Evaluation of simple non‐invasive techniques for assessment of lower extremity arterial disease

Abstract

To evaluate the reproducibility and precision of three, simple, non-invasive methods to measure blood pressure (BP) in the lower extremities by comparing reproducibility and sensitivity in finding abnormally low BP between ankle blood pressure (ABP) and toe blood pressure (TBP), by studying the concordance between TBP in toe 1 and 2 and evaluating the pole-pox method in patients with diabetes and lower extremity arterial disease (LEAD). The BP was measured twice, 1 week apart, in arms and legs in 13 controls and 12 patients with diabetes. ABP was assessed by using a Doppler pen for pulse registration. TBP was obtained by using a small cuff and a pulse oximetry sensor at toe 1 and 2. In eleven patients with diabetes and previously known LEAD ABP was obtained through the pole-pox method. No significant difference in reproducibility between absolute BPs and indices (coefficients of variation <9%) was found. A non-significant improvement with 4-8% in the sensitivity in detecting LEAD was seen when BP indices were used instead of absolute BP. A significant correlation in the variation over time for systemic and TBP (r = 0.34, P = 0.015) and a strong correlation was found between TBP measured at toe 1 and 2, respectively (r = 0.99, P < 0.001) was found. TBP measured with pole-pox method were significantly correlated with measurements made by the ordinary cuff technique (r = 0.75, P < 0.001). The use of TBP and ABP indices instead of absolute BP does not improve the reproducibility but may improve the sensitivity with respect to detection of LEAD, especially in patients with diabetes. The pole-pox method may be used as an alternative screening method in patients with diabetes and LEAD.