Using the 4-2-1 rule, what is the hourly maintenance IV rate for a 15-kg child?

• A. 30 mL per hour
• B. 50 mL per hour
• C. 60 mL per hour
• D. 70 mL per hour

Answer: (B)

The main idea is using the 4-2-1 rule to estimate maintenance IV fluids for a child. This rule breaks down as 4 mL/kg per hour for the first 10 kg, 2 mL/kg per hour for the next 10 kg, and 1 mL/kg per hour for each kg over 20.

For a 15-kg child:

• First 10 kg: 4 mL/kg × 10 kg = 40 mL/hour

• Next 5 kg: 2 mL/kg × 5 kg = 10 mL/hour

• Total maintenance rate: 40 + 10 = 50 mL/hour

So the hourly maintenance IV rate is 50 mL per hour. This is the starting maintenance amount; adjust as needed for fever, wound losses, vomiting/diarrhea, or insensible losses.