A 6-year-old child is admitted with 30% BSA thermal burns following a house fire. The attending physician needs to estimate the exact percentage of body surface area to calculate fluid requirements accurately. Which investigation would be most appropriate to account for the child's age-specific body proportions?

Explanation

## Age-Adjusted BSA Estimation in Pediatric Burns ### Why Age Adjustment is Critical in Children **Key Point:** In children, body proportions differ significantly from adults—the head and neck represent a much larger percentage of total BSA (approximately 18–19% in infants vs. 9% in adults), while the legs are proportionally smaller. The Lund and Browder chart is specifically designed with age-adjusted tables to account for these differences. **High-Yield:** The Rule of Nines (fixed proportions) is unreliable in children <15 years because it overestimates leg BSA and underestimates head BSA, leading to under-resuscitation in pediatric burns. ### Lund and Browder Chart: Age-Specific Adjustments | Body Region | Infant (0–1 yr) | Child (1–4 yr) | Child (5–9 yr) | Adult (≥15 yr) | |-------------|-----------------|-----------------|-----------------|----------------| | Head & Neck | 19% | 17% | 13% | 9% | | Anterior Trunk | 13% | 13% | 13% | 18% | | Posterior Trunk | 13% | 13% | 13% | 18% | | Each Leg | 14% | 14% | 16.5% | 18% | | Each Arm | 9% | 9% | 9% | 9% | **Clinical Pearl:** In this 6-year-old with 30% BSA burns, the Lund and Browder chart would classify the child in the 5–9 year age group, adjusting head BSA to ~13% (not 9%) and leg BSA to ~16.5% per leg (not 18%). This ensures accurate Parkland formula calculation: 4 mL × 30% × body weight (kg). ### Why Other Methods Fail in Pediatrics **Mnemonic:** **LB = Lund & Browder = Little Bodies** (essential for children with disproportionate head size). - **Rule of Nines without modification:** Uses fixed adult proportions; systematically underestimates head involvement and overestimates leg involvement in children, leading to inadequate fluid resuscitation and risk of hypovolemic shock. - **Tape measure measurement:** Measures linear dimensions, not surface area. Cannot account for irregular burn shapes and does not provide the percentage of total BSA. - **Thermographic imaging:** Useful for assessing burn depth and perfusion but not for estimating total BSA percentage; requires specialized equipment and is not standard of care for acute BSA assessment. [cite:Park 26e Ch 14]