CCS Hemostasis and Coagulation Management 3

Question 1

In the coagulation cascade, which pathway is initiated by tissue factor exposure at the site of vascular injury?

Accepted Answer

Extrinsic pathway

Answer

The extrinsic pathway is triggered when tissue factor (TF), exposed after vascular injury, binds circulating factor VIIa to initiate coagulation.

Question 2

Which topical hemostatic agent works by providing a physical matrix that activates the intrinsic coagulation pathway and is derived from bovine or human thrombin?

Accepted Answer

Fibrin sealant (Tisseel)

Answer

Fibrin sealants contain concentrated fibrinogen and thrombin; when applied, they mimic the final common pathway of coagulation, rapidly forming a fibrin clot at the bleeding site.

Question 3

Which point-of-care viscoelastic test provides information about clot formation, clot strength, and fibrinolysis and is commonly used to guide transfusion in cardiac surgery?

Accepted Answer

Thromboelastography (TEG) or ROTEM

Answer

TEG (thromboelastography) and ROTEM (rotational thromboelastometry) are viscoelastic tests that assess whole-blood clotting dynamics, including clot initiation, propagation, strength, and fibrinolysis.

Question 4

Which coagulation factor is activated by thrombin and serves as the final enzyme in converting fibrinogen to fibrin?

Accepted Answer

Thrombin (Factor IIa)

Answer

Thrombin (Factor IIa) cleaves fibrinogen into fibrin monomers that polymerize to form a fibrin clot, and also activates Factor XIII to cross-link and stabilize the clot.

Question 5

A patient with known heparin-induced thrombocytopenia (HIT) requires cardiac surgery with CPB. Which anticoagulant is the preferred alternative to heparin?

Accepted Answer

Bivalirudin

Answer

Bivalirudin is the preferred alternative anticoagulant for CPB in HIT patients; it directly inhibits thrombin, has a short half-life, and can be monitored by ACT.

CCS - Certified Cardiac Surgeon Practice Test

CCS - Certified Cardiac Surgeon Practice Test

CCS Hemostasis and Coagulation Management 3