Adequacy of fluid resuscitation in burn patients is indicated by which of the following?

A. Urine output of 45 ml. per hr. in a 70-kg. 30-year-old man with flame burns involving 55% of the total body surface.

B. Hourly urine output of 7 ml. in a 7-kg. 15-month-old child with burns involving 40% of the total body surface.

C. A pulmonary capillary wedge pressure of 17 to 20 mm. Hg.

DISCUSSION: The goal of burn patient resuscitation is the maintenance of vital organ function at the least immediate or delayed physiologic cost. Fluid resuscitation of burn patients does not need to be a test of maximum renal function. Adequacy of volume replacement and of renal blood flow are indicated by an hourly urine output of 30 to 50 ml. in adults and 1 ml. per kg. per hr. in children weighing less than 30 kg. In patients with extensive muscle damage caused by high-voltage electric injury, heavy loads of hemochromagens give the urine the appearance of port wine. Such patients are prone to develop acute renal failure unless brisk urine output is maintained until the pigment concentration is reduced to insignificant levels. Fluid should be infused into such patients at the rate needed to achieve an hourly urine output of 75 to 100 ml., but if the patient does not respond to increased fluid input with an increase in urine volume and clearing of the heme pigments, a diuretic should be given. A pulmonary capillary wedge pressure of 17 to 20 mm. Hg is indicative of an adequate circulating blood volume, but a urinary sodium concentration of less than 20 mEq. per liter is consistent with an intravascular volume deficit.