REDUCED RESUSCITATION FLUID VOLUME FOR 2ND-DEGREE EXPERIMENTAL BURNS WITH DELAYED INITIATION OF VITAMIN-C THERAPY (BEGINNING 6-HOUR AFTER INJURY)

We studied the hemodynamic effects of delayed initiation (6 h postburn ) of antioxidant therapy with high-dose vitamin C in second-degree the rmal injuries. Seventy percent body surface area burns were produced b y subxiphoid immersion of 12 guinea pigs into 100 degrees C water for 3 s. The animals were resuscitated with Ringer's lactate solution (R/L ) according to the Parkland formula (4 ml/kg/% burn during the first 2 4 h) from 6 h postburn, after which the resuscitation fluid volume was reduced to 25% of the Parkland formula volume. Animals were divided i nto two groups, The vitamin C group (n = 6) received R/L to which vita min C (340 mg/kg/24 h) was added after 6 h postburn. The control group (n = 6) received R/L only. Both groups received identical resuscitati on volumes. Heart rates, mean arterial blood pressure, cardiac output, hematocrit level, and water content of burned and unburned tissue wer e measured before injury and at intervals thereafter. No animals died. There were no significant differences in heart rates or blood pressur es between the two groups throughout the 24-h study period, The vitami n C group showed significantly (P < 0.05) lower hematocrits 8 and 24 h postburn, and higher cardiac outputs after 7 h postburn, At 24 h post burn, the burned skin in the vitamin C group had a significantly (P < 0.05) lower water content (73.1 +/- 1.1) than that of the control grou p (76.0 +/- 0.8). In conclusion, delayed initiation of high-dose vitam in C therapy beginning 6 h postburn with 25% of the Parkland formula v olume significantly reduced edema formation in burned tissue, while ma intaining stable hemodynamics. (C) 1997 Academic Press.