Cardiac Surgery Certification Exam Cardiopulmonary Bypass Techniques 2 — Questions and Answers
Question 1: Which agent is most commonly used to achieve myocardial protection during aortic cross-clamping?
- Cardioplegia solution (Correct answer)
- Nitroglycerin
- Adenosine
- Magnesium sulfate
Correct answer: Cardioplegia solution
Cardioplegia solution arrests the heart and protects myocardium from ischemia during aortic cross-clamping.
Question 2: What is the primary advantage of retrograde cardioplegia delivery via the coronary sinus?
- Ensures cardioplegia reaches areas with obstructed coronary arteries (Correct answer)
- Delivers higher cardioplegia volumes
- Avoids aortic cannulation
- Provides more rapid cardiac arrest
Correct answer: Ensures cardioplegia reaches areas with obstructed coronary arteries
Retrograde cardioplegia via the coronary sinus ensures uniform myocardial protection even in areas distal to severely stenotic coronary arteries.
Question 3: Hypothermia during CPB protects organs primarily by:
- Reducing metabolic demand and oxygen consumption (Correct answer)
- Increasing cardiac output
- Improving blood viscosity
- Enhancing diuresis
Correct answer: Reducing metabolic demand and oxygen consumption
Hypothermia decreases cellular metabolic rate and oxygen demand, extending the safe ischemic time for organs during CPB.
Question 4: Which complication is most commonly associated with excessive hemodilution on cardiopulmonary bypass?
- Coagulopathy and impaired oxygen delivery (Correct answer)
- Hypertension
- Hypercalcemia
- Arrhythmia
Correct answer: Coagulopathy and impaired oxygen delivery
Excessive hemodilution dilutes clotting factors and reduces hemoglobin concentration, leading to coagulopathy and decreased oxygen-carrying capacity.
Question 5: The arterial filter in the CPB circuit is used primarily to:
- Remove gaseous and particulate microemboli before arterial return (Correct answer)
- Monitor blood pressure
- Regulate flow rate
- Measure oxygen saturation
Correct answer: Remove gaseous and particulate microemboli before arterial return
The arterial line filter captures microemboli (air bubbles and particulates) to prevent them from reaching the patient's systemic circulation.
Question 6: During weaning from cardiopulmonary bypass, the perfusionist should gradually:
- Decrease pump flow while the heart fills and cardiac output recovers (Correct answer)
- Increase pump flow to maintain MAP
- Administer protamine immediately
- Lower the venous reservoir level rapidly
Correct answer: Decrease pump flow while the heart fills and cardiac output recovers
Gradual reduction of pump flow allows the heart to assume progressive responsibility for circulation while venous return fills the cardiac chambers.
Cardiac Surgery Certification Exam Cardiopulmonary Bypass Techniques 2
Which agent is most commonly used to achieve myocardial protection during aortic cross-clamping?