Randomized controlled trial of topical hyperbaric oxygen for treatment of diabetic foot ulcers

Recent advances in the adjunctive management of diabetic foot ulcer: Focus on noninvasive technologies

Diabetic foot ulcer (DFU) is one of the most costly and serious complications of diabetes. Treatment of DFU is usually challenging and new approaches are required to improve the therapeutic efficiencies. This review aims to update new and upcoming adjunctive therapies with noninvasive characterization for DFU, focusing on bioactive dressings, bioengineered tissues, mesenchymal stem cell (MSC) based therapy, platelet and cytokine-based therapy, topical oxygen therapy, and some repurposed drugs such as hypoglycemic agents, blood pressure medications, phenytoin, vitamins, and magnesium. Although the mentioned therapies may contribute to the improvement of DFU to a certain extent, most of the evidence come from clinical trials with small sample size and inconsistent selections of DFU patients. Further studies with high design quality and adequate sample sizes are necessitated. In addition, no single approach would completely correct the complex pathogenesis of DFU. Reasonable selection and combination of these techniques should be considered.

Effects of Oxygen Therapy on Patients with a Chronic Wound: A Systematic Review and Meta-analysis

OBJECTIVE

To synthesize the effects of oxygen-based therapy on patients with a chronic wound.

DATA SOURCES

The authors searched PubMed, EMBASE, and Cochrane Central Register of Controlled Trials for relevant randomized controlled trials from database inception. Investigators measured risk of bias using the Cochrane Collaboration's Risk of Bias tool.

STUDY SELECTION

The included randomized controlled trials focused on the effects (short- or long-term wound healing, amputation rate, percentage of reduction in ulcer size, and poststudy transcutaneous oxygen measurement [TcPO2]) of oxygen-based therapy (including hyperbaric oxygen therapy, topical oxygen therapy, and continuous diffusion of oxygen) on patients with a chronic wound.

DATA EXTRACTION

Researchers extracted information regarding participant characteristics and primary and secondary outcomes from the included studies.

DATA SYNTHESIS

Pooled effects of 31 included studies showed that patients treated with oxygen had better short-term wound healing (risk ratio [RR], 1.544; 95% CI, 1.199 to 1.987), a higher percentage reduction in the ulcer area (standardized mean difference [SMD], 0.999; 95% CI, 0.439 to 1. 599), lower amputation rates (RR, 0.529; 95% CI, 0.325 to 0.862), shorter wound healing time (SMD, -0.705; 95% CI, -0.908 to -0.501), and higher poststudy TcPO2 (SMD, 2.128; 95% CI, 0.978 to 3.278) than those in the control group. For long-term wound healing, there was no statistically significant difference (RR, 1.227; 95% CI, 0.976 to 1.542).

CONCLUSIONS

Oxygen-based therapy improves short-term parameters of wound healing in patients with chronic wounds.

Effectiveness of interventions to enhance healing of chronic foot ulcers in diabetes: A systematic review

BACKGROUND

It is critical that interventions used to enhance the healing of chronic foot ulcers in diabetes are backed by high-quality evidence and cost-effectiveness. In previous years, the systematic review accompanying guidelines published by the International Working Group of the Diabetic Foot performed 4-yearly updates of previous searches, including trials of prospective, cross-sectional and case-control design.

AIMS

Due to a need to re-evaluate older studies against newer standards of reporting and assessment of risk of bias, we performed a whole new search from conception, but limiting studies to randomised control trials only.

MATERIALS AND METHODS

For this systematic review, we searched PubMed, Scopus and Web of Science databases for published studies on randomised control trials of interventions to enhance healing of diabetes-related foot ulcers. We only included trials comparing interventions to standard of care. Two independent reviewers selected articles for inclusion and assessed relevant outcomes as well as methodological quality.

RESULTS

The literature search identified 22,250 articles, of which 262 were selected for full text review across 10 categories of interventions. Overall, the certainty of evidence for a majority of wound healing interventions was low or very low, with moderate evidence existing for two interventions (sucrose-octasulfate and leucocyte, platelet and fibrin patch) and low quality evidence for a further four (hyperbaric oxygen, topical oxygen, placental derived products and negative pressure wound therapy). The majority of interventions had insufficient evidence.

CONCLUSION

Overall, the evidence to support any other intervention to enhance wound healing is lacking and further high-quality randomised control trials are encouraged.

Guidelines on interventions to enhance healing of foot ulcers in people with diabetes (IWGDF 2023 update)

AIMS

Principles of wound management, including debridement, wound bed preparation, and newer technologies involving alternation of wound physiology to facilitate healing, are of utmost importance when attempting to heal a chronic diabetes-related foot ulcer. However, the rising incidence and costs of diabetes-related foot ulcer management necessitate that interventions to enhance wound healing of chronic diabetes-related foot ulcers are supported by high-quality evidence of efficacy and cost effectiveness when used in conjunction with established aspects of gold-standard multidisciplinary care. This is the 2023 International Working Group on the Diabetic Foot (IWGDF) evidence-based guideline on wound healing interventions to promote healing of foot ulcers in persons with diabetes. It serves as an update of the 2019 IWGDF guideline.

MATERIALS AND METHODS

We followed the GRADE approach by devising clinical questions and important outcomes in the Patient-Intervention-Control-Outcome (PICO) format, undertaking a systematic review, developing summary of judgements tables, and writing recommendations and rationale for each question. Each recommendation is based on the evidence found in the systematic review and, using the GRADE summary of judgement items, including desirable and undesirable effects, certainty of evidence, patient values, resources required, cost effectiveness, equity, feasibility, and acceptability, we formulated recommendations that were agreed by the authors and reviewed by independent experts and stakeholders.

RESULTS

From the results of the systematic review and evidence-to-decision making process, we were able to make 29 separate recommendations. We made a number of conditional supportive recommendations for the use of interventions to improve healing of foot ulcers in people with diabetes. These include the use of sucrose octasulfate dressings, the use of negative pressure wound therapies for post-operative wounds, the use of placental-derived products, the use of the autologous leucocyte/platelet/fibrin patch, the use of topical oxygen therapy, and the use of hyperbaric oxygen. Although in all cases it was stressed that these should be used where best standard of care was not able to heal the wound alone and where resources were available for the interventions.

CONCLUSIONS

These wound healing recommendations should support improved outcomes for people with diabetes and ulcers of the foot, and we hope that widescale implementation will follow. However, although the certainty of much of the evidence on which to base the recommendations is improving, it remains poor overall. We encourage not more, but better quality trials including those with a health economic analysis, into this area.

Efficacy of Topical Wound Oxygen Therapy in Healing Chronic Diabetic Foot Ulcers: Systematic Review and Meta-Analysis

Objective: To conduct a systematic review and meta-analysis of recently published randomized controlled trials (RCTs) that employed the use of topical oxygen therapy (TOT) as an adjunct therapy in the treatment of Wagner 1 and 2 diabetic foot ulcers. Approach: Following a literature search of eligible studies from 2010 onward, four RCTs were included. Studies were analyzed for patient and wound characteristics, outcomes, risk of bias, and quality of the evidence assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology. A random-effects meta-analysis for complete wound healing was carried out due to statistical heterogeneity of included studies. Results: Risk of bias judgment (RoB2 analysis) resulted in one low-risk trial and three trials with some risk. One study was determined to be the origin of the statistical heterogeneity. Pooled results showed statistical significance with a risk ratio (RR) of 1.59 (95% confidence interval [CI]: 1.07-2.37; p = 0.021). Sensitivity analysis, based on imputed values for missing outcomes, demonstrated that both the RR and 95% CIs changed little. The GRADE ratings for each domain were as follows: (a) risk of bias: moderate (3); (b) imprecision: moderate (2), high (1); (c) inconsistency: low (2), high (1); (d) indirectness: moderate (2), high (1); and (e) publication bias: moderate (1), high (2). Overall, the evidence was moderate. Innovation: Our study shows that TOT is a viable diabetic foot ulcer therapy. Conclusions: These data support the use of TOT for the treatment of chronic Wagner 1 or 2 diabetic foot ulcers in the absence of infection and ischemia.

Adjunctive topical oxygen therapy for wound healing in patients with peripheral arterial disease

INTRODUCTION

While the use of hyperbaric oxygen therapy has been supported by randomized prospective trials for the use of selective lower extremity wounds, it is associated with significant cost, inconvenience, and a small risk of pneumothorax, barotrauma to the tympanic membrane, and severe hypoglycemia. As topical oxygen therapy (tOT) avoids these issues and there is little literature examining its use for patients with peripheral arterial disease (PAD), we reviewed our experience with tOT as an adjunctive technique for wound healing with arterial wounds.

METHODS

We reviewed our experience with tOT for lower extremity wounds over 8 years. PAD patients with non-healing ulcers were referred to tOT after having revascularization of the limb and/or debridement where appropriate. tOT was administered to affected areas 4 times a week with a local boot that delivered 100% oxygen to the wound at 1.03 atm for 90-min sessions. We had 28 patients with PAD, 57.1% male, and 36 individual wounds. Ages ranged from 37 to 93 (mean 62 ± 13.7). 82% had a history DM, 75% hypertension, and 60.7% hyperlipidemia. 78% had lower extremity arterial angioplasty and 11% had a LE bypass. The remainder had a debridement only and were not candidates for arterial revascularization.

RESULTS

tOT duration ranged from 1 to 7 months (mean 3 ± 2). 29% stopped tOT before healing. 25% healed completely. One died during follow-up. Overall, 66% had reduction of the wound area ranging from 12% to 100%. None had major limb amputation. 18% underwent toe amputations. 25% of our patients were lost to follow-up.

CONCLUSION

While these data are from a single-center and are single-armed, they represent the largest reported series of this therapy. This home-based therapy does show promise and warrants further investigation.

Topical Wound Oxygen Therapy in the Treatment of Chronic Diabetic Foot Ulcers

Oxygen is a critical component of many biological processes and is essential for wound healing. Chronic wounds are typically characterized as being hypoxic in that the partial pressure of oxygen (pO2) in the center of the wound is often below a critical threshold necessary to fully support those enzymatic processes necessary for tissue repair. Providing supplemental oxygen can effectively raise pO2 levels to better optimize functioning of these essential enzymes. While hyperbaric oxygen therapy has been well studied in this regard, comparative clinical studies have fallen short of providing clear evidence in support of this modality for healing chronic diabetic foot ulcers (DFU). Topical oxygen therapy (TOT) has been in clinical use for over 50 years with encouraging pre-clinical and clinical studies that have shown improved healing rates when compared to standard care. Nonetheless, TOT has heretofore been discounted as an unproven wound healing modality without theoretical or clinical evidence to support its use. This review shall provide a brief summary of the role of oxygen in wound healing and, specifically, discuss the different types of topical oxygen devices and associated studies that have convincingly shown their efficacy in healing chronic DFUs. The time has come for topical oxygen therapy to be embraced as a proven adjunctive modality in this regard.

Oxygen therapy: evidence base

The evidence base for the different methods of oxygen therapy ranges from systematic reviews and meta-analyses to case series evaluations. A common thread running through the assorted evidence is that oxygen therapy accelerates healing and reduces healing times. This article summarises the clinical evidence produced on this therapy.

Effectiveness of interventions to enhance healing of chronic foot ulcers in diabetes: a systematic review

The management of diabetic foot ulcers (DFU) remains a challenge, and there is continuing uncertainty concerning optimal approaches to wound healing. The International Working Group of the Diabetic Foot (IWGDF) working group on wound healing has previously published systematic reviews of the evidence in 2008, 2012 and 2016 to inform protocols for routine care and to highlight areas which should be considered for further study. The working group has now updated this review by considering papers on the interventions to improve the healing of DFU's published between June 2014 and August 2018. Methodological quality of selected studies was independently assessed by a minimum of two reviewers using the recently published 21-point questionnaire as recommended by IWGDF/European Wound Management Association, as well as the previously incorporated Scottish Intercollegiate Guidelines Network criteria. Of the 2275 papers identified, 97 were finally selected for grading following full text review. Overall, there has been an improvement in study design and a significant rise in the number of published studies. While previous systematic reviews did not find any evidence to justify the use of newer therapies, except for negative pressure wound therapy in post-surgical wounds, in this review we found additional evidence to support some interventions including a sucrose-octasulfate dressing, the combined leucocyte, fibrin and platelet patch as well as topical application of some placental membrane products, all when used in addition to usual best care. Nonetheless, the assessment and comparison of published trials remains difficult with marked clinical heterogeneity between studies: in patient selection, study duration, standard of usual care provision and the timing and description of the clinical endpoints.

A Multinational, Multicenter, Randomized, Double-Blinded, Placebo-Controlled Trial to Evaluate the Efficacy of Cyclical Topical Wound Oxygen (TWO2) Therapy in the Treatment of Chronic Diabetic Foot Ulcers: The TWO2 Study

OBJECTIVE

Topical oxygen has been used for the treatment of chronic wounds for more than 50 years. Its effectiveness remains disputed due to the limited number of robust high-quality investigations. The aim of this study was to assess the efficacy of multimodality cyclical pressure Topical Wound Oxygen (TWO2) home care therapy in healing refractory diabetic foot ulcers (DFUs) that had failed to heal with standard of care (SOC) alone.

RESEARCH DESIGN AND METHODS

Patients with diabetes and chronic DFUs were randomized (double-blind) to either active TWO2 therapy or sham control therapy-both in addition to optimal SOC. The primary outcome was the percentage of ulcers in each group achieving 100% healing at 12 weeks. A group sequential design was used for the study with three predetermined analyses and hard stopping rules once 73, 146, and ultimately 220 patients completed the 12-week treatment phase.

RESULTS

At the first analysis point, the active TWO2 arm was found to be superior to the sham arm, with a closure rate of 41.7% compared with 13.5%. This difference in outcome produced an odds ratio (OR) of 4.57 (97.8% CI 1.19, 17.57), P = 0.010. After adjustment for University of Texas Classification (UTC) ulcer grade, the OR increased to 6.00 (97.8% CI 1.44, 24.93), P = 0.004. Cox proportional hazards modeling, also after adjustment for UTC grade, demonstrated >4.5 times the likelihood to heal DFUs over 12 weeks compared with the sham arm with a hazard ratio of 4.66 (97.8% CI 1.36, 15.98), P = 0.004. At 12 months postenrollment, 56% of active arm ulcers were closed compared with 27% of the sham arm ulcers (P = 0.013).

CONCLUSIONS

This sham-controlled, double-blind randomized controlled trial demonstrates that, at both 12 weeks and 12 months, adjunctive cyclical pressurized TWO2 therapy was superior in healing chronic DFUs compared with optimal SOC alone.

Editorial and Mini-Review: Topical Oxygen Therapy for Diabetic Foot Ulcerations - Avenue Towards New Hope?

Diabetic foot complications now represent the 10th leading cause of disease burden and disability. Wound healing is impaired, leading to chronic ulceration. Local high oxygen concentration is required by the metabolically active cells in the wound, which may render the region hypoxic, even in the absence of peripheral arterial disease. Therefore, the contribution of hyperbaric oxygen to improved healing rates has been extensively investigated. More recent developments include products delivering topical oxygen therapy (TOT) directly at the wound site, either by continuous delivery or by pressurized systems. A very recent systematic review has found that TOT increases wound healing rates in chronic, less severe diabetic foot ulcers (DFUs), and it promotes high rates of healing in more severe ulcers. Thus, TOT appears to be very promising to improve healing in DFUs. We now need more experience regarding its therapeutic place in the algorithm of DFU management and in relation to optimal patient selection.

Topical oxygen therapy & micro/nanobubbles: a new modality for tissue oxygen delivery

Up to 15 billion dollars of US health care expenditure each year is consumed by treatment of poorly healing wounds whose etiologies are often associated with aberrancies in tissue oxygenation. To address this issue, several modes of tissue oxygen delivery systems exist, including Hyperbaric Oxygen Therapy (HBOT) and Topical Oxygen Therapy (TOT), but their efficacies have yet to be fully substantiated. Micro/nanobubbles (MNBs), which range anywhere from 100 μm to <1 μm in diameter and are relatively stable for hours, offer a new mode of oxygen delivery to wounds. The aim of this article is to systematically review literature examining the use of TOT for wound healing and use of MNBs for tissue oxygenation using the MEDLINE database. The search yielded 87 articles (12 MNB articles and 75 TOT articles), of which 52 met the inclusion criteria for this literature review (12 MNB articles and 40 TOT articles). Additionally, we present an analysis on the efficacy of our MNB generating technology and propose its use as a wound healing agent.

Saccharomyces cerevisiae osteomyelitis in an immunocompetent baker

Invasive infection caused by Saccharomyces cerevisiae is rare. We report the first case of osteomyelitis caused by S. cerevisiae (baker's yeast) in a post-traumatic patient. The clinical outcome was favorable after surgical debridement, prolonged antifungal treatment and hyperbaric oxygen therapy.

Effectiveness of interventions to enhance healing of chronic ulcers of the foot in diabetes: a systematic review

The outcome of management of diabetic foot ulcers remains a challenge, and there remains continuing uncertainty concerning optimal approaches to management. It is for these reasons that in 2008 and 2012, the International Working Group of the Diabetic Foot (IWGDF) working group on wound healing published systematic reviews of the evidence to inform protocols for routine care and to highlight areas, which should be considered for further study. The same working group has now updated this review by considering papers on the interventions to improve the healing of chronic ulcers published between June 2010 and June 2014. Methodological quality of selected studies was independently assessed by two reviewers using Scottish Intercollegiate Guidelines Network criteria. Selected studies fell into the following ten categories: sharp debridement and wound bed preparation with larvae or hydrotherapy; wound bed preparation using antiseptics, applications and dressing products; resection of the chronic wound; oxygen and other gases, compression or negative pressure therapy; products designed to correct aspects of wound biochemistry and cell biology associated with impaired wound healing; application of cells, including platelets and stem cells; bioengineered skin and skin grafts; electrical, electromagnetic, lasers, shockwaves and ultrasound and other systemic therapies, which did not fit in the aforementioned categories. Heterogeneity of studies prevented pooled analysis of results. Of the 2161 papers identified, 30 were selected for grading following full text review. The present report is an update of the earlier IWGDF systematic reviews, and the conclusion is similar: that with the possible exception of negative pressure wound therapy in post-operative wounds, there is little published evidence to justify the use of newer therapies. Analysis of the evidence continues to present difficulties in this field as controlled studies remain few and the majority continue to be of poor methodological quality.

Challenges in the Treatment of Chronic Wounds

Significance: Chronic wounds include, but are not limited, to diabetic foot ulcers, venous leg ulcers, and pressure ulcers. They are a challenge to wound care professionals and consume a great deal of healthcare resources around the globe. This review discusses the pathophysiology of complex chronic wounds and the means and modalities currently available to achieve healing in such patients. Recent Advances: Although often difficult to treat, an understanding of the underlying pathophysiology and specific attention toward managing these perturbations can often lead to successful healing. Critical Issues: Overcoming the factors that contribute to delayed healing are key components of a comprehensive approach to wound care and present the primary challenges to the treatment of chronic wounds. When wounds fail to achieve sufficient healing after 4 weeks of standard care, reassessment of underlying pathology and consideration of the need for advanced therapeutic agents should be undertaken. However, selection of an appropriate therapy is often not evidence based. Future Directions: Basic tenets of care need to be routinely followed, and a systematic evaluation of patients and their wounds will also facilitate appropriate care. Underlying pathologies, which result in the failure of these wounds to heal, differ among various types of chronic wounds. A better understanding of the differences between various types of chronic wounds at the molecular and cellular levels should improve our treatment approaches, leading to better healing rates, and facilitate the development of new more effective therapies. More evidence for the efficacy of current and future advanced wound therapies is required for their appropriate use.

Topical Oxygen for Chronic Wounds: A PRO/CON Debate

The role of oxygen in wound healing is universally accepted and does not require any further evidence; however the controversy as to whether oxygen delivery systems have the potential to improve wound healing remains to be concluded. Topical oxygen treatment (TOT) involves the delivery of 100% oxygen for a mean of 90 min, once a day at an atmospheric pressure slightly above 1 atm abs. The use of TOT gained increasing interest recently. The current manuscript will summarize the pros and cons of TOT in the view of the available literature.

Hyperbaric oxygen for chronic wounds

Hyperbaric oxygen therapy (HBOT), the administration of pressurized 100% oxygen, is used as an adjunct to aid healing in selected chronic wounds. Though the therapy has had a controversial history, research is now elucidating the mechanisms by which HBOT helps to heal wounds. HBOT increases growth factors and local wound signaling, while also promoting a central stem cell release of endothelial progenitor cells from the bone marrow via nitric oxide pathways. The clinical data continue to accumulate in support of HBOT to help hasten wound healing, and reduce the amputation rate in diabetic ulcers. In appropriate patients, HBOT is an effective, noninvasive, adjunct modality that can be used to hasten chronic wound healing.

Skin oxygen tension is improved by immersion in oxygen-enriched water

OBJECTIVE

The perceived health and physiologic functioning of skin depends on adequate oxygen availability. Economical and easily used therapeutic approaches to increase skin oxygenation could improve the subjective appearance of the skin as well as support the management of some cutaneous conditions related to chronic hypoxic ischaemia (e.g. ulcerative wounds). We have tested the hypothesis that the O2 partial pressure of skin (PskO2 ) increases during immersion in water enriched with high levels of dissolved oxygen.

METHODS

A commercially available device was used to produce water containing 45 to 65 mg L(-1) of dissolved O2 . Young adults (YA; n = 7), older adults (OA; n = 13) and older adults with diabetes (OAD; n = 11) completed different experiments that required them to immerse their feet in tap water (<2 mg L(-1) of O2 ; control) or O2 -enriched water (O2 -H2 O; experimental) for 30 min. Transcutaneous oximetry was used to measure PskO2 for 20 min pre- and post-immersion.

RESULTS

Pre-immersion mean (standard deviation) PskO2 on the plantar surface of the big toe was 75 (10), 67 (10) and 65 (10) mmHg in YA, OA and OAD, respectively. Post-immersion PskO2 was 244 (25), 193 (28) and 205 (28) mmHg for the same groups. We also show that post-immersion PskO2 varies by location and with advancing age.

CONCLUSION

Water is an effective vehicle for transporting dissolved O2 across the skin surface and could be used as a basis for development of economical therapeutic approaches that improve skin oxygen tension to support skin health and function.

Systematic review of the effectiveness of hyperbaric oxygenation therapy in the management of chronic diabetic foot ulcers

OBJECTIVE

To assess the efficacy and safety of hyperbaric oxygenation (HBO) therapy as adjunctive treatment for diabetic foot ulcers with a systematic review and meta-analysis of the literature.

METHODS

MEDLINE, EMBASE, and the Cochrane Library were searched to find relevant articles published up to April 20, 2012, without restriction as to language or publication status. All controlled trials that evaluated adjunctive treatment with HBO therapy compared with treatment without HBO for chronic diabetic foot ulcers were selected. A meta-analysis was performed to assess the efficacy and safety of hyperbaric oxygen in managing foot ulcers.

RESULTS

Thirteen trials (a total of 624 patients), including 7 prospective randomized trials, performed between January 1, 1966, and April 20, 2012, were identified as eligible for inclusion in the study. Pooling analysis revealed that, compared with treatment without HBO, adjunctive treatment with HBO resulted in a significantly higher proportion of healed diabetic ulcers (relative risk, 2.33; 95% CI, 1.51-3.60). The analysis also revealed that treatment with HBO was associated with a significant reduction in the risk of major amputations (relative risk, 0.29; 95% CI, 0.19-0.44); however, the rate of minor amputations was not affected (P=.30). Adverse events associated with HBO treatment were rare and reversible and not more frequent than those occurring without HBO treatment (P=.37).

CONCLUSIONS

This meta-analysis reveals that treatment with HBO improved the rate of healing and reduced the risk of major amputations in patients with diabetic foot ulcers. On the basis of these effects, we believe that quality of life could be improved in selected patients treated with HBO.

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.

Hyperbaric oxygen in the treatment of a diabetic foot ulcer

Although simultaneous pancreas and kidney transplant improves most complications of type 1 diabetes, suppression of the immune system increases the risk for infection. The authors report the case of a patient who, despite receiving a simultaneous pancreas and kidney transplant, subsequently developed neuro-ischemic ulcers of his right foot requiring repeated amputations. He then developed an infected ulcer of his remaining right big toe, with significant implications for his mobility. This ulcer proved resistant to multiple courses of antibiotics and care in a specialist foot clinic but resolved completely following a course of hyperbaric oxygen therapy. The role of hyperbaric oxygen in diabetic foot ulcers is not yet fully established but should be considered in resistant cases with vascular insufficiency and a significant infective component.

The use of hyperbaric oxygen therapy to treat chronic wounds: A review

Chronic wounds, defined as those wounds which fail to proceed through an orderly process to produce anatomic and functional integrity, are a significant socioeconomic problem. A wound may fail to heal for a variety of reasons including the use of corticosteroids, formation of squamous cell carcinoma, persistent infection, unrelieved pressure, and underlying hypoxia within the wound bed. Hypoxia appears to inhibit the wound healing process by blocking fibroblast proliferation, collagen production, and capillary angiogenesis and to increase the risk of infection. Hyperbaric oxygen therapy (HBOT) has been shown to aid the healing of ulcerated wounds and demonstrated to reduce the risk of amputation in diabetic patients. However, the causal reasons for the response of the underlying biological processes of wound repair to HBOT, such as the up-regulation of angiogenesis and collagen synthesis are unclear and, consequently, current protocols remain empirical. Here we review chronic wound healing and the use of hyperbaric oxygen as an adjunctive treatment for nonhealing wounds. Databases including PubMed, ScienceDirect, Blackwell Synergy, and The Cochrane Library were searched for relevant phrases including HBOT, HBO/HBOT, wound healing, and chronic/nonhealing wounds/ulcers.

A systematic review of the effectiveness of interventions to enhance the healing of chronic ulcers of the foot in diabetes

The outcome of management of diabetic foot ulcers is poor and there is uncertainty concerning optimal approaches to management. We have undertaken a systematic review to identify interventions for which there is evidence of effectiveness. A search was made for reports of the effectiveness of interventions assessed in terms of healing, ulcer area or amputation in controlled clinical studies published prior to December 2006. Methodological quality of selected studies was independently assessed by two reviewers using Scottish Intercollegiate Guidelines Network (SIGN) criteria. Selected studies fell into the following categories: sharp debridement and larvae; antiseptics and dressings; chronic wound resection; hyperbaric oxygen (HBO); reduction of tissue oedema; skin grafts; electrical and magnetic stimulation and ultrasound. Heterogeneity of studies prevented pooled analysis of results. Of the 2251 papers identified, 60 were selected for grading following full text review. Some evidence was found to support hydrogels as desloughing agents and to suggest that a systemic (HBO) therapy may be effective. Topical negative pressure (TNP) may promote healing of post-operative wounds, and resection of neuropathic plantar ulcers may be beneficial. More information was needed to confirm the effectiveness and cost-effectiveness of these and other interventions. No data were found to justify the use of any other topically applied product or dressing, including those with antiseptic properties. Further evidence to substantiate the effect of interventions designed to enhance the healing of chronic ulcers is urgently needed. Until such evidence is available from robust trials, there is limited justification for the use of more expensive treatments and dressings.

Double blind, randomized, placebo controlled clinical trial for the treatment of diabetic foot ulcers, using a nitric oxide releasing patch: PATHON

Background

Diabetes Mellitus constitutes one of the most important public health problems due to its high prevalence and enormous social and economic consequences. Diabetic foot ulcers are one of the chronic complications of diabetes mellitus and constitute the most important cause of non-traumatic amputation of inferior limbs. It is estimated that 15% of the diabetic population will develop an ulcer sometime in their lives. Although novel therapies have been proposed, there is no effective treatment for this pathology. Naturally produced nitric oxide participates in the wound healing process by stimulating the synthesis of collagen, triggering the release of chemotactic cytokines, increasing blood vessels permeability, promoting angiogenic activity, stimulating the release of epidermical growth factors, and by interfering with the bacterial mitochondrial respiratory chain. Topically administered nitric oxide has demonstrated to be effective and safe for the treatment of chronic ulcers secondary to cutaneous leishmaniasis. However, due to their unstable nitric oxide release, the topical donors needed to be applied frequently, diminishing the adherence to the treatment. This difficulty has led to the development of a multilayer polymeric transdermal patch produced by electrospinning technique that guarantees a constant nitric oxide release. The main objective of this study is to evaluate the effectiveness and safety of this novel nitric oxide releasing wound dressing for the treatment of diabetic foot ulcers.

Methods and design

A double-blind, placebo-controlled clinical trial, including 100 diabetic patients was designed. At the time of enrollment, a complete medical evaluation and laboratory tests will be performed, and those patients who meet the inclusion criteria randomly assigned to one of two groups. Over the course of 90 days group 1 will receive active patches and group 2 placebo patches. The patients will be seen by the research group at least every two weeks until the healing of the ulcer or the end of the treatment. During each visit the healing process of the ulcer, the patient's health status and the presence of adverse events will be assessed. Should the effectiveness of the patches be demonstrated an alternative treatment would then be available to patients.

Trial registration

NCT00428727.

Topical hyperbaric oxygen and low-energy laser for the treatment of chronic ulcers

BACKGROUND

Diabetic foot ulcers (DFU) and chronic venous ulcers (CVU) are persistent cutaneous lesions that are difficult to treat and heal. Topical hyperbaric oxygen (THO) and low-energy laser (LEL) are therapies that have been employed separately for ulcer treatment, but their concomitant use has not been investigated.

METHODS

In this unblinded, open-label non-randomized trial, we treated 374 consecutive patients with treatment-refractory chronic ulcers (218 patients with DFU and 156 individuals with CVU) with a combination of THO and LEL. THO was administered by pumping 100% oxygen into a disposable, sealed polyethylene chamber for 2 h, two to three times weekly. LEL was administered concurrently using a helium-neon laser at 4 J/cm(2) for 20 min.

RESULTS

Complete ulcer closure was obtained in 78% of patients in each group (170 patients with DFU and 127 patients with CVU). Treatment failure resulting in amputation in DFU was seen in 48 patients (22%); non-closure of ulcers within 18 months in individuals with CVU was seen in 29 (22%). The length of therapy was also similar in the two groups (3.7+/-3 versus 4.1+/-3 months in DFU and CVU cohorts, respectively). However, the number of treatments required to affect healing was greater in the CVU group than among the DFU patients (40+/-25 versus 31.4+/-20 treatments).

CONCLUSION

THO and LEL therapies are safe, effective, simple and inexpensive therapies for DFU and CVU. Confirmation must await the performance of double-blind, randomized, controlled trials currently under way.

Counterpoint: hyperbaric oxygen for diabetic foot wounds is not effective

BACKGROUND

Diabetic foot ulceration is common, affecting 1.0%-4.1% of diabetic persons per year and up to 25% in a lifetime. Diabetic foot ulcers are multifactorial in origin, and many are slow to heal and/or are complicated by infection, frequently leading to amputation. Hyperbaric oxygen therapy has been suggested for numerous indications, and it is recognized by funding agencies for a smaller number including diabetic foot wounds.

METHODS

I reviewed the literature about the history and practice of hyperbaric oxygen therapy and key issues relevant to efficacy, effectiveness, and cost-effectiveness.

RESULTS

Although recognized for reimbursement by Medicare and major insurers, the evidence base for hyperbaric oxygen therapy for diabetic foot care remains weak. A systematic review for the Cochrane Collaboration concluded that hyperbaric oxygen therapy may have value in treating diabetic wounds, but the studies reviewed all had methodological weaknesses, and the positive effect of treatment was not seen in the single reviewed randomized trial to include a sham treatment arm. Hyperbaric oxygen therapy consumes very substantial resources--and has the potential to consume far more--that could be better spent on other aspects of management or prevention of diabetic foot ulceration.

CONCLUSIONS

Hyperbaric oxygen therapy should not be offered for diabetic foot wounds until large-scale, adequately blinded, controlled, and powered randomized studies have clearly demonstrated efficacy and cost effectiveness in the healing of ulcers and the prevention of major amputation.

Changing perspectives in diabetic foot ulcer management

Diabetic foot ulceration is a serious complication of diabetes mellitus; it is the cause of more than half of nontraumatic lower limb amputations. Diabetic foot ulcers are the major cause of hospital admission for diabetic patients. Treatment costs are high. There have been advances in managing diabetic foot ulceration with the development of new dressings, growth factors, skin substitutes, and other novel approaches to stimulating wound healing. The management of vascular disease in the patient with diabetes mellitus is an essential and important consideration. However, the need for a multidisciplinary team to provide good foot care to diabetic patients is still vital for the prevention and treatment of diabetic foot ulceration.

Tratamiento de las úlceras crónicas

Chronic ulcers are a challenge in dermatological therapy. It is essential to establish their etiology in order to treat them, but on many occasions local therapy is of great interest. Treatment of chronic ulcers is currently based on so-called moist wound healing, and it takes two aspects into consideration: the underlying pathology and local treatment. Local treatment is always necessary and includes: cleaning, debridement, the control of any infection, and the application of different topical agents, both medication and dressings. Recently, new therapeutic strategies are being established, some of which are still being assessed, and which include: skin replacement using biological skin substitutes, growth factors, laser, hyperbaric oxygen, electrical stimulation and negative pressure dressings. In this work, we review the therapeutic advances in this pathology, without neglecting the validity of classic treatments.

Healing of diabetic foot ulcers in l-arginine-treated patients

Experimentally, we demonstrated the beneficial effects of L-arginine on regulation of hyperglycemia and dyslipidemia in experimental diabetes, in addition to a positive anti-aggregating effect in platelets in animals and humans. Here, the effect of L-arginine on foot ulcers from diabetic patients was studied. Three groups of diabetic patients were included: 11 patients without ulcer received neither treatment and served as controls. Eleven patients with diabetic ulcer received the standard treatment, this group served as diabetic control with diabetic ulcer. Eleven remain patients with diabetic ulcer received 10 mM L-arginine subcutaneously on the site of the wound. Biopsy with punch number 5 on wound site comprising both ulcerative and contiguous undamaged skin were performed in all patients with ulcerative lesions before any treatment. Patients with intact skin had biopsy performed with punch number 5 on external malleolar region of right lower limb. Biopsies were examined by light and confocal microscopy utilizing histochemical and immunohistochemical methods. Initial and final blood samples were collected to determine glucose, triglycerides, total cholesterol, glycated hemoglobin (HbA(1c)), low (LDL), and high density lipoproteins (HDL). Significant differences (P < 0.05) were observed between initial and final serum glucose levels for treated patients, and initial serum glucose levels between treated and control patients without diabetic ulcer. Glycated hemoglobin, triglycerides, cholesterol, and lipoprotein levels showed no significant changes. Eight patients treated with L-arginine reached total wound healing and the remaining three who abandoned the study because of change of residence showed relevant improvement. Histochemistry and immunohistochemistry methods have shown vascular impairment in both patients with diabetic ulcer (prior to treatment) and control patients without diabetic ulcer. Our observations strongly support efficacy of L-arginine for successful wound healing of diabetic ulcers.

New and experimental approaches to treatment of diabetic foot ulcers: a comprehensive review of emerging treatment strategies

Diabetic foot ulcers occur in up to 15% of all diabetic patients and are a leading cause of nontraumatic amputation worldwide. Neuropathy, abnormal foot biomechanics, peripheral vascular disease and external trauma are the major contributors to the development of a foot ulcer in the diabetic patient. Therapy today includes repeated debridement, offloading, and dressings, for lower grade ulcers, and broad spectrum antibiotics and occasionally limited or complete amputation for higher grades, requiring a team effort of health care workers from various specialties. The large population affected by diabetic foot ulcers and the high rates of failure ending with amputation even with the best therapeutic regimens, have resulted in the development of new therapies and are the focus of this review. These include new off loading techniques, dressings from various materials, methods to promote wound closure using artificial skin grafts, different growth factors or wound bed modulators and methods of debridement. These new techniques are promising but still mostly unproven and traditional approaches cannot be replaced. New and generally more expensive therapies should be seen as adding to traditional approaches.

Diabetic foot ulcerations: management and adjunctive therapy

Foot ulcerations, infections, gangrene, and lower extremity amputation are major causes of disability to the patient who has diabetes mellitus, often resulting in significant morbidity, extensive periods of hospitalization, and mortality. Although not all such lesions can be prevented, it is possible to dramatically reduce their incidence through appropriate management and prevention protocols incorporating a multidisciplinary team approach.

Saving the diabetic foot with special reference to the patient with chronic renal failure

The chronic renal failure patient with diabetes has a lower limb amputation rate 10 times greater than the diabetic population at large. In studies of causal pathways leading to non-traumatic related lower extremity amputation, foot ulcers preceded approximately 84% of the amputations. Even though foot ulcers are more likely to develop in patients with diabetic nephropathy, they are no less likely to heal than are those in diabetic patients with normal renal function. Consequently, attempts to save the diabetic foot even in this high-risk population are justified. The pathogenesis of foot ulceration in the chronic renal failure patient with diabetes is primarily due to peripheral neuropathy. Loss of protective sensation due to sensory neuropathy combined with motor and autonomic neuropathy and macrovascular compromise result in increased risk for foot complications. Evaluation of the foot includes a selective history and a focused examination of skin integrity, presence of sensory neuropathy or vascular insufficiency, and biomechanical and footwear inspection. Effective treatment of diabetic foot complications include appropriate antibiotics (when indicated), meticulous wound care, off-loading, vascular surgery (when indicated), and selective/elective or prophylactic nonvascular surgery. Failure to heal an ulcer can often be traced to common pitfalls, which include: A "cavalier" attitude. W.N.L. exam (We Never Looked). Inadequate off-loading. Failure to establish depth of ulcer and miss "probe to bone." Non-healing means unrelieved pressure and/or no blood. Failure to correct edema. The multidisciplinary diabetic foot clinic model provides an ideal setting for early intervention, treatment, and assistance with preventive strategies.

A systematic review of foot ulcer in patients with Type 2 diabetes mellitus. II: treatment

AIM

To assess the value of treatments for foot ulcers in patients with Type 2 diabetes mellitus.

METHODS

A systematic review of interventions to treat diabetic foot ulcers.

RESULTS

The evidence base for treating infections and dressing wounds is poor. A number of new and potentially promising treatments are being developed but currently available studies are often small, inadequately powered and use different methods and outcomes.

CONCLUSIONS

Given the prevalence, morbidity and healthcare costs of diabetic foot disease, it is surprising that available trials provide inadequate evidence to improve upon current empirically based treatment approaches. Substantial effort and resources should be deployed in order to investigate both new and existing treatments in a co-ordinated, systematic and consistent manner, so that a proper evidence base can be established for this important disease area.

Infections and diabetes: mechanisms and prospects for prevention

Infections remain a serious hazard for the diabetic patient. Good metabolic control is a major factor in limiting the development and spread of infections and, most importantly, the development of diabetic complications which predispose to infections. In some patients recurrent infections can pose a problem, particularly if there is evidence of secondary immunodeficiency. In these patients adjuvant therapies, including Biological Responses Modifiers (BRMS) should be considered. Several factors could predispose diabetic patients to infections. These factors include: genetic susceptibility to infection; altered cellular and humoral immune defense mechanisms; local factors including poor blood supply and nerve damage, and alterations in metabolism associated with diabetes. In the context of a diabetic patient all or some of these factors may operate. The purpose of this review is to assess the relative contribution of these potential mechanisms in leading to infection in patients with diabetes.