Coagulation Disorders Flashcards
How is the body’s clotting system balanced?
- Clotting factors (platelets, TF, etc)
- Anti-clotting factors (NO, protein C/S, etc)
What are examples of vessel bound clot INHIBITORS?
- NO
- Prostacyclin
- Vascular endothelial ADPase
What are examples of vessel bound clot initiators?
- TF
- vWF
- TXA2
- Collagen
What does the cascade of soluble clotting factors consist of?
Intrinsic and extrinsic pathways leading to the common pathway
Which blood test evaluates the extrinsic pathway of clotting?
PT
Which blood test evaluates the intrinsic pathway of clotting?
aPTT
What is the MC inherited bleeding disorder?
von Willebrand disease
Describe vWF
- Promotes adhesion and aggregation of platelets
- Carrier of Factor VIII
What breaks down ultra-large multimers of vWF?
ADAMTS13 enzyme
MC type of vWF disease?
Type 1
Describe Type 1 vWF disease
- Autosomal co-dominant
- MC type
- Decreased quantity of vWF and FVIII activity (results in increased bleeding)
- Tx: DDAVP (nasal spray or IV)
What patients normally have low levels of vWF and F VIII?
Type O blood
What type of vWF disease should NOT be treated with DDAVP?
Type 2b (excessively big multimers of vWF) - can worsen thrombocytopenia and precipitate abnormal clotting
Describe hemophilia A
- Deficiency of F VIII
- X linked recessive (severe only in males)
Clinical presentation of hemophilia A
Easy bruising or bleeding (especially in male toddlers)
How to differentiate child abuse from hemophilia A?
Hemophilia A is NOT a/w fractures
Treatment of hemophilia A
IV recombinant F VIII
prophylaxis also desirable
Describe hemophilia B
- Deficiency of F IX
- X-linked recessive
- Clinically identical to hemophilia A
Treatment of hemophilia B
Recombinant F IX concentrate
Describe F XI deficiency
- Autosomal co-dominant
- MC in Jewish population
Clinical presentation of F XI deficiency
- Few are symptomatic
- Most present in adulthood
- Similiar symptoms to hemophilia (easy bruising and bleeding)
Treatment of F XI deficiency
FFP
Describe Vitamin K including its role in clotting
- Fat soluble vitamin, absorbed through gut
- Activation of many proteins including clotting factors II, VII, IX, X
- Activation of anti-thrombotic proteins C and S
Why can pathological bleeding/thrombosis occur in liver failure?
Liver is major homeostatic organ - dysfunction throws the hemostatic balance out of whack
How to treat coagulopathy of liver disease?
FFP - then you can anticoagulate after if thrombosis is a significant problem
Describe coagulopathy of kidney disease
Usually more mild than that of liver disease
Treatment of coagulopathy of kidney disease
Restore renal function first! Then FFP/transfusion may help
Clinical hallmark of DIC?
Diffuse bleeding frequently from mucosa/sites of previous surgery and organ failure d/t thromboses
Lab findings characteristic of DIC
- Microangiopathic Hemolytic Anemia
- Thrombocytopenia
How to differentiate DIC from TTP?
PT and aPTT should be NORMAL in TTP (also fibrin degradation products)
How to treat DIC?
- First, address underlying cause
- Next consider FFP
- Use transfusions sparingly
- Anticoag is risky
What blood test monitors unfractionated heparin activity?
aPTT
Describe hypercoaguable states in general
- Pathologic thrombosis (particularly in venous structures)
- Excessive activation of soluble clotting factors
What are the inherited hypercoaguable states?
- Factor V Leiden
- Prothrombin gene mutation G20210A
What is the MC inherited hypercoaguable state?
Factor V Leiden
What does the Factor V Leiden mutation cause?
Resistance to the inhibitory effects of activated Protein C
Situational risk factors for hypercoaguable states?
- Surgery
- Immobilization
- Pregnancy
- HRT
- HIT
Acquired risk factors for hypercoaguable states?
- IBD
- Portal HTN
- Cancer and chemo
- Nephrotic syndrome
- Anti-phospholipid antibody syndrome (lupus anticoag)
