4.3 Other Disorders of Hemostasis Flashcards
What is the cause of heparin induced thrombocytopenia?
Platelet destruction arises secondary to heparin therapy because of the formation of heparin-PF4 complexes that result in the creation of antibodies that can be directed against platelets.
What is a feared complication of HIT?
Thrombosis due to the fragments of destroyed platelets activating aggregation of other platelets
What are the cause and effects of disseminated intravascular coagulation?
Pathologic activation of the coagulation cascade leads to widespread micro thrombi that can cause ischemia and infarction. This will consume many platelets.
What are some diseases that can lead to DIC?
DIC is almost always secondary. Examples of primary causes are:
- Sepsis
- Cancer
- Rattlesnake Bite
What happens to the platelet levels in DIC?
Decreased platelet count
What happens to PT in DIC?
Increased
What happens to APTT in DIC?
Increased
What happens to the levels of fibrinogen in DIC?
Decreased fibrinogen
What is the main lab indication of DIC?
Elevated D-dimer
What is the general cause of disorders of fibrinolysis?
Overactive plasmin will cause excessive fibrinogen lysis
What are the 3 functions of plasmin?
- Cleaves fibrin and cleaves fibrinogen
- Destroys coagulation factors
- Blocks platelet aggregation
What is the main inactivator of plasmin?
alpha2-antiplasmin
How can you tell plasmin overactivity (fibrinolysis disorder) from DIC?
DIC will have elevated levels of D-dimer
What is the main treatment of fibrinolysis disorders?
Aminocaproic Acid. It blocks activation of plasmin.
