What is the recommended formula for calculating burns fluid requirements?

Burns Fluid Resuscitation Formula

Recommended Formula

For adults with severe burns, use the Parkland formula: 2-4 mL/kg/%TBSA of crystalloid (Ringer's Lactate or Hartmann's solution) over the first 24 hours, with half administered in the first 8 hours and the remainder over the next 16 hours. 1, 2

Initial Emergency Resuscitation

Immediately administer 20 mL/kg of balanced crystalloid within the first hour, regardless of burn size assessment, to address early hypovolemic shock. 1, 3

• This initial bolus is given before calculating TBSA due to difficulties in accurate early assessment 1
• Use Ringer's Lactate or Hartmann's solution as first-line fluid; avoid 0.9% NaCl due to risk of hyperchloremic acidosis and acute kidney injury 3, 4

Calculating 24-Hour Requirements

Adults

• Parkland formula: 2-4 mL/kg/%TBSA over 24 hours 1, 2
• Half of calculated volume in first 8 hours post-burn 2, 4
• Remaining half over next 16 hours 2, 4
• Resuscitation indicated for burns ≥10% TBSA 2, 4

Children

• Modified Parkland formula: 3-4 mL/kg/%TBSA plus basal maintenance fluids 1, 3
• Calculate basal requirements using Holliday-Segar 4-2-1 rule and add to modified Parkland calculation 1
• Children require approximately 6 mL/kg/%TBSA total in first 48 hours due to higher surface area-to-weight ratio 1, 2
• Resuscitation indicated for burns ≥5% TBSA (lower threshold than adults) 2, 4
• For burns 10-20% TBSA in children, consider reducing total fluid intake to decrease hospital stay and skin graft requirements 1

Critical Monitoring and Adjustment

These formulas provide only a starting point—actual infusion rates must be adjusted based on clinical response. 1, 5

Primary Endpoint

• Target urine output: 0.5-1 mL/kg/hour 1, 2, 4
• This is the most important parameter for guiding resuscitation 5

Additional Monitoring Parameters

• Arterial lactate concentration 1
• Mean arterial pressure 6
• Advanced hemodynamic monitoring (echocardiography, cardiac output, central venous pressure) if available 1

Alternative Formulas

While other formulas exist (Evans, Brooke, Rule of Tens), none have been rigorously validated or proven superior to Parkland 1:

• Brooke formula: 2 mL/kg/%TBSA 1
• Rule of Tens: Suitable for prehospital phase only, validated in silico but not clinically 1, 7
• All formulas estimate 2-4 mL/kg/%TBSA range over first 24 hours 1

Albumin Supplementation

Consider albumin 5% starting at 8-12 hours post-burn to reduce crystalloid volumes and prevent "fluid creep." 4

• Target serum albumin >30 g/L with doses of 1-2 g/kg/day 4, 8
• Reduces crystalloid administration and associated morbidity 4
• Particularly beneficial in severe burns to maintain plasma oncotic pressure at 20 mmHg 8

Critical Pitfalls to Avoid

Fluid Creep (Over-resuscitation)

• Excessive fluid administration increases morbidity including compartment syndrome, ARDS, and acute kidney injury 1, 3, 4
• Studies show 48% of patients receive over-resuscitation, with actual volumes often 5.6-6.1 mL/kg/%TBSA 5, 9
• Only 12-14% of patients actually receive volumes matching the Parkland formula 5

Under-resuscitation

• Delayed or inadequate resuscitation (>2 hours post-burn) increases morbidity and mortality, especially in children 1
• Early hypovolemic shock occurs within first 4 hours with nadir of cardiac output 1

Calculation Errors

• Use of nomograms reduces calculation errors compared to manual or calculator methods 10
• Nomograms show lowest error rates (5.7% high-magnitude errors vs 28.6% for pen-and-paper) 10

Contraindications

Never use hydroxyethyl starch (HES) in burn resuscitation—it is contraindicated 4

• Avoid gelatins and synthetic starches due to negative effects on coagulation 4