Metabolism of Skin Following Frostbite

¹ From the Department of Physiology, School of Medicine, Stanford University, Stanford, California

The nature of the tissue damage produced by frostbite was investigated by measuring Q_o² and Q^N_g² of skin removed from the previously frozen feet of rats both immediately after thawing and at various later times. The longer feet were frozen at –25°C, the greater was the tissue loss and the lower the Q_oo2 and Q^N_G² of the injured skin. Freezing and thawing produce tissue injury which is apparent as soon as thawing is complete. With very brief durations of freezing (less than 5 min.) further (postthawing) injury can be demonstrated. The sum of freezing-thawing and postthawing injury to skin respiration is about 90%, but the damage already present at the time of thawing is much larger. The extent of tissue loss following frostbite is reduced if the frozen limb is rapidly thawed in water at +42°C and the Q_oo2 of skin from feet thawed rapidly is higher with all durations of freezing than that from feet thawed slowly in air. It is shown that rapid thawing reduces total tissue loss by reducing the freezing-thawing damage. This is a specific effect on the frozen tissue; rapid thawing does not merely decrease the duration of the frozen state.