Burn Fluid Calculator

The Parkland formula calculates fluid requirements for burn patients in the first 24 hours: Total fluid = 4 mL × weight (kg) × %TBSA burned. Give half in the first 8 hours, the remaining half over the next 16 hours. Use Lactated Ringer’s (LR).

First 8-hour rate = Total Parkland fluid / 2 / 8 = Total / 16. For a 70 kg patient with 40% TBSA: total = 4×70×40 = 11,200 mL. First 8h = 5600 mL (700 mL/hr). Next 16h = 5600 mL (350 mL/hr).

The modified Parkland formula uses 3 mL/kg/%TBSA (instead of 4 mL/kg/%TBSA) for less severe burns or when inhalation injury is absent. Some centers use 2 mL/kg/%TBSA for < 20% TBSA burns. Always individualize based on urine output.

The Rule of Nines estimates %TBSA burned by dividing the body into multiples of 9: head and neck 9%, each arm 9%, anterior trunk 18%, posterior trunk 18%, each leg 18%, perineum 1%. Modified for children due to proportionally larger head.

Lactated Ringer’s (LR) is the recommended fluid due to its balanced electrolyte composition. Normal saline (NS) may be used if LR is unavailable but carries risk of hyperchloremic acidosis. Colloids (albumin) are not recommended in the first 24 hours.

LR closely mimics plasma electrolyte composition, contains lactate as a buffer, and is less likely to cause hyperchloremic metabolic acidosis compared to NS. It is isotonic and remains in the intravascular space effectively during the capillary leak phase.

Target urine output is 0.5–1.0 mL/kg/hr in adults and 1.0–1.5 mL/kg/hr in children. Adjust fluid rates to maintain this output. Output < 0.5 mL/kg/hr suggests inadequate resuscitation; > 1.0–1.5 mL/kg/hr suggests fluid overload.

Use the palmar method: the patient’s palm (including fingers) represents approximately 1% TBSA. Count how many palm areas are covered by the burn. This is useful for scattered or irregularly shaped burns.

Children have a proportionally larger head and smaller legs. In infants, head = 21%, each leg = 10%. For children, head = 18%, each leg = 13.5%. The trunk and arms remain the same as adults.

Inhalation injury increases capillary permeability and fluid requirements by 30–50% above the Parkland estimate. These patients require more aggressive monitoring with arterial lines, central venous pressure, and frequent reassessment of fluid status.

Fluid creep refers to the tendency for burn patients to receive more fluid than predicted by the Parkland formula, often due to opioid use, sedation, mechanical ventilation, and delayed resuscitation. This leads to worse outcomes (compartment syndrome, ARDS).

Primary endpoint: urine output 0.5–1 mL/kg/hr. Secondary endpoints: normalization of heart rate, blood pressure, base deficit < 2, lactate < 2, mixed venous oxygen saturation (SvO2) > 65%, and resolution of hemoconcentration.

Colloids (albumin, fresh frozen plasma) are typically reserved for after the first 24 hours when capillary leak has resolved. Early colloid use (in first 12–24 hours) is controversial but may be considered in severe burns with inadequate response to crystalloids.

High-dose vitamin C (66 mg/kg/hr) given in the first 24 hours may reduce fluid requirements by 30–40% through antioxidant and anti-inflammatory effects. It reduces capillary leak but requires monitoring for oxalate nephropathy.

Use Parkland: 4 mL/kg/%TBSA. For a 20 kg child with 30% TBSA: total = 4×20×30 = 2400 mL. First 8h = 1200 mL (150 mL/hr). Next 16h = 1200 mL (75 mL/hr). Use LR. Add D5 1/2NS maintenance for children < 30 kg.

Elderly patients have reduced cardiac reserve and renal function. Consider using modified Parkland (3–3.5 mL/kg/%TBSA) and resuscitate more cautiously with lower targets (0.3–0.5 mL/kg/hr urine output).

Complications include abdominal compartment syndrome, extremity compartment syndrome (may require escharotomy), pulmonary edema, ARDS, cerebral edema, pleural effusions, ascites, and worsening of burn wound edema.

Under-resuscitation leads to burn shock, acute kidney injury, acute tubular necrosis, multi-organ failure, increased mortality, and conversion of viable stun zone into non-viable tissue (burn wound progression).

Place a Foley catheter for hourly urine output monitoring. Insert arterial line for blood pressure and blood gases. Consider CVP and ScvO2 monitoring in severe cases. Check electrolytes (Na, K) and hematocrit every 4–6 hours. Recalculate every hour.

The Brooke formula (modified) uses LR at 2 mL/kg/%TBSA for the first 24 hours, with half in first 8 hours and half in next 16 hours. It is a more conservative alternative to the Parkland formula for military and mass casualty settings.

Transfusion is generally avoided in the first 24–48 hours. After 24 hours, transfuse for Hb < 7–8 g/dL. Packed RBCs are preferred. Avoid whole blood. Transfusion thresholds are more liberal if active bleeding or significant ongoing surgical procedures.

Electrical burns cause deep tissue damage (muscle necrosis) with relatively small surface burns. Fluid requirements are much higher than Parkland predicts due to myoglobinuria and compartment syndrome. Use Parkland as a starting point but titrate to urine output.

The 2025 ISBI and ABA guidelines recommend LR as the primary resuscitation fluid, start at Parkland 4 mL/kg/%TBSA, titrate to urine output 0.5–1 mL/kg/hr, consider colloids after 24 hours, and use adjunctive therapies (vitamin C, vasopressors) in refractory cases.

Use actual body weight for Parkland formula. Obese patients have higher absolute fluid requirements. However, monitor closely for fluid overload as they have lower cardiopulmonary reserve. Consider using ideal body weight for maintenance components.

Diuretics (furosemide) are not recommended in the first 24 hours as they may worsen hypovolemia. After 24–48 hours, diuretics may be used to mobilize edema fluid if urine output is adequate and the patient is hemodynamically stable.

Use modified Parkland (3 mL/kg/%TBSA or less), target lower urine output (0.3–0.5 mL/kg/hr), monitor CVP/PAP closely, consider early inotrope support, and use colloids cautiously after 24 hours. Avoid fluid overload.

Abdominal compartment syndrome (ACS) is one of the most feared complications, occurring when intra-abdominal pressure > 20 mmHg with new organ dysfunction. It results from massive fluid resuscitation and requires decompressive laparotomy.

If the patient arrives > 2 hours after burn, calculate total Parkland fluid and give the first half-rate over the remaining portion of the first 8 hours from the time of injury, not from the time of arrival. Adjust based on clinical status and urine output.

Crystalloids (LR, NS) are salt solutions that equilibrate across the capillary membrane. Colloids (albumin, plasma) contain large molecules that stay in the intravascular space. In burns, capillary leak makes colloids ineffective in the first 24 hours.

Mortality increases with TBSA: > 20% TBSA requires formal resuscitation. > 40% TBSA has significant mortality. > 60% TBSA has high mortality despite aggressive care. The Baux score (age + %TBSA + 17 if inhalation injury) estimates mortality risk.