## Calculation of TBSA Using Rule of Nines **Key Point:** The Rule of Nines divides the body into segments, each representing 9% or multiples thereof of total body surface area. ### Rule of Nines Distribution | Body Region | % TBSA | | --- | --- | | Head and neck | 9% | | Each upper limb (anterior + posterior) | 9% | | Anterior trunk (chest + abdomen) | 18% | | Posterior trunk (back + buttocks) | 18% | | Each lower limb (anterior + posterior) | 18% | | Genitalia | 1% | ### Calculation in This Case - Face and neck: 9% - Anterior chest: 9% (half of anterior trunk) - Bilateral forearms and hands: ~4.5% each = 9% total (approximately half of each upper limb) - Bilateral anterior thighs: ~9% each = 18% total (half of each lower limb) **Total: 9 + 9 + 9 + 9 = 36%** **High-Yield:** The Rule of Nines is the gold standard for rapid TBSA estimation in the field and ED. Accuracy improves with practice; for small burns (<15% TBSA), the "palm rule" (patient's palm = 1% TBSA) is more accurate. **Clinical Pearl:** This patient's burn depth (erythema with blistering and pain) indicates partial-thickness (2nd degree) burns. With 36% TBSA, he meets criteria for transfer to a specialized burn center and requires fluid resuscitation using the Parkland formula. ## Parkland Formula Application **Mnemonic: PARKLAND** — **P**erfusion **A**ssessment **R**equires **K**nowledge **L**iquid **A**dministration **N**eeds **D**etermination - Formula: 4 mL × body weight (kg) × %TBSA burned - Half given in first 8 hours, half over next 16 hours - For a 70 kg patient: 4 × 70 × 36 = 10,080 mL ≈ 10 L over 24 hours - Ringer's lactate is the preferred fluid (not normal saline due to hyperchloremic acidosis risk). 
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