Influence of wound scores and microbiology on the outcome of the diabetic foot syndrome

Aims To establish if the microbiology and the TEXAS, PEDIS and Wagner wound classifications of the diabetic foot syndrome (DFS) predict amputation. Methods Prospective cohort study of 250 patients with DFS from 2009 to 2013. Tissue samples for culture were obtained and wound classification scores were recorded at admission. Results Infection was monomicrobial in 131 patients (52%). Staphylococcus aureus was the most frequent pathogen (76 patients, 30%); being methicillin-resistant S. aureus in 26% (20/76) Escherichia coli and Enterobacter faecalis were 2nd and 3rd most frequent pathogens. Two hundred nine patients (85%) needed amputation being major in 25 patients (10%). The three wound scales associated minor amputation but did not predict this outcome. Predictors of minor amputation in the multivariate analysis were the presence of osteomyelitis, the location of the wound in the forefoot and of major amputation elevated C reactive proteine (CRP) levels. A low ankle-brachial index (ABI) predicted major amputation in the follow-up. Overall, 74% of gram-positives were sensitive to quinolones and 98% to vancomycin and 90% of gram-negatives to cefotaxime and 95% to carbapenems. Conclusions The presence of osteomyelitis and the location of the wound in the forefoot predict minor amputation and elevated CRP levels predict major amputation. In the follow-up a low ABI predicts major amputation.