Clinical outcome of diabetic foot ulcers treated with negative pressure wound therapy and the transition from acute care to home care

Analysis of Distribution and Drug Susceptibility Test Results of Pathogenic Bacteria in Diabetic Foot Ulcers

INTRODUCTION

This study aimed to determine the pathogen distribution and drug susceptibility of diabetic foot wound secretions in a tertiary hospital in a coastal area of southeastern China to guide clinical antibiotic selection.

METHODS

A retrospective analysis was conducted on 212 patients with diabetic foot hospitalized at Xiamen Third Hospital from 2018 to 2023, and foot wound secretions were collected for microbial culture and drug susceptibility testing.

RESULTS

Among 212 cases of patients with diabetic foot wound secretions, 163 cases (76.9%) were cultured with pathogenic bacteria, and a total of 207 strains of pathogenic bacteria were cultured, including 75 strains (36.23%) of Gram-positive (G+) bacteria, 118 strains of Gram-negative (G-) bacteria (57.00%), 14 strains of fungi (6.76%), 120 cases of single microorganism infection (73.62%), 43 cases of mixed infection (26.38%), and 15 strains of multidrug-resistant bacteria (7.25%). The top three pathogenic bacteria were Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa. G+ bacteria were dominated by S. aureus. Drug susceptibility results showed that G+ bacteria were highly susceptible to vancomycin, linezolid, tigecycline, quinupristin/dalfopristin, rifampicin, and furotoxin, and somewhat resistant to penicillin, erythromycin, clindamycin, and cefoxitin. Among G- bacterial infections, Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, and Proteus were the major species. Drug susceptibility testing indicated that carbapenems such as imipenem and ertapenem were the most effective antibacterial drugs against G- strains, followed by amikacin, piperacillin, and tazabactams to which these bacteria were also relatively sensitive, while resistance to penicillins and first-generation cephalosporins increased significantly. We isolated one strain of pathogenic bacteria from a Wagner grade 1 ulcer, which was G+ bacteria. In Wagner grade 2 ulcers, the distribution of pathogenic bacteria was mainly G+ bacteria. In Wagner grade 3 and 4 ulcers, the distribution of pathogenic bacteria was mainly G- bacteria, and the increased rate of mixed infection was mainly due to mixed infection of G+ and G-. Two strains of pathogenic bacteria were isolated at Wagner grade 5, which were mixed infections of G+ and G-.

CONCLUSIONS

Pathogenic bacteria in diabetic foot wounds are predominantly G- bacteria, followed by G+ bacteria. As the Wagner ulcer grade increases, the distribution of pathogenic bacteria changes from G+ bacteria to G- bacteria, and the mixed infection rate increases. G+ bacteria are highly susceptible to vancomycin, linezolid, tigecycline, quinupristin/dalfopristin, rifampicin, and furotoxin, and somewhat resistant to penicillin, erythromycin, clindamycin, and cefoxitin. G- bacteria are more sensitive to the antimicrobial drugs ertapenem, imipenem, amikacin, piperacillin tazobactam, and have high resistance to penicillin and first-generation cephalosporins.

Nurses' Readiness to Undertake Controlled Negative Pressure Therapy in the Treatment of Chronic Wounds-Research Report

Local wound treatment with negative pressure wound therapy (NPWT) shortens the healing process but requires the supervision of trained medical personnel for administering the therapeutic procedures. Professional supervision and control of the effectiveness of NPWT, as well as education conducted by nurses, are of particular importance for therapeutic and caring processes, both in hospital and at home. The aim of the study was the assessment of the perception of NPWT by certified nurses in the topical treatment of chronic wounds. The study was conducted using the method of estimation and a diagnostic survey with the proprietary NPWT perception questionnaire: 495 subjects were enrolled in the study and 401 respondents aged 25-67 years qualified for statistical analysis. Despite their experience and competence, the respondents critically assessed their knowledge, pointing to an average subjective level of knowledge related to wound treatment and a low level of knowledge related to NPWT. Most of the respondents had no experience of independent treatment using this method. The data obtained from the questionnaire clearly indicate theoretical preparation and high motivation to undertake activities related to the implementation of NPWT in their own practice. Low readiness values suggested that the subjects did not have the resources or the ability to implement the method. The perception of NPWT in the surveyed group of nurses was determined by numerous factors, including self-assessment of their own knowledge, motivation and readiness to use NPWT. A high level of NPWT perception was noted, despite low motivation related to the availability and knowledge of the method. Theoretical knowledge is insufficient to implement innovative methods in local wound treatment. Practical skills and motivation are indispensable elements that should be met during the training and education of nurses in the field of wound care.

Consensus on the health education of home-based negative pressure wound therapy for patients with chronic wounds: a modified Delphi study

Background

The study aimed to develop consensus on the components of health education of home-based negative pressure wound therapy (NPWT) for patients with chronic wounds.

Methods

A Delphi method was used to achieve consensus on the components of health education and 75% agreement and coefficient of variation (CV) <0.25 were used as cutoff. Sixteen experts were recruited purposefully to finish this study.

Results

Two rounds of consultation were implemented. Consensus was achieved on 36 of the 42 statements. The final agreed list of statements represented three domains: health education before carrying out home-based NPWT, health education for the treatment day of NPWT at hospital and health education for NPWT at home.

Conclusions

This study was the first attempt to develop consensus on the comprehensive components of health education of home-based NPWT for patients with chronic wounds. According to the established framework and components of health education, wound professionals can safely and effectively implement health education of home-based NPWT for patients with chronic wounds and improve their self-care ability and treatment experience at home.

Consensus on the application of negative pressure wound therapy of diabetic foot wounds

Because China is becoming an aging society, the incidence of diabetes and diabetic foot have been increasing. Diabetic foot has become one of the main health-related killers due to its high disability and mortality rates. Negative pressure wound therapy (NPWT) is one of the most effective techniques for the treatment of diabetic foot wounds and great progress, both in terms of research and its clinical application, has been made in the last 20 years of its development. However, due to the complex pathogenesis and management of diabetic foot, irregular application of NPWT often leads to complications, such as infection, bleeding and necrosis, that seriously affect its treatment outcomes. In 2020, under the leadership of Burns, Trauma and Tissue Repair Committee of the Cross-Straits Medicine Exchange Association, the writing group for ‘Consensus on the application of negative pressure wound therapy of diabetic foot wounds’ was established with the participation of scholars from the specialized areas of burns, endocrinology, vascular surgery, orthopedics and wound repair. Drawing on evidence-based practice suggested by the latest clinical research, this consensus proposes the best clinical practice guidelines for the application and prognostic evaluation of NPWT for diabetic foot. The consensus aims to support the formation of standardized treatment schemes that clinicians can refer to when treating cases of diabetic foot.

Comparison home care service hospital-based care ulcer economic evaluation study

Introduction

Providing health care to patients at home could be causing the mortality and readmission rates reduction in addition to satisfaction of both patients and health care providers increase. The aim of this study was to assess the cost-effectiveness of home care service compared to hospital based care in patients with diabetic foot ulcer.

Methods

An economic evaluation study and a trial study were simultaneously conducted in Iran. In trial phase, patients with diabetic foot ulcer were randomly assigned to the home care or hospital care. The Cost and Quality of life data were determined as measures of the study. Incremental cost-effectiveness ratio was calculated for comparative purposes. The model consisted of five stages of the disease. The Tree Age Pro 2009 and R software's were used for data analysis.

Results

120 patients were enrolled in our trial; among which 30 patients were in home care service group and 90 patients in hospital based care group. The rate of ulcer size reduction in hospital based care was significant (P value = 0.003) in comparison with home care service. The total cost of the home care and hospital strategies were 1720.4 US$, 3940.3 US$ and the total effectiveness were 0.31 and 0.29, respectively. The incremental cost-effectiveness ratio (ICER) was 117,300 US$ per quality-adjusted life year for home care intervention compared to hospital based care. Based on ICER plane home care treatment will be placed on the southeastern quadrant of the Cost-Effectiveness Plane, and is suggested as a more dominant treatment alternative.

Conclusions

Regarding current evidence, home care strategy for patients suffering diabetic foot ulcer enjoys more cost effectiveness compared to hospital care. It is suggested that healthcare policy makers determine the tariff for health care services for disease groups according to the activity based costing approach.

EWMA Document: Negative Pressure Wound Therapy

1. Introduction Since its introduction in clinical practice in the early 1990's negative pressure wounds therapy (NPWT) has become widely used in the management of complex wounds in both inpatient and outpatient care.¹ NPWT has been described as a effective treatment for wounds of many different aetiologies^2,3 and suggested as a gold standard for treatment of wounds such as open abdominal wounds,^4-6 dehisced sternal wounds following cardiac surgery^7,8 and as a valuable agent in complex non-healing wounds.^9,10 Increasingly, NPWT is being applied in the primary and home-care setting, where it is described as having the potential to improve the efficacy of wound management and help reduce the reliance on hospital-based care.¹¹ While the potential of NPWT is promising and the clinical use of the treatment is widespread, highlevel evidence of its effectiveness and economic benefits remain sparse.^12-14 The ongoing controversy regarding high-level evidence in wound care in general is well known. There is a consensus that clinical practice should be evidence-based, which can be difficult to achieve due to confusion about the value of the various approaches to wound management; however, we have to rely on the best available evidence. The need to review wound strategies and treatments in order to reduce the burden of care in an efficient way is urgent. If patients at risk of delayed wound healing are identified earlier and aggressive interventions are taken before the wound deteriorates and complications occur, both patient morbidity and health-care costs can be significantly reduced. There is further a fundamental confusion over the best way to evaluate the effectiveness of interventions in this complex patient population. This is illustrated by reviews of the value of various treatment strategies for non-healing wounds, which have highlighted methodological inconsistencies in primary research. This situation is confounded by differences in the advice given by regulatory and reimbursement bodies in various countries regarding both study design and the ways in which results are interpreted. In response to this confusion, the European Wound Management Association (EWMA) has been publishing a number of interdisciplinary documents^15-19 with the intention of highlighting: The nature and extent of the problem for wound management: from the clinical perspective as well as that of care givers and the patients Evidence-based practice as an integration of clinical expertise with the best available clinical evidence from systematic research The nature and extent of the problem for wound management: from the policy maker and healthcare system perspectives The controversy regarding the value of various approaches to wound management and care is illustrated by the case of NPWT, synonymous with topical negative pressure or vacuum therapy and cited as branded VAC (vacuum-assisted closure) therapy. This is a mode of therapy used to encourage wound healing. It is used as a primary treatment of chronic wounds, in complex acute wounds and as an adjunct for temporary closure and wound bed preparation preceding surgical procedures such as skin grafts and flap surgery. Aim An increasing number of papers on the effect of NPWT are being published. However, due to the low evidence level the treatment remains controversial from the policy maker and health-care system's points of view-particularly with regard to evidence-based medicine. In response EWMA has established an interdisciplinary working group to describe the present knowledge with regard to NPWT and provide overview of its implications for organisation of care, documentation, communication, patient safety, and health economic aspects. These goals will be achieved by the following: Present the rational and scientific support for each delivered statement Uncover controversies and issues related to the use of NPWT in wound management Implications of implementing NPWT as a treatment strategy in the health-care system Provide information and offer perspectives of NPWT from the viewpoints of health-care staff, policy makers, politicians, industry, patients and hospital administrators who are indirectly or directly involved in wound management.

A neglected causative agent in diabetic foot infection: a retrospective evaluation of 13 patients with fungal etiology

Background/aim

Clinicians often neglect fungal infections and do not routinely investigate deep tissue from the wound for fungal culture and sensitivity due to insufficient information in the literature. In this study, we aimed to evaluate fungal etiology of invasive fungal diabetic foot which is rarely reported in the literature.

Materials and methods

The patients who were unresponsive to antibiotic therapy and those with positive fungal in bone or deep tissue culture were enrolled in the study. Detailed hospital records were retrieved for demographics and clinical features.

Results

A total of 13 patients who were diagnosed with invasive fungal diabetic foot (ten females, three males, mean age 59.8 ± 9 years) were included. All of the patients had type-2 diabetes mellitus. Eleven (84.6%) patients had mixed infection. The most common cause of fungal infections of diabetic foot ulcers was the Candida species. Ten (76.9%) patients underwent amputation, two (15.4%) patients refused amputation, and one patient died before surgery.

Conclusion

Invasive fungal infections may also be a causative pathogen in deep tissue infections. Therefore, fungal pathogens should be considered in patients unresponsive to long-term antibiotic therapy. Early detection of fungal infections in high-risk individuals is critical for the prevention of severe consequences such as foot amputation.

Advancements in improving health-related quality of life in patients living with diabetic foot ulcers

INTRODUCTION

Diabetic foot ulcer (DFU) constitutes a burden to patients with diabetes deteriorating their quality of life. Health related quality of life (HRQoL) can now be quantified with the use of specific tools; some of them provide a holistic approach to patients' well-being, while others are disease specific or even region specific. Many of these tools are applicable to patients with DFU. This review will present current data about the impact different interventions in the management of DFU on quality of life related parameters.

AREAS COVERED

We performed a search of literature using keywords 'diabetes mellitus', 'diabetic foot ulcer', 'diabetic foot', 'health related quality of life', 'quality of life' and 'SF-36' to identify studies that contained data about the relationship between different interventions and quality of life of patients with diabetic foot ulcers.

EXPERT COMMENTARY

Available data are not sufficient to conclude on the impact of interventions aimed to heal DFU on HRQoL. There is need for more, better designed studies and meta-analysis to estimate the effect of treatments on HRQoL in patients with DFUs. The development of new, diabetic foot specific tools will help to improve our knowledge in this field.

Rapid identification of slow healing wounds

Chronic nonhealing wounds have a prevalence of 2% in the United States, and cost an estimated $50 billion annually. Accurate stratification of wounds for risk of slow healing may help guide treatment and referral decisions. We have applied modern machine learning methods and feature engineering to develop a predictive model for delayed wound healing that uses information collected during routine care in outpatient wound care centers. Patient and wound data was collected at 68 outpatient wound care centers operated by Healogics Inc. in 26 states between 2009 and 2013. The dataset included basic demographic information on 59,953 patients, as well as both quantitative and categorical information on 180,696 wounds. Wounds were split into training and test sets by randomly assigning patients to training and test sets. Wounds were considered delayed with respect to healing time if they took more than 15 weeks to heal after presentation at a wound care center. Eleven percent of wounds in this dataset met this criterion. Prognostic models were developed on training data available in the first week of care to predict delayed healing wounds. A held out subset of the training set was used for model selection, and the final model was evaluated on the test set to evaluate discriminative power and calibration. The model achieved an area under the curve of 0.842 (95% confidence interval 0.834-0.847) for the delayed healing outcome and a Brier reliability score of 0.00018. Early, accurate prediction of delayed healing wounds can improve patient care by allowing clinicians to increase the aggressiveness of intervention in patients most at risk.

Negative pressure wound therapy technologies for chronic wound care in the home setting: A systematic review

The use of negative pressure wound therapy (NPWT) is increasing in both the inpatient and outpatient settings. We conducted a systematic review on the efficacy and safety of NPWT for the treatment of chronic wounds in the home setting. We searched MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, and the Cumulative Index to Nursing and Allied Health Literature, up to June 2014. Two independent reviewers screened search results. Seven studies met our criteria for inclusion. Six of the studies compared NPWT devices to other wound care methods and one study compared two different NPWT technologies. Data were limited by variability in the types of comparator groups, methodological limitations, and poor reporting of outcomes. We were unable to draw conclusions about the efficacy or safety of NPWT for the treatment of chronic wounds in the home setting due to the insufficient evidence. Consensus is needed on the methods of conducting and reporting wound care research so that future studies are able inform decisions about the use of NPWT in the home environment for chronic wounds.

Exploring portable negative pressure wound therapy devices in the community

Case studies and clinical reviews support the use of negative pressure wound therapy (NPWT) for managing a range of wound types, yet very few scientific studies fully support its effectiveness. However, it has been argued that NPWT can provide excellent symptom management, reduce the frequency of dressing changes and provide a cost-effective alternative to traditional wound therapies due to faster healing times, leading to a reduction in overall treatment costs. Use of NPWT within community environments is increasing as length of hospital in-patient stay decreases, and many patients who would have traditionally been admitted to an acute setting with a complex or highly exuding wound are now managed by community nurses. This article presents a narrative review of NPWT, identifies safety precautions that require consideration and explores the application of smaller/disposable NPWT systems that are now available.

Pain and trauma in negative pressure wound therapy: a review

Negative pressure wound therapy (NPWT) is considered an effective wound treatment, but there are a number of issues that need to be addressed for improvements to be made. This review aimed to explore the literature relating to the pain and skin trauma that may be experienced during NPWT. A literature search was carried out using the following databases: Academic Search Complete, CINAHL, PsychINFO, MEDLINE and PsyARTICLES. A total of 30 articles were reviewed. Studies reported varying levels of pain in patients undergoing NPWT, with certain treatment factors affecting the level of pain, such as the NPWT system and the dressing/filler used. Similarly, although there is much less research exploring NPWT-related trauma, findings suggest that dressing and filler type may impact on whether trauma occurs. However, further research needs to consider the different stages of NPWT and how pain and trauma can be minimised during the whole procedure. As both pain and skin trauma impact on the patient's well-being and on wound healing, it is essential that research further explores the factors that may affect the experience of pain and trauma, so as to inform developments in wound care.

Four-stage regimen for operative treatment of diabetic foot ulcer with deformity - a results of 300 patients

BACKGROUND

An operative four-stage regimen (stage 1, debridement; stage 2, closure; stage 3, unloading; stage 4, correction) for operative treatment of diabetic foot ulcer with deformity, and first clinical results are introduced.

METHODS AND RESULTS

335 patients entered stage 1 between 01/09/2006 and 31/08/2010. Stage 1: In 189 cases (56%), one debridement resulted in sterile postoperative specimens. Stage 2: 210 cases (63%) sustained secondary closure, 97 (29%) local shifted skin graft, and 20 (6%) functional amputation. Stage 3: 304 (90%) finished stage 3, 14 (4%) presented with recurrent ulcer. Stage 4: In 185 cases (55%), correction arthrodeses were performed successfully.

FOLLOW-UP

300 (90%) completed follow-up at 26months on average (12-48months). Recurrent ulcer was registered in 46 (15%). Overall amputation rate was 14%, the majority at digital or midfoot level. Four cases (1%) required a below-knee amputation.

CONCLUSIONS

The management of diabetic foot ulcer combined with deformity with the introduced regimen showed low major amputation rate and low recurrent ulcer rate compared with the literature.

A retrospective cohort study evaluating efficacy in high-risk patients with chronic lower extremity ulcers treated with negative pressure wound therapy

The purpose of this study was to evaluate the efficacy of negative pressure wound therapy (NPWT) compared with standard of care on wound healing in high-risk patients with multiple significant comorbidities and chronic lower extremity ulcers (LEUs) across the continuum of care settings. A retrospective cohort study of 'real-world' high-risk patients was conducted using Boston University Medical Center electronic medical records, along with chart abstraction to capture detailed medical history, comorbidities, healing outcomes and ulcer characteristics. A total of 342 patients, 171 NPWT patients with LEUs were matched with 171 non-NPWT patients with respect to age and gender, were included in this cohort from 2002 to 2010. The hazard ratios (HRs) were estimated by COX proportional hazard models after adjusting for potential confounders. The NPWT patients were 2·63 times (95% CI = 1·87-3·70) more likely to achieve wound closure compared with non-NPWT patients. Moreover, incidence of wound closure in NPWT patients were increased in diabetic ulcers (HR = 3·26, 95% CI = 2·21-4·83), arterial ulcers (HR = 2·27, CI = 1·56-3·78) and venous ulcers (HR = 6·31, 95% CI = 1·49-26·6) compared with non-NPWT patients. In addition, wound healing appeared to be positively affected by the timing of NPWT application. Compared with later NPWT users (1 year or later after ulcer onset), early NPWT users (within 3 months after ulcer onset) and intermediate NPWT users (4-12 months after ulcer onset) were 3·38 and 2·18 times more likely to achieve wound healing, respectively. This study showed that despite the greater significant comorbidities, patients receiving NPWT healed faster. Early use of NPWT demonstrated better healing. The longer the interval before intervention is with NPWT, the higher the correlation is with poor outcome.

Optimal use of negative pressure wound therapy in treating pressure ulcers

Pressure ulcers (PrUs) are a challenging health concern for both the clinician and the patient. The exact incidence and prevalence of PrUs varies widely among specific clinical populations, from 0.4% to 38% in acute care, from 2.2% to 24% in long-term care and from 0% to 17% in home care. The economic impact of these wounds is impressive with an estimated cost of $11 to $17.2 billion annually in the USA. Guidelines from the National Pressure Ulcer Advisory Panel and European Pressure Ulcer Advisory Panel have provided recommendations for the prevention and treatment of PrUs. Negative pressure wound therapy with reticulated open cell foam (NPWT/ROCF; V.A.C.® Therapy, KCI USA, Inc. San Antonio, TX) has been successfully used for managing PrUs. This review combines expert opinion with scientific evidence to describe the use of NPWT/ROCF in patients with PrUs.

Targeted treatment of invasive fungal infections accelerates healing of foot wounds in patients with Type 2 diabetes

AIM

To test the hypothesis that fluconazole plus standard care is superior to the standard care for diabetic foot wounds infected with deep-seated fungal infections.

METHODS

We carried out a randomized, controlled, open-label, parallel-arm study in 75 patients with both fungal and bacterial infections in deep tissues of diabetic foot wounds. Thirty-seven patients (control group) were given standard care (surgical debridement + culture-specific antibiotics + offloading + glycaemic control) and 38 patients (treatment group) were given fluconazole 150 mg daily plus standard care. Wound surface area was measured every 2 weeks until the endpoints (complete epithelialization or skin grafting) were met.

RESULTS

By week 4, the mean wound surface area reduced to 27.3 from 111.5 cm(2) in the treatment group, as opposed to 67.1 from 87.3 cm(2) in the control group. Subsequently, the mean wound surface areas were remarkably smaller in the treatment group compared with the control group, and statistically significant differences (P ≤ 0.05) in mean wound surface area were observed between the treatment group and the control group at week 6. However, no statistically significant (P ≤ 0.47) difference in complete healing was observed between the treatment group and the control group, 20 vs. 24. The mean wound healing time for the treatment group was 7.3 weeks, whereas for the control group it was 11.3 weeks (P ≤ 0.022). Similarly, the probability of wound healing in the treatment group was 50 vs. 20% in the control group at week 10.

CONCLUSIONS

Fluconazole plus standard care was superior to standard care alone in accelerating wound reduction among patients with diabetes with deep-seated fungal infections in diabetic foot wounds. Those in the treatment group who did heal, healed more quickly (P ≤ 0.022), but overall healing was not different.

Comparative effectiveness of mechanically and electrically powered negative pressure wound therapy devices: a multicenter randomized controlled trial

This study was designed to compare the ultraportable mechanically powered Smart Negative Pressure (SNaP) Wound Care System (Spiracur, Sunnyvale, CA) with the electrically powered Vacuum-Assisted Closure (VAC) Therapy System (Kinetic Concepts, Inc. [KCI], San Antonio, TX) in a multicenter, comparative efficacy, noninferiority-powered, randomized controlled trial. We enrolled 132 people with noninfected, nonischemic, nonplantar lower extremity diabetic and venous wounds. Each subject was randomly assigned (1:1) to treatment with either system in conjunction with appropriate off-loading and compression therapy. The trial evaluated treatment for up to 16 weeks or complete wound closure (defined as complete reepithelialization without drainage). Primary end point analysis of wound size reduction found that SNaP-treated subjects demonstrated noninferiority to the VAC-treated subjects at 4, 8, 12, and 16 weeks (p = 0.0030, 0.0130, 0.0051, and 0.0044, respectively). Kaplan-Meier analysis showed no significant difference in complete wound closure between SNaP- and VAC-treated subjects at all time points. Device related adverse events and complications such as infection were also similar between treatment groups. These data support similar wound healing outcomes between the SNaP system and the VAC system in the population studied.

Comparison of negative pressure wound therapy with an ultraportable mechanically powered device vs. traditional electrically powered device for the treatment of chronic lower extremity ulcers: a multicenter randomized-controlled trial

The purpose of this study was to compare the ultraportable mechanically powered Smart Negative Pressure (SNaP(®)) Wound Care System to the traditional electrically powered Vacuum-Assisted Closure (VAC(®)) Therapy System in the treatment of chronic lower extremity wounds. This 12-center randomized-controlled trial of patients with noninfected, nonischemic, nonplantar lower extremity wounds had enrolled 65 patients, as of January 5, 2010, at the time of a planned interim analysis. Subjects were randomly assigned to treatment with either the SNaP(®) or VAC(®) Systems. The trial evaluated treatment for up to 16 weeks or till complete closure was achieved. Fifty-three patients (N=27 SNaP(®), N=26 VAC(®)) completed at least 4 weeks of therapy. Thirty-three patients (N=18 SNaP(®), N=15 VAC(®)) completed the study with either healing or 16 weeks of therapy. At the time of planned interim analysis, no significant differences (p=0.99) in the proportion of subjects healed between the two devices evaluated were found. In addition, the percent wound size reduction between treatment groups was not significantly different at 4, 8, 12, and 16 weeks, with noninferiority analysis at 4 weeks of treatment reaching the p-value <0.05 significance level (*p=0.019). These interim data suggest no difference in wound closure between the SNaP(®) System and the VAC(®) System in the population studied. We look forward to the final analysis results.

Comparative effectiveness of the SNaP™ Wound Care System

Diabetic lower extremity wounds cause substantial burden to healthcare systems, costing tens of thousands of dollars per episode. Negative pressure wound therapy (NPWT) devices have been shown to be cost-effective at treating these wounds, but the traditional devices use bulky electrical pumps that require a durable medical equipment rental-based procurement process. The Spiracur SNaP™ Wound Care System is an ultraportable NPWT system that does not use an electric pump and is fully disposable. It has superior healing compared to standard of care with modern dressings and comparable healing to traditional NPWT devices while giving patients greater mobility and giving clinicians a simpler procurement process. We used a mathematical model to analyse the costs of the SNaP™ system and compare them to standard of care and electrically powered NPWT devices. When compared to standard of care, the SNaP™ system saves over $9000 per wound treated and more than doubles the number of patients healed. The SNaP system has similar healing time to powered NPWT devices, but saves $2300 in Medicare payments or $2800 for private payers per wound treated. Our analysis shows that the SNaP™ system could save substantial treatment costs in addition to allowing patients greater freedom and mobility.

The SNaP Wound Care System: a case series using a novel ultraportable negative pressure wound therapy device for the treatment of diabetic lower extremity wounds

Although there is significant evidence supporting the use of negative pressure wound therapy (NPWT) for the treatment of lower extremity diabetic ulcers, currently available electrically powered NPWT systems are not ideally suited for treating smaller diabetic foot ulcers. The Smart Negative Pressure (SNaP) Wound Care System is a novel, ultraportable device that delivers NPWT without the use of an electrically powered pump. It was specifically designed to meet the wound care needs of patients with diabetes. The SNaP System is compact, silent, mobile, easy-to-use, and available off-the-shelf. It is fully disposable and may offer other important benefits over electrically powered systems to both the clinician and patient. We review the evidence for use of NPWT for the treatment of diabetic wounds and discuss the potential benefits of this new NPWT technology for patients with diabetes. We also present a case series of four difficult lower extremity diabetic ulcers that were successfully treated with the SNaP System. This study suggests that the SNaP System may be a useful addition to the armamentarium of the diabetic wound care clinician.

Spectrum and prevalence of fungi infecting deep tissues of lower-limb wounds in patients with type 2 diabetes

The prevalence rate and spectrum of fungi infecting deep tissues of diabetic lower-limb wounds (DLWs) have not been previously studied. Five hundred eighteen (382 male and 136 female) consecutive patients with type 2 diabetes hospitalized due to infected lower-limb wounds were enlisted in this study. Deep tissue (approximately 0.5- x 0.5-cm size) taken perioperatively from the wound bed was cultured for fungi. Fungi was found in 27.2% (141/518) of the study population. Candida parapsilosis (25.5%), Candida tropicalis (22.7%), Trichosporon asahii (12.8%), Candida albicans (10.6%), and Aspergillus species (5.0%) were the most predominant fungal isolates. Of the fungal isolates, 17.7% were resistant to itraconazole, 6.9% were resistant to amphotericin B, 6.9% were resistant to voriconazole, 3.9% were resistant to fluconazole, and 1.5% were resistant to flucytosine. Of the population, 79.7% (413/518) had bacterial infection in deep tissue. The predominant isolates were Enterococcus faecalis (14.1%), Staphylococcus aureus (12.2%), and Pseudomonas aeruginosa (10.8%). Mixed fungal and bacterial infections were seen in 21.4% of patients, while 5.8% had only fungal infection and 58.3% had only bacterial infections. Another 14.5% had neither bacteria nor fungi in the deep tissue. Patients with higher glycosylated hemoglobin levels had significantly more fungal infections. Our study reveals that deep-seated fungal infections are high in DLWs. In the context of delayed wound healing and amputation rates due to DLWs, it is important to study the pathogenicity of fungi in deep tissues of DLWs and their possible contribution to delayed wound healing. The role of antifungal agents in wound management needs to be evaluated further.

Wound chemotherapy by the use of negative pressure wound therapy and infusion

INTRODUCTION

Although the use of negative pressure wound therapy (NPWT) is broadly efficacious, it may foster some potentially adverse complications. This is particularly true in patients with diabetes who have a wound colonized with aerobic organisms. Traditional antiseptics have been proven useful to combat such bacteria but require removal of some NPWT devices to be effective.

METHODS

In this article, we describe a method of "wound chemotherapy" by combining NPWT and a continuous infusion of Dakins' 0.5% solution either as a standardized technique in one device (ITI Sved) or as a modification of standard technique in another (KCI VAC) NPWT device. The twin goals of both techniques are to effectively reduce bacterial burden and to promote progressive wound healing.

RESULTS

We present several representative case examples of our provisional experience with continuous streaming therapy through 2 foam-based negative pressure devices.

DISCUSSION

Wound chemotherapy was successfully applied to patients with diabetes, without adverse reactions, complications, or recolonization during the course of treatment. We believe this to be a promising method to derive the benefits of NPWT without the frequent adverse sequela of wound colonization.

Human skin wounds: a major and snowballing threat to public health and the economy

ABSTRACT In the United States, chronic wounds affect 6.5 million patients. An estimated excess of US$25 billion is spent annually on treatment of chronic wounds and the burden is rapidly growing due to increasing health care costs, an aging population and a sharp rise in the incidence of diabetes and obesity worldwide. The annual wound care products market is projected to reach $15.3 billion by 2010. Chronic wounds are rarely seen in individuals who are otherwise healthy. In fact, chronic wound patients frequently suffer from "highly branded" diseases such as diabetes and obesity. This seems to have overshadowed the significance of wounds per se as a major health problem. For example, NIH's Research Portfolio Online Reporting Tool (RePORT; http://report.nih.gov/), directed at providing access to estimates of funding for various disease conditions does list several rare diseases but does not list wounds. Forty million inpatient surgical procedures were performed in the United States in 2000, followed closely by 31.5 million outpatient surgeries. The need for post-surgical wound care is sharply on the rise. Emergency wound care in an acute setting has major significance not only in a war setting but also in homeland preparedness against natural disasters as well as against terrorism attacks. An additional burden of wound healing is the problem of skin scarring, a $12 billion annual market. The immense economic and social impact of wounds in our society calls for allocation of a higher level of attention and resources to understand biological mechanisms underlying cutaneous wound complications.

'Indirect VAC': a novel technique of applying vacuum-assisted closure dressing

Vacuum-assisted closure (VAC) wound dressing is increasingly used to assist closure in various wounds ranging from simple finger pulp defect to complex wounds such as laparostomy or infected sternotomy. The traditional application of direct vacuum therapy can cause discomfort and put the patient at risk of injuring the affected area while mobilising. We describe a novel technique of applying VAC therapy indirectly which is much more comfortable and convenient for the patient while mobilising.