Diabetic Foot Infection Presenting Systemic Inflammatory Response Syndrome: A Unique Disorder of Systemic Reaction from Infection of the Most Distal Body

Microbiome of limb-threatening diabetic foot ulcers indicates the association of fastidious Stenotrophomonas and major amputation

BACKGROUND

Proper identification of the polymicrobial microorganisms in patients with limb-threatening diabetic foot ulcers (LTDFUs) using conventional culture is insufficient. This prospective study evaluates the potential value of adjuvant molecular testing assisting in identify fastidious micro-organisms in LTDFUs compared to standard treatment alone.

METHODS

Ninety patients with LTDFUs received interdisciplinary and standard antibiotic treatment in a referral diabetic foot center. A simultaneous 16S amplicon sequencing (16S AS) specimen along with conventional culture collected at admission was used to retrospectively evaluate the microbiological findings and its association with amputation outcomes.

RESULTS

The microorganism count revealed by 16S AS overwhelmed that of conventional culturing (17 vs. 3 bacteria/ulcer respectively). The Stenotrophomonas spp. revealed in 29 patients were highly correlated with major (above ankle) amputation (OR: 4.76, 95% CI 1.01-22.56), while only one had been concomitantly identified by conventional culturing. Thus, there were 27 cases without proper antibiotics coverage during treatment.

CONCLUSIONS

Adjuvant molecular testing assisted identification of fastidious pathogens such as Stenotrophomonas infection and might be associated with major amputation in patients with LTDFUs.

Thou shall not heal: Overcoming the non-healing behaviour of diabetic foot ulcers by engineering the inflammatory microenvironment

Diabetic foot ulcers (DFUs) are a devastating complication for diabetic patients that have debilitating effects and can ultimately lead to limb amputation. Healthy wounds progress through the phases of healing leading to tissue regeneration and restoration of the barrier function of the skin. In contrast, in diabetic patients dysregulation of these phases leads to chronic, non-healing wounds. In particular, unresolved inflammation in the DFU microenvironment has been identified as a key facet of chronic wounds in hyperglyceamic patients, as DFUs fail to progress beyond the inflammatory phase and towards resolution. Thus, control over and modulation of the inflammatory response is a promising therapeutic avenue for DFU treatment. This review discusses the current state-of-the art regarding control of the inflammatory response in the DFU microenvironment, with a specific focus on the development of biomaterials-based delivery strategies and their cargos to direct tissue regeneration in the DFU microenvironment.

Elevated HbA1c level associated with disease severity and surgical extension in diabetic foot patients

BACKGROUND

Diabetic foot is a complex syndrome that is associated with other diabetic complications, such as peripheral arte-rial disease and peripheral neuropathy. Optimization of plasma glucose and glycated hemoglobin (HbA1c) is one of the main principles of standard care and treatment approaches in individuals with diabetes mellitus (DM). In this study, the relationship of HbA1c level at the time of diagnosis was evaluated with diabetic foot disease severity score and surgical extension in patients with Type 2 DM.

METHODS

This study included 301 consecutive patients who were diagnosed with diabetic foot in the general surgery diabetic foot clinic and were hospitalized for surgery. The relationships between the HbA1c levels of the patients with the Wagner and PEDIS (Perfusion, Extent, Dept, Infection, Sensation) classification system grades, and the surgical procedures performed were analyzed and the treatment outcomes were evaluated.

RESULTS

It was determined that there was a 90% statistically significant relationship between HbA1c values of ≥10.1% and the de-velopment of Wagner Grade 4 diabetic foot ulcer (DFU) (P=0.037). A strong statistically significant relationship at the rate of 85% was determined between HbA1c values of ≥10.1% and the development of PEDIS Grade 3 ulcers. As the HbA1c values increased, so there was determined to be a statistically significant relationship with the development of PEDIS Grade 3 ulcer (P=0.003). In the comparison of the HbA1c values according to the type of surgery performed, a weak relationship was determined at the rate of 26%, and it was determined that as the HbA1c values increased, so there could be an increase in the amputation level.

CONCLUSION

The results of this study showed that as HbA1c values at diagnosis increased in patients with diabetic foot; Wagner/PEDIS grades, disease severity, surgical extension, amputation level, and tissue loss increased. To reduce the severity of diabetic foot disease and prevent amputation, compliance with diabetic treatment and glycemic control should be increased.

Does Metabolic Control Have Any Influence on the Clinical Presentation and Short-Term Outcomes of Diabetic Foot Infections?

Objective: We hypothesized that patients with poor glycemic control undergoing treatment for diabetic foot infections (DFIs) would have a poorer prognosis than those with better metabolic control assessed by glycated hemoglobin (HbA1c). Approach: We analyzed a retrospective cohort of 245 patients with moderate and severe DFIs. HbA1c values were dichotomized (<7% or ≥7% and ≤75th percentile (P75) and >P75) to analyze patient outcomes regarding metabolic control. The present study adhered to the STROBE guidelines for cohort studies. Results: One hundred sixty-nine patients (69%) were men. Their mean age was 60.7 years (10.8). HbA1c ≥7% was detected in 203 patients (82.9%). P75 HbA1c was 10.9%. After performing univariate analysis, we found an association of HbA1c <7% with major amputations and mortality. However, after applying the logistic regression model, we did not find HbA1c <7% to be a predictive factor of major amputation. The risk factors for mortality following application of Cox's proportional hazards model were osteomyelitis (HR: 0.2, 95% CI: 0.07-0.62, p < 0.01), eGFR <60 mL/min/1.73 m² (HR: 2.7, 95% CI: 1.0-7.5, p = 0.04), and HbA1c <7% (HR: 4.9, 95% CI: 1.8-13.2, p < 0.01). Innovation: The group with optimal glycemic control (HbA1c <7%) had a shorter survival time than those with worse metabolic control. Conclusions: We did not find a longer duration of hospitalization, a higher rate of amputations, or longer healing times in the groups with worse metabolic control. HbA1c <7% was a risk factor for mid-term mortality.

The amputation and mortality of inpatients with diabetic foot ulceration in the COVID-19 pandemic and postpandemic era: A machine learning study

This study aimed to explore the clinical characteristic and outcomes of inpatients with diabetic foot ulceration (DFU) in 2019 (prelockdown) and 2020 (postlockdown) due to the COVID-19 pandemic, at an emergency medical service unit. Prediction models for mortality and amputation were developed to describe the risk factors using a machine learning-based approach. Hospitalized DFU patients (N = 23) were recruited after the lockdown in 2020 and matched with corresponding inpatients (N = 23) before lockdown in 2019. Six widely used machine learning models were built and internally validated using 3-fold cross-validation to predict the risk of amputation and death in DFU inpatients under the COVID-19 pandemic. Previous DF ulcers, prehospital delay, and mortality were significantly higher in 2020 compared to 2019. Diabetic foot patients in 2020 had higher hs-CRP levels (P = .037) but lower hemoglobin levels (P = .017). The extreme gradient boosting (XGBoost) performed best in all models for predicting amputation and mortality with the highest area under the curve (0.86 and 0.94), accuracy (0.80 and 0.90), sensitivity (0.67 and 1.00), and negative predictive value (0.86 and 1.00). A long delay in admission and a higher risk of mortality was observed in patients with DFU who attended the emergency center during the COVID-19 post lockdown. The XGBoost model can provide evidence-based risk information for patients with DFU regarding their amputation and mortality. The prediction models would benefit DFU patients during the COVID-19 pandemic.

Severe Diabetic Foot Infections without Systemic Inflammatory Response Syndrome. Prospective Validation of a New Category

We aimed to validate the prognostic value of subclassifying moderate diabetic foot infections into two categories: moderate and moderate/severe. We conducted a prospective study of a cohort of 200 patients with moderate and severe infections. Moderate infections were subclassified after applying a previously published score. Variables associated with prognosis were: need for any amputation, major amputation, need for hospitalization, length of hospitalization, length of antibiotic therapy, reinfection rate and infection-related mortality. Infections were moderate in 111 cases (55.5%) and severe in 89 (44.5%). Osteomyelitis was diagnosed in 114 cases (57%), 73 moderate (36.5%) and 41 severe (20.5%). Patients with severe OM had a higher rate of amputations, major amputations, hospitalizations and need for antibiotic therapy, and a longer duration of antibiotics when compared with moderate OM. After applying the score, moderate infections were subclassified into 73 moderate cases (65.7%) and 38 moderate/severe cases (34.3%). Moderate/severe had a higher rate of amputations, major amputations, hospitalizations and need for antibiotics than moderate ones. No differences regarding prognosis were found between moderate/severe and severe infections with systemic inflammatory response syndrome. Moderate/severe diabetic foot infections, which could also be known as severe infections without systemic inflammatory response syndrome, should be recognized as a new subgroup. We propose to merge severe diabetic foot infections with and without systemic inflammatory response syndrome into a unique category due to its prognostic value. Furthermore, osteomyelitis should be added to both moderate and severe new categories of diabetic foot infections. This article is protected by copyright. All rights reserved.

A perspective on the benefits of consumption of parboiled rice over brown rice for glycaemic control

PURPOSE

Rice is a staple food for over 3.5 billion people worldwide. The nutritional content of rice varies with different post-harvest processing techniques. Major varieties include brown rice (BR), white rice (WR) and parboiled rice (PBR). While consumption of BR is advocated due to its higher nutritional content compared to other varieties, some studies have indicated lower post-prandial blood glucose (PPBG) levels when PBR is consumed. This apparent benefit of PBR consumption is not well publicised and no commentaries on underlying mechanisms are available in literature.

METHODS

In this review, we looked into differential nutrient content of PBR, as compared to BR and WR, and tried to understand how their consumption could be associated with glycaemic control. Various roles played by these nutrients in mechanisms of insulin secretion, insulin resistance, nutrient absorption and T2DM-associated inflammation were reviewed from literature-based evidence.

RESULTS

We report differential nutritional factors in PBR, with respect to BR (and WR), such as higher calcium and selenium content, lower phytic acids, and enriched vitamin B6 which might aid PBR's ability to provide better glycaemic control than BR.

CONCLUSION

Our interpretation of reviewed literature leads us to suggest the possible benefits of PBR consumption in glycaemic control and its inclusion as the preferred rice variant in diets of T2DM patients and at-risk individuals.

Clinical, microbiological and inflammatory markers of severe diabetic foot infections

AIMS

In addition to systemic inflammatory response syndrome (SIRS), various clinical signs, microbiological findings and inflammatory markers could be associated with severe diabetic foot infections (DFI).

METHODS

This study included a retrospective cohort of 245 patients with DFI treated at San Juan de Dios Hospital in San José de Costa Rica. Erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), CRP/albumin ratio, peripheral blood leucocyte ratios and the Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) scoring system were evaluated. Univariate analysis was carried out between moderate and severe infections. ROC curves were plotted. Cut-off value of inflammatory markers for diagnosing severe infections was established and then dichotomized to be included in a logistic regression model. A score was designed based on its results.

RESULTS

Skin necrosis (p < 0.01, OR = 8.5, 95% CI = 3.5-20.9), ESR > 94 mm/h (p < 0.01, OR = 2.5, 95% CI = 1.2-5.1), albumin < 2.8 g/dl (p = 0.04, OR = 2.0, 95% CI = 1.0-4.1) and neutrophil-to-lymphocyte ratio (NLR) > 4.52 (p < 0.01, OR = 3.3, 95% CI = 1.6-6.5) were found to be predictive of severe infections. Score >5 had a good diagnosis performance for classifying severe infections. Moderate infections with a score >5 had a worse prognosis than moderate ones.

CONCLUSIONS

We found an association of necrosis, serum albumin, ESR and NLR values with severe DFI. The presence of these predictive factors of severity in cases of moderate infections was significantly associated with a higher rate of amputations and recurrences, longer duration of antibiotic treatment and longer hospital stays. DFI could be classified as mild, moderate, severe without SIRS and severe.

Impact of wound microbiology on limb preservation in patients with diabetic foot infection

AIMS/INTRODUCTION

To investigate the association between specific bacterial pathogens and treatment outcome in patients with limb-threatening diabetic foot infection (LT-DFI).

MATERIALS AND METHODS

Consecutive patients treated for LT-DFI in a major diabetic foot center in Taiwan were analyzed between the years 2014 and 2017. Patients with positive wound culture results at first aid were enrolled. Clinical factors, laboratory data, and wound culture results were compared. Lower-extremity amputations and in-hospital mortality were defined as a poor outcome.

RESULTS

Among the 558 patients, 272 (48.7%) patients had lower extremity amputation and 22 (3.9%) patients had in-hospital mortality. Gram-negative bacterial (GNB) infection was the independent factor following factors adjustment. When all the 31 microorganisms were analyzed, only E. coli (adjusted odds ratio [aOR], 3.01; 95% CI, 1.60-5.65), Proteus spp. (aOR, 2.99; 95% CI, 1.69-5.29), and Pseudomonas aeruginosa (aOR, 2.00; 95% CI 1.20-3.32) were associated with poor outcome. The analysis of specific GNB species in association with major- or minor- amputation have been reported. No specific pathogen was associated with cause of death in patients with mortality within 30 days. The antimicrobial-resistant strains were not associated with a poor treatment outcome.

CONCLUSIONS

The presence of GNB was associated with limb amputations. This study provides insight into more timely and appropriate management of the diabetic foot infection.

The analysis for time of referral to a medical center among patients with diabetic foot infection

Background

Diabetic foot infection (DFI) is a limb- and life-threatening complication for diabetic patients needing immediate and comprehensive treatment. Early referral of DFI patients to a diabetic foot center is recommended but there appears limited validated evidence, with the association between referral time and clinical outcomes of limb- preservation or in-hospital mortality still lacking.

Methods

This retrospective research studied consecutive type 2 diabetic patients with DFI treated at the major diabetic foot center in Taiwan from 2014 to 2017. Six hundred and sixty-eight patients presented with limb-threatening DFI. After stratifying their referral days into quartiles, the demographic information and clinical outcomes were analyzed.

Results

One hundred and seventy-two patients were placed in the first quartile (Q1) with less than 9 days of referral time; 164 in the second quartile (Q2) with 9-21 days; 167 in the third quartile (Q3) with 21-59 days; and 165 in the fourth quartile (Q4) with >59 days. End-stage renal disease (ESRD), major adverse cardiac events (MACE) and peripheral arterial disease (PAD) were noted as being higher in the Q4 group compared with the Q1 group (25.45% vs 20.35% in ESRD, 47.27% vs 26.16% in MACE and 78.79% vs 52.33% in PAD respectively). The Q1 group had more patients presenting with systemic inflammatory responsive syndrome (SIRS) (29.07% in Q1 vs 25.45% in Q4 respectively, P=0.019). Regarding poor outcome (major lower-extremity amputation (LEA) or in-hospital mortality), the Q4 group had 21.21% of patients in this category and the Q1 group had 10.47%. The odds ratio of each increased referral day on poor prognosis was 1.006 with 95% confidence interval 1.003–1.010 (P=<0.001). In subgroups, the impact on poor prognosis by day was most obvious in patients with SIRS (OR 1.011, 95% CI 1.004–1.018, P=0.003) and those with PAD (OR 1.004, 95% CI 1.001–1.008, P=0.028).

Conclusions

The deferred referral of DFI patients to the diabetic foot center might be associated with poor treatment outcome either in major LEA or mortality, particularly in patients with SIRS or PAD. Both physician and patient awareness of disease severity and overcoming the referral barrier is suggested.

Trial registration

Not applicable.