Coagulation testing

Question 1

Sample collection

Answer 1

-Minimal excitement
-Clean venipuncture
-Citrated (blue top)
-Centrifuge and remove plasma within 30min of collection (freeze if you can’t)

Question 2

Activated clotting time

Answer 2

Screens the intrinsic and common pathways

Question 3

Activated clotting time

Answer 3

Screens the intrinsic and common pathways
Not sent to laboratory and best done at 37 C

Question 4

Problems with ACT

Answer 4

-Not very sensitive, need very deficient coagulation to see effect
-Requires pt platelets so if they are thrombocytopenic it can give you longer clotting times

Question 5

Activated Partial Thromboplastin Time (PTT)

Answer 5

Screens intrinsic and common pathways and more sensitive and not affected by thrombocytopenia (phospholipid and Ca added for a negative surface)
Blue top

Question 6

Prothrombin Time (PT)

Answer 6

Screens extrinsic and common pathways more sensitive to and not affected by thrombocytopenia
Sensitive indicator of warfarin toxicity

Question 7

Fibrin/Fibrinogen Degradation Products

Answer 7

Produced constantly in health but rapidly cleared fragments of fibrin from plasmin. Measured to detect increased fibrinolysis associated with excessive coagulation. Reported as 3 options based off of 2 dilutions

Question 8

Increased FDP

Answer 8

DIC, Hemorrhage, Thrombosis

Question 9

Decreased FDP

Answer 9

Liver failure

Question 10

D-Dimer

Answer 10

Fibrinogen that has been converted to fibrin and cross linked by XIII fives rise to specific degradation product when cleaved by plasmin. These are the crosslinks put in from XIII so we know it was from a clot. and much more accurate than FDPs

Question 11

Antithrombin (AT or ATIII)

Answer 11

Will bind to heparin like molecule and will bind and inactivate thrombin and responsible for most of the anticoagulant activity. Can be lost with glomerular dz and can result for coagulability and thrombosis