Evaluation of a Bleeding Patient

Question 1

What are the steps in platelet plug formation?

Answer 1

a. PLATELETS attach to exposed collagen
b. aggregation trigger (ADP and TXA2 release)
c. ADP attracts more platelets
d. TXA2 causes vasocontriction

Question 2

Suppose you get a patient that clots after being cut then bleeds again in 6-9 hours. What should you consider?

Answer 2

Factor XIII mutation

Question 3

What 4 types of bleeding are you likely to see with bleeding disorders?

Answer 3

• Purpura
• Petechiae
• Ecchymoses
• Hemarthroses

Question 4

T or F: Portal HTN can be a sign of low platelets.

Answer 4

True

Question 5

What nutritional defects have the potential to lead to thrombocytopenia?
• What are some things that should be in your ddx for thrombocytopenia?

Answer 5

Nutritional:
• B12 or Folate Deficiency

Others:
Bone marrow failure, Chemo/Rad Exposure, Marrow infiltration

Question 6

What level of platelets is classified as thrombocytopenia?

Answer 6

Less than 150,000

Question 7

You see large platelets on the peripheral smear and a patient is thombocytopenic. What is most likely the cause of the thrombocytopenia?

Answer 7

Increased Consumption of Platelets: 
• ITP
• HIT
• HUS
• TPP
• DIC

Question 8

How would you run through the DDx of a 75 yr old man who has macrocytosis, pancytopenia, and a low platelet count?

Answer 8

Nutritional - Run Tests
• B12, Folate

Alcohol or Medications - Get from Hx.

If all else is negative take a bone marrow biopsy to test for Myelodysplasias or other pathologies

Question 9

At what percent platelet hypoaggregation do you begin to suspect qualitative disorders?

Answer 9

less than 20%

Question 10

In what cases might a patient who is actually hypercoagulable present with a lower PTT?

Answer 10

Lower PTT:
• Lupus Anticoagulant - in vivo it promotes thombosis, but in vitro it blocks phospholipids that act as a platform for catalysis of promthrombin activation

Lower PTT:
• Factor XII deficiency in vitro causes Hypercoagulable state

Question 11

What is hemophilia C?
• How is it inherited?
• Epidemiology?
• Prolonged PT or PTT?

Answer 11

Factor XI deficiency

Inherited as Autosomal Recessive in A. Jews

**PTT prolonged

Question 12

How are Hemophilia A and B inherited?

Answer 12

X-linked Recessive

Question 13

If von Willibrand’s disease is present will you see a change in PT or PTT?

Answer 13

PTT is prolongued but not always - this makes sense because vW being low would lead to Factore VIII being destabilized

Question 14

If someone has an autoimmune disease, what types of bleeding disorders should you expect?

Answer 14

Things that are Antibody Mediated like ITP and Lupus Anticoagulant

Question 15

What clotting factors would be depressed in:
• Liver Disease
• Vitamin K Deficiency
• DIC

Answer 15

Liver Disease:
• Decreased V, VII, X

Vit. K Deficiency:
• Decreased VII, X

DIC
• Decreased V, VII, VIII, X

Question 16

When taking Warfarin, what happens to the PT and PTT in the short term and Long Term?

Answer 16

Short Term:
• HIGH PT (because of factor VII decrease)

Long Term:
• HIGH PTT and PT (because of

Question 17

What clotting factors are Vit. K dependent?

Answer 17

• Factor II, VII, IX, X, protein C and S.

Question 18

What are some factors that can cause a Vit. K deficiency?

Answer 18

• Nutritional Deficit
• Antibiotic Use
• Fat Malabsorption

Question 19

How would you treat a vitamin K deficiency?

Answer 19

Mild:
• Vit K replacement

Severe:
• Fresh Frozen Plasma

Question 20

Is Vit. K replacement an effective way to treat Clotting Factor deficiencies caused by Liver Disease?
• What if fibrinogen is low?

Answer 20

NO, the liver can’t do anything with the Vit. K, you should give these patients Fresh Frozen Plasma (all clotting factors)

Low Fibrinogen
• Cryoprecipitate (with Fibrinogen, VIII, XIII, and vWF would do)

Question 21

What’s the idea behind giving a patient IVIG or anti-Rh?

Answer 21

IVIG:
• Throwing a dog a bone…Spleen will have to take up Ig therefore it won’t attack the platelets bound by ig

anti-Rh:
• Causes RBC lysis and the liver and spleen attack the remnants and it prevents them from attacking platelets

Question 22

What common bacteria is associated with ITP?

Answer 22

H. Pylori

Question 23

Why do you see elevated LDH in the microangiopathic hemolytic anemia/thrombocytopenia?

Answer 23

1. Anoxic Injury - blood isn’t getting to the periphery so cells there die without oxygen
2. RBC lysis - lots of LDH because all they can do is glycolysis

**Not Seen in Extravascular Hemolysis Diseases

Question 24

What are the effects of Hemoglobin that results from extravascular hemolysis?

Answer 24

• HEMOSIDEROSIS in kidney’s
• LOW Haptoglobin
• HIGH Unconjugated/Direct Bilirubin

Question 25

Compare the following for extravascular and Intravascular hemolysis: • LDH • Bilirubin • Haptoglobin

Answer 25

Intarvascular: • LDH - VERY ELEVATED • Bilirubin - Elevated • Haptoglobin - ABSENT Extravascular: • LDH - elevated • Bilirubin - elevated • haptoglobin - Normal/absent

Question 26

Compare the following for extravascular and Intravascular hemolysis: • Hemoglobinurea • Free Hb • Urine Hemosiderin

Answer 26

Intravascular: • Hemoglobinurea - present • Free Hb - present • Urine Hemosiderin - present Extravascular: • Hemoglobinurea - absent • Free Hb - Absent • Ureine Hemosiderin - absent

Question 27

T or F: ITP causes microangiopathic Hemolytic Anemia

Answer 27

False, diseases like TTP, HUS, and DIC do this

Question 28

``` Which of the following microangiopathic hemolytic anemias corrects on a mixing study? Explain. • HUS • TTP • DIC • aHUS • SLE ```

Answer 28

ONLY DIC will correct in a mixing study because it is not antibody mediated and there will be enough factor to make a clot • IN all the others the amount of antibody in the plasma will block clot formation

Question 29

What causes are some factors besides sepsis that can cause DIC?

Answer 29

* Metabolic Stress * Obsterical Complication (pre-eclampsia/eclampsia) * Malignancies * Severe Burns

Question 30

What single lab test can tell you that someone is in DIC?

Answer 30

NONE, it takes SEVERAL lab tests to confirm DIC

Question 31

How do you treat DIC?

Answer 31

DIC is treated by treating the organism or disease that is causing DIC

Question 32

What should be on your differential for DIC?

Answer 32

* Severe Liver Failure/Liver Disease * Vit. K Deficiency * TTP * Congenital Abnormalities of Fibrinogen * HELLP syndrome

Question 33

When is plasma Therapy given:

Answer 33

ONLY indicated in ACTIVE bleeding (or invasive procedures) ***Avoid having to do this in procedures by choosing a tamponadable site (e.g. put a central line into the femoral artery instead of subclavian etc.)***

Question 34

What is a good option to give your patient if they only need fibrinogen?

Answer 34

• Cryoprecipitate (provides vWF, VII, X, and fibrinogen)

Question 35

When do you give a whole blood transfusion? | • how much do you give?

Answer 35

Indication: * Active Bleeding * Loss of RBCs in hemolysis 1 unit/10kg

Question 36

Should you give heparin during DIC?

Answer 36

• Use is very controversial MAYBE implicated with evidence of fibrin deposition and a large clot

Question 37

When should you start getting suspicious of HIT?

Answer 37

ANYONE who has been in the HOSPITAL recently or has had a procedure done that may have required heparin.

Question 38

What is the pathophysiology of HIT?

Answer 38

1. Heparin Binds to PF4 on the platelet 2. Ab. binds the Heparin:PF4 combo after it dissociates from the surface 3. Fc receptor on the platelet binds Fc region on Ab 4. Macrophages in the Spleen Remove the Platelet

Question 39

T or F: everybody that has HIT associated antibodies needs to avoid heparin

Answer 39

FALSE, many people have HIT associated Abs. HOWEVER only a small portion of these patients will have the HIT syndrome itself **30% of the population is positive for these abs. but only a small portion would ever experience HIT

Question 40

What test would you for sure want to use on a patient with an autoimmune disease if testing for HIT?

Answer 40

Serotonin Assay (aka Functional assay)

Question 41

How does the pyrimid model apply to HIT?

Answer 41

Thrombosis: only 0.2-1.0% of ppl. Thrombocytopenia: only 1-3% of ppl. 30% are + for the Heparin Ab.

Question 42

**What are the 4 Ts of determining whether or not to run a Heparin Lab Assay.

Answer 42

Thrombocytopenia: >50% (2); 30-50% (1) **Timing: 5-10 days or less than 1 with prior exposure Thrombosis: New Thrombosis, Skin Necrosis oTher cause: none (2); possible (1) **test anyone with 5 or higher

Question 43

T or F: if someone has a weakly positive immunologic Heparin assay, you might still want to run a functional assay because they still might have HIT.

Answer 43

TRUE, this would happen if the clinical probability of them having the disease was high (functional assay = serotonin assay)

Question 44

T or F: its still only to give Low Molecular Weight Heparin with HIT.

Answer 44

FALSE