Parkland formula calculator

What is the Parkland formula?

The Parkland formula estimates the lactated Ringer's solution a burn patient needs in the first 24 hours after the injury: 4 mL × body weight in kg × percent of body surface burned. Half is given in the first 8 hours and the other half over the next 16. It comes from work by Charles Baxter and Tom Shires at Parkland Hospital in Dallas, published in 1968. For a 70 kg adult (154 lb) with 31.5% burned, 4 × 70 × 31.5 = 8,820 mL, of which 4,410 mL goes in the first 8 hours (551 mL/h).

Which burns are counted?

Only partial-thickness and full-thickness burns count toward the percentage; superficial (first-degree) burns are left out, according to the StatPearls review of the formula. The same review gives its use for large burns: more than 20% of body surface in adults and more than 10% in children. The 2008 American Burn Association guideline also applies to adults and children with burns over 20%. Small burns usually do not need this calculation.

When does the 24-hour clock start?

At the time of the burn, not when the patient reaches the hospital. Fluid given before arrival is subtracted from the first-half amount, and a late arrival means the rest of the first half has to run faster. If this patient arrives 2 hours after the burn having already received 500 mL, 3,910 mL remains of the first half to run over the remaining 6 hours, about 652 mL/h; the page does this arithmetic when you enter the hours and the volume.

Is 4 mL per kg still the standard?

Not as a fixed number. The 2008 American Burn Association practice guideline says that common formulas estimate 2 to 4 mL/kg per percent burned over 24 hours and that fluids should be titrated to urine output; it adds that the data are insufficient to support a standard. The modified Brooke formula uses 2 mL. For the same 70 kg patient with 31.5% burned, 2 mL gives 4,410 mL, half of the Parkland figure. Giving more fluid than needed carries its own harm, which the literature calls fluid creep, with complications such as compartment syndrome, acute respiratory distress syndrome and organ dysfunction, so starting numbers are adjusted to the response.

What urine output do burn guidelines describe?

The 2008 ABA guideline targets about 0.5 to 1.0 mL/kg/h in adults and 1.0 to 1.5 mL/kg/h in children. For 70 kg that is 35 to 70 mL/h. Fluid is adjusted to keep urine output in that range, which is why the formula is a starting estimate and not a prescription.

What is the rule of 10?

A military simplification from the US Army Institute of Surgical Research (Chung and colleagues, 2010): round the burn size to the nearest 10%, multiply by 10 to get the starting rate in mL/h for an adult weighing 40 to 80 kg, and add 100 mL/h for every 10 kg above 80 kg. For 31.5% (rounded to 30%), the rate is 300 mL/h; for a 100 kg patient with 50%, it is 700 mL/h. In the study's simulation of adult combat casualties, 87.8% of patients had a rule-of-10 rate between the modified Brooke and Parkland starting rates. It was validated by computer simulation, not in a clinical trial.

What about children?

Children differ in several ways. The StatPearls review gives 3 mL/kg/% for children, a urine target of 1.0 to 1.5 mL/kg/h, a Lund and Browder chart to measure the burn, and maintenance fluid with glucose on top of the calculated volume. For a 20 kg child with 25% burned, 3 × 20 × 25 = 1,500 mL over 24 hours before maintenance fluid. This page does not calculate maintenance fluid and the rule of nines mode is an adult chart; children's use needs a pediatric burn protocol.

Measuring the burn: rule of nines

For adults, the rule of nines, described by Alexander Wallace in 1951, splits the body surface into: head and neck 9%, right arm 9%, left arm 9%, chest and abdomen (front of trunk) 18%, upper and lower back (back of trunk) 18%, right leg 18%, left leg 18%, perineum and genitals 1%. These add up to 100%. In the page's rule-of-nines mode you choose how much of each region is burned (none, a quarter, half, three quarters or all), and the page adds the percentages. In the worked example, the whole front of the trunk (18%), the right arm (9%) and half the head and neck (4.5%) make 31.5%. Estimates by eye vary between examiners, and only partial- and full-thickness areas count.

Worked example

A 70 kg adult with 31.5% partial-thickness burns. Parkland: 4 × 70 × 31.5 = 8,820 mL in 24 hours; 4,410 mL in the first 8 hours (551 mL/h) and 4,410 mL in the next 16 hours (276 mL/h). The rule of 10 would start at 300 mL/h and the 2 mL version would total 4,410 mL. The three numbers differ, and the clinicians' task is to adjust the rate to the patient's urine output and other signs.

Limits of this method

The formula is an estimate for the first day. Its inputs are only weight and burn size, so it has no place for inhalation injury, electrical burns, delayed resuscitation, other injuries, kidney disease or heart failure, and it is meant for burns above the size ranges given earlier. The StatPearls review lists the risks on both sides: under-resuscitation can deepen the burn and add organ failure, and over-resuscitation can cause compartment syndrome, lung injury and organ dysfunction. The ABA guideline notes there is insufficient evidence to set a standard. Real resuscitation follows the written protocol of a burn center and is adjusted to the patient’s response.

Common mistakes

Counting superficial redness toward the percentage, which inflates the volume. Using the adult rule of nines for a child; the Lund and Browder chart is preferred for children. Starting the clock at arrival instead of at the burn. Entering pounds as kilograms: the page's unit switch converts, but a weight in pounds typed into the kilogram box more than doubles the volume. And treating the first-8-hours half as a rigid schedule rather than a starting point that is adjusted to urine output.

Sources: Baxter CR, Shires T, “Physiological response to crystalloid resuscitation of severe burns,” Ann N Y Acad Sci 1968;150:874–894; Pham TN, Cancio LC, Gibran NS, “American Burn Association practice guidelines: burn shock resuscitation,” J Burn Care Res 2008;29:257–266; Chung KK, Salinas J, Renz EM, et al., “Simple derivation of the initial fluid rate for the resuscitation of severely burned adult combat casualties: in silico validation of the rule of 10,” J Trauma 2010;69 Suppl 1:S49–S54; StatPearls, “Parkland Formula” (NCBI Bookshelf NBK537190); Wallace AB, “The exposure treatment of burns,” Lancet 1951 (rule of nines). The ATLS and Advanced Burn Life Support course manuals were not available to us; use them for current teaching. Related: body surface area calculator, IV drip rate calculator, mean arterial pressure.

For general information only — not medical advice, and not a tool for patient care decisions. A burn that is large, deep, on the face, hands, feet or genitals, or caused by electricity or chemicals needs emergency care. How we check our calculators.