How do you determine the Body Surface Area (BSA) of a pediatric burn injury in children?

Determining Body Surface Area (BSA) in Pediatric Burn Injuries

Primary Recommendation

Use the Lund-Browder chart as the primary standardized method for calculating burn body surface area in children, as it accounts for age-related variations in body proportions and provides the most accurate TBSA quantification. 1, 2

Why the Lund-Browder Chart is Essential for Pediatric Burns

The Lund-Browder chart is specifically designed to address the unique anatomical proportions of children at different ages, which differ significantly from adults:

• Children have proportionally larger heads and smaller lower extremities compared to adults, making adult-based assessment tools inaccurate 1
• The chart adjusts for these age-related variations and has been validated as the most accurate method available 1
• Do NOT use the Rule of Nines for children—this method fails to account for pediatric body proportions and leads to systematic overestimation in 70-94% of cases 1, 3, 2

Step-by-Step Assessment Algorithm

1. Select Age-Appropriate Lund-Browder Chart

• Use the pediatric version of the Lund-Browder chart that corresponds to the child's age group 2
• Digital tools like the 3D PED BURN smartphone application can improve accuracy by providing 15 different 3D models categorized into four age groups: <1 year, 1-4 years, 5-9 years, and 10-15 years 4

2. Measure Actual Epidermal Detachment

• Record the extent of epidermal detachment separately from erythema on the body map 1
• Include both detached epidermis AND detachable epidermis (Nikolsky-positive areas) 1
• The amount of epidermal detachment, not erythema alone, has prognostic value for mortality risk 1

3. Perform Serial Assessments

• Reassess TBSA during the first hours of care, as initial estimates are often inaccurate 1, 2
• Prehospital providers overestimate pediatric TBSA by an average of 40%, outside hospital physicians by 18.7%, and even burn center ED physicians by 7.2% 5

Alternative Methods for Field Assessment

When the Lund-Browder chart is impractical (prehospital setting, mass casualty):

• Use the patient's entire palmar surface (palm plus fingers), which represents approximately 1% TBSA 1
• The palm alone represents only 0.5% TBSA—ensure you include the fingers 1
• The serial halving method can also be used as an alternative 1, 3
• Consider using smartphone applications (E-Burn, FireSync EMS, 3D PED BURN) to reduce overestimation bias 3, 4

Critical Pediatric-Specific Considerations

Fluid Resuscitation Thresholds

• Children require formal fluid resuscitation for burns ≥5% TBSA (compared to ≥10% in adults) 3
• For burns ≥15% TBSA, children need IV fluid resuscitation to prevent burn shock due to their small circulating blood volumes 6, 7
• Delays in resuscitation result in increased complications and mortality in pediatric patients 6

Higher Fluid Requirements

• Children require approximately 6 mL/kg/%TBSA due to their higher surface area-to-weight ratio (compared to 2-4 mL/kg/%TBSA in adults) 3
• Initial bolus: 20 mL/kg of balanced crystalloid solution (preferably Ringer's Lactate) within the first hour for burns >10% TBSA 2

Common Pitfalls and How to Avoid Them

Overestimation of TBSA

• TBSA is overestimated in 70-94% of cases, leading to excessive fluid administration and "fluid creep" 1, 3, 2
• This overestimation can cause compartment syndrome, abdominal compartment syndrome, and acute kidney injury 3
• Be conservative in your estimation and use validated tools rather than visual estimation 3

Using Inappropriate Assessment Tools

• Never rely on the Rule of Nines for children—it significantly overestimates TBSA 1, 2
• Do not rely on erythema alone for TBSA calculation in severe burns 1

Delayed Specialist Consultation

• Contact a burn specialist immediately to determine need for transfer to a burn center 3, 2
• Telemedicine can reliably improve TBSA measurement when specialists are not readily available 3

Assessment for Non-Accidental Injury

• Unique to pediatrics is the additional assessment for non-accidental injury, which must be considered in all pediatric burn cases 7

Transfer Criteria to Burn Centers

Children meeting any of these criteria should be referred to a burn center:

• TBSA >10% 2
• Deep burns >5% 2
• Infants <1 year of age 2
• Smoke inhalation injuries 2
• Deep burns in function-sensitive areas (face, hands, feet, genitals, perineum, flexure lines) 3, 2
• Circular/circumferential burns 2
• Electrical or chemical burns 2