Utility of digital pulse oximetry in the screening of lower extremity arterial disease

PURPOSE: The aim of this study was to evaluate screening methods in the lower extremities by measurement of the digital pulse oximetry (oxygen percent saturation [SpO(2)]) of toes for peripheral arterial disease (PAD). METHODS: A prospective study was performed among 49 patients (98 limbs) with lower extremity arterial occlusive disease. We attempted to measure the ankle-brachial index (ABI), digital pulse oximetry (SpO(2)), and computerized tomographic angiography (CTA). Patients were divided into three groups by the traditional Fontaine classification system by symptom and CTA criteria: 1) Critical limb ischemia (Fontaine III and IV), 2) Claudication; (Fontaine II), and 3) asymptomatic limbs (Fontaine I). RESULTS: The sensitivity, specificity, positive and negative predictive values between active treatment groups (group I and II; endovascular and open surgery) and conservative group (group III) are all statistically significant. ABI; 55.09%, 94%, 96.7%, 39.02% (R = 12.54, P < 0.000) SpO(2); 87.06%, 87.8%, 84.3%, 90% (R = 40.11, P < 0.000). Pre-SpO(2) and pre-ABI all show statistically significant correlation in group I vs. group II, symptomatic PAD (group I and II) vs. asymptomatic PAD (group III), and the total PAD comparison. The Pearson's correlation coefficient between SpO(2) and ABI all show significant correlation in group II. Pre-SpO(2) vs. Pre-ABI show strong positive correlation except asymptomatic group (group III). CONCLUSION: Digital pulse oximetry can be a useful, simple, noninvasive screening device as well as ABI in PAD.