Hemostasis 1

Question 1

primary vs secondary hemostasis

Answer 1

primary: vessel wall and platelet
secondary: plasma proteins

Question 2

___ is a more stable clot than thrombin

Answer 2

fibrin

Question 3

these will activate thrombin (extrinsic pathway)

Answer 3

factor x with factor v –> prothrombin –> thrombin

Question 4

these will activate thrombin (intrinsic pathway)

Answer 4

factor 11 -> factor 9 +8 -> factor 10 + factor 5 -> prothrombin -> thrombin

Question 5

three major events in secondary hemostasis

Answer 5

initiation
amplification
propagation

Question 6

normal platelet count

Answer 6

150,000/uL to 450,00/uL

Question 7

indications for abnormal or high wbc

Answer 7

infection, examine bone marrow for leukemia

Question 8

low plt, hb and wbc is normal

Answer 8

peripheral smear must be done to see if plt are clumped (falsely low plt)

Question 9

fragmented rbcs in smear

Answer 9

microangiopathic hemolytic anemias

Question 10

normal rbc moprhology in smear

Answer 10

drug induced thrombocytopenia
infection induced thrombocytopenia
idiopathic immune thrombocytopenia
congenital thrombocytopenia

Question 11

causes for thrombocytopenia

Answer 11

decreased production (aplastic anemia, bone marrow infiltration)
increased destruction (immune mediated)
increased sequestration (hypersplenism)
infections
drugs

Question 12

memorable drugs that can cause thrombocytopenia

Answer 12

acetaminophen
amlodipine
ampicillin
ceftriaxone
cotrimoxazole
heparin

Question 13

pathophysio of hepatin induced thrombocytopenia

Answer 13

antibodies to pf-4 is recognized with heparin -> ig recognize and mark the hep-pf-4 complex -> macrophages in the spleen recognize complexes - platelet removal by splenic macro -> thrombocytopenia + thrombosis

LOW PLATELET + THROMBOSIS

Question 14

4t score

Answer 14

thrombocytopenia
timing of platelet count fall
thrombosis or other sequelae
other causes for thrombocytopenia

Question 15

4t score interpretation

Answer 15

predicts if patient might have heparin-induced thrombocytopenia

<4 = 0.8% risk
4-5 = 11% risk
>5 = 34% risk

Question 16

management of heparin induced thrombocytopenia

Answer 16

discontinue heparin
alternative anticoagulants (lepirudin, argatroban, fondparinux)
do not give low molecular weight heparins

Question 17

patho in immune thrombocytopenia

Answer 17

macrophages destroy antibody coated platelets resulting to thrombocytopenia

Question 18

clinical characteristics of ITP

Answer 18

children: acute, remits in 6 mos
adults: chronic and more persistent
- rule out other disorders
- mucocutaneous bleeding (gums, nose, petechiae)

Question 19

indications for treatment of ITP

Answer 19

indication: plt <30,000 + bleeding = transfution

Question 20

first line treatment for itp

Answer 20

ivig
steroids
anti-rh

Question 21

second line treatment for itp

Answer 21

rituximab (anti-cd20 antibody)
tpo receptor agonists (eltrombopag, romiplostim)
splenectomy (last resort)

Question 22

patho in thrombotic thrombocytopenic purpura

Answer 22

deficiency of mmp adamts13 or antibodies for adamts13

adamts13 = cleaves vwf to make is usable

non cleaved vwf -> large numbers of platelets attached to vwf –> one big clot -> thrombocytopenia

Question 23

pentad of ttp

Answer 23

hemolytic anemia
thrombocytopenia
renal failure (clots in gloms)
neurologic findings
fever

Question 24

conditions that push a patient to develop ttp

Answer 24

hiv, pregnancy, medications, malignancy

Question 25

prognosis of ttp

Answer 25

poor if not treated early, 95% mortality

Question 26

treatment for ttp

Answer 26

plasmapheresis with plasma exchange | steroids to temporize ttp

Question 27

most common inherited bleeding disorder

Answer 27

von willebrand disease

Question 28

patho in von willebrand disease

Answer 28

insufficient or dysfunctional vwf

Question 29

presentation of vwf disease

Answer 29

mucocutaneous bleeding post-op bleeding menorrhagia childhood: excessive bruising, epistaxis

Question 30

types of vwf disease

Answer 30

``` type 1 (quantitative): vwf production is low, most common type 2 (qualitative): vwf is sufficient but abnormal type 3 (combination): most severe, like hemophilia ```

Question 31

treatment for vwd

Answer 31

desmopressin: release the vwf stored in endothelium - prone to tachyphylaxis - hyponatermia vwf concentrates imtermediate purity factor 8 anti-fibrinolytic agents (txa)