Direct current reduces wound edema after full-thickness burn injury in rats

Objective: To observe the effect of 4 and 40 mu A direct current (DC) on edema formation after burn injury in rats. Design, Materials, and Methods: Silver-nylon wound dressings were used as either anodes (-) or cathodes (+) on 20% total body surface area full-thickness scalds in anesthetized male Sprague-Dawley rats. Untreated burned rats and rats treated with silver-nylon dressings without current were used as controls. Measurements and Main Results: Immediately applied, continuous DC reduced burn edema by 17 to 48% at different times up to 48 hours postburn (p < 0.001). Neither reversal of electrode polarity nor change in current density had any significant effect on the results of treatment. Starting treatment during the first 8 hours postburn produced the least edema accumulation, but the reduction was significant even when DC was applied 36 hours afterburn. If started immediately after injury, treatment had to be continued a minimum of 8 hours to be most effective. Conclusions: Direct electric current has a beneficial effect in reducing wound edema after burn injury.