Postburn vitamin C infusions do not alter early postburn edema formation

To determine whether vitamin C would alter burn induced edema accumulation, hind paw venous pressure, lymph flow (Q(L)), and lymph-to-plasma protein r atio (C-L/C-P) were monitored in groups of 5 dogs before and 4 hours after 1) a 5 sec 100 degrees C or 90 degrees C foot paw scald; 2) intravenous vit amin C given 30 min before or after a 100 degrees C scald; and 3) vitamin C given 30 min after a 90 degrees C scald. Throughout the experiments, hind paw venous pressure was elevated and maintained by outflow restriction unti l steady state Q(L) and (C-L/C-P)(min) were reached. Changes in protein per meability (C-L/C-P), fluid conductance properties (K-f) of the capillary me mbrane, and paw weight gain were determined. Compared with preburn values, scald uniformly produced significant (P < .05, ANOVA) increases in Q(L), C- L/C-P and K-f. Although preburn infusion of vitamin C significantly (P < .0 1) attenuated burn-induced increases in paw weight gain (36 +/- 3% vs 19 +/ - 4%), neither of the groups that received vitamin C postburn experienced s ignificant modulations in paw weight gain (28 +/- 4% vs 36 +/- 3% in 100 de grees C burn only; 23 +/- 4% vs 28 +/- 3% in 90 degrees C burn only) or in any of the variables used to monitor capillary membrane integrity. Vitamin C infusions initiated after graded scald produced no changes in the burn-in duced increases in microvascular permeability or in edema formation measure d at the injury site.