How good are clinicians in predicting the presence ofPseudomonasspp. in diabetic foot infections? A prospective clinical evaluation

Abstract

Introduction The most frequently prescribed empirical antibiotic agents for mild and moderate diabetic foot infections (DFIs) are amino‐penicillins and second‐generation cephalosporins that do not cover Pseudomonas spp. Many clinicians believe they can predict the involvement of Pseudomonas in a DFI by visual and/or olfactory clues, but no data support this assertion. Methods In this prospective observational study, we separately asked 13 experienced (median 11 years) healthcare workers whether they thought the Pseudomonas spp. would be implicated in the DFI. Their predictions were compared with the results of cultures of deep/intraoperative specimens and/or the clinical remission of DFI achieved with antibiotic agents that did not cover Pseudomonas. Results Among 221 DFI episodes in 88 individual patients, intraoperative tissue cultures grew Pseudomonas in 22 cases (10%, including six bone samples). The presence of Pseudomonas was correctly predicted with a sensitivity of 0.32, specificity of 0.84, positive predictive value of 0.18 and negative predictive value 0.92. Despite two feedbacks of the interim results and a 2‐year period, the clinicians' predictive performance did not improve. Conclusion The combined visual and olfactory performance of experienced clinicians in predicting the presence of Pseudomonas in a DFI was moderate, with better specificity than sensitivity, and did not improve over time. Further investigations are needed to determine whether clinicians should use a negative prediction of the presence of Pseudomonas in a DFI, especially in settings with a high prevalence of pseudomonal DFIs.

Short and oral antimicrobial therapy for diabetic foot infection: a narrative review of current knowledge

“…In DFOs originating from a macerated (or ischemic) ulcer or from (sub)tropical and arid geographical areas (mainly Asia and Africa), gram-negative microorganisms are more common. The anatomic site of infection may also influence the pathogens; for example, calcaneal DFO underlying a macerated ulcer may be associated with a higher likelihood of Pseudomonas than DFO affecting a toe (Charles et al, 2015;Waibel et al, 2019;Uçkay et al, 2021). In some patients, especially those with infections associated with a health care institution, drug-resistant pathogens, such as methicillin-resistant S. aureus (MRSA) (Zenelaj et al, 2014) are (co-) pathogens of DFO.…”

Impact of a syndrome-specific antibiotic stewardship intervention on antipseudomonal antibiotic use in inpatient diabetic foot infection management

“…We targeted antipseudomonal antibiotics because we, and others, had found that Pseudomonas aeruginosa was an uncommon DFI pathogen. 13,14 In comparing the preintervention and postintervention periods, we did not detect differences in important patient-centered outcomes such as mortality, readmission, length of stay, or rates of CDI and amputation. These findings indicate that avoiding empiric antipseudomonal antibiotics in DFI patients admitted to general medical floors is safe when local rates of Pseudomonas causing infection are low.…”

Initial antibiotic therapy for postoperative moderate or severe diabetic foot infections: Broad versus narrow spectrum, empirical versus targeted

“…However, the limited data suggest that results for the clinical guesses made regarding the infective agents in infected foot wounds, without any laboratory help, are disappointing. 28 Other possible aids (where available) might include the use of fluorescent light sources, and rapid diagnostic assays such as PCR. 28 In our literature review we found only one previous publication that addressed a similar study question to the one we posed in this study.…”