ABSTRACT
BACKGROUND: Lower extremity arterial disease is common disorder affecting large number of peoples and is frequently asymptomatic. Currently ABI is used as screening test for LEAD, which is time consuming and requires special instrument for measurement. We compare the role of pulse oximetry, ABI and its combination in diagnosis of LEAD. METHODS: Total 224 patients (448 limbs) were enrolled in the study. Complete history, examination was done. Pulse oximetry of all limbs and ABI of both lower limbs were measured. CT angiography and pulse Doppler was done to diagnose LEAD. RESULTS: Pulse oximetry was found to have sensitivity of 60.5%, specificity of 95.9% positive likelihood ratio 14.93 and negative likelihood ratio 0.41. ABI was found to have sensitivity of 69.7%, specificity of 97.3%, positive likelihood ratio 25.8 and negative likelihood ratio 0.32. But when both are combined, sensitivity increases to 84.2%, specificity decreases to 91.9%, positive likelihood ratio decreases to 10.39 and negative likelihood ratio decreases to 0.17. CONCLUSION: Our study suggests that pulse oximetry is simple and non-invasive test that provides quick result which is at least as accurate as ABI and thus is an easy alternative/ additional method for the screening of LEAD. However when used in combination with ABI the sensitivity for the detection of LEAD increases.
