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 (QL), and lymph-to-plasma protein ratio (CL/CP) 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 vitamin 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 until steady state QL and (CL/CP)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 QL, CL/CP 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 degrees 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-induced increases in microvascular permeability or in edema formation measured at the injury site.