Parkland Formula Calculator

Urine output is the single most important and accessible endpoint for monitoring burn resuscitation adequacy. Insert a urinary catheter in all patients receiving IV fluid resuscitation and record hourly output. Target rates are:

• Adults: 0.5–1.0 mL/kg/h (typically 30–50 mL/h for a 70 kg patient)
• Children (<30 kg): 1.0–2.0 mL/kg/h
• Electrical burns / myoglobinuria: 1.0–1.5 mL/kg/h (to clear myoglobin and prevent renal tubular injury)

If urine output falls below target for two consecutive hours, increase the fluid rate by 25–33%. If urine output exceeds 1.0 mL/kg/h for two consecutive hours, decrease the rate by 25–33%. Avoid abrupt changes — titrate gradually.

While urine output is the primary endpoint, additional parameters provide supporting data: mean arterial pressure (MAP) >65 mmHg, heart rate <120 bpm, palpable peripheral pulses, and adequate capillary refill. In ICU settings, central venous pressure (CVP), cardiac output monitoring via transpulmonary thermodilution, and echocardiography may guide resuscitation in complex cases. Serum lactate and base deficit trending toward normalisation suggest improving tissue perfusion — a rising lactate despite adequate urine output should prompt investigation for occult under-resuscitation or compartment syndrome.

“Fluid creep” refers to the phenomenon of patients receiving substantially more fluid than predicted by resuscitation formulas. Multiple studies have documented that actual fluid volumes delivered exceed Parkland calculations by 50–150% in many centres. Consequences of over-resuscitation include pulmonary oedema and acute respiratory distress syndrome, abdominal compartment syndrome (intra-abdominal pressures >20 mmHg), extremity compartment syndrome (even in unburned limbs), cerebral oedema, and prolonged mechanical ventilation.

To mitigate fluid creep: start with the Modified Brooke rate (2 mL/kg/%TBSA) rather than Parkland; titrate down as soon as urine output targets are met; consider colloid rescue with 5% albumin after 12–24 hours if crystalloid requirements are escalating; and monitor for the Ivy index — total 24-hour fluid exceeding 250 mL/kg (or 6 mL/kg/%TBSA) is associated with significantly worse outcomes.

Check baseline and serial (every 4–6 hours initially) laboratory values including: complete blood count (haemoconcentration in early resuscitation, anaemia later), electrolytes (hyperkalaemia from tissue destruction, hyponatraemia from large LR volumes), lactate and arterial blood gas (base deficit), coagulation profile (coagulopathy from dilution and consumption), glucose (especially in children — hypoglycaemia risk), and renal function (creatinine, BUN). In electrical burns, add creatine kinase (CK) and urine myoglobin. In suspected inhalation injury, obtain carboxyhaemoglobin (COHb) via co-oximetry — standard pulse oximetry will give falsely normal readings.

The single most common error in burn resuscitation is delivering the Parkland-calculated volume regardless of clinical response. The formula is an estimate derived from population averages — individual patients may need significantly more or less fluid depending on burn depth, inhalation injury, delays in resuscitation, pre-existing conditions, and individual physiology. Studies consistently show that the majority of patients receive more fluid than predicted. Clinicians must titrate to urine output and haemodynamic endpoints, adjusting the rate hourly rather than aiming for a fixed total volume.

Superficial burns cause erythema without blistering and do not result in the capillary leak that drives fluid losses. Including them in the TBSA calculation inflates the estimate and leads to unnecessary or excessive resuscitation. Only partial-thickness (2nd degree) and full-thickness (3rd/4th degree) burns should be counted. This distinction is particularly important in mixed-depth injuries — common in scald burns — where superficial areas are interspersed with deeper burns. When in doubt, err on the side of deeper classification initially and reassess at 48–72 hours as burn depth evolves.

The Parkland formula specifies that the first half of the 24-hour fluid volume must be delivered within 8 hours from the time of injury, not hospital presentation. In pre-hospital care, paramedics should document the time of burn injury (not just arrival time) and initiate fluid resuscitation en route when possible. Account for all fluids already administered when calculating remaining requirements. If the first 8-hour window has already passed at the time of presentation, begin at the second-half rate and titrate to clinical endpoints.

The Parkland formula (even at 3 mL/kg/%TBSA for paediatrics) does not account for normal physiological maintenance fluid requirements. Children — especially infants — have high baseline fluid needs relative to their weight. Holliday-Segar maintenance (100 mL/kg for the first 10 kg, 50 mL/kg for the next 10 kg, 20 mL/kg for each kg thereafter, per 24 hours) must be added to the calculated resuscitation volume. Maintenance fluid should contain dextrose (typically D5 half-normal saline) to prevent hypoglycaemia, as children have limited glycogen stores. Monitor serum glucose every 4–6 hours in paediatric burn patients.

Signs of fluid creep include: urine output persistently >1.5 mL/kg/h, rising central venous pressures, worsening oxygenation or ventilator requirements, tense abdomen (intra-abdominal pressure >20 mmHg), and tense extremity compartments. When 24-hour fluid volumes exceed 250 mL/kg (the “Ivy index”) or 6 mL/kg/%TBSA, morbidity and mortality increase significantly. If crystalloid requirements are escalating despite adequate urine output targets being met, consider colloid rescue with 5% albumin (0.3–0.5 mL/kg/%TBSA) to reduce total crystalloid load.