CCP Neonatal & Pediatric Perfusion 2 — Questions and Answers
Question 1: What is the recommended prime volume to blood volume ratio to avoid excessive hemodilution in neonates weighing less than 5 kg?
- Less than 100% (Correct answer)
- Less than 50%
- Less than 200%
- Less than 150%
Correct answer: Less than 100%
In neonates, the circuit prime volume should ideally be less than the patient's blood volume (less than 100%) to minimize hemodilution and avoid severe anemia.
Question 2: During neonatal CPB, which acid-base management strategy is typically preferred to optimize cerebral autoregulation?
- pH-stat (Correct answer)
- Alpha-stat
- Mixed strategy
- Bicarbonate buffering only
Correct answer: pH-stat
pH-stat management is preferred in neonates because it promotes cerebral vasodilation and better oxygen delivery during deep hypothermic conditions.
Question 3: A neonate on CPB develops a sudden increase in venous line pressure and decreased venous return. The most likely cause is:
- Superior vena cava obstruction (Correct answer)
- Air lock in arterial line
- Aortic root cannula malposition
- Pump head failure
Correct answer: Superior vena cava obstruction
SVC obstruction, often from cannula malposition or kinking, causes increased venous line pressure with decreased venous return in neonates.
Question 4: What is the primary purpose of using a modified ultrafiltration (MUF) technique after neonatal cardiac surgery?
- Remove excess fluid and inflammatory mediators (Correct answer)
- Increase systemic vascular resistance
- Correct metabolic acidosis
- Reduce cardiac preload only
Correct answer: Remove excess fluid and inflammatory mediators
MUF concentrates the blood after bypass, removing excess fluid and inflammatory cytokines accumulated during CPB, improving cardiac and pulmonary function.
Question 5: In a 3 kg neonate undergoing deep hypothermic circulatory arrest (DHCA), the typical cooling target temperature before arrest is:
- 15–18°C nasopharyngeal (Correct answer)
- 25–28°C nasopharyngeal
- 30–32°C nasopharyngeal
- 20–22°C nasopharyngeal
Correct answer: 15–18°C nasopharyngeal
DHCA in neonates requires cooling to 15–18°C nasopharyngeal temperature to maximize cerebral protection during the arrest period.
Question 6: Which pharmacological agent is most commonly added to the cardioplegia solution in pediatric perfusion to improve myocardial protection in immature hearts?
- Calcium chloride at reduced concentration
- High-dose potassium only
- Magnesium sulfate (Correct answer)
- Epinephrine
Correct answer: Magnesium sulfate
Magnesium sulfate is added to pediatric cardioplegia to counteract calcium-mediated injury; immature myocardium has less efficient calcium handling than adult hearts.
Question 7: During separation from CPB in a neonate with transposition of the great arteries post-arterial switch operation, which intervention most directly addresses right ventricular dysfunction?
- Milrinone infusion with volume loading (Correct answer)
- Phenylephrine bolus
- Increasing pump flow
- Vasopressin alone
Correct answer: Milrinone infusion with volume loading
Milrinone reduces RV afterload and improves contractility via PDE-III inhibition, which is critical when the right ventricle must now support systemic circulation.
CCP Neonatal & Pediatric Perfusion 2
What is the recommended prime volume to blood volume ratio to avoid excessive hemodilution in neonates weighing less than 5 kg?