The use of pegorgotein in the treatment of frostbite.

Free oxygen radicals have been postulated to be an important mediator of injury in frostbite. A long-acting version of the endogenous scavenger enzyme, superoxide dismutase, has been created by conjugating it with polyethylene glycol (pegorgotein, formerly known as PEG-SOD). This study evaluated the efficacy of pegorgotein on frostbite tissue survival when administered prior to rewarming. In a prospective study, two groups of nine rabbits received a standardized frostbite injury using a modified Weatherley-White model. A control group received no pharmacologic therapy; the treatment group received 10,000 IU/kg pegorgotein intravenously immediately postinjury. Healing was followed until a clear line of demarcation was apparent (10 days). The percentage of viable ear surface remaining at the end of the study was measured and used to compare the effectiveness of treatment. Student's t-test was used to determine statistical significance. The study was designed to have an 80% ability to detect a 35% difference in tissue survival. No significant difference in frostbite injury (p = 0.967) was observed between the control and treatment groups. The treatment group showed a 9.3 +/- 15.5% tissue survival, whereas the control group had 9.6 +/- 14.5% tissue survival. These results indicate no significant treatment effect for pegorgotein on tissue survival in a rabbit frostbite injury model when administered immediately postinjury.