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

Objective Ankle-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.  Methods A 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.  Results From 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).  Conclusion Although 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).