CVP Cardiopulmonary Bypass — Questions and Answers
Question 1: What is the primary function of a cardiopulmonary bypass machine?
- To temporarily replace the function of the heart and lungs during surgery (Correct answer)
- To monitor blood pressure
- To administer anesthesia
- To regulate body temperature only
Correct answer: To temporarily replace the function of the heart and lungs during surgery
The CPB machine takes over circulation and gas exchange, allowing the surgeon to operate on a still, bloodless heart.
Question 2: What anticoagulant is most commonly used during cardiopulmonary bypass?
- Heparin (Correct answer)
- Warfarin
- Aspirin
- Clopidogrel
Correct answer: Heparin
Heparin is the standard anticoagulant used during CPB because of its rapid onset, effectiveness, and reversibility with protamine.
Question 3: What is the activated clotting time (ACT) target range during cardiopulmonary bypass?
- Greater than 480 seconds (Correct answer)
- 60 to 120 seconds
- 200 to 300 seconds
- Less than 150 seconds
Correct answer: Greater than 480 seconds
An ACT greater than 480 seconds ensures adequate anticoagulation to prevent clot formation in the bypass circuit.
Question 4: What is the role of the oxygenator in the bypass circuit?
- To add oxygen and remove carbon dioxide from the blood (Correct answer)
- To filter blood clots
- To warm the blood only
- To measure blood flow
Correct answer: To add oxygen and remove carbon dioxide from the blood
The oxygenator functions as an artificial lung, performing gas exchange by adding oxygen and removing carbon dioxide.
Question 5: What is hemodilution during cardiopulmonary bypass?
- Dilution of blood with crystalloid or colloid priming solutions reducing hematocrit (Correct answer)
- Concentration of blood components
- Removal of plasma from the blood
- Addition of red blood cells
Correct answer: Dilution of blood with crystalloid or colloid priming solutions reducing hematocrit
Hemodilution occurs when the circuits priming volume mixes with the patients blood, lowering the hematocrit and viscosity.
Question 6: What drug is used to reverse heparin after cardiopulmonary bypass?
- Protamine sulfate (Correct answer)
- Vitamin K
- Fresh frozen plasma
- Aminocaproic acid
Correct answer: Protamine sulfate
Protamine sulfate binds to heparin and neutralizes its anticoagulant effect, restoring normal coagulation after bypass.
CVP Cardiopulmonary Bypass
What is the primary function of a cardiopulmonary bypass machine?