Accidents: Practice Question
An autopsy is performed on a 23 year old female who died in a house fire. Her anterior torso and entire left upper extremity and left lower extremity are burned. What approximate percentage body surface area was burned?
- 45%
- 18%
- 27%
- 36%
- 9%
Show Answer and Explanations
45% — Correct answer
Correct. Rule of 9's: Head: 9% (18% in a baby), anterior trunk: 18%, posterior trunk: 18%, upper extremity: 9%, lower extremity: 18%, perineum: 1%. In this case, the anterior torso is approximately 18% body surface area, the left upper extremity is 9%, the left lower extremity is 18%. 18 + 9 + 18 = 45.18%
Incorrect. Rule of 9's: Head: 9% (18% in a baby), anterior trunk: 18%, posterior trunk: 18%, upper extremity: 9%, lower extremity: 18%, perineum: 1%. 18% would be the anterior or posterior trunk alone, or both arms, or 1 leg, or the head and one arm etc.27%
Incorrect. Rule of 9's: Head: 9% (18% in a baby), anterior trunk: 18%, posterior trunk: 18%, upper extremity: 9%, lower extremity: 18%, perineum: 1%. 27% would be the anterior trunk and an arm, or the head, etc.36%
Incorrect. Rule of 9's: Head: 9% (18% in a baby), anterior trunk: 18%, posterior trunk: 18%, upper extremity: 9%, lower extremity: 18%, perineum: 1%. 36% would be the anterior and posterior trunk, or both legs, etc.9%
Incorrect. Rule of 9's: Head: 9% (18% in a baby), anterior trunk: 18%, posterior trunk: 18%, upper extremity: 9%, lower extremity: 18%, perineum: 1%. Each arm is 9% surface area, the head covers 9% surface area, an anterior surface or posterior surface of a leg is 9% etc.Summary
Summary:Rule of 9's
| Body Area | Percentage |
|---|---|
| Head | 9% (18% in a baby) |
| Anterior Trunk | 18% |
| Posterior Trunk | 18% |
| Upper Extremity | 9% |
| Lower Extremity | 18% |
| Perineum | 1% |