Detection of dialysis access induced limb ischemia by infrared thermography in children

High arteriovenous fistula (AV fistula) blood flow may impair distal limb perfusion and cause irreversible ischemic damage. Since tissue temperature reflects blood perfusion, we tried to assess distal blood flow using an infrared camera. We examined all 12 patients with an AV fistula in our dialysis unit. Seven were pediatric patients aged 11.0-18.9 years (mean 14.9 years) and five were adults aged 26.9-62.1 years (mean 38.6 years). Infrared thermal imaging (thermography) of their hands was performed after the completion of their regular dialysis sessions. In each patient, the spot temperature of each fingertip on both hands was assessed separately, with three measurements being performed for each measuring point. The mean spot temperature of all fingertips was calculated for each hand and the results compared. A statistically significant difference (P < 0.05) indicated distal perfusion insufficiency. Perfusion of the hands was also assessed by inspecting the visualized temperature distribution on the thermal image. Finally, we compared the results to the clinical findings in relevant patients. In 8/12 patients (66.7%), the mean spot temperature of the fingertips was statistically significantly lower on the fistula side (P < 0.05). Only 4/12 patients (33.3%) had clinical symptoms, and all were detected by thermography. Abnormal findings were more frequent in elderly patients. Although we realize that the diagnosis of steal syndrome is primarily clinical, thermography might be a safe, noninvasive, cheap tool for the timely detection of children at risk of developing symptoms of hand ischemia.