Why burns need so much fluid
A large burn damages blood vessels well beyond the wound. Fluid leaks from the circulation into the tissues for about 24 hours, and without replacement, blood pressure falls and organs fail: burn shock. The Parkland formula, described by Dr. Charles Baxter at Parkland Hospital in Dallas in 1968, estimates how much fluid to give.
The formula
- Total in 24 h = 4 mL × weight (kg) × %TBSA
- Half in the first 8 hours, counted from the time of the burn, not from arrival at hospital
- The other half over the next 16 hours
%TBSA is the percentage of total body surface area with partial-thickness or full-thickness burns. Superficial (first-degree) burns are not counted. The fluid is usually lactated Ringer’s solution.
Worked example
A 154 lb (70 kg) adult has 30% TBSA burns:
- Total = 4 × 70 × 30 = 8,400 mL over 24 hours.
- First 8 hours: 4,200 mL, or 525 mL/h if started right away.
- Next 16 hours: 4,200 mL, or about 263 mL/h.
- If the patient arrives 2 hours after the burn with no fluid given, the 4,200 mL must be given over the remaining 6 hours: 700 mL/h.
Estimating the burned area
- Rule of nines (adults): head 9%, each arm 9%, front of trunk 18%, back 18%, each leg 18%, perineum 1%.
- Palm method: the patient’s palm with fingers is about 1% of their body surface.
- Lund and Browder chart: more accurate, and preferred in children because their heads are larger.
Adjusting to urine output
The formula is a starting point. The rate is adjusted every hour to reach a urine output of:
| Patient | Target |
|---|---|
| Adult | 0.5 mL/kg/h (about 30–50 mL/h) |
| Child under 30 kg | 1 mL/kg/h |
Too much fluid, known as fluid creep, causes compartment syndromes and breathing problems. For this reason the American Burn Association advises starting at 2 to 4 mL/kg/%TBSA; the modified Brooke formula uses 2 mL.
When the formula applies
Formal resuscitation is usually needed for burns above 15% TBSA in adults and 10% in children. Children under about 30 kg also need maintenance fluids with glucose in addition to the Parkland volume.
Burn center referral
Burns over 10% TBSA, burns of the face, hands, feet, genitals or major joints, full-thickness, electrical, chemical and inhalation injuries should be referred to a burn center.
This calculator is for general information and education. It is not medical advice and does not replace the judgment of a doctor, nurse or pharmacist who knows the full clinical picture.