CVP Cardiopulmonary Bypass (CPB) Management 5

Question 1

During CPB weaning, the surgeon requests the heart to be loaded with volume. Which action should the perfusionist take?

Accepted Answer

Gradually reduce pump flow and allow venous reservoir to drain into the patient by releasing the venous clamp

Answer

During weaning, the perfusionist gradually reduces pump flow while releasing venous occlusion to allow controlled volume return to the heart for preload assessment.

Question 2

Which phenomenon explains why heparin doses required for CPB anticoagulation may vary significantly between patients?

Accepted Answer

Antithrombin III levels and individual heparin sensitivity vary between patients

Answer

Heparin requires antithrombin III (AT III) as a cofactor, and individual variation in AT III levels and heparin-protein binding causes significant dose-response variability.

Question 3

What is the significance of a persistently elevated venous line pressure during CPB?

Accepted Answer

Suggests venous cannula obstruction, kinked tubing, or elevated CVP from cardiac distension

Answer

Elevated venous line pressure during CPB indicates impaired drainage, which may result from cannula obstruction, tubing kinks, or heart distension compromising venous return.

Question 4

A perfusionist notices the oxygen saturation of blood leaving the oxygenator is 95% but SvO2 from the venous line is dropping to 60%. What does this indicate?

Accepted Answer

Increased oxygen consumption or inadequate systemic oxygen delivery requiring increased flow or FiO2

Answer

A well-functioning oxygenator with falling SvO2 indicates tissues are extracting more oxygen, signaling inadequate delivery relative to demand — increase pump flow or address the underlying cause.

Question 5

Which strategy is used to provide myocardial protection when the aortic valve is incompetent and antegrade cardioplegia cannot be used?

Accepted Answer

Deliver retrograde cardioplegia via the coronary sinus

Answer

Retrograde cardioplegia delivered through the coronary sinus bypasses the incompetent aortic valve, ensuring cardioplegic solution reaches the myocardium without regurgitation loss.

(CVP) Cardiovascular Perfusionist Practice Test

(CVP) Cardiovascular Perfusionist Practice Test

CVP Cardiopulmonary Bypass (CPB) Management 5