Coagulation (lec 11)

Question 1

3 methods of hemostasis?

Answer 1

1) Vascular contraction
2) Platelet adhesion, activation, aggregation
3) Fibrin formation/reinforcement of platelet plug

Question 2

Activated Partial Thromboplastin Time (PTT) measures?

Used for?

Answer 2

Measures Intrinsic Pathway (at XII, XI, IX):
time until clotting following Ca2+, phospholipids, kaolin

measures effectiveness of Heparin

Question 3

Prothrombin Time/International Normalized Ratio (INR/PT) measures?

Used for?

Answer 3

Measures Extrinsic Pathway (at VII):
time until clotting following thrombplastin

measures effectiveness of Warfarin

Question 4

S/E of all anticoag?

Tx?

Answer 4

hemorrhage

stop therapy,
protamine sulfate (bind heparin)

Question 5

Contraindications for all anticoag?

Answer 5

active bleeding

Question 6

Abrupt Anticoag cessation leads to?

Answer 6

thrombotic events

Question 7

Coag cascade can be inhibited by what 3 inhibitors?

Answer 7

Antithrombin III (at X and Thrombin)
TF inhibitor (at VII)
Protein C/S inhibitor (VIII and V)

Slide 4

Question 8

Site of drug action: Heparin?

Answer 8

Intrinsic: IXa
Common: Xa, Thrombin

Question 9

Site of drug interaction: Warfarin?

Answer 9

Intrinsic: IX
Extrinsic: VII
Common: X, prothrombin
Protein C/S