What is the purpose of indirect calorimetry in critically ill neonates?

• A. To determine actual energy expenditure for tailoring intake
• B. To provide a fixed energy target for all neonates
• C. To replace growth targets entirely
• D. To estimate energy needs using standard tables

Answer: (C)

Measuring actual energy expenditure allows nutrition to be tailored to what each critically ill neonate truly needs. Indirect calorimetry gauges how much energy the infant is using by analyzing gas exchange (oxygen used and carbon dioxide produced), providing a concrete value for energy needs rather than relying on guesses. In this setting, energy requirements can swing widely due to illness, ventilation, temperature, and stress, so using a measured expenditure helps prevent under- or over-feeding and supports appropriate growth and recovery. Growth targets remain important; caloric intake should align with those goals, but only after anchoring the plan to the baby’s real energy use. Standard tables offer estimates that may be inaccurate in critical illness, whereas indirect calorimetry gives a measured, individualized number to guide feeding.