Thermography of hands after a radial forearm flap has been raised

To evaluate possible circulatory changes in the donor hand 18 patients underwent cold stress testing and thermography of both hands a mean of 13 months after a radial forearm flap had been harvested. Temperatures were measured with a computed Inframetrics 600L infrared thermocamera, and the images were videotaped at room temperature and after a cold challenge (immersion in a water bath at 15 degrees C for five minutes). Temperatures were measured on the volar aspect of each fingertip, and rewarming curves were plotted for both hands. The patients could be divided into three groups according to the rewarming pattern: mean temperature of the donor hand was more than 0.5 degree C warmer than that of the other hand (n = 7), rewarming was similar in both hands (n = 6), and the mean temperature of the donor hand was less than 0.5 degree C colder than that of the other hand (n = 5). Patients with a colder donor hand had significantly wider (Pearson's r = 0.62, p = 0.005) and longer (r = 0.71, p = 0.001) defects. The rewarming pattern did not correlate with subjective cold intolerance, but the temperature of the donor hand was a mean of 0.5 degree C less than that of the other hand in room temperature in subjects who experienced cold intolerance (p = 0.019). We conclude that the raising of a radial forearm flap, particularly a large one, affects the thermoregulatory system of the donor hand, results in abnormal rewarming, and can cause subjective cold intolerance.