Comparison of Ankle Brachial Index (ABI), Toe Brachial Index (TBI), and Trans-Cutaneous Partial Pressure of Oxygen (TcPO2) in Prediction of Limb Outcome Among Patients with Diabetic Foot Ulcers (DFUs)

Diabetics develop foot ulcers due to peripheral ischaemia, neuropathy, or nero-ischaemia both. With rising prevalence of peripheral arterial occlusive disease (PAOD), it is considered the most important factor in development of foot ulcer and may subsequently lead to leg amputation among them. Various modalities available to assess the severity of vasculopathy among diabetic patients include measurement of Ankle Brachial Pressure Index (ABI), Toe Brachial Pressure Index (TBI), and Trans-cutaneous Partial pressure of Oxygen (TcPO2). Though, each modality, mentioned above, can predict the limb outcome (ulcer healing/ minor or major amputations) independently, but their predictive abilities are variable in various studies. This was a cross-sectional, observational study conducted over 100 patients with 108 diabetic feet, which has compared the accuracy of ABI, TBI, and TcPO2 in predicting limb outcome among patients with vasculopathy associated foot ulcers among diabetics. Patients who underwent major and minor amputations had mean ABI of 0.54 & PLUSMN; 0.22 and 0.85 & PLUSMN; 0.19, mean TBI of 0.25 & PLUSMN; 0.12 and 0.42 & PLUSMN; 0.26, and mean TcPO2 of 27.08 & PLUSMN; 11.88 and 41.29 & PLUSMN; 22.56 respectively. Out of three modalities, TcPO2 had the maximum predictive ability (AUC - 0.865009) for amputation followed by TBI (AUC - 0.825865). In patients with vaculopathy associated DFUs, TcPO2 is a better predictor of limb outcome when compared to TBI and ABI.