CVP Coagulation and Anticoagulation Management 1

Question 1

What is the minimum Activated Clotting Time (ACT) required before initiating cardiopulmonary bypass?

Accepted Answer

400 seconds

Answer

An ACT of 400 seconds or greater is required before initiating CPB to ensure adequate anticoagulation and prevent clot formation within the extracorporeal circuit.

Question 2

What is the standard initial heparin dose administered before cardiopulmonary bypass?

Accepted Answer

300 units/kg

Answer

The standard initial heparin dose for CPB is 300 units/kg, which typically achieves a target ACT greater than 400 seconds prior to bypass.

Question 3

Heparin exerts its anticoagulant effect primarily by potentiating which plasma protein?

Accepted Answer

Antithrombin III

Answer

Heparin binds to antithrombin III and dramatically accelerates its inhibition of thrombin (Factor IIa) and Factor Xa, preventing fibrin formation.

Question 4

What is the standard protamine-to-heparin ratio used to reverse anticoagulation after CPB?

Accepted Answer

1 mg protamine per 100 units heparin

Answer

The standard reversal ratio is 1 mg protamine per 100 units of heparin administered, titrated based on post-bypass ACT measurements.

Question 5

A patient requires escalating heparin doses to achieve a target ACT before CPB. The most likely cause of heparin resistance is:

Accepted Answer

Antithrombin III deficiency

Answer

Heparin resistance is most commonly caused by antithrombin III deficiency, since heparin cannot exert its anticoagulant effect without this cofactor.

(CVP) Cardiovascular Perfusionist Practice Test

(CVP) Cardiovascular Perfusionist Practice Test

CVP Coagulation and Anticoagulation Management 1