Skin and osteoarticular bacterial infections of the diabetic foot. Treatment

MULTIDISCIPLINARY CARE: A multidisciplinary approach is essential. General measures include immobilization of the focus, controlling blood glucose, anticoagulation, and anti-tetanus vaccination. Topical application of growth factors is currently under evaluation. ANTIBIOTIC THERAPY: The antibiotics chosen should diffuse well into bone tissue. Combinations with synergetic or additive effects against Staphylococcus aureus are best. Treatment duration depends on the depth of the ulceration. Two weeks is generally advised for superficial ulcers. For deep ulcers, treatment duration depends on the presence or not of osteitis and the quality of surgical debridement. In case of osteitis, after amputation with a healthy margin, antibiotics can generally be discontinued 2 weeks after surgery. Six weeks are required if the amputation margins do not lie in healthy zones. Finally, if no surgery is attempted, the antibiotic regimen should be continued for 3 months, or even longer, with a risk of failure greater than 50%. The best criterion for successful treatment is the absence of late recurrence. SURGERY: Surgery is an indispensable element in the overall treatment of deep infections and/or osteitis. The operation should be performed as early as possible to improve prognosis. Well-conducted early surgical debridement can prevent the infection from spreading and avoid the need for much more mutilating "salvage" procedures. Vascular surgery can help maintain sufficient blood supply for wound healing and antibacterial defense. Plastic surgery can be very helpful. PREVENTION: A certain number of simple measures help reduce the risk of diabetic foot ulcers. However, many patients, and practitioners, are insufficiently aware of their effectiveness. Prevention and treatment can best be accomplished by a multidisciplinary approach calling upon the endocrinologist and the vascular and orthopedic surgery teams. A carefully planned rehabilitation program using adapted soles, orthesis, orthopedic shoes or prostheses as needed can considerably reduce the frequency of recurrence. The risk of recurrence in a patient wearing adapted footwear is only 26% at 5 years compared with 83% in other cases.     

Skin infections of the foot

Skin infections of the foot are significant both in terms of frequency and variety. They are also significant in terms of possible complication, with primary infections such as tinea pedis having the potential to damage the skin and produce a portal of entry for bacterial infection in general and streptococcal infection in particular.¹³This in turn can produce problems such as an ascending cellulitis, lymphatic damage with subsequent lymphoedema, recurrent infections and even streptococcal gangrene. The key to the prevention of these complications is the correct diagnosis and treatment of the primary lesion.     

Role of magnetic resonance imaging in the diagnosis of osteomyelitis in diabetic foot infections

Purpose: The role of magnetic resonance imaging (MRI) in the diagnosis of osteomyelitis in foot infections in diabetics was investigated. The accuracy, sensitivity, and specificity of MRI, plain radiography, and nuclear scanning were determined for diagnosing osteomyelitis, and a cost comparison was made.Methods: Twenty-seven patients with diabetic foot infections were studied prospectively. All patients underwent MRI and plain radiography. Twenty-two patients had technetium bone scans, and 19 patients had Indium scans. Nineteen patients had all four tests performed. Patients with obvious gangrene or a fetid foot were excluded.Results: The diagnosis of osteomyelitis was established by pathologic specimen (n = 18), bone culture (n = 3), or successful response to medical management (n = 6). Osteomyelitis was confirmed in nine of the pathologic specimens. The diagnostic sensitivity, specificity, and accuracy for MRI was 88%, 100%, and 95%, respectively, for plain radiography it was 22%, 94%, and 70%, respectively, for technetium bone scanning it was 50%, 50%, and 50%, respectively, and for Indium leukocyte scanning it was 33%, 69%, and 58%, respectively. The data were analyzed statistically with the two-tailed Fisher's exact test. MRI was the only test that was statistically significant (p < 0.01).Conclusions: MRI appeared to be the single best test for the diagnosis of osteomyelitis associated with diabetic foot infections. It had a better diagnostic accuracy than conventional modalities and appeared to be more cost-effective than the frequently used Indium scan. (J Vasc Surg 1996;24:266-70.)     

Debridement of invasive diabetic foot infections

Diabetes pedal infections are too prevalent and will become more so as the numbers of diabetic patients increase. The goal is to prevent amputations or at least to remove as little of the foot as possible. Prompt surgical intervention and better diabetic pedal education will go a long way to achieving that goal.     

Update on the treatment of diabetic foot infections

This article brings the practicing clinician up to date on the current concepts regarding the medical treatment of diabetic foot infections. Topics include a review of the Infectious Diseases Society of America Practice Guidelines for the Diagnosis and Treatment of Diabetic Foot Infections and a discussion of newer antibiotics such as linezolid, ertapenem, moxifloxacin, dalbavancin, tigecycline, ceftobiprole and iclaprim.     

Role of an acidic environment in the treatment of diabetic foot infections: A review

Management of diabetic foot ulcers is the biggest challenge to the clinician, as conventional antibiotic therapies and local wound care have their own limitations. They are not effective for control of infections and promotion of healing because of cytotoxic effects. In view of cytotoxicity of routinely used topical antiseptic agents, this article focuses on the search of an ideal topical antiseptic agent that is safe and effective in controlling infectious agents and also in promoting the healing process. This review focuses on the use of various acids such as citric, acetic, hyaluronic, and hypochlorous acids as topical agents in diabetic foot infections. This article also focuses on the different roles of acids in the treatment of diabetic foot infections.     

Microbiology and antimicrobial therapy of diabetic foot infections

Infections of the foot in the person with diabetes are the result of a complex myriad of pathophysiologic alterations. Neuropathy, vascular disease, and host immune alterations all interact to present a fertile ground for significant microbiologic invasion. When infection occurs, it is commonly due to a mixed flora of aerobic and anaerobic organisms, although "pure" aerobic or anaerobic infections are sometimes seen. Treatment of these infections requires a broad approach, including surgery, local care, and antibiotics. Most often, treatment against aerobic and anaerobic pathogens will be necessary. These infections can be divided into two categories based on clinical appearance. Severe life- or limb-threatening infections can present with massive cellulitis of the foot and leg, high fever, significantly elevated white blood count, septicemia, and tissue gas. Appropriate antibiotics in this setting include either combination or single-agent therapy. Imipenem/cilastatin offers coverage of all usual pathogens along with potentially lower toxicity and lower cost than combinations. Combinations containing clindamycin and aztreonam or ciprofloxacin may be useful for patients allergic to beta-lactam antibiotics. Less severe infections can usually be treated with a single-agent antibiotic such as ticarcillin/clavulanic acid or ampicillin/sulbactam. Cephalosporins with anaerobic activity, including cefoxitin, cefotaxime, and ceftizoxime, can be used in areas where enterococci are not a major problem.     

Surgical management of diabetic foot and ankle infections

Delayed treatment of any diabetic foot infection can lead to a limb- or life-threatening scenario. Urgent and/or emergent surgery may be necessary in the early diagnosis of a severe diabetic foot infection that is followed by staged reconstructive procedures. This article provides the reader with a thorough understanding of the surgical management of severe diabetic foot infections and describes and guides treatment based on a rational schematic approach that identifies the anatomic location of the diabetic foot infection.     

Surgical management of diabetic foot infections and osteomyelitis

Foot ulceration and subsequent infection are a major complication of diabetes mellitus. Without proper diagnosis and treatment, these infections often lead to amputation. A multidisciplinary team approach is essential to maximize outcomes in the attempt to limit amputation and decrease patient morbidity. Mild to moderate diabetic foot infections often respond favorably to local wound care, offloading, and antibiotic therapy. When conservative measures fail or when faced with limb- or life-threatening infection, surgical intervention, whether it be incision and drainage or possible amputation, is warranted. The authors review underlying pathophysiology of diabetic foot infections and an evidenced-based approach to surgical management, with additional emphasis on treatment of osteomyelitis.     

Antibiotic selection for diabetic foot infections: a review.

Foot infections account for about 20% of all hospitalizations in people with diabetes and at least 50% of all nontraumatic lower-limb amputations performed annually in the United States. As many as 25% of all diabetics are expected to develop severe foot problems at some point in their lifetimes. Diabetic foot infections are generally more severe and more difficult to treat than infections in nondiabetics. This is due to impaired microvascular circulation, neuropathy, anatomical alterations, and impaired immune capacity in diabetic patients. Most moderate-to-severe soft-tissue diabetic foot infections are polymicrobial (i.e., due to gram-positive, gram-negative, aerobic, and anaerobic pathogens). Empiric antibiotic therapy should include broad-spectrum antibiotics capable of covering the most common pathogens found in diabetic infections. Other factors to consider in antibiotic selection include the severity of the infection, the presence of peripheral vascular disease, and the possibility of drug-resistant organisms in the infection. This review summarizes the clinical presentation and antimicrobial therapy of diabetic foot infections.     

Role of the microcirculation in diabetic foot ulceration

The concept of microcirculation being implicated in the pathogenesis of diabetic foot disease is being challenged by evidence that fails to confirm it. However, there is evidence of structural changes with capillary and in the basement membrane that do not permit the concept to be denied either. The lack of evidence should not be a reason to argue against surgery in the diabetic foot.     

New insights in diabetic foot infection

Foot ulcers are common in diabetic patients,have a cumulative lifetime incidence rate as high as 25%and frequently become infected.The spread of infection to soft tissue and bone is a major causal factor for lowerlimb amputation.For this reason,early diagnosis and appropriate treatment are essential,including treatment which is both local(of the foot)and systemic(metabolic),and this requires coordination by a multidisciplinary team.Optimal treatment also often involves extensive surgical debridement and management of the wound base,effective antibiotic therapy,consideration for revascularization and correction of metabolic abnormalities such as hyperglycemia.This article focuses on diagnosis and management of diabetic foot infections in the light of recently published data in order to help clinicians in identification,assessment and antibiotic therapy of diabetic foot infections.     

Assessment of infection in diabetic foot ulcers

Typical signs of infection in diabetic foot ulcers are often absent or late. This literature review outlines the factors practitioners must take into account when assessing for and managing such infections.     

Dakin's solution in the treatment of severe diabetic foot infections

Acute necrotising diabetic foot (DF) infections are common, costly, and do not infrequently result in debilitating major lower‐extremity amputations. Dakin's solution is a long‐standing topical antiseptic that has shown benefit in this clinical setting, but its use is undermined by a presumed risk of cytotoxicity. In this single‐centre case series, we retrospectively evaluated 24 patients with severe necrotising DF infections treated with a cyclical instillation of Dakin's solution at a referral multidisciplinary DF unit. Most patients achieved favourable outcomes in infection control and limb salvage, with only one patient (4.2%) requiring a major (at or above‐the‐ankle) amputation. The mean time to complete or near‐complete wound granulation was 5.4 weeks. Of the 12 patients who completed 12 or more months of longitudinal follow up, only 2 (12.2%) had a wound recurrence. In this severe DF infection patient cohort, Dakin's solution led to a clinically meaningful improvement. No remarkable impairment in the wound‐healing process was observed.     

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.