In burns , back constitutes how much %-
**Core Concept**
The rule of nines is a widely used estimating method to calculate the total body surface area (TBSA) affected by burns. This principle helps in assessing the extent of injury and guiding treatment decisions.
**Why the Correct Answer is Right**
The rule of nines assigns specific percentages to different body regions, allowing for quick estimation of TBSA. The back, specifically the upper and lower back, is considered 18% of the total body surface area. This is a critical calculation in burn care, as it directly influences fluid resuscitation and the risk of complications.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it is lower than the actual percentage of the back in the rule of nines.
**Option B:** This option is incorrect because it is higher than the actual percentage of the back in the rule of nines.
**Option C:** This option is incorrect because it does not accurately represent the percentage of the back in the rule of nines.
**Clinical Pearl / High-Yield Fact**
The rule of nines is a useful estimating tool, but it may not accurately reflect the extent of injury in patients with irregularly shaped burns or those with burns on multiple body regions. Always consider the patient's overall condition and adjust treatment plans accordingly.
**Correct Answer:** C. 18%