Hubbard thrombosis and hemostasis Flashcards
what is the most common cause of bleeding
thrombocytopenia
Normal PT?
tests what?
prolonged in what deficiencies?
prolonged with what drugs
- 10-13 seconds
- extrinsice system
- factors II, V, VII, X, and fibrinogen
- Warfarin or dicoumarol
Normal PTT?
test what?
Prolonged in what deficiencies?
prolonged with what drug?
- 25-40 seconds
- extrinsic
- factors VIII, IX, XI, XII
- Heparin
What is used to determine platelet abnormalities when platelets are normal in numbers (qualitative platelet defects)?
used for what diseases?
platelet aggregation studies
- vWB disease
- Bernard-Soulier syndrome
In patients with petechiae and thrombocytopenia, if you offer up the possibility of what causing it, you will look like a rockstar
medications
DIC is a complication of what situations?
- medical
- surgical
- obstetrical
- intrinsice and extrinsic coagulation systems are activation
- thrombin escapes (initial thrombosis stage may not be seen)
- platelets and clotting factors are depleted, causing bleeding
DIC
Treatment of DIC
- correction of underlying disorder–sepsis, bowel obstruction, etc
- Heparin .. not usually used unless overt thrombosis occurs
- supportive care–platelet and factor replacement
Microangiopathic hemolytic anemia, thrombocytopenia (<50,000), fever, neurological symptoms?
add renal failure to this?
TTP
HUS
- Schistocytes
- helmet cells
- “Waring blender” effect
TTP and HUS
pathologic lesion are hyaline thrombi which occlude the capillaries of virtually every organ in the body
TTP and HUS
2 forms of TTP
- hereditary mutation of ADAMTS13 gene
- acquired- autoantibodies directed at ADAMTS13
Treatment ofTTP
Plasmaphoresis–life saving in virtually 100% of cases
-Mortality virtually 100% if not treated
platelet aggregation tests abnormal, especially to ristocetin
vonWillebrand Disease
Treatment of vonWillebrand Disease
- Cryoprecipitate replaces vWF
- DDAVP causes release of vWF from endothelium
inheritance of Hemophilia A and B
X linked recessive
classifications of severity in hemophilia A
- mild (6-25% normal activity)
- moderate (1-5% normal activity)
- Severe (<1%)
Clinical features of hemophilia
- easy bleeding and bruisability
- hematomas from bleeding into soft tissue and muscles
- Hemarthroses
factors for Hemophilia A and B
VIII and IX respectively
characteristics of deficiency of vitamin K and dependent factors
- bleeding/hemorrhage
- Prolonged PT
- deficiency of factors II, VII, IX, X, protein C and S
What is the only endolthelial syndrome associated with hemostatic complications
-Hereditary hemorrhagic telangiectasia aka Osler-Weber-Rendu syndrome
- inheritance of hereditary hemorrhagic telangiectasia?
- defect in what gene?
- what chromosome
- autosomal dominant
- endoglin (CD 105) . a membrane glycoprotein expressed on endolthelial cells
- chromosome 9
symptoms of hereditary hemorrhagic telangiectasia
- epistaxis (most frequent)
- telangiectasias gradually apprering throughout life located in skin, mucous membranes, and visceral tissues
- bleeding to mild or inapparent trauma
course and treatment of hereditary hemorrhagic telangiectasia
- usually benign clinical course
- recurrent bleeds frequent but death from exsanguination is rare
- surgery and laser photoablation of telangiectasias of some value but care must be used in selecting site
normal bilirubin
.4 IU/dL
what organ can cause coagulopathy if severely damaged
liver . . think alcoholics or hepatitis or cirrhosis
what can be given to replace clotting factors?
fresh frozen plasma
50% of these patients have DVT and/or PE by age 30
AT-III deficiency
what is the normal job of anti-thrombin III
to slow progression from prothombin to thrombin
AT-III deficiency and pregnancy
significantly increased risk for DVT in pregnant women due to pregnancy induced hypercoagulability
Diagnosis of AT-III deficiency
diminshed levels of AT-III in serum (<50% normal activity)
Treatment of AT-III deficiency
- prophylactic treatement with anticoagulants
- patients with DVT should recieve heparin but much higher doses
- AT-III replacement is available for known AT-III deficient patients with DVT who do not respond initially to heparin
explain what protein C and S do
- both vitamin K dependent
- Protein C inactivated factors V and VIII
- protein S is a cofactor for protein C
What is used in patients with a deficiency of protein C and S to decrease the risk of thromboembolic disease
Warfarin
What is the most common cause of hypercoagulable state from deficiency of protein C and S
- initiation of warfarin therapy
- Proteins C and S are depleted prior to other factors, resulting in a temporary increase in coagulability
Abnormality of factor V at binding site for activated protein C
Factor V leiden
treatment of Factor V leiden
- no prior episodes: monitor; DVT prophylaxis and risk reduction
- prior episodes: consider lifelone anticoagulation
G-A mutation resulting in increased activity for prothrombin and inability to de-activate prothrombin
prothrombin 20210 . . . treatment same as factor V leiden
associated features with antiphospholipid syndrome
- Thromboembolic phenomena
- MISCARRIAGE
- thrombocytopenia
- cerebral ischemia and recurrent stroke (especially in young patients)
- UBOs: unidentified bright objects on MRIs
other associated features with antiphospholipid syndrome
- Connect tissue disease in >50%
- Prolonged PTT that fails to correct with mixing studies
- Valvular heart disease in some
- CAD in some
Diagnosis of Antiphospholipid syndrome
- Prolonged PTT
- Lack of correction in mixing studies
- Neutralization of inhibitor with excess phospholipid
What test can be used that is more specific in diagnosing antiphospholipid syndrome than PTT
DRVVT- Dilute Russell Viper Venom Time
General Treatment of antiphospholipid syndrome
- no benefit for anticoagulation in those WITHOUT a history of thromboembolic disease
- WITH history: lifelong anticoagulant (warfarin)–don’t base on single test. need multiple positive tests over a 3-12 month period to make diagnosis
specific treatment for antiphospholipid syndrome
- pregnancy: SC heparin
- patients with SLE: hydroxychloroquine
What is included in a hypercoagulability panel?
- factor V leiden
- prothrombin gene mutation
- protein C and S
