatments and 1 last line?
Steroids and IVIG
Anti rho d if patient is rho d positive and anti 20 rituximab
Take spleen out
What kind of heparin and what type of patient have a higher incidence of getting HIT?
Unfractionated vs. low molecular weight
Open heart surgery patients get it more
What drug is not a good alternative to heparin in the present of HIT and what drug is?
No warfarin but direct thrombin inhibitors are
What are the 4 Ts for diagnosing HIT?
Thrombocytopenia level
Timing of the platelet count fall
Thrombosis or other problems
Other causes of thrombocytopenia present
What is the 0,1,2 points for thrombocytopenia level?
0 - platelet count fall is less than 30% and a low count less than 10k
1 - platelet count falls 30-50% and a low of 10-19k
2 - platelet count falls more than 50% and a low of greater than 20k
0,1,2 points for timing of platelet drop?
0- platelet count fall is less than 4 days without recent exposure
1- looks like it fell 5-10 days but not documented or after 10 days or less than a day with exposure within 1-3 months
2- clear onset of 5-10 days or less than 1 day with exposure within the last month
0,1,2 points for thrombosis?
0 - no thrombosis
1 - suspected thrombosis that has not been proven
2 - confirmed skin necrosis or thrombosis
0,1,2 points for other causes of thrombocytopenia present?
0 - definite
1 - possible
2 - none apparent
Once you add all 4 categories up, what does 0-3, 4-5 and 6-8 mean?
Low probability
Medium probability
High probability
What 3 patient populations are at higher risk for TTP-HUS?
Pregnant women, HIV infected patients, and patients receiving cancer chemo or immunosuppressive
4 lab findings suggestive of TTP-HUS?
Schistocytes of blood smear
Decreased haptoglobin
LDH is up
Low platelets
Because it is hard to diagnose TTP-HUS from other microangiopathic diseases, what 4 clinical signs will help us direct towards TTP-HUS?
Platelets are low, kidney problems, fever, and neuro deficits
2 things to treat TTP-HUS?
Plasma exchange and glucocorticoids
How is Essential Thrombocythemia usually diagnosed and what 3 clinical symptoms may patients present with?
Unexpected high platelet levels for no reason
Headache, erythromelalgia, thromboembolic even or acute bleeding
What sort of qualifies for a diagnosis of ET? What two other conditions do we see high platelet counts and because of this what do we need to make sure is negative for diagnosis?
Persistent platelet counts over 600k, sometimes these people are over 1mil.
PRV and CML and half of patients with ET have the jak2 mutation, so need to make sure no Philadelphia chromosome to say no CML.
How do we treat ET, what is considered a low risk patient and high risk patient and what do we do with each?
Patients less than 60 with counts less than a mil with no prior thromboembolic event have an excellent prognosis and should be watched.
High risk patients, give hydroxyurea first with low dose aspirin. If that doesn’t work give IFN alpha and anagrelide.
What is the leading differential in patients suspected of ET and what are the 4 most common causes of it?
Reactive thrombocytosis
Iron deficiency, inflammation, cancer or infection
