Efficacy of a Pocket Pulse Oximeter and a Digital Pulse Oximeter as Screening Tools for Type 2 Diabetes Patients with Asymptomatic Lower Extremity Arterial Disease.

The risk of developing lower extremity arterial diseases (LEAD) increases by 2-4 folds in patients with diabetes mellitus. Diabetic individuals with LEAD are more likely than non-diabetic individuals to have limb amputations, and they have a higher risk of cardiovascular and cerebrovascular problems. The present study sought to assess the efficacy of two pulse oximeters, a high-quality standard digital pulse oximeter and an inexpensive pocket pulse oximeter, to detect LEAD in patients with diabetes mellitus. Qualifying patients were examined with a pocket pulse oximeter and digital pulse oximeter for measuring SpO2 of their index fingers, big toes in the supine position, and at 12-inch elevation. All patients underwent Doppler waveform analysis examination of their lower extremity arteries by an investigator, who was unaware of the pulse oximetry results. Doppler waveform analysis is used as the standard. Sensitivity, specificity, the positive and negative predictive values were compared. Twenty nine of 100 legs examined had a significant LEAD, i.e., monophasic waveform by Doppler waveform analysis. Pocket pulse oximetry showed a sensitivity of 72%, a specificity of 98% and a positive predictive value of 95%, and a negative predictive value of 90%. Digital pulse oximetry showed a sensitivity of 83%, 98%, a positive predictive value of 96%, and a negative predictive value of 93%. Pulse oximetry may be a useful additional tool to screen for LEAD in patients with diabetes mellitus. It has good sensitivity and specificity in detecting LEAD even in the asymptomatic phase, especially in type 2 diabetes mellitus patients. In comparison between two oximeters, digital pulse oximetry showed a sensitivity, and the higher sensitivity is desirable in a screening test.