Detection of Dialysis Access Induced Limb Ischemia by Infrared Thermography in Children

Abstract

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.

The Novel use of Infrared Thermal Imaging as an Adjunct for the Management of Haemodialysis Access Induced Distal Ischaemia

“…Allen and colleagues investigated the use of thermography in patients with suspected steal syndrome from AVFs and found an agreement between its use and clinical assessment of steal syndrome (9). Similarly, Novljan et al found similar results and therefore concluded that whilst the diagnosis of steal syndrome is primarily clinical, thermography might be a safe, non-invasive, cheap tool for the timely detection of at-risk patients (10).…”

Access Flow Monitoring Methods

“…However, unlike renal blood flow, there is no auto-regulation of access blood flow which is passively following the changes in mean arterial pressure. For example, when mean arterial pressure changes with exercise, and more blood flow is required for perfusion of the working muscle, access flow is going to passively increase, stealing blood flow from the systemic circulation or from the distal parts of the circulation (Novljan et al 2011). More important than the absolute volume flow rate is the fraction of cardiac output flowing through the peripheral arterio-venous access.…”