Correlation Between Ankle Brachial Index and Lower Limbs Digital Pulse Oximetry: A Referral Center Experience, Prevalence Study

Juan Sanjuan,Wilmer Botache,Francisco J Montoya,Estefania Barbosa,Rolando Medina,Maria Andrade,Gabriela Ruiz,Andres Ramirez,Edwin Romero,Roberto Diaz

doi:10.7759/cureus.6762

Abstract

ObjectiveAnkle-brachial index (ABI) is widely recommended and used to evaluate peripheral arterial disease. The oxygen saturation (SpO2) has been associated with ABI, showing a promising clinical practice utility; however, little literature regarding this matter has been reported. This study aims to assess the correlation between pulse oximetry and ABI. MethodsA cross-sectional study was conducted using ABI measuring devices, such as the MESI® Ankle Brachial Pressure Index (ABPI) (MESI, Ltd., Slovenia, EU) and pulse oximetry. We compared the SpO2 distribution by using the Wilcoxon test and evaluated its correlation by using logistic regression. ResultsFrom a total of 86 patients, 54 were males (62.8%) and the median age was 54 years old (interquartile range (IQR) = 37 - 65 yrs.). Regarding ABI measurements of the right lower limb (RLL), a total of 20 patients (22.3%) had an abnormal classification. On the other hand, a total of 21 patients (22.1%) had an abnormal classification of the left lower limb (LLL) ABI measurements. The distribution of SpO2 in relation to ABI categories was not statistically different (RLL p = 0.2433; LLL p = 0.1242). The SpO2 classification of ABI and abnormal pulse oximetry for the RLL was at 76.7% and at 77.9% in the LLL (Pearson’s goodness-of-fit test: RLL = p < 0.001 and LLL = p < 0.001). ConclusionAlthough we didn’t observe any statistical differences in the SpO2 distribution regarding ABI measurements, in their correlation, there seems to be a different tendency. The SpO2 might be a useful non-invasive tool to assess asymptomatic patients with risk factors for peripheral arterial disease (PAD).

Highlights

Ankle-brachial index (ABI) is the ratio of the systolic blood pressures of the ankles and arms
This study aims to assess the correlation between pulse oximetry and ABI
The SpO2 classification of ABI and abnormal pulse oximetry for the right lower limb (RLL) was at 76.7% and at 77.9% in the left lower limb (LLL) (Pearson’s goodness-of-fit test: RLL = p < 0.001 and LLL = p < 0.001)

Summary

Introduction

Ankle-brachial index (ABI) is the ratio of the systolic blood pressures of the ankles and arms It is one of the most useful tests for identifying peripheral arterial disease (PAD) because it can be applied, is simple, cheap, and non-invasive. PAD is often described as a decrease of blood supply to the lower limbs because of an obstruction narrowing the vessel walls, reducing blood flow, generally due to atherosclerosis [1,2]. This disease affects over 202 million people worldwide, and it seems to be an independent indicator of cardiovascular morbidity and mortality. It remains an important tool in practice [5,6,7]

Methods

Results

Conclusion