Burn Injury Fluid Resuscitation Notes

Burn Injuries and Hypovolemic Shock

• Burn injuries covering a large percentage of the body surface area (BSA) can lead to hypovolemic shock due to fluid loss.
• Early and aggressive fluid resuscitation is a priority.

Rule of Nines

• The rule of nines is a quick estimation method used in emergency settings to calculate the total body surface area (TBSA) affected by burns.
• It helps determine fluid needs based on the percentage of TBSA burned.
• The body is divided into sections, each representing 9% or a multiple of 9% of the total body surface area.

Body Surface Area Percentages:

• Head and Neck: 9% total
  • Front: 4.5%
  • Back: 4.5%
• Each Arm: 9% total
  • Anterior: 4.5%
  • Posterior: 4.5%
• Each Leg: 18% total
  • Anterior: 9%
  • Posterior: 9%
• Anterior Trunk: 18% (torso and abdomen)
• Posterior Trunk: 18%
• Perineum: 1%

Example Calculation

• Entire front of the chest and abdomen burned: 18%
• One entire arm burned: 9%
• Total EBSA burn: 18\% + 9\% = 27\%%

Parkland Formula for Fluid Resuscitation

• Used for burns covering more than 20% TBSA.
• Formula: 4 \text{ ml} \times \text{Patient Weight (kg)} \times \text{Percentage of TBSA Burn}
• Administration:
  • Half of the total calculated fluid is given in the first 8 hours.
  • The remaining half is given over the next 16 hours (total 24 hours).

Example Calculation

• Patient weight: 70 kg
• TBSA burn: 30%
• Total fluid replacement: 4 \text{ ml} \times 70 \text{ kg} \times 30 = 8400 \text{ ml}
  • First 8 hours: \frac{8400 \text{ ml}}{2} = 4200 \text{ ml}
  • Next 16 hours: \frac{8400 \text{ ml}}{2} = 4200 \text{ ml}

Monitoring Fluid Resuscitation

• Urine output is the best indicator of adequate fluid titration.
• Target urine output: 0.5 ml/kg/hour
  • Average adult (60 kg): 0.5 \frac{\text{ml}}{\text{kg} \cdot \text{hour}} \times 60 \text{ kg} = 30 \text{ ml/hour}
  • This guideline (0.5 ml/kg/hour) is applicable for children as well.

Preferred Fluid

• Lactated Ringer's solution is the preferred fluid because it closely matches the extracellular fluid composition.
• Skin protects us from the environment, and when a large area of skin is lost, there is a significant loss of fluids.
• Lactated Ringer's solution is the closest in composition to the extracellular fluid lost in burns.

Electrolyte Imbalances

• Monitor for electrolyte imbalances, especially hyperkalemia, in the first 24 hours.
• Large cell destruction can cause potassium to increase in circulation because it's the main intracellular electrolyte.
• Hyperkalemia can lead to cardiovascular complications.
• Treatment for hyperkalemia involves administering fluids and insulin.