Immediately following neonatal cardiac surgery, which range best estimates parenteral caloric requirements?

• A. 90-100 kcal/kg/day
• B. 120-170 kcal/kg/day
• C. 55-60 kcal/kg/day
• D. 100-110 kcal/kg/day

Answer: (C)

Immediately after neonatal cardiac surgery, the body is in a high-stress, catabolic state but the illness course and anesthesia can blunt energy expenditure and tolerance to intake. The goal of parenteral nutrition in this moment is to provide enough calories to support organ function, wound healing, and recovery without tipping into overfeeding, which can worsen hyperglycemia, fatty liver, and carbon dioxide production—especially in a fragile, recovering neonate with cardiopulmonary disease.

Starting with a modest calorie target, around 55–60 kcal/kg/day, strikes that balance. It supplies the baseline energy needed for recovery while staying conservative while the patient’s hemodynamics, respiratory status, and tolerance to nutrition are still precarious. As stabilization occurs over the next several days, energy can be gradually increased toward maintenance ranges (and then higher as growth and recovery demand), but in the immediate post-op period, the lower end of the spectrum is the most appropriate choice.

Higher initial targets (roughly 90–120 kcal/kg/day and above) would risk overfeeding in this unstable window, potentially causing metabolic complications.