For an adult with bilateral leg burns (approximately 36% total body surface area), what initial crystalloid bolus volume should be administered?

Initial Fluid Bolus for Bilateral Leg Burns

For an adult with bilateral leg burns (approximately 36% TBSA by Rule of Nines), administer an immediate bolus of 20 mL/kg of balanced crystalloid solution (Ringer's Lactate or Hartmann's) within the first hour, followed by calculated resuscitation using the Parkland Formula. 1, 2

Immediate Initial Bolus

• Give 20 mL/kg of Ringer's Lactate intravenously within the first hour regardless of precise burn size calculation—this addresses early hypovolemic shock and should not be delayed while performing detailed TBSA assessment. 1, 2
• For a 70 kg adult, this equals approximately 1,400 mL as the initial bolus. 1
• Use Ringer's Lactate or Hartmann's solution as first-line fluid, not normal saline (0.9% NaCl), because balanced crystalloids have electrolyte concentrations closer to plasma and avoid the risk of hyperchloremic metabolic acidosis and acute kidney injury associated with normal saline. 1, 2, 3

Subsequent 24-Hour Resuscitation (Parkland Formula)

After the initial bolus, calculate ongoing fluid requirements using the Parkland Formula:

• Total 24-hour crystalloid requirement = 2-4 mL/kg × body weight (kg) × %TBSA burned 1, 2
• For bilateral leg burns (36% TBSA) in a 70 kg adult: 5,040-10,080 mL over 24 hours (using 2-4 mL/kg range)
• Administer half of this calculated volume in the first 8 hours (measured from time of burn injury, not from hospital arrival), and the remaining half over the next 16 hours. 1, 2
• Use the upper end of the range (4 mL/kg) if burns are full-thickness or if inhalation injury is present. 2, 4

Critical Monitoring and Adjustment

• Target urine output of 0.5-1 mL/kg/hour (approximately 35-70 mL/hour for a 70 kg patient) as the primary endpoint for fluid adjustment. 1, 2
• Adjust fluid infusion rates continuously based on urine output—formulas provide only initial estimates and must be modified based on clinical response. 1, 2
• Monitor mean arterial pressure (target >65 mm Hg), arterial lactate concentration (should trend downward, normalizing within 24-32 hours), and consider advanced hemodynamic monitoring if persistent oliguria or hemodynamic instability occurs. 2

Common Pitfalls to Avoid

• Do not use the Rule of Nines for precise TBSA calculation—it overestimates TBSA in 70-94% of cases, leading to excessive fluid administration. Use the Lund-Browder chart as the gold standard for accurate assessment. 1, 2
• Avoid "fluid creep" (over-resuscitation), which occurs in 76% of burn resuscitations and causes complications including compartment syndrome, pulmonary edema, intestinal edema, and acute kidney injury. 1, 2, 4
• Do not continue excessive fluid rates once adequate urine output is achieved—rigid adherence to formulas without clinical adjustment increases morbidity. 2, 4
• Monitor for compartment syndrome in bilateral leg burns, especially if circumferential, and consider escharotomy within 48 hours if circulatory impairment develops. 1

Albumin Supplementation Consideration

• For burns >30% TBSA (which includes this 36% case), consider initiating 5% human albumin between 8-12 hours post-burn if fluid requirements exceed expected targets, targeting serum albumin levels >30 g/L with doses of 1-2 g/kg/day to reduce crystalloid volumes and prevent complications. 1, 2
• Albumin administration reduces mortality (OR=0.34, P<0.001) and decreases abdominal compartment syndrome from 15.4% to 2.8% when used appropriately. 1

Transfer to Burn Center

• Contact a burn specialist immediately to determine need for transfer to a burn center, as specialized care improves survival, reduces complications, and decreases length of stay for major burns. 1, 4