Management and prevention of diabetic foot ulcers and infections: a health economic review

Efficacy and Safety of Different Antibiotic Therapies for Bone and Joint Infections: A Network Meta-analysis of Randomized Controlled Trials

BACKGROUND

Although an increasing number of antibiotics are being used to treat bone and joint infections, their specific efficacy remains controversial. Thus, we aimed to systematically compare the efficacy and safety of antibiotic therapies for orthopedic infections.

METHODS

PubMed, Embase, The Cochrane Library, and Web of Science databases were searched from inception to April 2022. Two authors independently and rigorously conducted the screening, data extraction, and quality assessment of the relevant studies. All the extracted data were evaluated using traditional metaanalysis and network meta-analysis by STATA SE 16.0.

RESULTS

A total of eleven randomized controlled trials (RCTs) involving 1,063 patients were included for data analysis. The analysis results from the NMA indicated that in terms of the clinical effectiveness rate, linezolid (OR: 1.75, 95% CI: 1.01 to 3.02) showed significant efficacy compared to ampicillin/sulbactam. With regard to the microbiological eradication rate, linezolid showed significant efficacy compared to cephalosporins (OR: 8.13, 95% CI: 1.16 to 57.09) and quinolones (OR: 3.51, 95% CI: 1.18 to 10.49). Similar findings were obtained for subgroup populations with diabetic foot infections (DFI). However, linezolid was significantly related to higher adverse events than ampicillin/sulbactam (OR: 3.25, 95% CI: 1.68 to 6.30) and cephalosporins (OR: 18.29, 95% CI: 1.59 to 209.76).

CONCLUSION

Linezolid appeared to be the most promising treatment regimen for staphylococcal bone and joint infections. However, due to the overall limited evidence, the research results need further high-quality RCTs for confirmation.

Comparing the efficacy of different antibiotic regimens on osteomyelitis: A network meta-analysis of animal studies

Background

Despite the surge in the number of antibiotics used to treat preclinical osteomyelitis (OM), their efficacy remains inadequately assessed.

Objective

To establish network comparisons on the efficacy of antibiotic regimens on OM in animal studies.

Methods

PubMed, Embase, Web of Science, and The Cochrane Library were searched from inception to March 2022 for relevant articles. Odds ratios (ORs) were generated for dichotomous variants, and the standard mean difference (SMD) was calculated for constant variables. The predominant outcomes were the effective rate of sterility, also known as sterility rates, as well as the bacterial counts at the end of the experiments and antibiotic concentrations in serum or bone. All the network meta-analyses were performed using STATA MP 16.0. This study was registered in the International Prospective Register of Systematic Reviews (PROSPERO; no. CRD42022316544).

Results

A total of 28 eligible studies with 1,488 animals were included for data analysis, including 13 antibiotic regimens. Regarding the effective rate of sterility, glycopeptides (GLY), linezolid (LIN), rifampicin (RIF)+β-Lactam, and β-Lactam showed significant efficacy compared with placebo (OR ranging from 0.01 to 0.08). For radiological grade, only RIF+GLY (SMD: −5.92, 95%CI: −11.65 to −0.19) showed significant efficacy compared with placebo. As for reducing bacteria count, fosfomycin (FOS), tigecycline (TIG), GLY, LIN, RIF, RIF+β-Lactam, RIF+GLY, aminoglycosides (AMI), and clindamycin (CLI) showed significant efficacy compared with placebo (SMD ranging from −6.32 to −2.62). Moreover, the bone concentrations of GLY were higher 1 h after administration and the higher blood concentrations were higher after 1 h and 4 h compared with the other antibiotics.

Conclusion

Multiple antibiotic regimens showed significant efficacy in animals with OM, including increasing effective rates of sterility, reducing bacterial counts, and lowering radiological scores. Among them, RIF+GLY was the most promising treatment regimen owing to its optimal efficacy. Based on the preclinical studies included in our meta-analysis, head-to-head clinical randomized controlled trials are required to confirm these findings in humans.

New Perspective to Improve Care of Patients with Infected Diabetic Foot Ulcer: Early Economic Impact of the Use of Photodynamic Therapy with RLP068 (Based) System

Objective

To perform an early economic evaluation of a system based on photodynamic advanced adjuvant therapy with photosensitizer RLP068/CI to facilitate the healing process of foot/leg skin lesions/ulcers with an excellent safety profile.

Design

An early short-term (10 weeks) cost-effectiveness and a budget impact analysis (over 5 years) comparing photodynamic therapy with photosensitizer RLP068/CI based (PDT-RLP068) system added to Standard of Care (SoC) vs SoC alone.

Setting

The Italian National Healthcare System perspective considering both the outpatient and the day-hospital regimen.

Participants

Hypothetical patients with diabetic foot infection (DFI) grades I/IIB.

Interventions

The PDT-RLP068 system as an add-on to Standard of Care (SoC) vs SoC alone as the first-line treatment for the management of DFIs.

Main Outcomes

Days within which the clinical target was achieved and direct health costs for patients' management.

Results

Additional costs generated by the use of the PDT-RLP068 system progressively decreased as time to reach the target induced by the novel system decreased. In the outpatient regimen, when time to reach clinical target decreased in the range 7-28 days, ICERs varied from about 1€ to 70€ for each additional day gained with clinical target achieved. The system was dominant when halving time to reach the target in the outpatient regimen and even for modest reduction of time in day-hospital regimen. In terms of budget impact, when considering day-hospital regimen, if the PDT-RLP068 based system allowed a shortened duration to reach the clinical target of between 7-28 days, BI was 8,100,000€ to 700,000€, with saving less than 2,000,000€ with 50% reduction of time. Considering the inpatient setting, the use of the PDT-RLP068 system would result in saving even with the modest impact on the time needed to activate the healing process.

Conclusion

The early economic evaluation performed suggested that, if the claimed effectiveness of the technology demonstrated in case reports and in preliminary clinical studies can be confirmed in larger population studies, and allowing for shortening of the time needed to activate the healing process, the PDT-RLP068 system could offer the chance to improve care for DFI patients without compromising the sustainability of the system.

Multifunctional bioactive core-shell electrospun membrane capable to terminate inflammatory cycle and promote angiogenesis in diabetic wound

Diabetic wound (DW) healing is a major clinical challenge due to multifactorial complications leading to prolonged inflammation. Electrospun nanofibrous (NF) membranes, due to special structural features, are promising biomaterials capable to promote DW healing through the delivery of active agents in a controlled manner. Herein, we report a multifunctional composite NF membrane loaded with ZnO nanoparticles (NP) and oregano essential oil (OEO), employing a new loading strategy, capable to sustainedly co-deliver bioactive agents. Physicochemical characterization revealed the successful fabrication of loaded nanofibers with strong in vitro anti-bacterial and anti-oxidant activities. Furthermore, in vivo wound healing confirmed the potential of bioactive NF membranes in epithelialization and granulation tissue formation. The angiogenesis was greatly prompted by the bioactive NF membranes through expression of vascular endothelial growth factor (VEGF). Moreover, the proposed NF membrane successfully terminated the inflammatory cycle by downregulating the pro-inflammatory cytokines interleukin −6 (IL-6) and matrix metalloproteinases-9 (MMP-9). In vitro and in vivo studies revealed the proposed NF membrane is a promising dressing material for the healing of DW.

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A modified loading strategy was employed for dual bioactive agents through electrospinning.

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The nanofibers sustainedly released the two bioactive agents.

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The fabricated bioactive membranes turned out to be biocompatible, antioxidant and antibacterial.

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The proposed bioactive membranes have posesses the potential of healing diabetic wounds.

Research on the Treatment of Diabetic Foot with Ulcer Based on Nano-Silver Antibacterial Dressing

The incidence of diabetes has been increasing year by year. Long-term growth in blood sugar causes complications such as diabetic foot ulcer and infections, which will increase the difficulty of ulcer treatment. The diabetes brings great pain and heavy economic burden to patients and their families. In view of the above problems, a nano-silver antibacterial dressing is synthesized in this paper to control bacterial infection on the ulcer surface and promote wound healing. This paper describes the preparation process and morphological characterization of nano-silver antibacterial dressings. 100 patients were selected, which divided into two groups for comparative experiments. The conventional group used conventional vaseline dressing, and the control group was nano-silver antibacterial dressing. The ulcer surface healing time, the number of dressing changes, and the control of infection were analyzed separately, and statistical analysis was performed with SPSS19.0. The experimental results are as follows. The use of nano-silver antibacterial dressing can significantly reduce the incidence of infection in diabetic foot patients, which is helpful to reduce the number of dressing changes, shorten the healing time of ulcer, and accelerate the turnover rate. It helps to shorten the course of diabetic foot, and it is recommended to promote its clinical application.

Cost of Diabetic Foot Ulcer Management in China: A 7-Year Single-Center Retrospective Review

BACKGROUND

The cost of care for diabetic foot ulcers has became a global economic burden. The study aimed to analyze diabetic foot ulcer cost changes over time and to identify factors associated with these variables, so as to strengthen and improve the management of diabetic foot ulcers.

METHODS

We retrospectively analyzed the data in the electronic medical record system of our wound treatment center. The homepage of the system was queried using the national clinical version 2.0 disease diagnosis code (ICD-10), the data of patient's basic information were exported. Through the statistics and analysis of these data, the socioeconomic changes and possible risk factors of diabetic foot ulcers management in recent years were obtained.

RESULTS

There were 3654 patients included in the study, an average of 522 per year. The total cost per patient increased from ¥15,535.58 in 2014 to ¥42,040.60 in 2020, with an average of ¥21,826.91. The average length of stay between 14.29 days and 31.4 days from 2014 to 2020, with an average of 18.10 days. Besides, the average incidence of peripheral arterial disease in diabetic foot ulcers patients admitted was as high as 81.9%, and the average amputation rate was 9.9%. The study reflected the total cost and length of stay of diabetic foot patients increased significantly from 2014 to 2020, which were related to age (>85 years), gender (male), peripheral arterial disease, amputation (P < 0.05).

CONCLUSION

A heavy cost from diabetic foot ulcers and its complications was significantly increased yearly, which was related to older age, co-morbidity, amputation and duration of hospitalization. The prevention and treatment of diabetic foot ulcers have a long way to go, early comprehensive prevention and multi-disciplinary cooperation may still be an effective way.

Clinical, Pathological and Microbiological Evaluation of Diabetic Foot Syndrome

Background and objectives: Diabetic foot ulcer (DFU) is one of the serious complications of diabetes, being related to frequent and long-term hospitalisation, reduced quality of life of the patient, amputations, a high rate of morbidity and mortality. The bacterial aetiology is complex, sometimes involving more than one pathogen, playing a major role in the infection prognosis and development of microbial resistance. This study evaluated the current state of the aetiology, clinical and pathological characteristics of DFU in a single diabetes centre in order to provide some specific measures to prevent it. Materials and Methods: This retrospective study was conducted on patients with diabetes mellitus (252 individuals diagnosed with DFU) between January 2018–December 2019. All participants were assessed based on their clinical characteristics, including complications of diabetes and pathological and microbiological evaluations. Results: The present research revealed that diabetic foot ulcer prevalence was higher in males than in females and higher in type 2 diabetic patients than in type 1 diabetic patients. The patients with diabetic foot ulcer were older, had a higher body mass index (BMI), longer diabetic duration and had more diabetic complications, such as retinopathy, diabetic polyneuropathy and diabetic kidney disease, than patients without diabetic foot ulceration. Conclusions: Taking into account all factors involved, including the aetiology and the antibiotic susceptibility pattern of these isolates, planning the suitable treatment options of patients is possible.

Financial Impact of Magnetic Resonance Imaging in the Surgical Treatment of Foot and Ankle Osteomyelitis

Magnetic resonance imaging (MRI) is generally considered the most sensitive imaging for diagnosis of osteomyelitis; however, it is associated with significant cost and is at times ordered as initial screening imaging when a less resource-intensive test would suffice. The purpose of this retrospective cohort study was to examine the differences between patients with osteomyelitis of the foot and ankle, and their subsequent treatment course, who underwent MRI compared with those who did not. Financial impact of MRI as it relates to clinical decision-making was also calculated. Patients treated for a diagnosis of osteomyelitis of the foot and ankle from 2009 to 2015 were retrospectively identified. Demographics, imaging modalities, and operative procedures for each patient were collected. An "impact MRI" was defined as one that led to a subsequent operative procedure within the same admission. The impact cost of an MRI was estimated using the equation: (average MRI cost) × (total MRIs/impact MRIs). A total of 144 patients underwent 220 MRIs, and 399 patients did not have MRIs. The operative rate between the 2 groups was similar (70.8% versus 70.4%, p = .93). Multiple linear regression showed that MRI was not a significant predictor of operation (p = .50). However, we found a significant correlation between MRI use and operative intervention for patients with increased comorbidities. From 2011 to 2015, there was a significant increase in impact cost, while controlling for average MRI cost ($8172 to $15,292, p ≤ .05). Over the study period, the impact cost of an MRI significantly increased from 1.8 to 5.0 times the average cost.

Performance of a rapid two-sequence screening protocol for osteomyelitis of the foot

OBJECTIVE

Compare a two sequence protocol to a standard protocol in the detection of pedal osteomyelitis (OM) and abscesses and to identify patients that benefit from a full protocol.

MATERIALS AND METHODS

One hundred thirty-two foot MRIs ordered to assess for OM were enrolled, and the following items were extracted from the clinical reports: use of IV contrast, the presence of OM, reactive osteitis, and a soft tissue abscess. Using only one T1 nonfat-suppressed and one fluid sensitive fat-suppressed sequences, two experienced musculoskeletal radiologists reviewed each case for the presence of OM, reactive osteitis, or an abscess. A Kappa test was calculated to assess for interobserver agreement, and diagnostic performance was determined. The McNemar test was used to assess for the effect of contrast.

RESULTS

Agreement between both observers and the clinical report on the presence of osteomyelitis was substantial ( k = 0.63 and 0.72, p < 0.001), while the agreement for abscess was fair (k = 0.29 and 0.38, p < 0.001). For osteomyelitis, both observers showed good accuracy (0.85 and 0.86). When screening bone for a normal versus abnormal case, this method was highly sensitive (0.97-0.98), but was less sensitive for abscess (0.63-0.75). Fifty-one percent of exams used contrast, and it did impact the diagnosis of abscess for one observer.

CONCLUSION

This rapid protocol is accurate in making the diagnosis of OM, and its high sensitivity makes it useful to screen for patients that would benefit from a full protocol.

Topical effect of allogenous serum rich in growth factors (SRGF) on diabetic skin wound in rat

Diabetic foot ulcer is a major complication of diabetes mellitus with negative effects on the life quality. Management of diabetic foot ulcers is a big challenge with poor and low sufficient outcome management. Therefore, achievement to effective treatments may treat these ulcers. Nowdays, platelet products are used as an effective and safe agent for promotion of healing proposes in regenerative medicine. Serum rich in growth factors (SRGF) is a source of released growth factors from the platelets. In the present study, effect of allogenous SRGF was investigated on the streptozotocin (STZ)-induced diabetic wounds in rats. STZ (50 mg/kh, SC) caused significant increase in blood glucose and weight loss in rats. Full thickness cutaneous wounds (8 mm diameter) were created bilaterally on the dorsal of the diabetic rats. SRGF was injected at the edges of the wounds of one side only on the first day, and the contrary sides were considered as the control group. The percentage of wound contraction was demonstrared on day 3, 7, 11 after surgery. Tissue specimens were collected for microscopic study on days 7 and 14. Results showed a significant higher rate of wound contraction on days 5 and 7 in the treated group. Histopathologic findings displayed acceleration of re-epithelialization, increased angiogenesis and dense collagen fibers with better organization in the treated group. Current study suggests that SRGF was efficient because facilate wound healing and showed rapid re-epithelialization and increased angiogenesis.

Added value of MRI to X-ray in guiding the extent of surgical resection in diabetic forefoot osteomyelitis: a review of pathologically proven, surgically treated cases

OBJECTIVE

This study retrospectively evaluated the added value of MRI over X-ray in guiding the extent of amputation in a cohort of patients with surgically treated, pathologically proven osteomyelitis.

MATERIALS AND METHODS

A database search revealed 32 cases of pathology-proven diabetic forefoot osteomyelitis between 2006 and 2016, in which X-ray, MRI, and surgery occurred within 30 days. Data collection included extent of osteomyelitis reported on imaging and extent of subsequent amputation using a point system. Added value of MRI over X-ray in guiding surgical resection was stated if the X-ray was negative, MRI was positive, and there was MRI-surgical concordance; if both modalities were positive, X-ray was discordant whereas the MRI was concordant; or if MRI detected an abscess. Two-tailed Fisher's exact test compared proportions.

RESULTS

In 9 cases that were positive on both modalities, MRI identified an average of 1.2 additional bone segments of disease. There was surgical agreement with X-ray in 3 out of 31 cases (9.7%, 95%CI 0-20.1) and with MRI in 17 out of 31 cases (55%, 37.3-72.4; p < 0.0001). There was an added value of MRI over X-ray in guiding surgical treatment in 64.5% of cases (95% CI 47.7%-81.4%). MRI added value in 5 out of 9 X-rays positive for osteomyelitis and in 15 out of 22 negative (p value was not significant).

CONCLUSION

Magnetic resonance imaging demonstrated added value over X-ray in guiding surgical management in both X-ray-negative and -positive cases. Although multiple factors are involved in determining the degree of surgical excision, MRI is a clinically useful component of the diagnostic algorithm in patients who undergo surgical treatment.

Serum procollagen type 1 N propeptide: A novel diagnostic test for diabetic foot osteomyelitis - A case-control study

Background:

The objective of the study was to determine whether serum levels of procollagen type 1 N propeptide (P1NP), a bone formation turnover marker, differs between diabetic foot ulcer with osteomyelitis (DFO) and diabetic foot ulcers without osteomyelitis serving as controls. It was also aimed to assess the usefulness of P1NP in diagnosing DFO compared to other common inflammatory markers.

Materials and Methods:

A case–control study was designed comparing the aforementioned groups. Patients were classified as osteomyelitis and controls based on the International Working Group diagnostic criteria. Serum P1NP and three other inflammatory markers, namely, C-reactive protein (CRP), white blood cells (WBC), and platelets were analyzed on patients with DFO and controls.

Results:

The mean serum P1NP levels were significantly higher in the DFO group (n: 16), 10.5 ± 5.2 (ng/ml), than the control group (n: 11) 3.1 ± 2.8 (ng/ml), P = 0.001. P1NP showed the highest sensitivity/specificity 86.7%/80% compared to 70.6%/80%, 56.2%/45.4%, and 50%/37% for CRP, WBC and platelets, respectively. Receiver operator characteristic curves showed the best value of area under the curve of 0.9 for P1NP compared to 0.85, 0.54, and 0.46 for CRP, WBC, and platelets.

Conclusion:

We found marked elevation of serum P1NP in diabetic foot ulcer with bone infection with potential value in using it to diagnose DFO.

Cost-effectiveness of prevention and management of diabetic foot ulcer and amputation in a health resource-limited setting

BACKGROUND

The aim of the present study was to estimate the lifetime health and economic effects of different strategies of caring for diabetic foot in the Chinese setting.

METHODS

A mathematical model was developed to simulate the onset and progression of diabetic foot disease in patients with type 2 diabetes managed with optimal care and usual care. Clinical and utility data were obtained from the published literature. Direct medical costs and resource utilization in the Chinese healthcare setting were considered. Sensitivity analyses were undertaken to test the effects of a range of variables and assumptions on the results. Heath benefits and costs were the outcome measures assessed.

RESULTS

Compared with usual care, optimal care was a cost-saving option that exhibited lower costs with improved health benefits, including greater quality-adjusted life-years (QALYs) and reduced incidence of foot complications. The lifetime saving costs per additional QALY gained by optimal care were US$2015. The model outcome was most sensitive to the risk ratio of foot ulcers and amputation for optimal care over usual care.

CONCLUSIONS

Implementing guideline-based optimal care for diabetic foot is likely to be cost-effective in a health resource-limited setting.

Oxidized Regenerated Cellulose/Collagen Dressings: Review of Evidence and Recommendations

OBJECTIVE

Healthcare systems are being challenged to manage increasing numbers of nonhealing wounds. Wound dressings are one of the first lines of defense in wound management, and numerous options exist. The oxidized regenerated cellulose (ORC)/collagen dressing may offer healthcare providers a robust and cost-effective tool for use in a variety of wounds.

DESIGN

A multidisciplinary panel meeting was convened to discuss the use of ORC/collagen dressings in wound care and provide practice recommendations. A literature search was conducted to provide a brief review of the peer-reviewed studies published between January 2000 and March 2016 to inform the meeting.

SETTING

A 2-day panel meeting convened in February 2017.

PARTICIPANTS

Healthcare providers with experience using ORC/collagen dressings. This multidisciplinary panel of 15 experts in wound healing included podiatrists, wound care specialists (doctors, certified wound care nurses, and research scientists), and an orthopedist.

RESULTS

The literature search identified 58 articles, a majority of which were low levels of evidence (69.3% were level 3 or lower). Panel members identified wound types, such as abrasions, burns, stalled wounds, diabetic foot ulcers, and pressure injuries, where ORC/collagen dressing use could be beneficial. Panel members then provided recommendations and technical pearls for the use of ORC/collagen dressings in practice. Barriers to ORC/collagen dressing use were discussed, and potential resolutions were offered.

CONCLUSIONS

An ORC/collagen dressing can be a critical tool for clinicians to help manage a variety of wounds. Clinical and economic studies comparing standard-of-care dressings and plain collagen dressings to ORC/collagen dressings are needed.

Plantar pressures are elevated in people with longstanding diabetes-related foot ulcers during follow-up

Objective

High plantar pressures are implicated in the development of diabetes-related foot ulcers. Whether plantar pressures remain high in patients with chronic diabetes-related foot ulcers over time is uncertain. The primary aim of this study was to compare plantar pressures at baseline and three and six months later in participants with chronic diabetes-related foot ulcers (cases) to participants without foot ulcers (controls).

Methods

Standardised protocols were used to measure mean peak plantar pressure and pressure-time integral at 10 plantar foot sites (the hallux, toes, metatarsals 1 to 5, mid-foot, medial heel and lateral heel) during barefoot walking. Measurements were performed at three study visits: baseline, three and six months. Linear mixed effects random-intercept models were utilised to assess whether plantar pressures differed between cases and controls after adjusting for age, sex, body mass index, neuropathy status and follow-up time. Standardised mean differences (Cohen’s d) were used to measure effect size.

Results

Twenty-one cases and 69 controls started the study and 16 cases and 63 controls completed the study. Cases had a higher mean peak plantar pressure at several foot sites including the toes (p = 0.005, Cohen’s d = 0.36) and mid-foot (p = 0.01, d = 0.36) and a higher pressure-time integral at the hallux (p<0.001, d = 0.42), metatarsal 1 (p = 0.02, d = 0.33) and mid-foot (p = 0.04, d = 0.64) compared to controls throughout follow-up. A reduction in pressure-time integral at multiple plantar sites over time was detected in all participants (p<0.05, respectively).

Conclusions

Plantar pressures assessed during gait are higher in diabetes patients with chronic foot ulcers than controls at several plantar sites throughout prolonged follow-up. Long term offloading is needed in diabetes patients with diabetes-related foot ulcers to facilitate ulcer healing.

Soluble Receptor for Advanced Glycation End Products Improves Stromal Cell-Derived Factor-1 Activity in Model Diabetic Environments

Objective: In diabetes, hyperglycemia causes the accumulation of advanced glycation end products (AGEs) that trigger reactive oxygen species (ROS) generation through binding the receptor for AGEs (RAGE). Because exogenous growth factors have had little success in enhancing chronic wound healing, we investigated whether hyperglycemia-induced AGEs interfere with cellular responses to extracellular signals. We used stromal cell-derived factor-1 (SDF-1), an angiogenic chemokine also known to promote stem cell recruitment in skin wounds. Approach: Human leukemia-60 (HL-60) cells and mouse peripheral blood mononuclear cells (PBMCs), which express the SDF-1 receptor CXCR-4, were incubated for 24 h in medium supplemented with 25 mM d-glucose. Soluble RAGE (sRAGE) was used to block RAGE activation. Response to SDF-1 was measured in cellular migration and ROS assays. A diabetic murine excisional wound model measured SDF-1 liposome and sRAGE activity in vivo. Results: Hyperglycemia led to significant accumulation of AGEs, decreased SDF-1-directed migration, and elevated baseline ROS levels; it suppressed the ROS spike normally triggered by SDF-1. sRAGE decreased the ROS baseline and restored both the SDF-1-mediated spike and cell migration. Topically applied sRAGE alone promoted healing and enhanced the effect of exogenous SDF-1 on diabetic murine wounds. Innovation: While there is interest in using growth factors to improve wound healing, this strategy is largely ineffective in diabetic wounds. We show that sRAGE may restore signaling, thus potentiating the effect of exogenously applied growth factors. Conclusion: Blocking RAGE with sRAGE restores SDF-1-mediated cellular responses in hyperglycemic environments and may potentiate the effectiveness of SDF-1 applied in vivo.

Burden of Infected Diabetic Foot Ulcers on Hospital Admissions and Costs

BACKGROUND

Costs related to diabetic foot ulcer (DFU) care are greater than $1 billion annually and rising. We sought to describe the impact of diabetes mellitus (DM) on foot ulcer admissions in the United States, and to investigate potential explanations for rising hospital costs.

METHODS

The Nationwide Inpatient Sample (2005-2010) was queried using International Classification of Diseases, 9th Revision (ICD-9) codes for a primary diagnosis of foot ulceration. Multivariable analyses were used to compare outcomes and per-admission costs among patients with foot ulceration and DM versus non-DM.

RESULTS

In total, 962,496 foot ulcer patients were admitted over the study period. The overall rate of admissions was relatively stable over time, but the ratio of DM versus non-DM admissions increased significantly (2005: 10.2 vs. 2010: 12.7; P < 0.001). Neuropathy and infection accounted for 90% of DFU admissions, while peripheral vascular disease accounted for most non-DM admissions. Admissions related to infection rose significantly among DM patients (2005: 39,682 vs. 2010: 51,660; P < 0.001), but remained stable among non-DM patients. Overall, DM accounted for 83% and 96% of all major and minor amputations related to foot ulcers, respectively, and significantly increased cost of care (DM: $1.38 vs. non-DM: $0.13 billion/year; P < 0.001). Hospital costs per DFU admission were significantly higher for patients with infection compared with all other causes ($11,290 vs. $8,145; P < 0.001).

CONCLUSIONS

Diabetes increases the incidence of foot ulcer admissions by 11-fold, accounting for more than 80% of all amputations and increasing hospital costs more than 10-fold over the 5 years. The majority of these costs are related to the treatment of infected foot ulcers. Education initiatives and early prevention strategies through outpatient multidisciplinary care targeted at high-risk populations are essential to preventing further increases in what is already a substantial economic burden.

SDF-1 liposomes promote sustained cell proliferation in mouse diabetic wounds

Chronic skin wounds are a common complication of diabetes. When standard wound care fails to heal such wounds, a promising approach consists of using decellularized matrices and other porous scaffold materials to promote the restoration of skin. Proper revascularization is critical for the efficacy of such materials in regenerative medicine. Stromal cell-derived factor-1 (SDF-1) is a chemokine known to play a key role for angiogenesis in ischemic tissues. Herein we developed nanosized SDF-1 liposomes, which were then incorporated into decellularized dermis scaffolds used for skin wound healing applications. SDF-1 peptide associated with liposomes with an efficiency of 80%, and liposomes were easily dispersed throughout the acellular dermis. Acellular dermis spiked with SDF-1 liposomes exhibited more persistent cell proliferation in the dermis, especially in CD31(+) areas, compared to acellular dermis spiked with free SDF-1, which resulted in increased improved wound closure at day 21, and increased granulation tissue thickness at day 28. SDF-1 liposomes may increase the performance of a variety of decellularized matrices used in tissue engineering.

Cost-effectiveness of becaplermin gel on wound healing of diabetic foot ulcers

We sought to determine the long-term cost effectiveness (payer's perspective) of becaplermin gel plus good wound care (BGWC) vs. good wound care (GWC) alone in terms of wound healing and risk of amputation in patients with diabetic foot ulcers (DFUs). Outcomes data were derived from a propensity score-matched cohort from the Curative Health Services database between 1998 and 2004, which was followed for 20 weeks. A four-state Markov model was used to predict costs and outcomes of wound healing and risk of amputation for BGWC vs. GWC alone over 1 year in patients with DFU. The primary outcome was closed-wound weeks. Transition probabilities for healing and amputation were derived from the aforementioned propensity score-matched cohorts. Ulcer recurrence was estimated from the medical literature. Utilization for becaplermin was calculated using the dosing algorithm in the product labeling. Of 24,898 eligible patients, 9.6% received BGWC. Based on the model, patients treated with BGWC had substantially more closed-wound weeks compared with GWC (16.1 vs. 12.5 weeks, respectively). More patients receiving BGWC had healed wounds at 1 year compared with those receiving GWC (48.1% vs. 38.3%). Risk of amputation was lower in the BGWC cohort (6.8% vs. 9.8%). Expected annual direct costs for DFU were $21,920 for BGWC and $24,640 for GWC. BGWC was economically dominant over GWC, providing better outcomes at a lower cost in patients with DFU. Compared with GWC alone, BGWC is more effective in healing wounds and lowering amputation risk, thereby decreasing long-term costs for DFU.

Chronic wound infections: the role of Pseudomonas aeruginosa and Staphylococcus aureus

Chronic leg ulcers affect 1-2% of the general population and are related to increased morbidity and health costs. Staphylococcus aureus and Pseudomonas aeruginosa are the most common bacteria isolated from chronic wounds. They can express virulence factors and surface proteins affecting wound healing. The co-infection of S. aureus and P. aeruginosa is more virulent than single infection. In particular, S. aureus and P. aeruginosa have both intrinsic and acquired antibiotic resistance, making clinical management of infection a real challenge, particularly in patients with comorbidity. Therefore, a correct and prompt diagnosis of chronic wound infection requires a detailed knowledge of skin bacterial flora. This is a necessary prerequisite for tailored pharmacological treatment, improving symptoms, and reducing side effects and antibiotic resistance.

Management of hospitalized patients with diabetic foot infections

Diabetic foot infections (DFIs), which present with a variety of clinical manifestations, are commonly encountered by clinicians. They are associated with a high morbidity, a high amputation rate, a high mortality, and increased health care costs. An effective management of DFIs requires a multidisciplinary approach with a strong collaboration among all involved health care providers as well as patient involvement. Diagnosing DFIs appropriately requires consideration of the clinical symptoms and signs of infection in addition to supplementary laboratory testing such as inflammatory markers and imaging studies. The comprehensive patient assessment should include the predisposing risk factors for infection; the type, severity, and extent of the infection; and the assessment of neurologic and vascular status, comorbid conditions, and psychosocial factors. The comprehensive management of DFIs include not only effective antibiotic therapy but also surgical debridement, pressure offloading, wound care and moisture, maintaining good vascular perfusion, control of edema and pain, correction of metabolic abnormalities such as hyperglycemia, and addressing psychosocial and nutritional issues. Discharge planning that addresses full medical and social needs along with suitable follow-up, patient education and counseling, and clear communication with outpatient providers are critical for ensuring a safe and successful transition to outpatient management of hospitalized patients with DFIs.

Efficacy of topical recombinant human platelet-derived growth factor for treatment of diabetic lower-extremity ulcers: Systematic review and meta-analysis

OBJECTIVE

Recombinant human platelet-derived growth factor (rhPDGF) is used topically in the treatment of diabetic lower-extremity ulcers. There have been few meta-analyses of the efficacy of rhPDGF in this treatment context. The aim of this study was to perform an updated systematic review and meta-analysis to assess the clinical efficacy of rhPDGF in the treatment of diabetic lower-extremity ulcers.

METHODS

We searched the MEDLINE, Cochrane Library, EMBASE and Web of Knowledge databases up to April 30, 2014. Studies were identified and selected, and data were extracted by two independent reviewers. The primary efficacy outcome was complete healing rate. Adverse events were also assessed. The studies were evaluated for quality and publication bias.

RESULTS

A total of 6 randomized controlled trials including 992 patients were selected from 173 identified studies. The studies compared rhPDGF treatment in the context of standard of care (SOC) to placebo or SOC alone. In the absence of study heterogeneity, a fixed-effects model was performed, and the combined odds ratio (OR) indicated a significantly greater complete healing rate in patients treated with rhPDGF compared to placebo or SOC alone. The ORs ranged from 0.58 to 2.77, with a combined OR of 1.53 (95% CI = 1.14 to 2.04, p = 0.004). A sensitivity analysis (leave-one-out method) indicated good study reliability, and a funnel plot with Egger test showed no publication bias.

CONCLUSION

These results indicate that rhPDGF is efficacious in the treatment of diabetic lower-extremity ulcers.

Diabetic foot ulcers: Part II. Management

The management of diabetic foot ulcers can be optimized by using an interdisciplinary team approach addressing the correctable risk factors (ie, poor vascular supply, infection control and treatment, and plantar pressure redistribution) along with optimizing local wound care. Dermatologists can initiate diabetic foot care. The first step is recognizing that a loss of skin integrity (ie, a callus, blister, or ulcer) considerably increases the risk of preventable amputations. A holistic approach to wound assessment is required. Early detection and effective management of these ulcers can reduce complications, including preventable amputations and possible mortality.

Hyperbaric oxygen therapy as adjunctive treatment of diabetic foot ulcers

The widespread use of HBO as an adjunctive treatment of diabetic foot ulcers has been founded on weak scientific evidence, but the consistency in positive outcomes in trials evaluating HBO on ulcer healing is noteworthy, not least as these results are in concert with data from in vitro and physiologic studies supporting the theoretical framework of HBO reversing hypoxia-induced abnormality. The long-term ulcer-healing rates of the nonrandomized controlled studies before the recent study by Margolis and colleagues, 77% with HBO versus 25% with standard treatment, are in concert with 1-year follow-up data from the 2 double-blind RCTs, 54% versus 25%. These 2 trials have put the use of HBO on firmer ground, but several issues, including health economics, developing robust selection criteria for treatment, optimizing treatment protocols, and identifying standards for when to start and stop treatment, remain to be elucidated. Not least, outcomes from further high-quality studies are needed. At present, HBO may be used as an adjunctive therapy in a select group of patients with diabetic foot ulcers that are difficult to heal.

Cutaneous wound healing after treatment with plant-derived human recombinant collagen flowable gel

Chronic wounds, particularly diabetic ulcers, represent a main public health concern with significant costs. Ulcers often harbor an additional obstacle in the form of tunneled or undermined wounds, requiring treatments that can reach the entire wound tunnel, because bioengineered grafts are typically available only in a sheet form. While collagen is considered a suitable biodegradable scaffold material, it is usually extracted from animal and human cadaveric sources, and accompanied by potential allergic and infectious risks. The purpose of this study was to test the performance of a flowable gel made of human recombinant type I collagen (rhCollagen) produced in transgenic tobacco plants, indicated for the treatment of acute, chronic, and tunneled wounds. The performance of the rhCollagen flowable gel was tested in an acute full-thickness cutaneous wound-healing rat model and compared to saline treatment and two commercial flowable gel control products made of bovine collagen and cadaver human skin collagen. When compared to the three control groups, the rhCollagen-based gel accelerated wound closure and triggered a significant jumpstart to the healing process, accompanied by enhanced re-epithelialization. In a cutaneous full-thickness wound pig model, the rhCollagen-based flowable gel induced accelerated wound healing compared to a commercial product made of bovine tendon collagen. By day 21 post-treatment, 95% wound closure was observed with the rhCollagen product compared to 68% closure in wounds treated with the reference product. Moreover, rhCollagen treatment induced an early angiogenic response and induced a significantly lower inflammatory response than in the control group. In summary, rhCollagen flowable gel proved to be efficacious in animal wound models and is expected to be capable of reducing the healing time of human wounds.

A prospective, non comparative, multicenter study to investigate the effect of cadexomer iodine on bioburden load and other wound characteristics in diabetic foot ulcers

Few studies regarding wound treatment with topical antimicrobials evaluate change in the bacterial bioburden of the wound with treatment. This study sought out to determine the in vivo effect of cadexomer iodine antibacterial dressing on diabetic foot ulcers (DFUs) that were infected or achieved a critical level of colonisation, looking specifically at wound progression in relation to bioburden. Fifteen patients corresponding to 16 total DFUs met criteria of displaying clinical signs of infection or critical colonisation and were suitable for a topical antibacterial dressing. They underwent weekly treatment for 6 weeks. Cultures were taken at week 0, 3 and 6 as appropriate. At week 6 median log10 bacterial count reduction of 1.0 was observed from baseline (p = 0·025). At week 3- a median log10 bacterial count reduction of 0.3 was observed from baseline (p = 0·049). Over the study period there was a 53.6% median reduction of the wound surface area. There were no patients that completely healed their ulcer over the 6 week study period. There was a statistically significant median reduction in the bacterial load over the 6 week period (p = 0·025) as well as 3 weeks (p = 0·049). This was accompanied by a median reduction of 53.6% in ulcer surface area and 50% in ulcer depth from baseline to final.

The role of whirlpool in wound care

Evidenced-based-wound management continues to be a cornerstone for advancing patient care. The purpose of this article is to review the use of whirlpool as a wound treatment in light of evidence, outcomes, and potential harm. Whirlpool was initially harnessed as a means to impart biophysical energy to a wound or burn to enhance mechanical debridement and cleansing. Other credible single-patient-use technologies which provide an alternative to whirlpool in wound care are presented.

A review of the costs and cost effectiveness of interventions in chronic kidney disease: implications for policy

Given rising healthcare costs and a growing population of patients with chronic kidney disease (CKD), there is an urgent need to identify health interventions that provide good value for money. For this review, the English-language literature was searched for studies of interventions in CKD reporting an original incremental cost-utility (cost per QALY) or cost-effectiveness (cost per life-year) ratio. Published cost studies that did not report cost-effectiveness or cost-utility ratios were also reviewed. League tables were then created for both cost-utility and cost-effectiveness ratios to assess interventions in patients with stage 1-4 CKD, waitlist and transplant patients and those with end-stage renal disease (ESRD). In addition, the percentage of cost-saving or dominant interventions (those that save money and improve health) was compared across these three disease categories. A total of 84 studies were included, contributing 72 cost-utility ratios, 20 cost-effectiveness ratios and 42 other cost measures. Many of the interventions were dominant over the comparator, indicating better health outcomes and lower costs. For the three disease categories, the greatest number of dominant or cost-saving interventions was reported for stage 1-4 CKD patients, followed by waitlist and transplant recipients and those with ESRD (91%, 87% and 55% of studies reporting a dominant or cost-saving intervention, respectively). There is evidence of opportunities to lower costs in the treatment of patients with CKD, while either improving or maintaining the quality of care. In order to realize these cost savings, efforts will be required to promote and effectively implement changes in treatment practices.

An overview of foot infections in diabetes

Patients with diabetes are prone to ulcerations of the lower extremities, frequently complicated by infection, and are then reliant upon their caregivers for preservation of their limbs without the dreaded outcome of amputation. The enormous tolls of foot infections in diabetes, in terms of both health-related quality of life issues and associated economic burdens, have only been fully realized within the last few decades, and it is anticipated that these burdens will only increase over time. Early and appropriate antibiotic treatment targeting the most likely etiologic pathogens is a cornerstone of management of foot infections in diabetes, but these decisions are now complicated by the emergence of resistant organisms, particularly methicillin-resistant Staphylococcus aureus and multidrug-resistant Gram-negative species. This review will examine the impact of foot infections in diabetes and the overall care and management of the diabetes patient with foot infection, including the potential value of emerging antibiotic therapies within the milieu of antibiotic resistance.

The role of hyperbaric oxygen in the treatment of diabetic foot ulcers

Diabetic foot ulcers are still extremely difficult to heal. Therefore, therapeutic options to improve healing rates are continuously being explored. Hyperbaric oxygen (HBO) has been used in addition to standard treatment of the diabetic foot for more than 20 years. Evidence suggests that HBO reduces amputation rates and increases the likelihood of healing in infected diabetic foot ulcers, in association with improved tissue oxygenation, resulting in better quality of life. Nonetheless, HBO represents an expensive modality, which is only available in few centers. Moreover, adverse events necessitate a closer investigation of its safety. Finally, it is not entirely clear which patients stand to benefit from HBO and how these should be selected. In conclusion, HBO appears promising, but more experience is needed before its broad implementation in the routine care of the diabetic foot.

What is the role of hyperbaric oxygen in the management of diabetic foot disease?

Systemic hyperbaric oxygen (HBO) is accomplished when a patient is breathing 100% oxygen in an environment with increased barometric pressure. A typical HBO treatment protocol of diabetic foot ulcer involves 20 to 40 sessions. Treatment is usually given as daily 90- to 120-minute HBO sessions at pressures between 2.0 and 2.5 absolute atmospheres. The wide use of HBO as treatment of diabetic foot ulcers over the past decades has been founded on weak scientific ground (ie, few and small prospective studies with methodologic limitations on top of case series). However, the consistency in positive outcome in these trials evaluating HBO on ulcer healing is noteworthy because these findings are in concert with data from in vitro and physiologic studies supporting the theoretic framework of HBO reversing hypoxia-induced pathology. Two well-designed randomized double-blinded placebo-controlled studies have in recent years put HBO on firmer ground as treatment of a selection of diabetic patients with chronic foot. Some evidence indicates that microvascular parameters such as transcutaneous (partial) oxygen pressure (TcPO(2)) could be useful in predicting which patients will benefit from therapy. Health economic studies suggest potential cost-effectiveness of HBO. But because these analyses are limited by their deficient primary clinical data, they should be interpreted with caution. Thus, HBO is only indicated in a selected group of patients with chronic diabetic foot ulcers. Several key issues remain to be addressed such as developing robust criteria to determine which patients are likely to benefit and when to start and stop treatment.

Inhibition of stromal cell-derived factor-1α further impairs diabetic wound healing

OBJECTIVE

Impaired diabetic wound healing is associated with abnormal stromal cell-derived factor (SDF)-1α production, decreased angiogenesis, and chronic inflammation. Lentiviral-mediated overexpression of SDF-1α can correct the impairments in angiogenesis and healing in diabetic wounds. We hypothesized that SDF-1α is a critical component of the normal wound-healing response and that inhibition of SDF-1α would further delay the wound-healing process.

METHODS

dB/Db diabetic mice and Db/+ nondiabetic mice were wounded with an 8-mm punch biopsy and the wounds treated with a lentiviral vector containing either the green fluorescent protein (GFP) or SDF-1α inhibitor transgene. The inhibitor transgene is a mutant form of SDF-1α that binds, but does not activate, the CXCR4 receptor. Computerized planimetry was used to measure wound size daily. Wounds were analyzed at 3 and 7 days by histology and for production of inflammatory markers using real-time polymerase chain reaction. The effect of the SDF-1α inhibitor on cellular migration was also assessed.

RESULTS

Inhibition of SDF-1α resulted in a significant decrease in the rate of diabetic wound healing, (3.8 vs 6.5 cm(2)/day in GFP-treated wounds; P = .04), and also impaired the early phase of nondiabetic wound healing. SDF-1α inhibition resulted in fewer small-caliber vessels, less granulation tissue formation, and increased proinflammatory gene expression of interleukin-6 and macrophage inflammatory protein-2 in the diabetic wounds.

CONCLUSIONS

The relative level of SDF-1α in the wound plays a key role in the wound-healing response. Alterations in the wound level of SDF-1α, as seen in diabetes or by SDF-1α inhibition, impair healing by decreasing cellular migration and angiogenesis, leading to increased production of inflammatory cytokines and inflammation. Inhibition of SDF-1α further impairs diabetic wound healing.

Cost variation in diabetes care delivered in English hospitals

AIMS

We analysed the in-hospital costs of diabetic patients admitted to English hospitals and aimed to assess what proportions of cost variation are explained by patient and hospital characteristics.

METHODS

We used Hospital Episode Statistics and reference costs for all patients admitted to diabetes care for all English hospitals for the financial year 2005/2006. Our sample included 31 371 patients admitted to 148 hospitals. We applied a multi-level approach. We analysed the relationship between patient costs and patient characteristics. We estimated the average cost of being treated in each hospital after controlling for patient characteristics. In addition, we explored why these average costs vary across hospitals.

RESULTS

Much of the variation in the costs of controlling diabetes was driven by the Healthcare Resource Group to which the patient was allocated, but costs were also higher for patients who were transferred between hospitals, suffered infections and other complications, or for those who died in hospital. Even so, approximately 8-9% of the variation in costs was related to the hospital in which the patient was treated, with geographical variation in factor prices being the prime reason for this variation. The volume of patients, and the number and diversity of specialties involved in caring for diabetic patients did not explain the variation in the cost of treating diabetic patients across hospitals.

CONCLUSIONS

Healthcare Resource Groups and diagnostic markers are significant patient-related cost drivers in diabetes care. Costs are not lower in hospitals with a high volume of patients and where diabetes care is concentrated in few specialties.

The characterization and optimization of injectable silicone resin particles in conjunction with dermal fibroblasts and growth factors: an in vitro study

Minimally invasive subdermal injection of liquid silicone has been used clinically to augment the soft tissue of the foot to mitigate high pressures that cause diabetic foot ulcers. However, implant migration has been a clinical issue. The objective of this study was to assess the effects of three specific concentrations of silicone resin particles (12 mum average diameter) in conjunction with either platelet-derived growth factor (PDGF-BB) or basic fibroblast growth factor (bFGF) on fibroblast cell proliferation, collagen synthesis, cell morphology, and migration through in vitro assays and a monolayer scratch wound model. PDGF and bFGF enhanced the proliferation of fibroblasts 5.7-fold and fivefold, respectively, while the addition of silicone particles had no significant effect on proliferation. Collagen production was increased approximately twofold with the addition of bFGF and the medium concentration of particles over bFGF without particles and the PDGF groups. The addition of silicone particles had no significant effect on collagen production compared with control groups without particles. Fibroblast migration was enhanced by the addition of both PDGF and bFGF compared to controls, although slower scratch wound closure rates were observed in the presence of particles compared to controls without particles. Cell morphology suggested that particles induced cellular aggregation encircling silicone particles postwounding as well as migration into the wound area. These results suggest that silicone particles in combination with a growth factor might enhance fibroblast aggregation and implant stability, and could promote connective tissue ingrowth and implant encapsulation in the soft tissue of the diabetic foot.

Effect of growth factors in combination with injectable silicone resin particles on the biological activity of dermal fibroblasts: a preliminary in vitro study

Injections of silicone fluid have been clinically evaluated to treat and prevent foot ulcers due to diminished plantar fat-pad in neuropathic diabetics. The objective of this study was to determine preliminary in vitro effects of an injectable form of silicone resin particles in combination with growth factors to determine the suitability of this potential therapy for prevention of diabetic foot ulcers. Basic fibroblast growth factor (bFGF), epidermal growth factor (EGF) and platelet-derived growth factor (PDGF-BB) were added to monolayer culture along with silicone resin particles (12 microm average diameter). Growth factors were also combined as follows: bFGF+PDGF-BB, EGF+PDGF-BB, and bFGF+EGF. Growth factors alone and in combination increased fibroblast proliferation, but the presence of particles did not significantly affect cellular proliferation. The addition of particles significantly increased fibronectin production 117% in the control group and 151% in the PDGF only group. Collagen production was increased with exposure to EGF and growth factor combinations, but the presence of particles did not lead to any significant differences, except an 81% increase in the bFGF group. These preliminary results suggest that a combination of PDGF and bFGF may be effective in stimulating proliferation and matrix production around injectable silicone resin particles to generate a fibrous tissue pad to alleviate the abnormal distribution of high pressures that contribute to diabetic foot ulcer formation.