Bleeding and Bruising Disorders Flashcards
What is the normal platelet count per microliter in healthy blood?
150,000-300,000
Thrombocytopenia platelet count
<70,000
When does a bleeding tendency develop - severe thrombocytopenia
<10,000 - 20,000/ml
Aplastic anemia
loss of all hematopietic cells
leukemia
replacement of normal cells with tumor cells
Infectious agents that affect megakaryocytes?
Rubella
What is the genetic pattern of inheritence for Hemophilia
Sex-linked, located on the X chromosome
Who is affected by hemophilia, daughters or sons?
Daughters will be asymptomatic carriers
Sons with have the bleeding disease
Which hemophilia is more common and more severe?
Hemophilia A (VIII) is more common and more severe
Which hemophilia is associated with factor IX deficiency?
Hemophilia B (Christmas disease)
Hemophilia: characteristic clinical findings
- subcutaneous hematomoas
- hemarthrosis (bleeding around joint) –>joint deformity
What is the most significant abnormality in Hemophilia (lab)?
Prolonged activated partial thromboplastin time (PTT)
[intrinsic pathway]
What two things are normal in hemophilia?
- Prothrombin (PT)
- Bleeding time
[extrinsic pathway]
Why are hemophiliacs at high risk for hepatitis B or C or HIV?
frequent recombinant IV transfusions
Where does Von Willebrand Factor come from?
- endothelial cells (inner wall of blood cells)
2. Megakaryocytes
In the plasma what does vWF bind to and protect to promote sealing off the subendothelial injury?
vWF binds to and protects Factor VIII
important for platelet adhesion
so, when you don’t have vWF Factor VIII doesn’t work as well
What is the most common hereditary coagulation abnormality in humans?
von Willebrand Disease (1 in 100)
Which two types of vWD are autosomal dominant?
Types 1 and 2 and autosomal dominant
Which type of vWD is autosomal recessive?
Type 3
Which of the 3 types of vWD is most common?
Type 1, which is mild. Only an issue during minor surgery and dental extractions
Which chromosome is the vWF gene located?
chromosome 12
Which type of vWD is the most severe?
Type 3
-little to no vWD
What are the clinical manifestations of type 1 and 2 vWD
- easy bruising
- nosebleeds
- bleeding gums
- Heavy menstrual periods
What are the clinical manifestations of type 3 vWD?
- Life threatening GI hemorrhage
- Hemarthrosis
Treatment for vWD (3)
- Factor VIII
- vWF concentrate
- Cryoprecipitates
Disseminated Intravascular Coagulation (progression)
- Microvasculature fibrin thrombi
- Consumption of platelets and coagulation factors
- Hemorrhagic diathesis
A serious and often fatal, acquired thrombohemorrhagic disorder occuring as a secondary complication to a variety of diseases and emergency situations
Disseminated Intravascular Coagulation
Name 6 causes of DIC
- Massive Trauma (shock)
- Gram-negative sepsis
- Obstetric Emergencies
- Metastatic and primary carcinomas (ex. mucin-producing adenocarcinomas)
- Hematopoietic Disorders (AML) [granules start clotting cascade]
- Other: Surgery, Burns, Hypotensive states
What are some examples of DIC via the intrinsic pathway?
Widespread injury to endothelial cells
Compare the Extrinsic and Intrinsic Pathway
Extrinsic- triggered by release of procoagulant issue factor into circulation
Intrinsic- Widespread injury to the endothelial cells (ex. Burn, heat stroke, viral, rickettsial infection, antibody-antigen complexes)
Obstetrical accidents that can trigger extrinsic pathway in DIC
- Premature separation of placenta (abruptio placenta)
- retained dead fetus
- septic abortions
- amniotic fluid embolism
Microvascular obstruction is associated with widespread ischemic changes particularly where?
- Brain
- Kidneys
- Skin
- Lungs
- Adrenals
- GI tract
What is the cause of massive adrenal hemorrhages, shock and death?
Meningococcemia - massive adrenal hemorrhages (Waterhouse-Friderichsen Syndrome)
What skin finding is associated with Waterhouse-Friderichsen Syndrome?
purpura
Schistocytes
fragmented erythrocytes
What is the consequence of consumption of activated platelets?
thrombocytopenia
What will be seen on labs with depletion in clotting factors?
- Increased PT time (extrinsic) and PTT time (intrinsic)
- Decreased plasmin fibrinogen level
- Elevated Fibrinopeptide A and D dimers
D dimer elevation is an indication of what?
fibrinolytic activation
high D dimer? –>bleeding diathasis
Symptoms of DIC
Renal symptoms: mild azotemia to acute renal failure from bilateral cortical necrosis
Acute respiratory distress syndrome
Hemorrhage of GI ulcers
What are 3 hallmarks of the bleeding diathesis?
- cerebral hemorrhage
- ecchymosis
- Hematuria
TX for DIC
Heparin for cycle of intravascular coagulation
Platelets and clotting factors for bleeding diathesis
Hereditary Disorder of Platelets (Bernard- Soulier Syndrome)
“Giant Platelet Syndrome”
- Autosomal recessive
- Big platelets
- Fewer platelets
How is diagnosis of Hereditary Disorder of Platelets (Bernard-Soulier Syndrome) made?
- Thromocytopenia
2. Giant platelets on blood smear
Why does Hereditary Disorder of Platelets (Bernard-Soulier Syndrome) occur?
membrane protein defect
When does Hereditary Disorder of Platelets manifest?
infancy or childhood
How does Hereditary Disorder of Platelets (Bernard- Soulier Syndrome) manifest?
- ecchymosis
- epistaxis
- gingival bleeding
