CCS CCS Cardiopulmonary Bypass and Perfusion Management 2 — Questions and Answers
Question 1: Which cannulation site is most commonly used for venous drainage during standard CPB?
- Femoral vein
- Right atrium or inferior vena cava (Correct answer)
- Subclavian vein
- Left atrium
Correct answer: Right atrium or inferior vena cava
Venous drainage for CPB is most commonly obtained from the right atrium or bicaval cannulation of the superior and inferior vena cavae.
Question 2: Protamine sulfate is administered after CPB to reverse which drug?
- Aspirin
- Heparin (Correct answer)
- Warfarin
- Clopidogrel
Correct answer: Heparin
Protamine sulfate neutralizes unfractionated heparin by forming an inactive complex, restoring normal coagulation after bypass.
Question 3: Systemic hypothermia during CPB is used primarily to achieve which physiologic benefit?
- Increase oxygen delivery to tissues
- Reduce metabolic rate and organ oxygen consumption (Correct answer)
- Prevent venous air embolism
- Improve myocardial contractility
Correct answer: Reduce metabolic rate and organ oxygen consumption
Hypothermia decreases cellular metabolic rate and oxygen demand, providing protection to the brain and other organs during reduced perfusion.
Question 4: Which complication of CPB is characterized by diffuse end-organ dysfunction resulting from the systemic inflammatory response to extracorporeal circulation?
- Heparin-induced thrombocytopenia
- Post-perfusion syndrome (SIRS after CPB) (Correct answer)
- Ventricular septal rupture
- Aortic dissection
Correct answer: Post-perfusion syndrome (SIRS after CPB)
CPB activates complement, cytokines, and leukocytes, causing a systemic inflammatory response syndrome (SIRS) that can impair pulmonary, renal, and neurological function.
Question 5: The left ventricular vent is inserted during CPB primarily to prevent which problem?
- Aortic regurgitation
- Left ventricular distension and endocardial ischemia (Correct answer)
- Pulmonary embolism
- Atrial fibrillation
Correct answer: Left ventricular distension and endocardial ischemia
The LV vent decompresses the left ventricle during cross-clamping, preventing distension that would increase wall tension and worsen subendocardial ischemia.
Question 6: During CPB, pH-stat management differs from alpha-stat management in which primary way?
- pH-stat targets a lower ACT
- pH-stat corrects pH for temperature, increasing CO2 and cerebral blood flow (Correct answer)
- pH-stat maintains normothermic blood gas values regardless of temperature
- pH-stat uses bicarbonate infusion to raise pH above 7.45
Correct answer: pH-stat corrects pH for temperature, increasing CO2 and cerebral blood flow
pH-stat management corrects blood gas values for the patient's actual temperature, resulting in relative hypercapnia that increases cerebral blood flow — preferred in pediatric/deep hypothermic cases.
CCS CCS Cardiopulmonary Bypass and Perfusion Management 2
Which cannulation site is most commonly used for venous drainage during standard CPB?