The Functional Pathology of Frostbite and the Prevention of Gangrene in Experimental Animals and Humans

Abstract

Six rabbits were depilated on the abdomen and the skin exposed to dry ice for 5-90 mins. For the subsequent 30-120 mins. no injd. fluorescein was observed by U.V. light in the exposed areas. In the 2d stage there was an intense fluorescence and marked swelling in the treated areas. 8-14 hrs. later, after repeated injns. of fluorescein, the exposed spots were not fluorescent. The entire area then became gangrenous. Biopsies showed red cells clumping in the smaller vessels. These became organized thrombi only after 72 hrs. Of 10 other similarly treated rabbits, 5 were given heparin 4 hrs. after exposure. None of the 5 developed gangrene unlike the untreated controls. Dry ice was applied for 10 mins. to the lateral surface of the arm of a human group. Heparin was immediately given except to one control. A 2d group was given 2 exposures of dry ice for 30 mins. each, with the initial exposure being allowed to develop for 6 days before the 2d frostbite was induced. Immediately thereafter this group received heparin. All treated cases escaped deep injury. Their clotting time stayed between 25-60 mins.