Which statement is true regarding tidal volumes per kilogram in infants vs children?

Which statement is true regarding tidal volumes per kilogram in infants vs children?

• A. Infants require a higher per-kilogram tidal volume than children
• B. Children require a higher per-kilogram tidal volume than infants.
• C. They are the same
• D. Infants do not require tidal volumes per kilogram

Answer: (B)

Tidal volume per kilogram scales with lung size and mechanical maturity. Infants have very small lungs with delicate airways, so delivering too large a volume per kilogram increases the risk of volutrauma and gas trapping. To protect the immature lungs while still providing adequate ventilation, infants are ventilated with a smaller Vt per kg (about 4–6 mL/kg of predicted body weight). As children grow, their lungs and chest wall mechanics support slightly larger per-kilogram volumes, typically around 6–8 mL/kg. Therefore, children require a higher per-kilogram tidal volume than infants, making that statement true. The other options don’t fit because infants do ventilate with a per-kilogram tidal volume, and the per-kilogram volumes aren’t identical across ages.

Tidal volume per kilogram scales with lung size and mechanical maturity. Infants have very small lungs with delicate airways, so delivering too large a volume per kilogram increases the risk of volutrauma and gas trapping. To protect the immature lungs while still providing adequate ventilation, infants are ventilated with a smaller Vt per kg (about 4–6 mL/kg of predicted body weight). As children grow, their lungs and chest wall mechanics support slightly larger per-kilogram volumes, typically around 6–8 mL/kg. Therefore, children require a higher per-kilogram tidal volume than infants, making that statement true. The other options don’t fit because infants do ventilate with a per-kilogram tidal volume, and the per-kilogram volumes aren’t identical across ages.