Total Burn of Surface Area includes for right arm, chest and abdomen burn?

Appeared in: NORCET 5 Prelims - Sept 2023 (Shift-2)

Explanation

The 'Rule of Nines' is a standardized method used to quickly estimate the percentage of total body surface area (TBSA) affected by a burn in an adult.
This rule divides the body into sections that are each approximately 9% of the TBSA or multiples of 9%.
For an adult, a full arm is considered 9%, the anterior trunk (chest and abdomen) is 18%.
The question specifies the right arm (9%), chest (9%), and abdomen (9%).
Adding these percentages together (9% + 9% + 9%) results in a total of 27% TBSA.

Option A: 9% represents the TBSA for only one of the specified areas (e.g., just the right arm, or just the chest, or just the abdomen), not the total of all three.
Option B: 18% represents the TBSA for the entire anterior trunk (chest and abdomen combined) or for both arms. It does not include the additional 9% for the third area mentioned.
Option D: 36% represents the TBSA for the entire trunk (anterior and posterior) or for both legs. This value is too high for the areas specified in the question.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Calculation of Total Body Surface Area (TBSA) in adults using the Rule of Nines as background academic context rather than a clinical decision trigger.
Accurate TBSA calculation is a critical nursing skill in emergency care. It directly guides the initial fluid resuscitation plan, most commonly using the Parkland formula, to prevent hypovolemic shock (burn shock).
The TBSA estimate helps determine the severity of the burn, which influences decisions about patient disposition, such as whether the patient requires transfer to a specialized burn center.
What if? If the burn was on the entire right leg instead of the right arm, the TBSA for that part would be 18%. The total would then be 36% (18% leg + 9% chest + 9% abdomen), significantly increasing the fluid requirement and severity classification.

How to Approach the Question

First, identify that the question requires a calculation of the total percentage of body area burned.
Recognize that the standard method for this type of calculation in an adult is the 'Rule of Nines'.
Recall the TBSA percentages assigned to different body parts under this rule.
Assign the correct percentage to each body area mentioned in the question: right arm (9%), chest (9%), and abdomen (9%).
Sum the percentages for all the affected areas to arrive at the total TBSA.
Compare your calculated total with the given options to find the correct answer.

Concept Tested & Keywords

Concept Tested: Calculation of Total Body Surface Area (TBSA) in adults using the Rule of Nines.
Stem keywords: Total Burn Surface Area, right arm, chest, abdomen
Lead-in keywords: includes

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E6 Nelson Textbook of Pediatrics(2024) — Volume 1 p. 693-695

Practise the full NORCET 5 Prelims - Sept 2023 (Shift-2)

Attempt every question from this paper in a timed mock, then review the full solution for each one.