We have reported the results of a preliminary experimental study designed to determine if radioiodinated human serum albumin (RISA I¹³¹) can be used in a clinically applicable method to predict the degree of tissue loss soon after frostbite. The RISA was injected either immediately after the freezing injury or twenty-four hours after the injury. The pattern of daily counts permitted the accurate prediction of tissue loss forty-eight to ninety-six hours after the injection.

The counts on the group of rabbits whose paws subsequently showed loss of tissue were higher than those which did not. The difference was statistically significant, but there was some overlap in the values of the two groups.

The accuracy of predicting tissue loss based on the plateau count was 100 per cent for paws with counts above the mean for the groups with tissue loss. The predictability of tissue loss for each group as a whole was approximately 80 per cent when one standard deviation below the mean for loss was used as the determinant.

This preliminary study would indicate that this method of predicting tissue loss soon after frostbite could be of use in the clinical evaluations of therapeutic measures and in the triage of casualties.