Effects of topical nitroglycerin and flurbiprofen in the rat comb burn model.

Burn injury is known to cause thrombosis and occlusion of dermal vessels that come in direct contact with thermal energy. Progressive ischemia secondary to diminished blood flow may compromise dermal tissues immediately surrounding the primary burn site. A standardized brass bar was used to create uniform full-thickness "comb" burns on 10 rat backs. Topical petrolatum (N = 2), 2% nitroglycerin (N = 4), and 5% flurbiprofen (N = 4) was applied to the burns at 2 and 4 hours postinjury. The vascular patency of dermal vessels was visualized directly by latex vascular casts made 24 hours after the burn injury. The vascular casts showed an absence of patent vessels within the direct burn sites in all treatment groups, and within the burn interspaces of the petrolatum-treated rats. Interspacial dermal vessel patency was seen in the 2% nitroglycerin and 5% flurbiprofen-treated rats. Topical 2% nitroglycerin and 5% flurbiprofen applied 2 and 4 hours postinjury effectively prevented interspacial dermal vessel thrombosis at 24 hours postinjury.