The association of chronic, enhanced immunosuppression with outcomes of diabetic foot infections

Prevalence and risk factors of wound complications after transtibial amputation in patients with diabetic foot

BACKGROUND

Diabetic foot (DMF) complications are common and are increasing in incidence. Risk factors related to wound complications are yet to be established after trans-tibial amputation under the diagnosis of DMF infection.

AIM

To analyze the prognosis and risk factors related to wound complications after transtibial amputation in patients with diabetes.

METHODS

This retrospective cohort study included seventy-two patients with DMF complications who underwent transtibial amputation between April 2014 and March 2023. The groups were categorized based on the occurrence of wound complications, and we compared demographic data between the complication group and the non-complication group to analyze risk factors. Moreover, a multivariate logistic regression analysis was performed to identify risk factors.

RESULTS

The average follow-up period was 36.2 months. Among the 72 cases, 31 (43.1%) had wound complications. Of these, 12 cases (16.7%) received further treatment, such as debridement, soft tissue stump revision, and re-amputation at the proximal level. In a group that required further management due to wound complications after transtibial amputation, the hemoglobin A1c (HbA1c) level was 9.32, while the other group that did not require any treatment had a 7.54 HbA1c level. The prevalence of a history of kidney transplantation with wound complications after transtibial amputation surgery in DMF patients was significantly greater than in cases without wound complications (P = 0.02). Other factors did not show significant differences.

CONCLUSION

Approximately 43.1% of the patients with transtibial amputation surgery experienced wound complications, and 16.7% required additional surgical treatment. High HbA1c levels and kidney transplant history are risk factors for postoperative wound complications.

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

AIM

To retrospectively evaluate clinical and microbiological outcomes after combined surgical and medical therapy for diabetic foot infections (DFIs), stratifying between the empirical versus the targeted nature, and between an empirical broad versus a narrow-spectrum, antibiotic therapy.

METHODS

We retrospectively assessed the rate of ultimate therapeutic failures for each of three types of initial postoperative antibiotic therapy: adequate empirical therapy; culture-guided therapy; and empirical inadequate therapy with a switch to targeted treatment based on available microbiological results.

RESULTS

We included data from 332 patients who underwent 716 DFI episodes of surgical debridement, including partial amputations. Clinical failure occurred in 40 of 194 (20.6%) episodes where adequate empirical therapy was given, in 77 of 291 (26.5%) episodes using culture-guided (and correct) therapy from the start, and in 73 of 231 (31.6%) episodes with switching from empirical inadequate therapy to culture-targeted therapy. Equally, a broad-spectrum antibiotic choice could not alter this failure risk. Group comparisons, Kaplan-Meier curves and Cox regression analyses failed to show either statistical superiority or inferiority of any of the initial antibiotic strategies.

CONCLUSIONS

In this study, the microbiological adequacy of the initial antibiotic regimen after (surgical) debridement for DFI did not alter therapeutic outcomes. We recommend that clinicians follow the stewardship approach of avoiding antibiotic de-escalation and start with a narrow-spectrum regimen based on the local epidemiology.

Correction of hyperglycemia after surgery for diabetic foot infection and its association with clinical outcomes

Objective

Constantly high glycemia levels might influence outcomes in the management of patients undergoing surgery for diabetic foot infections (DFI). In our center for DFI, we performed a case–control study using a multivariate Cox regression model. Patients developing a new DFI could participate in the study several times.

Results

Among 1013 different DFI episodes in 586 individual adult patients (type I diabetes 148 episodes [15%], 882 [87%] with osteomyelitis; median antibiotic therapy of 21 days), professional diabetes counselling was provided by a specialized diabetes nurse in 195 episodes (19%). At admission, blood glucose levels were elevated in 110 episodes (11%). Treatments normalized glycemia on postoperative day 3 in 353 episodes (35%) and on day 7 for 321 (32%) episodes. Glycemia levels entirely normalized for 367 episodes (36%) until the end of hospitalization. Overall, treatment of DFI episodes failed in 255 of 1013 cases (25%), requiring surgical revision. By multivariate analysis, neither the provision of diabetes counseling, nor attaining normalizations of daily glycemic levels at day 3, day 7, or overall, influenced the ultimate incidence of clinical failures. Thus, the rapidity or success of achieving normoglycemia do not appear to influence the risk of treatment failure for operated DFI episodes.

Nutritional Interventions May Improve Outcomes of Patients Operated on for Diabetic Foot Infections: A Single-Center Case-Control Study

AIM

While a patient's nutritional status is known to generally have a role in postoperative wound healing, there is little information on its role as therapy in the multifaceted problem of diabetic foot infections (DFIs).

METHODS

We assessed this issue by conducting a retrospective case-control cohort study using a multivariate Cox regression model. The nutrition status of the DFI patients was assessed by professional nutritionists, who also orchestrated the nutritional intervention (counselling, composition of the intrahospital food) during hospitalization.

RESULTS

Among 1,013 DFI episodes in 586 patients (median age 67 years; 882 with osteomyelitis), 191 (19%) received a professional assessment of their nutrition accompanied by between 1 and 6 nutritional interventions. DFI cases who had professional nutritionists' interventions had a significantly shorter hospital stay, had shorter antibiotic therapies, and tended to fewer surgical debridements. By multivariate analysis, episodes with low Nutritional Risk Status- (NRS-) Scores 1-3 were associated with significantly lower failure rates after therapy for DFI (Cox regression analysis; hazard ratio 0.2, 95% confidence interval 0.1-0.7).

CONCLUSIONS

In this retrospective cohort study, DFI episodes with low NRS-Score were associated with lower rates of clinical failure after DFI treatment, while nutritional interventions improved the outcome of DFI. We need prospective interventional trials for this treatment, and these are underway.