Characteristics and clinical assessment of antibiotic delivery by chitosan sponge in the high-risk diabetic foot: a case series.

OBJECTIVE: The local delivery of antimicrobials is attractive for a number of reasons. Chitosan, a biodegradable polysaccharide sponge material, has been proposed as medium to deliver antibiotics directly to wounds. In this report we evaluate the safety and practicality of antimicrobial delivery via chitosan sponge. METHOD: We present the clinical course and systemic absorption characteristics of three cases of people with diabetic foot wounds treated with antibiotic soaked chitosan sponge (Sentrex BioSponge, Bionova Medical, Germantown, TN). The antibiotic sponge was made by reconstituting 1.2g tobramycin or 100mg doxycycline in 10-15ml saline and saturating the sponge with the solution. The sponge was then applied to the wounds. Serum levels of each respective antibiotic were evaluated after application. Additional in vitro studies were conducted evaluating elution of antibiotics from the chitosan sponge at established minimum inhibitory concentrations (MIC) for Staphylococcus aureus over 28 days. RESULTS: No patient experienced adverse local or systemic effects due to the sponge treatment. The measured serum levels applied antibiotics remained far less than established minimums after intravenous therapy. Each patient required further treatment, however local infection or contamination resolved during the course of their hospital stay after the chitosan/antibiotic application. CONCLUSION: The use of antibiotic-impregnated chitosan sponges appears a safe and effective mechanism of local delivery of antimicrobials in wounds. Future studies and clinical trials are ongoing to confirm these results and to guide clinical applications.

Is diabetic foot care efficacious or cost effective?

The incidence of diabetes-related lower extremity amputations continues to increase in the developed and developing world, costing nearly $2 billion and an estimated 2,600 patient-years of hospital stay per year in the United States alone. However, the federal government and private healthcare providers fail to place preventative intervention high on their respective healthcare policy agendas. This manuscript briefly evaluates literature that might support or refute the value of structured, regular care of the diabetic foot and wound. Although the literature is still glaringly sparse, an emerging body of research supports the fact that aggressive, proactive care may result in fewer lower extremity amputations and possibly a higher quality and quantity of life for patients with diabetes.

The potential benefits of advanced therapeutic modalities in the treatment of diabetic foot wounds.

This article discusses the advantages and disadvantages of primary wound healing as compared with primary amputation in individuals with chronic diabetic foot wounds. The authors review the potential benefits of vascular surgical procedures and advanced dressings, including two of the most promising modalities in modern wound care: growth factors and bioengineered skin. In this era of cost-conscious health-care administration, it is incumbent on the practitioner to consider not only the basic science of wound care, but also the economic aspect of treatment rendered. These various interventions, dressings, growth factor delivery systems, and new modalities could significantly reduce healing time, thereby reducing the risk of infection, hospitalization, and amputation while improving quality of life. If so, they may be truly cost-effective.

Cost of diabetes-related amputations in minorities.

The objective of this study was to identify the direct cost and length of hospitalization of diabetes-related lower extremity amputations among Hispanics, African Americans, non-Hispanic whites, and Asians. The authors used a database from the office of Statewide Planning and Development in California that identified all hospitalizations for lower extremity amputations in the state in 1991. Amputation level was defined by the ICD-9-CM codes 84.11-84.18. The total hospital charges for diabetes-related lower extremity amputations for the state of California in 1991 was $141 million. The mean hospital charge (HC) per patient with all ethnic groups combined was $27,930; and the mean length of stay (LOS) was 15.9 days. African Americans had significantly higher mean charges ($32,383) and longer stays (17.3 days) compared to all other ethnic groups (p < .05). Toe-level amputations had lower HC (p < .05) and LOS (p < .01) than other amputation levels for all race groups. One-quarter of the population received multiple amputations during their hospital stay. These patients incurred significantly higher hospital charges ($44,731) and stayed in the hospital longer (23.4 days) than those receiving only a single amputation. There was a considerable variation in the HC and LOS among ethnic groups by level of amputation. The direct charges reported in this study suggest considerably higher overall direct costs than have been previously reported in the medical literature. The greater burden of disease experienced by African Americans is probably related to their higher amputation cost and longer hospitalization.

A quantitative assessment of healing sandals and postoperative shoes in offloading the neuropathic diabetic foot.

The purpose of this report is to compare plantar pressures between custom healing sandals and postoperative shoes using unmodified prescription shoe gear as a control. Using a repeat measures design, we recorded the plantar forefoot pressures of eight patients classified as diabetic foot category 1 (neuropathy, no significant deformity, no history of ulceration) with each ambulating in three devices: 1) unmodified prescription shoe gear, 2) postoperative shoe gear, and 3) a custom-fabricated healing sandal. Each subject served as his or her own control. The healing sandal significantly reduced plantar forefoot pressure in all areas of the forefoot except the fifth metatarsal head. The postoperative shoe did not significantly reduce pressure at any site in the forefoot when compared with unmodified prescription shoe gear.

Treatment-based classification system for assessment and care of diabetic feet.

Appropriate care of feet of patients with diabetes requires a clear, descriptive classification system that may be used to direct appropriate therapy and possibly predict outcome. Ideally, this system would be used by all participants in a multidisciplinary limb-salvage team. The authors report on a logical, treatment-oriented system that may improve communication, leading to a less complex, more predictable treatment course and, ultimately, an improved result.