Coagulopathy Cases

Question 1

2 areas of focus for a PE in a patient with a suspected bleeding disorder

Answer 1

Evidence of recent bleeding

Evidence of a systemic disease which may have secondary bleeding complications

Question 2

Platelet type bleeding (what is it, 2 indications)

Answer 2

The physical findings suggest a platelet problem as the cause for the patient’s bleeding
2 indications: petechiae and mucosal surface bleeding

Question 3

Factor type bleeding

Answer 3

Suggested by hemarthroses and deep tissue hematomas

Question 4

3 tests that form part of a coagulation screening panel

Answer 4

PT/INR
PTT
CBC with a PBS

Question 5

What will the lab results look like for someone with a non-hematological bleeding?

Answer 5

Normal INR, PTT, and platelet count

Question 6

Is PTT or PT intrinsic or extrinsic?

Answer 6

PTT: intrinsic

PT/INR: extrinsic

Question 7

vW Disease

Answer 7

In the category of factor deficiency (vWF)
VWF is a carrier protein for factor 8
If severely deficient, can lead to a prolonged PTT via associated factor 8 deficiency

Question 8

Factor inhibitors

Answer 8

Can be medications, specific factor inhibitors, or non specific factor inhibitors

Question 9

Mixing studies

Answer 9

Determines whether a prolonged PTT is due to a factor deficiency or inhibitor
Mix patient’s plasma with a control plasma
If deficient, the PTT will be corrected
If there is an inhibitor, the PTT will remain long
Only can be interpreted with confidence when the PTT is significantly prolonged

Question 10

vWD clinical and lab presentation

Answer 10

Platelet-type bleeding (mucosal bleeding)
Normal or mildly prolonged PTT
Mild vWD is one of the causes of hematologic bleeding with a normal PTT, INR and CBC!

Question 11

Why is an inherited deficiency of factor 12 unlikely?

Answer 11

12 deficiency is not associated with bleeding

Question 12

Do platelte abnormalities cause INR and PTT abnormalities

Answer 12

NO

The coagulation cascade is completely separate from platelet activity in vitro

Question 13

Coagulopathy

Answer 13

Increased tendency to bleed, impaired hemostasis, or bleeding disorder

Question 14

Thrombophilia

Answer 14

Predisposition to clotting

Question 15

Are single deficiencies of factors in the common pathway common?

Answer 15

Nope!

If PT and PTT are both abnormal, more likely to be multiple factor deficiencies

Question 16

How does liver disease contribute to reduced factor production

Answer 16

Liver synthesizes most of the coagulation factors

Liver probs = multiple deficiencies = INR and PTT prolonged

Question 17

Vitamin K is required for the synthesis of what factors?

Answer 17

10, 9, 7, 2

Question 18

How does vitamin K deficiency contribute to reduced factor production

Answer 18

Needed for the synthesis of 4 factros

Vit K deficiency = prolongation of INR and PTT (INR more so)

Question 19

How to determine between factor deficiencies from liver disease and vitamin K deficiencies

Answer 19

Give vitamin K
If vitamin K is the problem, the factor levels, INR and PTT will normalize within 1-2 days
No effect if liver synthesis is the problem

Question 20

Specific factor inhibitors

Answer 20

Antibodies with activity against a specific clotting factor

Question 21

Non specific factor inhibitors

Answer 21

The inhibitor is not specific against a certain factor - broadly inhibits the formation of a clot
AKA lupus anticoagulant

Question 22

How can medications be factor inhibitors

Answer 22

Anticoag meds can prolog the PTT and prevent correction of the pTT when mixed with normal plasma
Ex: DOACs
May also prolong INRO
Don’t do a mixing study if they are on these drugs!

Question 23

Lupus anticoagulant

Answer 23

Anti-phospholipid antibody
Autoantibodies that tend to lead to a thrombotic tendency, NOT a bleeding tendency
It is an in VITRO anticoagulant phenomenon, not in VIVO
Add extra phospholipid to PTT test and it will normalize

Question 24

If you see a patient with a prolonged PTT who is NOT bleeding and has no history, what do you think of?

Answer 24

It may well be due to a lupus anticoagulant

Question 25

If you did a PTT mixing study on a patient on warfarin, would it correct or not?

Answer 25

It would correct
Warfarins MOA isnt factor inhibition (its factor depletion)
But you would never order a PTT mixing study on a patient on warfarin