Heparin Induced Thrombocytopenia (HIT) Accurate Answer.

What is HIT? - correct answer It's defined as a drop in the platelet count to 15,000 or having a 50% drop in platelets while on heparin There are 2 types of HIT. Describe the 1st type (3) - correct answer 1) This is a transient drop in platelet count that occurs within the first 2 days of heparin therapy 2) platelet count eventually normalizes 3) non-immune mediated A big difference between type 1 and type 2 HIT, is that type 2 is BLANK-meditated thrombocytopenia - correct answer IMMUNE When does type 2 HIT typically occur? - correct answer 4-10 days after being on heparin Type 2 HIT can be caused by both unfractionated heparin or low molecular weight heparin, but which is it more common with? - correct answer More common with unfractionated heparin True or false, type 2 HIT can occur regardless of the dose, schedule or route of heparin - correct answer True Which populations does HIT tend to affect? (2) - correct answer Females, 40 Does HIT affect surgical or medical patients more? - correct answer Surgical patients Does HIT result in thrombosis or hemorrhage? - correct answer It results in thrombosis and endothelial damage! What is the pathophysiology behind HIT? (4) - correct answer 1) heparin binds to PF4 2) antibodies form against the heparin-PF4 complex 3) this immune complex (antibodies + heparin + PF4) activates platelets 4) thrombosis What are 6 ways HIT can present? - correct answer 1) limb ischemia and gangrene 2) skin lesions at injection site 3) purpura 4) systemic symptoms 5) DVT 6) PE What are 5 systemic symptoms you can get with HIT? - correct answer 1) fever 2) chills 3) dyspnea 4) chest pain 5) flushing The diagnosis of HIT is clinical but supported by confirmatory laboratory testing. We can use the "4 Ts" to diagnose HIT. What are they? - correct answer 1) Thrombocytopenia 2) Timing of platelet count fall after initiation of heparin 3) Thrombosis 4) thrombocytopenia from other causes (check if there is a possibility the thrombocytopenia was caused by something else, not the heparin) The highest score you can get with the "4Ts" is an 8. How do you get this score? - correct answer 1) thrombocytopenia where platelet fall 50% and moderate nadir 20,000 2) platelet count fell intermediate or fast with recent heparin (5-10 days or 1 day) 3) new thrombosis confirmed = skin necrosis, acute systemic rxn 4) no other strong explanation of thrombocytopenia