Bleeding Disorders Flashcards
(36 cards)
Some bleeding disorders are caused by platelets would be…
Thrombocytopenia and platelet dysfunction
Some bleeding disorders caused by cloting wolud be….
Vitamine K deficiency, hemophilia, von Willebrand syndrome, liver disease
Some bleeding disorders caused by blood vessel integrity would be…
Vitamin C deficiency - makes collagen not work and then arterial walls get weaker. Cushing Syndrome - cortisol causes decreased vessel wall integrity
What signs and symptoms would exist with someone with a bleeding disorder?
Bleeding gums, nosebleeds, petechiae, purpura, echymoses, easy bruising, prolonged bleeding following trauma, surgery, and dental work. Blood in stools and urine, bleeding into a joint (hemarthrosis), excessive menstrual bleeding (menorrhagia)
What’s another word for platelets?
Thrombocytes. They hang out in the spleen and also removed by the spleen after 8 to 12 days.
Where do thrombocytes come from?
They develop from megakaryocytes in the bone marrow. They break apart into fragments which become platelets. One megakaryocyte makes 1000’s of platelets.
What hormone stimulates thrombopoiesis?
Thrombopoietin - which is in the liver, kidney, smooth muscle and bone marrow.
Does thrombocytopenia affect clotting?
No, it just affects how the platelet plug is formed because there’s just not enough platelets.
Does thrombocytopenia affect big vessels much?
No, it affects smaller blood vessels like the skin or mucous membranes of the mouth, nose, gi tract, and uterus.
What is the etiology of thrombocytopenia?
1) Decreased platelet production
2) Increased platelet destruction
3) Increased sequestration by the spleen
What would cause decreased platelet production?
1) Folate and vitamine b12 deficiency
2) aplastic anemia (idiopathic or chemo)
3) Radiation therapy or chemo
4) Leukemia (crowding of bone marrow by malignant cells)
5) Infections (HIV, cytomegalovirus)
What would cause increased platelet destruction?
1) Drug induced thrombocytopenia (heparin)
2) Immune Thrombocytopenia purpura (ITP) (antibodies target platelets)
3) Autoimmune disorders (Lupus)
4) Mechanical injury (heart valves, malignant hypertension)
What would cause splenic sequestration (pooling) of platelets?
1) Splenomegaly (from portal htn, or liver or heart failure) The spleen becomes overactive and destroys platelets and WBC’s
2) Hypothermia
Does whole blood have platelets?
No
In Heparin induced thrombocytopenia, what do antibodies bind onto?
They bind onto heparin-platelet factor 4 (PF-4) complexes. PF-4 is released from platelets and bind to heparin and then 10% people develop antibodies against this complex.
What happens when antibodies bind to PF-4?
1) Platelets are targeted for destruction in the spleen - Transient thrombocytopenia
2) Platelets get activated causing increased risk of thrombosis.
What autoimmune disorder can cause platelets to be destroyed by macrophages in the spleen?
Immune Thrombocytopenia Purpura (ITP). In this illness, autoantibodies against platelet glycoproteins target platelets for destruction by macrophages in the spleen. This also triggers MAC.
ITP can be classified as Primary or Secondary. Explain the difference.
1) Primary or secondary. Primary is idiopathic. Secondary is due to AIDS, lupus, antiphospholipid syndrome, certain drugs.
ITP can also be classified as acute or chronic. Explain the difference.
ITP that’s acute is less than 6 months. Chronic ITP is > 12 months. The in between part is called “persistent” - 6 months to 1 year.
Childhood (acute) ITP can happen after viral infections and certain vaccinations. What common vaccination can trigger this issue?
MMR. People usually get better after 2 weeks - 6 months when the infection is cleared.
What age group is commonly affected by childhood ITP?
5 years old.
What are the symptoms of childhood ITP?
Petechiae and purpura.
What age group commonly gets adult ITP?
18 years old to 40 years old.
Who’s more likely to get ITP? A man or a woman?
A woman
