Comprehensive Analysis of Prognostic Factors Affecting Postoperative Mortality in Adult Patients Undergoing Lower Extremity Amputation due to Diabetic Foot Ulcer

Aim:Mortality is significantly increased in patients undergoing amputation for diabetic foot ulcers (DFUs). The new biomarkers prognostic nutritional index (PNI), C-reactive protein (CRP)/albumin ratio, and comorbidities may help predict prognosis. This study aimed to determine the factors affecting mortality in DFU patients undergoing amputation.Methods:This study is a retrospective case series of patients who underwent lower extremity amputation due to DFU between 2016 and 2018. Data on demographics, clinical information, laboratory test results, comorbidities, hospital stays, re-amputations, and complications were recorded. PNI was calculated using serum albumin concentration and lymphocyte count.Results:A total of 97 patients (21 females and 76 males) were analyzed in the study, with 18 patients having bilateral lower extremity amputations (foot amputation, below-knee amputation, and above-knee amputation). The mean age was 64.48 years, and the mean follow-up period was 34.27 months. The mean length of hospital stay was 19.09 days, with a mean of 1.34 days spent in the intensive care unit. Preoperative laboratory test results showed a mean creatinine level of 1.4 mg/dL, a urea level of 55.22 mg/dL, an albumin level of 2.8 g/L, and a fasting blood glucose level of 168.8 mg/dL. The mean preoperative PNI was 39.31, and the mean CRP/albumin ratio was 42.51. Intensive care unit admission, CRP/albumin ratio, and CRP levels significantly affect 1-year postoperative mortality. The cut-off value for CRP as determined by receiver operating characteristic analysis was 89.9 mg/L. No significant association was found between comorbidities and mortality.Conclusion:We demonstrated that comorbidities and the new biomarker PNI did not affect mortality. CRP levels, intensive care unit admission, and the new predictor CRP/albumin ratio significantly affected 1-year mortality.