Review: The laboratory evaluation of lower limb perfusion in diabetes mellitus. A clinical review

Abstract

on-invasive laboratory tests are commonly employed in the assessment of lower limb perfusion. The accuracy of non-invasive assessments in diabetes remains a concern. We evaluated the more commonly used methods with particular reference to diabetic foot disease. A literature review and clinical evaluation of tests for macrovascular disease, including hand held Doppler, blood pressure measurement and indices, Doppler waveform analysis, colour duplex imaging and plethysmography was performed. Tests reflecting tissue perfusion, including infrared detectors, transcutaneous oxygen tension, laser Doppler, capillaroscopy and skin temperature were also reviewed. Non-invasive laboratory tests reduce the requirement for invasive investigations and their inherent risks. More traditional non-invasive methods are being replaced by evolving techniques employing ultrasound technology. Arterial calcification and peripheral neuropathy associated with diabetes can potentially reduce the reliability of these methods. Distal limb and tissue perfusion assessments are more likely to reflect local vascularity. Tissue perfusion indicators are generally slow and vulnerable to environmental influences, thus limiting their clinical use. Nevertheless, non-invasive tests are an important adjunct to the clinical evaluation of diabetic foot disease. However, diabetes potentially reduces their reliability and the results require careful interpretation. Distal perfusion tests have potential advantages over macrovascular assessments. The influence of diabetes on non-invasive tests needs further evaluation.