Reduced resuscitation fluid volume for second-degree burns with delayed initiation of ascorbic acid therapy

Oxygen radicals may play an important role in injury due to thermal burns. High-dose antioxidant ascorbic acid (vitamin C, Cenolete, Abbott Laboratory, Abbott Park, Ill) therapy reduces edema of burned and unburned tissue, lipid peroxidation, and subsequent resuscitation fluid volume requirement in experimental burn models.

To determine the hemodynamic effects of delayed initiation (2 hours after injury) of antioxidant therapy in patients with second-degree burns.

Experimental study. MATERIALS AND INTERVENTION: Burns over 70% of body surface area were produced by subxiphoid immersion of 12 guinea pigs in 100 degrees C water for 3 seconds. The animals were resuscitated with Ringer's lactated solution according to the Parkland formula (4 mL/kg for 1% of burned body surface area during the first 24 hours) from 0.5 to 2 hours following injury, after which the resuscitation fluid volume was reduced to 25% of the Parkland formula. Animals received Ringer's lactated solution to which ascorbic acid (340 mg/kg during the first 24 hours) was added (vitamin C group [n = 6]) or Ringer's lactated solution only (control group [n = 6]).

Heart rates, mean arterial blood pressure, cardiac output, hematocrit level, and water content in burned and unburned tissue were measured before injury and at intervals thereafter.

There were no significant differences in heart rates (P = .29) and blood pressures (P = .53) between the 2 groups throughout the 24-hour study period. No animal died. The vitamin C group showed significantly lower hematocrit levels (P < .05) and significantly higher cardiac output values (P < .05) at 7 hours following burn injury and at intervals thereafter (P < .001).

With delayed initiation of high-dose ascorbic acid therapy, the 24-hour fluid resuscitation volume was reduced to 32.5% of the Parkland formula, while maintaining adequate cardiac output values.