The relationship between temperature isotherms and skin blood flow in the ischemic limb.

This study was conducted in order to establish a relationship between thermographically defined levels of viability in the ischemic limb and a measurement of skin blood flow. Color thermograms (10 colors, 0.6 degree C apart) defined the temperature gradient and skin blood flow was measured, using the radioactive clearance method in three discrete isotherms set 1.8 degrees C apart. The differences in skin blood flow measured in the three separate isotherms were significant (P less than 0.001). The results of this study support previously unqualified assertions that thermographic temperature gradients along an ischemic limb are indicative of local microcirculatory status. The potential of the thermographic method for demarcating viable and nonviable skin flaps at the chosen site of amputation is confirmed.