Association of Demographic Characteristics and Laboratory Values in Diabetic Foot Infections Leading to Lower-Extremity Amputation

Abstract

Background: Lower-extremity amputations are a common complication of poorly controlled diabetes and contribute to significant morbidity and mortality in diabetic patients. We sought to determine whether objective data points obtained on presentation or hospital admission, including white blood cell (WBC) count, hemoglobin A1c (HbA1c), C-reactive protein (CRP), and descriptive patient demographics allow for the ability to predict optimal amputation levels and outcomes of lower-extremity amputation in the diabetic population. Methods: A retrospective analysis of 162 patients was performed evaluating laboratory and descriptive values on hospital presentation for lower-extremity infection during a 16-year period. Occurrence of multiple amputations and level of amputation were assessed against laboratory values to determine whether these objective values would provide clinicians with a better understanding of amputations in the diabetic patient. Results: The mean patient age was 60.6 years. A significantly higher percentage of patients who underwent amputations through the tibia and fibula or of the foot midtarsal were male compared with patients who underwent amputations of the thigh through femur. Patients who had amputations through the tibia and fibula had a significantly higher WBC count compared with patients who had a transmetatarsal amputation (P = .03). There was no significant difference in type or quantity of amputations when analyzing HbA1c and CRP levels. Conclusions: An admission WBC count may be used as a predictor of lower-extremity amputation level and outcomes in diabetic infections. Although a statistically significant difference was not found for CRP or HbA1c levels between amputation procedures and number of procedures performed, these values remain useful in managing lower-extremity infections in diabetic patients.