Evaluation of mortality risk factors in diabetic foot infections

[Development and Validation of a Risk Prediction Model for Prolonged Hospitalization in Patients With Diabetic Foot Ulcers]

Objective

To investigate the risk factors associated with prolonged hospitalization in patients diagnosed with diabetic foot ulcers (DFU), to develop a predictive model, and to conduct internal validation of the model.

Methods

The clinical data of DFU patients admitted to West China Hospital, Sichuan University between January 2012 and December 2022 were retrospectively collected. The subjects were randomly assigned to a training cohort and a validation cohort at a ratio of 7 to 3. Hospital stays longer than 75th percentile were defined as prolonged length-of-stay. A thorough analysis of the risk factors was conducted using the training cohort, which enabled the development of an accurate risk prediction model. To ensure robustness, the model was internally validated using the validation cohort.

Results

A total of 967 inpatients with DFU were included, among whom 245 patients were identified as having an extended length-of-stay. The training cohort consisted of 622 patients, while the validation cohort comprised 291 patients. Multivariate logistic regression analysis revealed that smoking history (odds ratio [OR]=1.67, 95% confidence interval [CI], 1.13 to 2.48, P=0.010), Wagner grade 3 or higher (OR=7.13, 95% CI, 3.68 to 13.83, P<0.001), midfoot ulcers (OR=1.99, 95% CI, 1.07 to 3.72, P=0.030), posterior foot ulcers (OR=3.68, 95% CI, 1.83 to 7.41, P<0.001), multisite ulcers (OR=2.91, 95% CI, 1.80 to 4.69, P<0.001), wound size≥3 cm2 (OR=2.00, 95% CI, 1.28-3.11, P=0.002), and white blood cell count (OR=1.11, 95% CI, 1.05 to 1.18, P<0.001) were associated with an increased risk of prolonged length of stay. Additionally, a nomogram was constructed based on the identified risk factors. The areas under the receiver operating characteristic (ROC) curves for both the training cohort and the validation cohort were 0.782 (95% CI, 0.745 to 0.820) and 0.756 (95% CI, 0.694 to 0.818), respectively, indicating robust predictive performance. Furthermore, the calibration plot demonstrated optimal concordance between the predicted probabilities and the observed outcomes in both the training and the validation cohorts.

Conclusion

Smoking history, Wagner grade≥3, midfoot ulcers, posterior foot ulcers, multisite ulcers, ulcer area≥3 cm2, and elevated white blood cell count are identified as independent predictors of prolonged hospitalization. Therefore, it is imperative that clinicians conduct a comprehensive patient evaluation and implement appropriate diagnostic and therapeutic strategies to effectively shorten the length of stay for DFU patients.

Independent association of history of diabetic foot with all-cause mortality in patients with type 2 diabetes: the Renal Insufficiency And Cardiovascular Events (RIACE) Italian Multicenter Study

BACKGROUND

Foot ulcers and/or infections are common long-term complications of diabetes and are associated with increased mortality, especially from cardiovascular disease, though only a few studies have investigated the independent contribution of these events to risk of death. This study aimed at assessing the association of history of diabetic foot with all-cause mortality in individuals with type 2 diabetes, independent of cardiovascular risk factors, other complications, and comorbidities.

METHODS

This prospective cohort study enrolled 15,773 Caucasian patients in 19 Italian centers in the years 2006-2008. Prior lower extremity, coronary, and cerebrovascular events and major comorbidities were ascertained by medical records, diabetic retinopathy by fundoscopy, diabetic kidney disease by albuminuria and estimated glomerular filtration rate, cardiovascular risk factors by standard methods. All-cause mortality was retrieved for 15,656 patients on 31 October 2015.

RESULTS

At baseline, 892 patients (5.7%) had a history of diabetic foot, including ulcer/gangrene and/or amputation (n = 565; 3.58%), with (n = 126; 0.80%) or without (n = 439; 2.78%) lower limb revascularization, and revascularization alone (n = 330; 2.09%). History of diabetic foot was associated with all-cause death over a 7.42-year follow-up (adjusted hazard ratio, 1.502 [95% confidence interval, 1.346-1.676], p < 0.0001), independent of confounders, among which age, male sex, smoking, hemoglobin A1c, current treatments, other complications, comorbidities and, inversely, physical activity level and total and HDL cholesterol were correlated independently with mortality. Both ulcer/gangrene and amputation alone were independently associated with death, with a higher strength of association for amputation than for ulcer/gangrene (1.874 [1.144-3.070], p = 0.013 vs. 1.567 [1.353-1.814], p < 0.0001). Both ulcer/gangrene/amputation and lower limb revascularization alone were independently associated with death; mortality risk was much higher for ulcer/gangrene/amputation than for revascularization (1.641 [1.420-1.895], p < 0.0001 vs. 1.229 [1.024-1.475], p = 0.018) and further increased only slightly for combined ulcer/gangrene/amputation and revascularization (1.733 [1.368-2.196], p < 0.0001).

CONCLUSIONS

In patients with type 2 diabetes, an history of diabetic foot event, including ulcer/gangrene, amputation, and lower limb revascularization, was associated with a ~ 50% increased risk of subsequent death, independent of cardiovascular risk factors, other complications and severe comorbidities, which were also significantly associated with mortality. The association with mortality was greatest for amputation, whereas that for revascularization alone was relatively modest.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT00715481, retrospectively registered 15 July, 2008.

Analysis of risk factors of infection in diabetic foot patients

This cross-sectional study assessed the risk factors for infection in 150 diabetic foot patients admitted to the Xiamen University Hospital between October 2020 and October 2022. Patients were categorised as infected (n = 80) or uninfected (n = 70) cohorts. The diabetic foot was evaluated using the American Diabetic Foot Grading system, whereas ulcers were categorised using Wagner's method. Analysed were patient-specific information, clinical data and risk factors including neuropathy, arterial disease and foot deformities. Our findings revealed no statistically significant differences between infected and uninfected cohorts concerning age, body mass index, gender, duration of diabetes or ankle-brachial index values (p > 0.05). However, infected group had a higher proportion of smokers and reduced socio-economic status (p < 0.05). Wagner grades indicated a greater severity in the infected group, with grade 3, grade 4 and grade 5 differing significantly (p < 0.05). Comparative analysis of ulcer characteristics revealed no statistically significant differences in ulcer surface area and depth, but the infected group had a higher prevalence of osteomyelitis and a greater number of ulcers (p > 0.05). Blood vessel complications, retinopathy, the presence of three or more ulcers, osteomyelitis and diabetic nephropathy were substantially more prevalent in the infected group, as determined by univariate analysis (p < 0.05). Subsequent multivariate logistic analysis revealed that patients with blood vessel complications, retinopathy, osteomyelitis, diabetic nephropathy and three or more ulcers were at increased risk for infection (p < 0.05). In addition, lifestyle factors, such as smoking, sedentary behaviour, inadequate foot hygiene, obesity and poor glycaemic control, were also associated with higher infection rates. A multivariate analysis of foot wound factors revealed that deeper, longer and recurrent lesions increased the likelihood of infection. Escherichia coli was the most frequently isolated bacterium from the infected group's bacterial culture, followed by Pseudomonas aeruginosa and Staphylococcus aureus. The study enhanced our comprehension of the multifactorial risk factors associated with infections in diabetic foot patients, highlighting the need for thorough clinical evaluation, lifestyle modification and vigilant infection control.

The Preoperative Neutrophil-Lymphocyte Ratio Is an Independent Predictive Factor in Predicting 1-Year Mortality in Amputated Diabetic Foot Patients

In this study, we aimed to evaluate the efficacy of neutrophil/lymphocyte ratio values in preoperative blood tests of patients amputated due to diabetic foot in predicting 1-year mortality. We assumed that the neutrophil/lymphocyte ratio predicted 1-year mortality in these patients. The inclusion criteria were as follows: to be diagnosed with diabetic foot, being >18 years of age, having a confirmed type 1 or type 2 diabetes mellitus diagnosis, stage 3 to 5 Wagner ulcers, and having at least 1 year of follow-up. The patients with acute traumatic injuries observed in less than 1 week, traumatic amputations, and nondiabetic amputations, and those whose data could not be obtained were excluded from the study. After the exclusion, 192 patients were included in the study. Age (p < .001), low preoperative hemoglobin (p = .024), high preoperative neutrophil (p < .001), low preoperative lymphocyte (p = .023), low preoperative albumin (p < .001), high preoperative neutrophil-to-lymphocyte ratio (p < .001), major amputation (p = .002), and were related to 1-year mortality. According to these results: (1) it was observed that a preoperative neutrophil/lymphocyte ratio value over 5.75 increases the risk of death 1.1 times and (2) it was observed that a preoperative albumin value under 2.67 increases the risk of death 5.74 times. In conclusion, the age, preoperative neutrophil/lymphocyte ratio, and albumin values of patients planning to undergo amputation surgery can be independent predictive factors in predicting 1-year mortality.

Evaluating Classification Systems of Diabetic Foot Ulcer Severity: A 12-Year Retrospective Study on Factors Impacting Survival

(1) Background: This study examines the survival of patients after their first presentation with diabetic foot ulcers (DFUs) to the regional Diabetes, Nutrition, and Metabolic Diseases Clinic within the Emergency Clinical Hospital "Sf. Spiridon", Iaşi, and analyzes the factors associated with this outcome. (2) Methods: In this retrospective study, patients with DFUs consecutively referred between 1 January 2007 and 31 December 2017 were followed up until 31 December 2020 (for 13 years). The study group included 659 subjects. (3) Results: During the study period, there were 278 deaths (42.2%) and the average survival time was 9 years. The length of hospitalization, diabetic nephropathy, chronic kidney disease, glomerular filtration rate, cardiovascular disease, hypertension, anemia, and DFU severity were the most significant contributors to the increase in mortality. Patients with severe ulcers, meaning DFUs involving the tendon, joint, or bone, had a higher mortality risk than those with superficial or pre-ulcerative lesions on initial presentation (Texas classification HR = 1.963, 95% CI: 1.063-3.617; Wagner-Meggitt classification HR = 1.889, 95% CI: 1.024-3.417, SINBAD Classification System and Score HR = 2.333, 95% CI: 1.258-4.326) after adjusting for confounding factors. (4) Conclusions: The findings of this study suggested that patients presenting with severe ulcers involving the tendon, joint, or bone exhibited a significantly higher risk of mortality, even when potential confounders were taken into consideration.

Should Long-Term Survival in Elderly Patients Presenting with Diabetic Foot Complications Impact Treatment Decision Making?

Patients presenting with diabetic foot ulceration (DFU) and associated complications often require revascularisation. Although current evidence advocates for an open bypass first strategy if patients are expected to live more than two years, this may not be appropriate in octogenarians. We sought to investigate the survival of patients aged over 70 years presenting with complicated DFU and chronic limb threatening ischaemia (CLTI) to clarify its prognosis and guide subsequent management. A database of patients admitted into a large tertiary service over the age of 70 years with DFU and CLTI between 2014 and 2017 were included. Survival data was obtained from medical records and public obituaries through to 2020. Patients were divided into three age groups: seventies (70-79 years), eighties (80-89 years) and nineties (≥90 years). Survival was evaluated using a stratified log-rank test and Kaplan-Meier methods. A total of 323 patients were included for analysis. Survival information was available for 225 patients (69%). Mean duration of follow-up was 19 months. There were 113 deaths recorded (35%). Mean survival for patients in their seventies, eighties and nineties was 63 months (95% CI 48.8-65.5), 37 months (95% CI 27.4-44.9) and 6 months (95% CI 2.3-19.2), respectively. In patients over 70 years of age presenting with DFU and CLTI, long-term survival decreases rapidly with increasing age, especially in the octogenarians. With recent technological advances and reduced morbidity, an endovascular approach may sufficiently treat acute presentations in octogenarians while reserving an open first strategy for younger patients with better long-term survival and adequate autologous conduit.

Clinical Features, Inflammatory Markers, and Limb Salvage in Older Adults with Diabetes-Related Foot Infections

Little information exists about diabetic foot infections (DFIs) in older patients. We hypothesize that older patients with DFIs have different clinical features and worse outcomes than younger patients. We conducted a prospective observational study consisting of a cohort of patients with diabetes and moderate to severe DFIs. Patients included in the cohort were dichotomized into two groups using percentile 75 (P75) of age as the cut-off value. Patients aged > P75 presented with more comorbidities and foot-related complications, a higher rate of peripheral arterial disease (PAD), worse renal function (higher values of blood urea nitrogen and creatinine, and lower values of estimated glomerular filtration rate), and lower values of HbA1c compared with younger patients. Infection severity, microbiological features, and inflammatory markers were similar in both groups. In the multivariate analysis, minor amputations were associated with age > P75 (OR = 2.8, 95% CI 1.3-5.9, p <0.01), necrosis (OR = 4.2, 95% CI 1.8-10.1, p < 0.01), and CRP values (OR = 1.045, 95% CI 1.018-1.073, p < 0.01). Major amputations were associated with a history of amputation (OR = 4.7, 95% CI 1.3-16.7, p = 0.01), PAD (OR = 4.3, 95% CI 1.2-14.6, p = 0.01), and albumin values (OR = 0.344, 95% CI 0.130-0.913, p = 0.03). In conclusion, limb salvage can be achieved in older patients with diabetes-related foot infections at the same rate as in younger patients, despite the fact that they have more comorbidities and foot-related complications, a higher rate of PAD, and worse renal function.

Diabetic foot infection caused by bacteria of the Burkholderia cepacia complex: report of an unusual case and a scoping literature review

Burkholderia cepacia complex (BCC) is group of widespread gram-negative bacillus organized in over 20 phylogenetically distinct bacterial species. According to previous studies, BCC species pathogens are widely reported in patients with cystic fibrosis (CF), but not in individuals with diabetes mellitus (DM). In this case report, a 42-year-old male patient with DM and a foot infection caused by BCC is presented. The patient was hospitalized after antibiotic treatment failure and improved after two surgical debridement procedures and a high-dose extended infusion (EI) of meropenem. The team of vascular surgeons and the infectious disease specialists worked fervently to solve the case. Finally, a scoping review was conducted to map BCC infections in patients with DM.

Virulent and multidrug-resistant Klebsiella pneumoniae from clinical samples in Balochistan

Klebsiella pneumoniae is an important pathogen causing hospital-acquired infections in human beings. Samples from suspected patients of K pneumoniae associated with respiratory and urinary tract infections were collected at Bolan Medical Complex, Quetta, Balochistan. Clinical samples (n = 107) of urine and sputum were collected and processed for K pneumoniae isolation using selective culture media. Initially, 30 of 107 isolates resembling Klebsiella spp. were processed for biochemical profiling and molecular detection using gyrase A (gyrA) gene for conformation. The K pneumoniae isolates were analysed for the presence of drug resistance and virulence genes in their genomes. The 21 of 107 (19.6%) isolates were finally confirmed as K pneumoniae pathogens. An antibiogram study conducted against 17 different antibiotics showed that a majority of the isolates are multidrug resistant. All the isolates (100%) were resistant to amoxicillin, cefixime, amoxicillin-clavulanic acid, cefotaxime, and ceftriaxone followed by tetracycline (95.2%), ciprofloxacin and gentamicin (76.2%), sulphamethoxazol (66.7%), nalidixic acid (61.9%), norfloxacine (42.9%), piperacillin-tazobactam (23.8%), cefoperazone-sulbactam (19%), and cefotaxime-clavulanic acid (33.3%), whereas all the isolates showed sensitivity to amikacin, chloramphenicol, and imipenem. The presence of tetracycline, sulphamethoxazol-resistant genes, and extended-spectrum beta-lactamase was reconfirmed using different specific genes. The presence of virulence genes fimH1 and EntB responsible for adherence and enterobactin production was confirmed in the isolates. The high virulence and drug resistance potential of these Klebsiella isolates are of high public health concern. Multidrug resistance and virulence potential in K. pneumoniae are converting these nosocomial pathogens into superbugs and making its management harder.

Anti-inflammation biomaterial platforms for chronic wound healing

Nowadays, there has been an increase in the number of people with chronic wounds, which has resulted in serious health problems worldwide. The rate-limiting stage of chronic wound healing has been found to be the inflammation stage, and strategies for shortening the prolonged inflammatory response have proven to be effective for increasing the healing rate. Recently, various anti-inflammatory strategies (such as anti-inflammatory drugs, antioxidant, NO regulation, antibacterial, immune regulation and angiogenesis) have attracted attention as potential therapeutic pathways. Moreover, various biomaterial platforms based on anti-inflammation therapy strategies have also emerged in the spotlight as potential therapies to accelerate the repair of chronic wounds. In this review, we systematically investigated the advances of various biomaterial platforms based on anti-inflammation strategies for chronic wound healing, to provide valuable guidance for future breakthroughs in chronic wound treatment.

Exploring the barriers of patients with diabetic foot complications in China: a qualitative interview study

Background

Patients with diabetic foot complications are associated with high rates of morbidity, disability, and mortality. Through findings of qualitative interviews with patients with this disease, we aimed to explore the barriers they encountered, provide evidence to improve the efficacy of medical services, discuss prevention and treatment strategies for future policymakers, and attract widespread attention from the Chinese society.

Methods

Patients with diabetic foot complications were recruited from three tertiary hospitals in China between July to September 2020. Patients were included who had a clinical diagnosis of diabetic foot complications, were 18 years or older, spoke Chinese as their first language, and were willing to share treatment experiences. An interview guide was used during the in-person semi-structured interviews that lasted 20 to 50 minutes and were audio-recorded. Transcripts were analyzed for qualitative themes.

Results

Forty-one patients (range, 38-79 years; 12 men, 29 women) were recruited. Data analysis indicated five thematic dimensions on barriers encountered by patients with diabetic foot complications: hospital visits, doctor-patient communication, mental burden, economic burden, and social support.

Conclusions

Patients with diabetic foot complications face serious financial, mental, and social burdens in China. Future studies can use the five dimensions to help solve the existing problems and improve treatment outcomes of this patient population.

Evaluation of mortality risk factors in diabetic foot infections

Identifying risk factors for mortality is crucial in the management of diabetic foot syndrome. We aimed to evaluate risk factors for mortality in patients with diabetic foot infection (DFI). A retrospective chart review was conducted on 401 patients from 2010 through 2019. Our primary endpoint was in-hospital mortality. Patients were divided into two groups according to the outcome (survival or death). Clinical data were compared between the two groups statistically. A total of 401 patients were enrolled in the study, 280 (69.8%) of them were male and the mean age was 59.6 ± 11.1 years. The mean follow-up period was 23.7 ± 22.9 months. In-hospital mortality rate was 3%. Univariate analysis indicated that ischaemic wound (P = .023), hindfoot infection (P = .038), whole foot infection (P = .010), peripheral arterial disease (P = .024), high leucocyte levels (>12 040 K/μL) (P = .001), high thrombocyte levels (>378 000 K/μL) (P < 0.001), high C-reactive protein levels (>8.81 mg/dL) (P = .022), and polymicrobial growth in deep tissue culture (P = .041) were significant parameters in predicting mortality. In multivariate analysis, peripheral arterial disease (odds ratio [OR]: 13.430, 95% confidence interval [Cl]: 1.129-59.692; P = .040), high thrombocyte levels (OR: 1.000, 95% Cl: 1.000-1.000; P = .022), and polymicrobial growth in deep tissue culture (OR: 7.790, 95% Cl: 1.592-38.118; P = .011) were independent risk factors for mortality. In conclusion, peripheral arterial disease, high thrombocyte levels, and polymicrobial growth in deep tissue culture were independent risk factors for mortality in DFI.