Pathology Part 2- Bleeding Disorders Flashcards
What are 3 main causes of bleeding abnormalities?
- Derangement of coagulation proteins
- Abnormalities in blood vessel walls
- Platelet deficiency or dysfunction
- CAN BE ANY COMBO
When do you see large ecchymoses and/or hematomas with bleeding into GI tract, urinary tract, or joints?
When there’s an abnormality in clotting factors
What is the initial presentation of abnormality in clotting factors?
Males bleed lots after circumcision
What factors is vitamin K required for?
2, 7, 9, 10, protein S, protein C
What can cause Vit. K deficiency?
Nutritional or iatrogenic (WARFARIN)
4 screening tests for Vit. K Deficiency?
- Bleeding time- don’t do this, it’s barbaric
- Platelet count (decreased)
- PT- EXTRINSIC
- PTT- INTRINSIC
What makes vWF?
ENDOTHELIAL CELLS
What does vWF do?
Facilitate platelet adhesion to subendothelial collagen
What indicates the presence of vWF?
Ristocetin (these dudes bind to platelets and activate vWF on surface and WHAM BAM PLATELET AGGREGATION
What receptor does vWF bind to on platelets?
GP Ib
What happens to you if you have VW disease?
- BLEED
- Mucous membranes (versus clotting deficiency which is more joints), wounds, periods, ect.
3 types of vWF, tell me bout em?
1: Heterozygote: NOT ENOUGH, mild-mod bleeding, most common
2. Heterozygote: DEFECTIVE, mild-mod bleeding
3. Homozygous: NONE, severe bleeding
If you have hemophilia A, what are you missing and how did you get it?
FACTOR 8
-X-Linked (boys more often affected)
If you have hemophilia B, what are you missing and how did you get it?
FACTOR 9 (CHRISTMAS DISEASE...HOHOHO) -X-linked
Are the symptoms the same for hemophilia A and B
YES
- Spontaneous hemorrhages (into joints)
- NO petechiae and ecchymoses (usually absent)
- Hemorrhage after trauma or operation
- Normal bleeding time and platelet counts
In hemophilia A and B, whats the deal with the PT and PTT?
PTT is LOOOOONG (but corrects with mixing study when you give the blood the FACTOR IT NEEDS 8 or 9)
PT is NORMAL
What is a secondary complication of many diseases causing activation of the coagulation system, then fibrin thrombi produces throughout microcirculation, then activation of the fibrinolytic system?
DIC
What does DIC consume?
Platelets, coagulation factors, and fibrinogen
-Initial clotting, but eventual bleeding as you use up all the factors
What are 5 things DIC is associated with?
- Infection and Sepsis
- Bleeding
- Childbirth (for the momma)
- Massive inflammation or organ failure
- Malignancies (acute promyelocytic leukemia)
How do you treat DIC?
Give em fibrinogen (cryoprecipitate)
-Treat underlying condition
What is a condition where you get small skin petechiae and purpura, with normal lab values (bleeding time, coag times, platelet count)?
Non-thrombocytopenic purpura
What else is on a ddx for non-thrombocytopenic purpura?
- Infectious diseases
- Drug reactions
- Collagen disorders
- Henoch-Schoenlein Purpura
- Hereditary hemorrhagic telangiectasia
What can be caused by
- Inadequate production (via megakaryocytes in BM)
- Increased peripheral destruction (immune mediated)
- Splenic sequestration (primary or secondary)
- Hemodilution
THROMBOCYTOPENIA
What causes neonatal or post-transfusion purpura?
Development of antibodies agaisnt platelet antigens
