Shock Syndromes II

The 2008 American Burn Association (ABA) practice guidelines for burn shock resuscitation promote

fluid resuscitation to target a urine output of 0.5–1 mL/kg/hour in adults, with the initial rate determined

by the total body surface area (TBSA) burned and body weight. Given a lack of strong evidence, the

ABA recommends against a preload-driven resuscitation target from an invasive monitor unless special

circumstances exist (e.g., older patients or inadequate response to treatment).

Many formulas exist to estimate crystalloid need, but the most common strategy is administering

crystalloid fluid using lactated Ringer solution by the Parkland formula: 4 mL x kg x % TBSA, with

half administered over the first 8 hours from the time of the burn injury and the remaining half over

the next 16 hours.

In practice, significantly more fluid is often given to burn patients than is predicted by traditional

formulas.

While maintaining a urinary output more than 0.5 mL/kg/hour, the average patient with a severe

burn receives around 6 mL/kg/% body surface area within the first 24 hours, leading to the potential

for “fluid creep” and associated complications of over-resuscitation.

Therefore, some formulas now advocate less initial fluid, such as the “modified” Brooke formula

(2 mL/kg/% body surface area).

The U.S. Army Institute of Surgical Research (USAISR) rule of 10 (% TBSA burn x 10 = initial

rate) is a simplified equation that determines the initial starting rate for fluid resuscitation, and

subsequent rate changes are guided by maintaining a urinary output greater than 0.5 mL/kg/hour.

Burn resuscitation formulas serve as an initial starting dose, and ongoing resuscitation should be

individualized.

Difficult to resuscitate: When a patient’s fluid requirement exceeds what is expected according to the

traditional formulas, albumin may be added. When added, the current fluid rate is maintained, but

albumin replaces 33%–66% of the total rate. High dose ascorbic acid (e.g., 66 mg/kg/hr) has been

shown to decrease total fluid requirements, but guidelines state more evidence is needed before this

therapy can be recommended routinely.

Patient Case

the lower extremities and buttocks after a fall into a molten slag at work in a steel mill. He received 500 mL

of normal saline during transfer to the hospital. On his presentation to the burn unit, the surgical resident

asks for your help in calculating the patient’s fluid resuscitation needs. Which is best for resuscitation?

by 250 mL/hour, titrating to goal urinary output of 1 mL/kg/hour.

406 mL/hour, titrating to goal urinary output of 0.5 mL/kg/hour.

of 0.5 mL/kg/hour.

nary output of 0.5 mL/kg/hour.

Lethal triad: Hypothermia, acidosis, and coagulopathy

Hypothermia, severe acidemia (pH less than 7.20), and hypocalcemia inhibit the procoagulant

enzyme function.