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Nursing & Med-Math · Clinical formulas

Parkland Formula

Burn fluid volumes for the first 24 hours, with a Rule of Nines helper for %TBSA.

Weight unit
kg
%
Partial-thickness and full-thickness burns only — superficial burns are not counted.
Total lactated Ringer’s in the first 24 hours
8,400mL

4 mL × 70 kg × 30% TBSA — timed from the moment of injury, not from arrival.

First 8 hours — half the volume
4,200 mL
525 mL/hr
Next 16 hours — the other half
4,200 mL
263 mL/hr

The Parkland formula estimates fluid for the first 24 hours after a major burn: 4 mL × body weight in kg × %TBSA burned. For a 70 kg adult with 30% TBSA that is 8,400 mL of lactated Ringer’s — half in the first 8 hours from the time of injury, the rest over the next 16.

Why a burn needs so much fluid

A large burn makes capillaries leak. Plasma moves out of the circulation into the burned and surrounding tissue, and the volume lost is far greater than the wound itself suggests, so a patient who looks stable in the first hour can be profoundly hypovolaemic by the fourth. Burn shock is a predictable consequence of the injury rather than a complication of it, which is why resuscitation starts on a formula rather than waiting for the blood pressure to fall.

The timing is the part most often got wrong. The 24-hour clock starts at the moment of injury, not at arrival in hospital. If a patient reaches the emergency department two hours after the burn, the first half of the volume still has to be delivered by the eighth hour after injury — which means it now has to run over six hours, at a correspondingly higher rate.

A starting point, not a prescription

The formula gives an estimate to begin with; it is titrated from there. The standard endpoint is urine output, usually 0.5–1.0 mL/kg/hr in an adult, and the rate is adjusted up or down against it. The American Burn Association’s Advanced Burn Life Support guidance accepts a range of 2–4 mL/kg/%TBSA for the first 24 hours, with the modified Brooke formula starting at 2 mL, and contemporary practice tends to begin at the lower end to avoid over-resuscitation. Prescribing and titration belong to a qualified professional working to local protocol.

Total 24 h fluid = 4 mL × weight (kg) × %TBSA

half in the first 8 hours from the time of injury, the remaining half over the next 16 hours

  1. 1
    Work out the burned area as a percentage. Use the Rule of Nines: for an adult, head 9%, each arm 9%, each leg 18%, front of trunk 18%, back of trunk 18%, perineum 1%.
  2. 2
    Count only partial- and full-thickness burns. Superficial first-degree burns, such as ordinary sunburn, are excluded from the %TBSA figure.
  3. 3
    Multiply 4 mL by weight in kilograms and by the percentage. For 70 kg and 30% TBSA: 4 × 70 × 30 = 8,400 mL over the first 24 hours.
  4. 4
    Split the volume in half. 4,200 mL goes in over the first 8 hours, which is 525 mL/hr.
  5. 5
    Run the second half over 16 hours. The remaining 4,200 mL over 16 hours is about 263 mL/hr, then titrate against urine output.

Rule of Nines — adult

Each region is a percentage of total body surface area; the regions listed sum to 100%.

Region% TBSA
Head and neck9%
Each arm9% (18% both)
Anterior trunk18%
Posterior trunk18%
Each leg18% (36% both)
Perineum1%

Worked volumes at 4 mL/kg/%TBSA

Total for the first 24 hours, with the first-8-hour rate measured from the time of injury.

Weight%TBSA24-hour totalFirst 8 hours
70 kg20%5,600 mL350 mL/hr
70 kg30%8,400 mL525 mL/hr
80 kg40%12,800 mL800 mL/hr
60 kg25%6,000 mL375 mL/hr
90 kg50%18,000 mL1,125 mL/hr

Where the estimate goes wrong

Over-estimating the burned area is the commonest error, and it compounds: every extra percentage point adds 4 mL per kilogram. Including superficial burns, or applying the adult Rule of Nines to a small child, both inflate the figure. Children have proportionally larger heads and smaller legs, so paediatric burns use the Lund and Browder chart rather than the adult nines.

Over-resuscitation carries its own harm — oedema, compartment syndrome and pulmonary complications — which is the reason modern guidance starts lower and titrates. The formula covers crystalloid for the first 24 hours only; it says nothing about maintenance fluid in children, colloid in the second 24 hours, or analgesia, and it does not replace assessment of the airway in an inhalation injury.

What is the Parkland formula?
Total fluid for the first 24 hours after a burn = 4 mL × body weight in kg × %TBSA burned, given as lactated Ringer’s. Half is delivered in the first 8 hours and half over the following 16.
Does the clock start at injury or at arrival?
At the moment of injury. If the patient arrives two hours later, the first half still has to be in by the eighth hour after the burn, so it runs over the remaining six hours at a higher rate.
Which burns count towards %TBSA?
Partial-thickness and full-thickness burns only. Superficial first-degree burns, such as sunburn, are excluded — including them inflates the volume substantially.
What is the Rule of Nines?
A quick way to estimate burned area in adults: head and neck 9%, each arm 9%, front of trunk 18%, back of trunk 18%, each leg 18% and perineum 1%, totalling 100%.
Why do some sources say 2 mL instead of 4 mL?
The modified Brooke formula starts at 2 mL/kg/%TBSA, and Advanced Burn Life Support guidance accepts a 2–4 mL range. Contemporary practice often begins at the lower end to reduce over-resuscitation, then titrates upward on response.
How is the rate adjusted after it is started?
Against urine output, typically 0.5–1.0 mL/kg/hr in an adult. The formula only sets the starting rate; the actual infusion is titrated up or down to hit that endpoint.
Does the same rule of nines apply to children?
No. Children have proportionally larger heads and smaller legs, so paediatric burn area is estimated with the Lund and Browder chart, which adjusts the regions by age.