Hematology

Question 1

Ddx for Microcytic anemia (MCV <100)

Answer 1

Iron Deficiency
Thalassemia
Anemic or Chronic disease (low normal MCV)
Sideroblasic anemia
Lead poisoning

Question 2

DDX Macrocytic amenia (MCV >100)

Answer 2

Megaloblastic anemia:folic acid or Vit B12 def
Liver diease
Alcoholism 
Reticulocytosis
Hypothyroidism
Myelodysplastic syndrome
Antiretrovirals (AZT)

Question 3

What is the onset and peak effect of vitamin k? IV and PO

Answer 3

IV 1-2 hours onset peak effect 6-12 hours

PO 6-12 hours onset peak effect 12-24 hours

Question 4

What are the vitamin K sensitive clotting factors?

Answer 4

2,7,9,10

Question 5

At what platelet count do you worry about spontaneous hemorrage?

Answer 5

<20

Question 6

What are some common anti-platelet drugs?

Answer 6

1. Aspirin (irreversible* cyclooxygenase inhibitor)
2. Adenosine diphosphate (ADP) receptor inhibitors
   - Clopidogrel (Plavix)
   - Prasugrel (Effient)
   - Ticagrelor (Brilinta)
   - Ticlopidine (Ticlid)
3. Glycoprotein IIB/IIIA inhibitors (intravenous use only)

Question 7

With low platelets or patients with platlet dysfunction, where do they normally bleed?

Answer 7

• Can bleed anywhere but may present with petechiae, have mucosal bleeding
• May have purpura - usu non palpable

Question 8

What time course does HIT (heparin induced thrombocytopenia) appear?

Answer 8

5-7 days after starting heparin or LMWH. There is such thing as delayed onset hit usu up to 14 days post starting, but has been reported to occur 40 days after starting heparin

Question 9

Other than low platelets itself what are other complications of HIT?

Answer 9

Patients can develop an arterial or venous thrombus.

Question 10

What is the HUS triad?

Answer 10

Microangiopathic hemolytic anemia (MAHA)
Renal failure
Thrombocytopenia

Question 11

What is the TTP pentad?

Answer 11

MAHA
Renal Failure (less prominent feature)
Thrombocytopenia
Fever
Neurologic symptoms
- AMS
- Stroke
- Headaches
- Bizarre behavior

Its not common to see this pentad..

Question 12

If you suspect TTP what therapy should you avoid?

Answer 12

Transfusing platelets, may actually worsen condition causing additional thrombi in the micro-circulation.
- Consult Hematology

Question 13

DDX incr INR (measures extrinsic pathway)

Answer 13

• Warfarin
• Vit K deficency
• Severe Liver disease
• Factor 7 def or inhibitor

Question 14

DDX elevated PT/INR and PTT

Answer 14

1. Deficencies of prothrombin, fibrinogen, Factors V and X
2. Heparin + warfarin
3. DIC *
4. Liver Dx

Question 15

DDX incr PTT (measures intrinsic pathway)

Answer 15

1. Heparin
2. Hemophilias
3. vWF

Question 16

Hemophilia A effects what factor?

Answer 16

8

Question 17

Hemophilia B effects what factor?

Answer 17

9 aka. Christmas disease

Question 18

In Hemophiliacs where do they most commonly bleed?

Answer 18

Joints, Deep muscle, urinary tract, Intracranial

Question 19

In platelet disorders like vWF where do they commonly bleed?

Answer 19

Oral bleeding, epistaxis, menorragia,

GIB rare unless other cause - like ulcer etc.

Question 20

What is in cryoprecipitate?

Answer 20

1. Fibrinogen 150-250 mg with a half-life of 100-150 hours
2. Factor VIII 80-150 U with a half-life of 12 hours
3. von Willebrand factor 100-150 U with a half-life of 24 hours
4. Factor XIII 50-75 U with a half-life of 150-300 hours.

Question 21

What is in FFP?

Answer 21

All the blood clotting components, even the liable ones (5,8) but you have to give early after thawing.

Question 22

What is the INR of FFP?

Answer 22

1.5

Question 23

What is a d-dimer?

Answer 23

D-dimers are cross-linked fibrin degradation products

• it is a product of plasmin mediated fibrinoyltic degradation
• They are an excellent marker of fibrinolytic activity

Question 24

What non-pathologic conditions are assoc with an elevated D-dimer? (5)

Answer 24

Non-pathological conditions associated with elevated D-dimer titres include:

1. Age (healthy elderly people)
2. Cigarette smoking
3. Functional impairment
4. Post-operatively
5. Pregnancy
6. Race (e.g. African Americans)

Question 25

When can D-dimer be used to r/o VTE?

Answer 25

In a patient with low pre-test probability of having a VTE

- Need to use Wells criteria for PE or DVT.