CCS CCS Cardiopulmonary Bypass and Perfusion Management 1 — Questions and Answers
Question 1: What is the primary purpose of cardiopulmonary bypass (CPB) during cardiac surgery?
- To provide intraoperative analgesia
- To temporarily take over heart and lung function allowing a bloodless operative field (Correct answer)
- To increase systemic blood pressure during surgery
- To administer cardioplegia directly to the myocardium
Correct answer: To temporarily take over heart and lung function allowing a bloodless operative field
CPB temporarily assumes the functions of the heart and lungs, providing oxygenated blood to the body while the surgeon operates on a still, decompressed heart.
Question 2: Cardioplegia solution is used intraoperatively primarily to achieve which goal?
- Maintain normal sinus rhythm during bypass
- Arrest and protect the heart during aortic cross-clamping (Correct answer)
- Dilate coronary arteries for graft anastomosis
- Prevent ventricular fibrillation after bypass
Correct answer: Arrest and protect the heart during aortic cross-clamping
Cardioplegia causes diastolic cardiac arrest and reduces myocardial oxygen demand, protecting the heart during the ischemic cross-clamp period.
Question 3: The standard target activated clotting time (ACT) for full anticoagulation during cardiopulmonary bypass is greater than how many seconds?
- 150 seconds
- 200 seconds
- 300 seconds (Correct answer)
- 480 seconds
Correct answer: 300 seconds
An ACT greater than 300 seconds (often targeted >480 seconds at some centers) is required to prevent clot formation in the CPB circuit.
Question 4: Which drug is the primary anticoagulant used during cardiopulmonary bypass?
- Warfarin
- Aspirin
- Heparin (Correct answer)
- Bivalirudin
Correct answer: Heparin
Unfractionated heparin is used for anticoagulation during CPB because it is rapidly reversible with protamine sulfate after bypass.
Question 5: What is the typical target mean arterial pressure (MAP) maintained during cardiopulmonary bypass?
- 30–40 mmHg
- 50–80 mmHg (Correct answer)
- 90–110 mmHg
- 120–140 mmHg
Correct answer: 50–80 mmHg
A MAP of 50–80 mmHg is targeted during CPB to ensure adequate cerebral and end-organ perfusion while minimizing hemodilution effects.
Question 6: Aortic cross-clamping during CPB isolates the coronary circulation and results in which immediate myocardial state?
- Hyperkinesis
- Global ischemia (Correct answer)
- Atrial fibrillation
- Myocardial hyperoxia
Correct answer: Global ischemia
Aortic cross-clamping stops all coronary flow, producing global myocardial ischemia that must be mitigated by cardioplegia and hypothermia.
CCS CCS Cardiopulmonary Bypass and Perfusion Management 1
What is the primary purpose of cardiopulmonary bypass (CPB) during cardiac surgery?