14 part 2 Bleeding Disorders Flashcards
What does bleeding time measure?
platelet response to a LIMITED vascular injury
What will make bleeding time abnormal?
deficit in platelet number or function
What test assesses the function of the extrinisic and common pathways?
Prothrombbin Time
What will be elevated with deficiencies in factor VII and /or factors X, V, prothrombin II and fibrinogen I?
PT
What test assesses the intrinsic and common pathways?
Partial Thromboplastin Time (PTT)
What will cause elevation of PTT?
deficiciencies in factors VIII, IX, XI, XII and or factors X,V, Pro II, and fib I
What is a normal platelet count?
150000 - 450000/mm3
If platelet count is abnormal, what should be done?
do PB smear to rule out false thrombocytopenia
What is a normal PT?
10-13 sec
What is a normal PTT?
25-35 sec
What are used to clot in plasma for PTT?
kaolin, cephalin, and Ca
What can clue to bleeding due to vessel wall abnormalities?
petechiae and purpura
normal PTT and PT
What microbes can cause vasculitis or DIC?
menigococcus, IE orgs (strep/staph) and rickettsia
What is a particular term for the kind of hypersensitvity vasculaitis that occurs with drug reactions?
leukocytoclastic
What happens in Ehler-Danlos syndrome?
imparied collagen around the vessel walls causes hemorrhage
How is cushing syndrome similar to Ehlers-Danlos?
loss of perivascular support tissue, but this is due to the protein wasting effects of corticosteroids
What is the name of a vessel wall abnormality that is described by systemic hypersensitvity disease of unknown etiology, which manifests as purpura, colic, polyarhtralgia, and acute glomerulonephritis?
Henoch-Schonlein purpura
What is the mechanism of Sx seen in Hencoh-Schonlein purpura?
immune complex deposition on vessels and glomeruli
WHat is the name for an autosomal dominant vascular disorder, that causes bleeding in dialted, tortuous, thin walled vessels, and manifests primarily in the mucous mambranes of the nose, mouth, and eyes and GI tract mucosa?
Hereditary Hemorrhagic Telangiectasia
What protein is deposited, systemically, from plasma cells in primary amyloidosis?
AL protein
Which two tests are ususally normal in the setting of thrombocytopenia?
PT and PTT
What can occur at a platelet count of <20,000?
spontaneous bleeding
What affect do megalolastic anemias have on platelet production?
ineffective megakaryocyte production
How long are platelets viable in transfusable blood?
24 hours