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 ratio (C L /C P ) were monitored in groups of 5 dogs before and 4 hours after 1) a 5 sec 100°C or 90°C foot paw scald; 2) intravenous vitamin C given 30 min before or after a 100°C scald; and 3) vitamin C given 30 min after a 90°C scald. Throughout the experiments, hind paw venous pressure was elevated and maintained by outflow restriction until steady state Q L and (C L /C P ) min were reached. Changes in protein permeability (CL/CP), fluid conductance properties (Kf) of the capillary membrane, 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 Kf. Although preburn infusion of vitamin C significantly (P <.01) attenuated burn-induced increases in paw weight gain (36 ± 3% vs 19 ± 4%), neither of the groups that received vitamin C postburn experienced significant modulations in paw weight gain (28 ± 4% vs 36 ± 3% in 100°C burn only; 23 ± 4% vs 28 ± 3% in 90°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-induced increases in microvascular permeability or in edema formation measured at the injury site.