Hem Test 1: Platelets

Front 1

3 roles in platelet plug formation

Back 1

adhesion (vWF on collagen, then GPIb-IX on platelet)
aggregation (via fibrinogen bridges)
secretion

Front 2

Fibrinogen bridges form between what?

Back 2

GP IIb-IIIa

Front 3

Collection of mucocutaneous bleeding locations?

Back 3

epistaxis, gum, heavy menses, bruising, GI/GU bleeding

Front 4

Where do petechiae tend to occur? What is going on with platelets?

Back 4

legs, LE; low platelets

Front 5

too few platelets

Back 5

thrombocytopenia

Front 6

too many platelets

Back 6

thrombocytosis

Front 7

Describe pseudothrombocytopenia (platelet clumping)

Back 7

EDTA-anticoagulation, certain pts have a change that causes platelets to clump together (otherwise no bleeding consequence)

check peripheral blood smear

Front 8

levels of platelets that need tx or risk for hemorrhage

Back 8

<20,000

Front 9

three broad causes of thrombocytopenia

Back 9

underproduction (don't make them)
peripheral destruction (make before destroyed)
splenic sequestration (hiding out)

Front 10

Causes of underproduction of thrombocytopenia

Back 10

marrow failure (myelodysplasia, aplastic anemia, vitamin def.)
marrow infiltration (tumors)
marrow toxins (chemo, radiation, infections, alcohol)

Front 11

Non-immune mechanisms of peripheral destruction

Back 11

DIC, TTP

Front 12

process of abnormal generation of thrombin, consumption of clotting factors, destruction of platelets, and activate fibrinolysis

Back 12

DIC

Front 13

Components of DIC diagnosis

Back 13

elevated PT (using up FVII)
low platelets
low/falling fibrinogen
Inc fibrin degradation (D-Dimer)
maybe schistocytes

Front 14

Etiologies of DIC

Back 14

gram- sepsis, severe burns, obstetrical disasters, certain leukemias, shock, insect/snake venoms

regardless, treat underlying cause
-can support with platelets, clotting factors, or fibrinogen

Front 15

Process with abnormal activation of platelets with vWF and fibrin deposition in microvasculature & peripheral destruction of platelets and RBCs

Back 15

thrombotic thrombocytopenic purpura

Front 16

Pentad of Thrombotic thrombocytopenic purpura

Back 16

MAHA(microangiopathic hemolytic anemia)(MUST HAVE)
-inc LDH, inc bilirubin, schistocytes present
low platelets (MUST HAVE)
fever
neurologic manifestations
renal manifestations

Front 17

Underlying Cause of TTP

Back 17

antibody against protease (ADAMTS-13)
-can measure activity levels of ADAMTS-13 or presence of inhibitor to ADAMTS-13

Front 18

When can TTP occur?

Back 18

Drugs (ticlopidine, quinine, cyclosporine, tacrolimus, gemcitabine)
inc incidence with pregnancy or AIDS

Front 19

Tx of TTP

Back 19

plasma exchange (avoid platelet transfusions, fuels the fire)

Front 20

Common HUS manifestations

Back 20

fewer neuro than TTP, more renal manifestations

post diarrheal illness (shiga toxin)

Tx with plasma exchange or supportive care

Front 21

Drugs that can cause thrombocytopenia immune mechanism

Back 21

B-lactam antibiotics
Trimeth-sulfa drugs
quinine/quinidine
heparin

Front 22

What occurs with heparin-induced thrombocytopenia?

Back 22

about 7-10d after heparin starts, platelets drop by 30-50%.

STOP heparin immediately (can lead to thrombosis)

Front 23

Diagnosis of immune/idiopathic thrombocytopenic purpura

Back 23

dx of exclusion (unlike Coombs test in hemolytic a)
-megakaryocytes should be present in marrow

Front 24

When is ITP treated?

Back 24

Not in children, usually resolves

In adults, treat below 30,000 w/ corticosteroids

Front 25

Tx protocol for ITP

Back 25

2/3 resolve on steroids
1/3 have splenectomy

2/3 respond to splenectomy
1/3 have immunosuppression

Front 26

Differences between ITP and TTP

Back 26

TTP has schistocytes; ITP had normal RBCs

Front 27

How many platelets are normally in spleen?

Back 27

1/3; if spleen enlarges, platelet count drops

Front 28

When are platelet transfusions used?

Back 28

when bleeding or prevent bleeding

NOT TTP

Front 29

Describe secondary thrombocytosis

Back 29

working at appropriate reactive responses

inflammation, infection, bleeding, iron deficiency

Front 30

Describe diseases causing primary thrombocytosis

Back 30

essential thrombocythemia, polycythemia vera, CML, and myelofibrosis

Front 31

Qualitative bleeding disorders marked by...

Back 31

prolonged bleeding time

Front 32

2 congenital qualitative platelet disorders

Back 32

Glanzmann's thrombaesthenia (defect in IIb/IIIa)
Bernard-Soulier (defect in Ib/IX)

Front 33

4 main sources of acquired qualitative platelet disorders

Back 33

uremia
drugs (ASA, NSAIDs)
Herbs
Myeloproliferative diseases