Blood: 4.3: Other disorders of hemostasis Flashcards
What does HIT stand for?
heparin-induced thrombocytopenia
What is heparin-induced thrombocytopenia (HIT)?
platelet destruction post heparin therapy due to antibody formation
Why does heparin cause HIT?
Heparin can form complexes with platelet factor 4, and an IgG autoantibody can develop against this, leading to destruction in the spleen
What is the major complication of HIT and how does it work?
thrombosis due to platelet fragments activating other platelets
What is the treatment of HIT?
stop Heparin and give anticoagulant, but NOT COUMADIN
What is DIC?
pathologic (abnormal)activation of the coagulation cascade (as opposed to physiologic)
What is the result of DIC?
widespread microthrombi –> ischemia, infarction; also consumption of platelets and factors –> bleeding
Where will DIC pts bleed from?
IV sites, mucosal surfaces
DIC is almost always 2a to another disease process, such as _____, _____, _____, _____, and _____.
- obstetric complications2. sepsis3. adenocarcinoma4. APL5. rattlesnake bite
How do obstetric complications lead to DIC?
amniotic fluid contains a lot of tissue thromboplastin (TT), which is a strong activator of the coagulation cascade
How does sepsis lead to DIC?
- bacterial endotoxin can activate coag. cascade2. cytokines produced by macs can activate coag. cascade
How does adenocarcinoma lead to DIC?
mucin produced by the adenocarcinoma can activate coag. cascade
How does APL lead to DIC?
Auer rods/primary granules activate coag cascade in circulation
How does a rattlesnake bite lead to DIC?
venom in circulation activates the coag cascade
What lab findings will be seen in DIC?
- decreased platelet count 2. increased PT3. increased PTT4. decreased fibrinogenmicroangiopathic hemolytic anemia (schistocytes)5. elevated fibrin split products (D-dimer)*** best test
