The correct answer is:

lactated Ringer solution at 1360 mL/hour for 8 hours, then 680 mL/hour for 16 hours

Educational Objective:

Determine a fluid resuscitation strategy for patients with burn injuries.

Key Point:

The fluid-resuscitation rate after major burns depends on the percent total body surface area burned, as approximated by the Rule of Nines, and the patient’s weight. These 2 data points are incorporated into the Parkland formula to determine the volume and rate of crystalloid to administer in the first 24 hours after burn injury.

Explanation:

In the setting of a burn injury, degree of hypovolemic and distributive shock depends on the percentage of body surface area affected. The more extensive the second-, third-, and fourth-degree burns, the greater the fluid losses and the more profound the systemic inflammatory response.

To approximate the percent of total body surface area (TBSA) affected by burns in adults, clinicians use the Rule of Nines (see Figure), so-called because major body regions comprise percentages in multiples of 9. Of note, the Rule of Nines refers only to second-, third-, and fourth-degree injury; first-degree burns are not included in the calculation.

Figure: Estimation of Total Body Surface Area Burned (Adult).

According to the Rule of Nines, the patient in this scenario presents with an approximately 64% TBSA burn (18% × 2 for lower extremities, 1% for genitalia, 9% for abdomen, 18% for the back). This constitutes a major burn, and profound shock is inevitable without diligent resuscitation.

To avert multiorgan failure, resuscitation is now recommended to begin according to ½ the traditional Parkland formula: Volume of crystalloid in 24 hours = % TBSA burned × 2 mL/kg × weight (in kg). One-half of this volume is administered in the first 8 hours after injury, and the remaining volume is administered over the next 16 hours.

According to the traditional Parkland formula, this patient requires 21,760 mL of crystalloid over the next 24 hours, according to the following rates: 1,360 mL/hour × 8 hours, and then 680 mL/hour × 16 hours.

Given the newer recommendation of starting only with half the calculated Parkland formula’s volume, the above patient would be started on 1,360 mL/hour/2 × 8 hours, and then 680 mL/hour/2 × 16 hours or 680 mL/hour for first 8 hours and then 340 mL/hr for the next 16 hours. These calculated rates are only a starting point, to be adjusted according to the patient’s clinical response.

Regarding choice of fluid, normal saline in such high volumes as those required by patients with burn injuries can cause hyperchloremic metabolic acidosis. To avoid this among patients already acidotic from impending shock, lactated Ringer solution is the crystalloid of choice for burn resuscitation.

The Table below reviews the types of burns.

References:

Saffle JR. Fluid creep and over-resuscitation. Crit Care Clin. 2016;32(4):587-598.

Singer AJ. Lee CC. Thermal Burns. (Chapter 56) In: Walls R, et al. Rosen’s Emergency Medicine: Concepts and Clinical Practice. 9th ed., 2018: 715-723.2e