Burn Surface Area Calculator (Rule of Nines)

Rule of Nines:

\[ \%TBSA = (Head 9\% + Each\ arm\ 9\% + Each\ leg\ 18\% + Front\ torso\ 18\% + Back\ torso\ 18\% + Genitals\ 1\%) \]

Head (%):

% (0-9)

Left Arm (%):

% (0-9)

Right Arm (%):

% (0-9)

Left Leg (%):

% (0-18)

Right Leg (%):

% (0-18)

Front Torso (%):

% (0-18)

Back Torso (%):

% (0-18)

Genitals (%):

% (0-1)

Total Burn Surface Area (TBSA):

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1. What is the Rule of Nines?

The Rule of Nines is a method used to estimate the total body surface area (TBSA) affected by burns. It divides the body into sections that represent 9% or multiples of 9% of the total body surface area, making it easy to calculate the extent of burns quickly.

2. How Does the Calculator Work?

The calculator uses the Rule of Nines formula:

\[ \%TBSA = (Head 9\% + Each\ arm\ 9\% + Each\ leg\ 18\% + Front\ torso\ 18\% + Back\ torso\ 18\% + Genitals\ 1\%) \]

Where:

Head — 9% of TBSA
Each Arm — 9% of TBSA
Each Leg — 18% of TBSA
Front Torso — 18% of TBSA
Back Torso — 18% of TBSA
Genitals — 1% of TBSA

Explanation: The percentages are based on the proportion of body surface area each region represents in adults. For children, different percentages apply due to their different body proportions.

3. Importance of TBSA Calculation

Details: Accurate TBSA estimation is crucial for determining fluid resuscitation needs, prognosis, and treatment decisions in burn patients. It helps classify burn severity and guides transfer to specialized burn centers.

4. Using the Calculator

Tips: Enter the percentage of each body region that is burned. The calculator sums these values to give total burn surface area. Values should be within the possible range for each body part (e.g., 0-9% for arms).

5. Frequently Asked Questions (FAQ)

Q1: Is the Rule of Nines accurate for all patients?
A: It's most accurate for adults. Children have different body proportions (larger heads, smaller legs), so pediatric modifications are needed.

Q2: What's considered a major burn?
A: Generally, burns covering >20% TBSA in adults or >10% in children/elderly, or burns involving sensitive areas (face, hands, feet, genitals).

Q3: How does TBSA affect fluid resuscitation?
A: The Parkland formula uses TBSA to calculate fluid needs: 4mL × %TBSA × weight(kg) in first 24 hours, with half given in first 8 hours.

Q4: Are there alternatives to the Rule of Nines?
A: The Lund-Browder chart is more accurate as it accounts for age-related changes in body proportions, but is more complex to use.

Q5: How to estimate irregular burns?
A: For scattered burns, the palm method can help (patient's palm ≈ 1% TBSA). Combine with Rule of Nines for larger areas.