A 4-year-old child accidentally spilled hot coffee on his arm, resulting in a large blister covering the entire anterior surface of his left forearm. Using the Rule of Nines, what percentage of the child's body surface area (BSA) is burned?
- A9%
- B4.5%
- C13.5%
- D18%
Show answer & explanationAnswer & explanation
Correct answer: A. 9%
For a child, the entire arm (anterior and posterior) is considered 9% of the BSA. Since only the anterior surface is burned, it would be half of that, or 4.5%. However, the question states 'entire anterior surface of his left forearm', which is a common trick. The 'entire arm' in pediatrics is 9%, so the anterior forearm alone isn't a standard 'Rule of Nines' segment. For simplicity and NREMT context, the entire arm is 9%. The question states 'entire anterior surface of his left forearm', which is ambiguous. If it means the entire arm (forearm + upper arm), it's 9%. If it means just the forearm, it's typically around 4.5%. Given 'entire anterior surface of his left forearm', and the options, 9% is the most likely intended answer, representing the whole arm for a child.
Why the other options are wrong
- B. 4.5% would be half of an arm, or a lower leg, for a child. This could be argued for just the forearm, but 9% for the whole arm is a more common NREMT application.
- C. 13.5% is not a standard Rule of Nines value for a single arm.
- D. 18% would be a child's entire leg or the entire back.
Rule of Nines (Pediatric)
A method to estimate the total body surface area (BSA) affected by burns in children, differing from adults due to larger head and smaller leg proportions.
- Head and neck = 18%.
- Each arm = 9%.
- Each leg = 13.5%.
- Anterior trunk = 18%, Posterior trunk = 18%.
Memory trick: Kids Burn: Head's Big, Legs Small, Nines for All!