Parkland Formula (Burns)

The Parkland Formula, also known as the Baxter formula, is the most widely used method for estimating initial crystalloid fluid resuscitation requirements in patients with major burn injuries. Developed by Dr. Charles Baxter at Parkland Memorial Hospital in Dallas, Texas, during the 1960s and 1970s, this formula has become the standard of care recommended by the American Burn Association and is taught in Advanced Trauma Life Support (ATLS) courses worldwide.

Burn injuries trigger a massive systemic inflammatory response that dramatically increases capillary permeability, leading to rapid fluid shifts from the intravascular compartment into the interstitial space. This phenomenon, known as burn shock, can result in hypovolemia, organ hypoperfusion, and death if not adequately treated with aggressive fluid resuscitation. The Parkland Formula provides a calculated starting point for this critical intervention.

The formula calculates the total crystalloid fluid (lactated Ringer solution) needed in the first 24 hours post-burn as: Total Fluid (mL) = 4 mL x body weight (kg) x percentage of total body surface area (%TBSA) burned. This volume is then divided into two phases: half of the calculated volume is administered during the first 8 hours from the time of injury, and the remaining half is infused over the subsequent 16 hours.

The timing of fluid delivery is critically important. The first 8 hours represent the period of maximum capillary leak and fluid loss, necessitating the higher infusion rate. The 8-hour window is calculated from the time of burn injury, meaning any prehospital fluids should be subtracted from the first-period calculation. If a patient arrives 2 hours after injury, the remaining first-period fluid must be delivered within the remaining 6 hours.

Accurate estimation of %TBSA is essential for proper application of the Parkland Formula. The Rule of Nines is the most common rapid assessment method, dividing the adult body into regions representing approximately 9% (or multiples thereof) of total body surface area. For smaller or irregular burns, the patient palm (including fingers) represents approximately 1% TBSA.

While the Parkland Formula provides an excellent starting estimate, it is crucial to understand that it represents a guideline, not an absolute prescription. Actual fluid requirements vary significantly based on inhalation injury (which can increase needs by 30-50%), depth of burns, patient comorbidities, and individual physiological responses. The infusion rate should be continuously titrated based on clinical endpoints, primarily targeting urine output of 0.5-1.0 mL/kg/hour in adults and 1.0-1.5 mL/kg/hour in children.

Over-resuscitation, sometimes called fluid creep, has emerged as a significant concern in modern burn care. Excessive fluid administration can lead to abdominal compartment syndrome, pulmonary edema, and extremity compartment syndrome. Regular reassessment of fluid balance and clinical response is therefore as important as the initial calculation. This calculator implements the standard Parkland Formula, providing the total 24-hour requirement, the breakdown between the two delivery phases, and the corresponding hourly infusion rates for clinical convenience.