Clotting Disorders
last authored: Oct 2009, Dave LaPierre
Introduction
The Case of...
a simple case introducing clincial presentation and calling for a differential diagnosis. To get students thinking.
Causes and Risk Factors
Clotting disorders are characterized by bleeding into joints and muscles, as well as forming large, spreading ecchymoses and hematomas.
Platelet disorders are characterized by peteciae, purpura, bruising, mucocutaneous bleeding (epstaxis, ginigival bleeding), mennhoragia, and bleeding from superficial cuts.
In the eldery, do a malignancy workup.
target
|
condition
|
mechanism
|
coagulation cascade |
hemophilia A hemophilia B |
factor VIII deficiency factor IX deficiency abnormal vWF vitamin K deficiency |
platelets |
idiopathic thrombocytopenic purpura (ITP), infection, drugs DIC, hemangioma, hypersplenism vonWillebrand disease, ASA, uremia marrow infiltration, leukemias, drugs |
increased destruction increased consumption dysfunction decreased production |
blood vessels |
Henoch-Schonlein purpura |
vasculitis |
HELLP stands for hemolysis, elevevated liver enzymes, low platelets
Pathophysiology
Signs and Symptoms
- history
- physical exam
History
Can be platelets or coagulation cascade.
Bruises bigger than a size of a toonie.
Locations not likely to be trauma.
Nosebleeds (epistaxis): duration, oozing from both nostrils.
Hematemesis
Petechiae can be normal on chest and neck following vigorous coughing, vomiting, etc.
It is, however, a red flag, suggestive of platelet dysfunction.
Physical Exam
Assessing Bleeding
- prolonged INR
- low platelets
- prolonged PTT
- normal values
Prolonged INR
50:50 correction suggests factor deficiency.
VII deficiency - genetic
X, IX, VII, II
- warfarin
- vitamin K deficiency
Prolonged PTT
50:50 correctible
VIII, IX
sex-linked, hemophilia A and B
PTT 60-80s
XI, XII
autosomal dominant
VWB
normal platelet numbers, but increased PFA (platelet function analysis)
50:50 - non-correctible
inhibitory antibody
- someone with hemophilia who has been getting VIII replacement
- elderly (cause unknown; difficult to treat)
- lymphoma
- pregnancy (transient)
Treatment
- emergent: exogenous activated F VII
- imunosuppressants (cytoxan, prednisone)
- IVi
heparin (commonly from line flushing)
- identify with thrombin time (TT) or hepabsorb
APLA
Normal Values
Normal platelets, INR, PTT
Suggests dysfunctional platelets
- ASA, clopidogrel
- uremia (prevents aggregation)
PFA (platelet function analysis) will show dysregulation
Treatments
Consequences and Course
The Case of...
Case #2 - a small story wrapping it all up and asking about esp management.
Additional Resources
Topic Development
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