REDUCED RESUSCITATION FLUID VOLUME FOR 2ND-DEGREE BURNS WITH DELAYED INITIATION OF ASCORBIC-ACID THERAPY

Background: Oxygen radicals may play an important role in injury due t o thermal burns. High-dose antioxidant ascorbic acid (vitamin C, Cenol ete, Abbott Laboratory, Abbott Park, ill) therapy reduces edema of bur ned and unburned tissue, lipid peroxidation, and subsequent resuscitat ion fluid volume requirement in experimental burn models. Objective: T o determine the hemodynamic effects of delayed initiation (2 hours aft er injury) of antioxidant therapy in patients with second-degree burns . Design: Experimental study. Materials and Intervention: Burns over 7 0% of body surface area were produced by subxiphoid immersion of 12 gu inea pigs in 100 degrees C water for 3 seconds. The animals were resus citated with Ringer's lactated solution according to the Parkland form ula (4 mL/kg for 1% Of burned body surface area during the first 24 ho urs) from 0.5 to 2 hours following injury, after which the resuscitati on fluid volume was reduced to 25% of the Parkland formula. Animals re ceived Ringer's lactated solution to which ascorbic acid (340 mg/kg du ring the first 24 hours) was added (vitamin C group [n=6]) or Ringer's lactated solution only (control group [n=6]). Measurements: Heart rat es, mean arterial blood pressure, cardiac output, hematocrit level, an d water content in burned and unburned tissue were measured before inj ury and at intervals thereafter. Results: There were no significant di fferences in heart rates (P=.29) and blood pressures (P=.53) between t he 2 groups throughout the di-hour study period. No animal died. The v itamin C group showed significantly lower hematocrit levels (P<.05) an d significantly higher cardiac output values (P<.05) at 7 hours follow ing burn injury and at intervals thereafter (P<.001). Concluston: With delayed initiation of high-dose ascorbic acid therapy, the 24-hour fl uid resuscitation volume was reduced to 32.5% of the Parkland formula, while maintaining adequate cardiac output values.