1. Resuscitation Formulas and Selection Rationale

Standardized resuscitation formulas provide a critical starting point for estimating initial fluid volume requirements in severe burn injuries. However, these formulas are merely guides. Dynamic, hourly adjustment based on individual patient response and specific injury characteristics is essential to prevent the significant morbidity associated with both under- and over-resuscitation.

Common Resuscitation Formulas

• Parkland Formula: 4 mL/kg × % Total Body Surface Area (TBSA) of Lactated Ringer’s (LR) solution administered over 24 hours. Half of the total volume is given in the first 8 hours post-injury, with the remaining half delivered over the subsequent 16 hours.
• Modified Brooke Formula: 2 mL/kg × %TBSA of LR over 24 hours. Colloid administration is typically deferred until at least 24 hours post-injury.
• Evans Formula: A combination approach using 1.4 mL/kg × %TBSA of LR plus 0.7 mL/kg × %TBSA of colloid solution in the first 24 hours.

2. Crystalloids vs. Colloids: Pharmacotherapy Depth

The choice between crystalloid and colloid solutions is a central tenet of burn resuscitation. Lactated Ringer’s remains the first-line agent due to its balanced electrolyte profile and physiologic pH. Colloid rescue therapy, primarily with albumin, is reserved for specific indications such as refractory hypotension or massive crystalloid requirements, typically after the initial phase of capillary leak has begun to resolve.

Fluid Options

• Crystalloids (First-Line):
  • Lactated Ringer’s (LR): The standard of care. It is a balanced, isotonic fluid whose lactate component is metabolized by the liver to bicarbonate, helping to buffer metabolic acidosis.
  • Other Balanced Fluids (e.g., Plasma-Lyte): Use acetate and gluconate as buffers instead of lactate. May be considered in patients with severe liver failure.
• Colloid Rescue (Second-Line):
  • Albumin 5%: Provides oncotic support to help retain fluid within the intravascular space. Typically initiated 8–12 hours post-burn if crystalloid requirements are massive (>200 mL/kg) or in the presence of severe hypoalbuminemia. A common dose is 0.5–1 g/kg infused over 2–4 hours.
  • Hydroxyethyl Starch (HES 130/0.4): Its use is highly controversial and generally discouraged. It should only be considered if albumin is unavailable due to documented risks of coagulopathy and acute kidney injury (AKI).

3. Dosing, Titration, and Monitoring

Effective burn resuscitation is a dynamic process. Fluid infusion rates must be adjusted hourly based on key physiological parameters to optimize end-organ perfusion while minimizing the risks of fluid overload, edema, and compartment syndromes.

Essential Monitoring

• Core Parameters: Hourly intake/output (I&O) and vital signs are mandatory.
• Laboratory Monitoring: Check hematocrit every 4–6 hours to assess hemoconcentration. Monitor electrolytes and acid-base status regularly.

4. Special Populations and Fluid Adjustments

Fluid resuscitation must be carefully tailored in patients with pre-existing comorbid conditions that affect volume tolerance, such as renal disease or heart failure. Extremes of age also require specific considerations.

Renal Impairment

Patients with chronic kidney disease have a limited ability to excrete large fluid volumes. Consider reducing the initial crystalloid volume by 10–20% from the formula calculation and introducing colloid therapy earlier to minimize total volume. Maintain a low threshold for initiating early continuous renal replacement therapy (CRRT) if oliguria or signs of volume overload persist.

Heart Failure

Patients with pre-existing heart failure, particularly with reduced ejection fraction, are at high risk for iatrogenic pulmonary edema. Start resuscitation at approximately 75% of the calculated formula volume. Monitor preload indicators (e.g., CVP, POCUS) closely. It may be necessary to initiate low-dose norepinephrine early to support MAP and organ perfusion without relying solely on large fluid volumes.

5. Infusion Logistics and Devices

The safe and effective delivery of high-volume fluid resuscitation depends on appropriate vascular access and reliable infusion devices. The choice of access impacts achievable flow rates and potential complications.

Vascular Access

• Peripheral IVs: The preferred initial access. Use large-bore catheters (14-16 gauge) placed in unburned skin. A single large-bore peripheral IV can deliver up to 3 L/hr. Rotate sites every 48-72 hours to minimize the risk of phlebitis and infection.
• Central Venous Catheters (CVCs): Reserved for patients requiring very high flow rates, those with poor peripheral access, or the need for invasive hemodynamic monitoring and frequent vasopressor titration. CVCs carry a higher risk of central line-associated bloodstream infections (CLABSI) and thrombosis.

6. Pharmacoeconomic Analysis and Protocol Development

Institutional fluid resuscitation policies are driven by a balance of drug acquisition costs, the burden of monitoring, and the costs associated with managing complications. A standardized, evidence-based protocol is key to optimizing both clinical and economic outcomes.

Cost Comparison of Resuscitation Fluids

Protocol Development and Quality Metrics

Effective institutional protocols should be monitored with key performance indicators, including:

• Adherence to formula-based initiation of fluids.
• Timeliness of hourly fluid rate adjustments based on urine output.
• Incidence of resuscitation-related complications, such as abdominal compartment syndrome, pulmonary edema, and acute kidney injury.