Other disorders of hemostasis

Question 1

heparin induced thrombocytopenia pathophys

Answer 1

heparin forms a complex with platelet factor 4, leading to formation of igG antibodies and consumption of platelets

Question 2

DIC pathophys

Answer 2

• widespread microthrombi lead to ischemia and infarction

- consumption of platelets and factors leads to bleeding

Question 3

What disease processes may DIC occur secondarily to…

Answer 3

Obstetrics complications -tissue thromboplastin activates coagulation
Sepsis – endotoxins/cytokines induce Tissue factor
Adenocarcinoma - mucin activates coagulation
Acute promyelocytic leukemia -primary granules activate coagulation
Rattlesnake bite -venom activates coagulation

Question 4

Lab findings in DIC

Answer 4

Decreased platelet count
Decreased fibrinogen
Increased PT/PTT
Microangiopathic hemolytic anemia
Elevated fibrin split products -D Dimer

Question 5

Treatment of DIC

Answer 5

Treat underlying cause

Blood transfusion and cryoprecipitate as needed

Question 6

alpha-2 antiplasmin function

Answer 6

inactivates plasmin

Question 7

tPA function

Answer 7

activates plasminogen to plasmin

Question 8

What are the two disorders of fibrinolysis?

Answer 8

Radial prostateectomy – release of urokinase activates plasmin
Cirrhosis of liver – reduced production of alpha-2 antiplasmin

Question 9

presentation and lab findings of disorders of fibrinolysis

Answer 9

plasmin overactivity –> increased bleeding time
Increased PT/PTT
Increased bleeding time with normal platelets
Increased fibrinogen split products with absent D-Dimers(no fibrin thrombi present)

Question 10

treatment of disorders of fibronolysis

Answer 10

aminocaproic acid (blocks activation of plasminogen)

Question 11

how to distinguish thrombus from post mortem clot?

Answer 11

lines of zahn (alternating platelets/fibrin and RBC layers) and attachment to blood vessel wall

Question 12

virchows triad

Answer 12

blood flow disruption, endothelial damage, hypercoaguable state

Question 13

Lack of B12 or folate results in build up of what?

Answer 13

homocysteine

Question 14

Homocysteine causes waht

Answer 14

endothelial damage

Question 15

What is cystathionine beta synthase deficiency

Answer 15

Cause of high homocysteine with homocystinuria

CBS usually converts homocysteine to cystathione

Characterized by vessel thrombosis, mental retardation, lens dislocation and long fingers

Question 16

What is factor V leiden?

Answer 16

A mutated form of factor V that lacks the cleavage site for deactivation by protein C and S

Question 17

What is prothrombin 20210A?

Answer 17

An inherited point mutation in prothrombin that results in increased gene expression

Question 18

What is ATIII deficiency and what will happen with heparin dosages?

Answer 18

ATIII usually inactivates thrombin and coag factors, thus with a deficiency PTT does not rise with standard heparin dosing

Must give high dose of heparin then switch to Coumadin

Question 19

How does estrogen effect coagulation?

Answer 19

Increases production of coag factors

Question 20

Atherosclerotic embolus histology

Answer 20

Will have cholesterol clefts

Question 21

Fat embolus histology

Answer 21

fat with bone marrow elements

Question 22

What is the cause of a gas embolus?

Answer 22

Usually from rapid ascent of a diver, as nitrogen gas precipitates out of blood, leading to the bends

Question 23

Symptoms of the ‘bends’

Answer 23

Joint, muscle pain. Respiratory symptoms

Question 24

Amniotic fluid embolus presentation

Answer 24

DIC, SOB, neurological symptoms

Question 25

Amniotic fluid embolism histology

Answer 25

squamous cells and keratin debris in embolus from fetal skin

Question 26

Death from PE is caused by what?

Answer 26

electromechanical dissociation in heart