Burn Surface Area, commonly referred to as Total Body Surface Area (TBSA), is a critical medical metric used to estimate the extent of burn injuries. Accurate calculation of TBSA is vital for determining the severity of the injury, the patient's prognosis, and the volume of fluid resuscitation required in the first 24 hours.
Our calculator uses the "Rule of Nines" and adjustments for children (Lund-Browder approximation) to provide a quick and reliable estimate.
Key Features of Our Burn Surface Area Tool
This interactive tool is designed for educational and estimation purposes:
- Interactive Body Map: Click on specific body parts (Head, Torso, Arms, Legs) on the visual SVG manikin to toggle them as burned.
- Partial Area Adjustment: Sliders allow you to specify if a body part is only partially burned (e.g., "50% of the Left Arm"), rather than assuming the whole part is affected.
- Pediatric Adjustments: The "Patient Age" slider automatically adjusts the percentages allocated to the head and legs, accounting for the different body proportions of infants and children compared to adults.
- Fluid Resuscitation: Automatically calculates the estimated fluid requirements (Ringers Lactate) using the Parkland Formula based on the patient's weight and calculate TBSA.
- Dynamic Severity Grading: Instantly categorizes the burn as Minor, Moderate, or Severe based on the TBSA percentage.
How to Use the Calculator
1. Set Patient Profile: Use the sliders to set the patient's Age and Weight. This ensures the body surface percentages and fluid calculations are accurate for their specific physiology.
2. Select Burned Areas: Click on the anterior (front) or posterior (back) sections of the body map to mark them as burned.
3. Refine Extent: If a selected part is not fully burned, use the slider that appears to adjust the coverage (e.g., to 25% or 50% of that specific part).
4. Review Results: Read the Total Body Surface Area (TBSA) percentage and the severity classification.
5. Check Fluid Needs: Look at the "Fluid Resuscitation" panel to see the total 24-hour fluid volume required, split into the first 8 hours and subsequent 16 hours.
Medical Formulas Used
1. Rule of Nines (Adults):
The body is divided into sections that represent multiples of 9%:
- Head & Neck: 9%
- Each Arm: 9%
- Anterior Trunk: 18%
- Posterior Trunk: 18%
- Each Leg: 18%
- Perineum: 1%
2. Lund-Browder (Children):
For children, the head represents a larger portion (up to 19% at birth), and the legs a smaller portion (13% at birth). Our calculator adjusts these values dynamically based on age.
3. Parkland Formula (Fluid Resuscitation):
Total Fluid (24h) = 4 mL × Body Weight (kg) × %TBSA
- First 50% of fluid is given in the first 8 hours.
- Remaining 50% is given over the next 16 hours.
Who Uses This Tool?
- Emergency Responders: For quick triage and fluid orders during transport.
- Medical Students: To practice TBSA estimation and understand pediatric differences.
- Trauma Centers: As a rapid verification tool during initial assessment.
Disclaimer
WARNING: This calculator is a support tool for estimation only. It is not a substitute for professional medical advice, diagnosis, or treatment. Severe burns require immediate professional medical attention. Fluid resuscitation should always be titrated to clinical markers like urine output, not just calculated values.
Frequently Asked Questions (FAQs)
Why does the head percentage change with age?
Infants and young children have disproportionately larger heads relative to their bodies compared to adults. As a child grows, the relative surface area of the head decreases while the legs increase.
What is the "Rule of Palms"?
Another method where the patient's palm (including fingers) represents approximately 1% of their total body surface area. This is useful for estimating small or scattered burns.
Why is accurate TBSA important?
Under-estimation can lead to under-resuscitation and shock (kidney failure), while over-estimation can lead to fluid overload (pulmonary edema). Accuracy is key to patient survival.
Conclusion
The Burn Surface Area Calculator provides a fast, visual, and adaptable way to apply the Rule of Nines and Parkland Formula. By automatically adjusting for pediatric proportions and allowing for partial area burns, it offers a more nuanced estimation than simple mental math.
