Using Case-Based Reasoning in a Learning System: A Prototype of a Pedagogical Nurse Tool for Evidence-Based Diabetic Foot Ulcer Care

Background:Currently, evidence-based learning systems to increase knowledge and evidence level of wound care are unavailable to wound care nurses in Denmark, which means that they need to learn about diabetic foot ulcers from experience and peer-to-peer training, or by asking experienced colleagues. Interactive evidence-based learning systems built on case-based reasoning (CBR) have the potential to increase wound care nurses’ diabetic foot ulcer knowledge and evidence levels.Method:A prototype of a CBR-interactive, evidence-based algorithm-operated learning system calculates a dissimilarity score (DS) that gives a quantitative measure of similarity between a new case and cases stored in a case base in relation to six variables: necrosis, wound size, granulation, fibrin, dry skin, and age. Based on the DS, cases are selected by matching the six variables with the best predictive power and by weighing the impact of each variable according to its contribution to the prediction. The cases are ranked, and the six cases with the lowest DS are visualized in the system.Results:Conventional education, that is, evidence-based learning material such as books and lectures, may be less motivating and pedagogical than peer-to-peer training, which is, however, often less evidence-based. The CBR interactive learning systems presented in this study may bridge the two approaches. Showing wound care nurses how individual variables affect outcomes may help them achieve greater insights into pathophysiological processes.Conclusion:A prototype of a CBR-interactive, evidence-based learning system that is centered on diabetic foot ulcers and related treatments bridges the gap between traditional evidence-based learning and more motivating and interactive learning approaches.     

The role of Sudoscan feet asymmetry in the diabetic foot

The aim of this study was to investigate the role of Sudoscan asymmetry parameters in the diabetic foot.Patients and methodsIn this study we included 165 participants: 84 type 2 diabetes patients divided into three HbA1c matched groups – group 1: newly diagnosed diabetics (n = 31), group 2: people with longer diabetes duration and established neuropathy (n = 33), group 3: patients with diabetic foot ulcer (n = 20), and a control group of 81 people with prediabetes. All subjects underwent peripheral sudomotor evaluation using Sudoscan device (Impeto Medical, Paris).ResultsPatients with diabetic foot had significantly higher Sudoscan feet asymmetry (19.6%) compared to those with only diabetic neuropathy (7.9%), compared to the group with newly diagnosed diabetes (7.44%), and compared to controls (2.5%). This test has shown a good discriminative value (with a threshold of 9.5%) for diabetic foot with area under the ROC curve of 0.955 (p = 0.001). Additionally, in a regression model feet asymmetry proved its predictive value for participants with diabetic foot.ConclusionIn this study Sudoscan feet asymmetry proved to be a novel discriminator and predictor for diabetic foot patients. It might be considered as a marker for early damage in the neuropathy evaluation protocol.     

The effects of ulcer size and site, patient's age, sex and type and duration of diabetes on the outcome of diabetic foot ulcers.

AIMS: The outcome of foot ulcers is affected by wound depth, infection, ischaemia and glycaemic control. The aim of this study was to determine the effects of ulcer size, site, patient's age, sex and type and duration of diabetes on the outcome of diabetic foot ulcers. METHODS: Diabetic patients with new foot ulcers presenting during a 12-month period had demographics and ulcer characteristics recorded at presentation. Ulcers were followed-up until an outcome was noted. RESULTS: One hundred and ninety-four patients (77% males) with a mean (+/- SD) age and duration of diabetes of 56.6 +/- 12.6 and 15.4 +/- 9.9 years, respectively, were included in the study. The majority of ulcers were neuropathic (67.0%) and present on the forefoot (77.8%) with a median (interquartile range) area of 1.5 (0.6-4.0) cm2. Amputations were performed for 15% of ulcers; 65% healed; 16% remained unhealed and 4% of patients died. The median (95% confidence interval) time to healing was 10 (8.8-11.6) weeks. Ulcer area at presentation was greater in the amputation group compared to healed ulcers (3.9 vs. 1.2 cm2, P < 0.0001). Ulcer area correlated with healing time (rs = 0.27, P < 0.0001) and predicted healing (P = 0.04). Patient's age, sex, duration/type of diabetes, and ulcer site had no effect on outcome. CONCLUSIONS: Ulcer area, a measure of ulcer size, predicts the outcome of foot ulcers. Its inclusion into a diabetic wound classification system will make that system a better predictor of outcome.     

Comparison of negative pressure wound therapy and moist wound care in patients with diabetic foot ulcers: A protocol for systematic review and meta-analysis of randomized controlled trials

Background:This study conducted a meta-analysis to compare the effectiveness and safety of the negative pressure wound therapy (NPWT) with the moist wound care (MWC) in the treatment of diabetic foot ulcers (DFUs).Methods:The PubMed, EMBASE, and CENTRAL were searched by 2 of the authors, to identify randomized controlled trials comparing the clinical outcomes of patients treated with NPWT versus MWC for DFUs. Meta-analyses were performed for several outcomes, including wound healing results, amputation or resection incidence, and risk of adverse events, utilizing the “meta” package of R language version 4.0.3.Results:A total of 10 trials (619 patients in NPWT group and 625 in MWC group) and 8 trials were included for the qualitative and quantitative syntheses, respectively. As a result, significantly lower risk of non-closure of the wound (risk ratio [RR] = 0.74, 95% confidence interval [CI]: 0.63–0.87; P = .001), lower average wound area (standard mean difference = −0.80, 95% CI: −1.54 to −0.06; P = .034), more wound area decrease (standard mean difference = 0.81, 95% CI: 0.36–1.26; P = .001), increased appearance rate of granulation tissue (RR = 1.61, 95% CI: 1.07–2.41; P-0.021), and lower risk of amputation or resection (RR = 0.70, 95% CI: 0.50–0.99; P = .045), were demonstrated for the NPWT group when compared to MWC group. However, no statistically significant difference was found for the disappearance rate of wound discharge at 8 weeks, the rate of blood culture positivity, VAS-pain score, and the overall frequency of adverse events between the 2 treatment groups (P = .05).Conclusion:NPWT could accelerate process of the wound healing, and decrease the risk of post-treatment amputation or resection, without any additional frequency of adverse events, when compared with MWC, in patients with DFUs.     

Reliability of a Three-Dimensional Wound Camera and Correlation With Routine Ruler Measurement in Diabetes-Related Foot Ulceration

Background:In an era of increasing technology and telehealth utilization, three-dimensional (3D) wound cameras promise reliable, rapid, and touch-free ulceration measurements. However, reliability data for commercially available devices in the diabetes foot service setting is lacking. We aimed to evaluate the reliability of diabetes-related foot ulceration measurement using a 3D wound camera in comparison to the routinely used ruler and probe.Method:Participants were prospectively recruited from a tertiary interdisciplinary diabetes foot service. Ulcerations were measured at each visit by two blinded observers, first by ruler and probe, and then using a 3D wound camera twice. Reliability was evaluated using intraclass correlation coefficients (ICC). Measurement methods were compared by Pearson correlation.Results:Sixty-three ulcerations affecting 38 participants were measured over 122 visits. Interobserver reliability of ruler measurement was excellent for estimated area (ICC 0.98, 95% CI 0.97-0.98) and depth (ICC 0.93, 95% CI 0.90-0.95). Intraobserver and interobserver reliability of the 3D wound camera area was excellent (ICC 0.96, 95%CI 0.95-0.97 and 0.97 95% CI 0.96-0.98, respectively). Depth was unrecordable in over half of 3D wound camera measurements, and reliability was inferior to probe measurement. Area correlation between methods was good (R = 0.88 and 0.94 per observer); however, depth correlation was poor (R = 0.49 and 0.65).Conclusions:3D wound cameras offer practical advantages over ruler-based measurement. In diabetes-related foot ulceration, the reliability and comparability of area measurement was excellent across both methods, although depth was more reliably obtained by the probe. These limitations, together with cost, are important considerations if implementing this technology in diabetes foot care.     

两种伤口负压治疗模式对糖尿病足溃疡治疗作用的比较

目的比较两种伤口负压治疗模式对糖尿病足溃疡的治疗作用。方法选取2018年4至8月广西壮族自治区人民医院内分泌科收治的糖尿病足溃疡患者,经全身综合治疗和创面评估、清创后,对创面床适合伤口负压治疗的16例患者(男10例,女6例)按入组时间顺序进行随机分组,采用开放、平行、交叉方法,分为先负压辅助闭合(VAC)组(8例)和先负压封闭引流(VSD)组(8例),先VAC组第一周采用VAC治疗,第二周接受VSD治疗;先VSD组第一周采用VSD治疗,第二周接受VAC治疗。分别于治疗前、治疗1周末及治疗2周末对所有患者足部溃疡创面拍照,采用Image J软件分析溃疡面积及肉芽组织面积变化,同时采用丹麦雷度经皮氧分压测定仪测定2个部位的组织氧分压。运用两阶段交叉设计的方差分析方法,对治疗期间第1周和第2周两种治疗模式的溃疡面积及肉芽组织面积变化、经皮氧分压变化进行比较。结果(1)16例糖尿病足溃疡患者与治疗前比较,治疗后溃疡面积缩小[4.61(3.11)比9.51(6.55)cm^2,Z=3.517]、肉芽面积增加[4.08(2.49)比0.90(1.12)cm^2,Z=-3.516],2个部位的经皮氧分压值均升高[(54.19±6.91)比(32.16±10.16)mmHg(1 mmHg=0.133 kPa)、(56.75±12.95)比(30.56±11.93)mmHg,t=-11.814、-14.028],差异均有统计学意义(均P<0.05)。(2)VSD和VAC两种不同负压治疗模式对患者的溃疡面积、肉芽组织面积及2个部位的经皮氧分压变化有统计学意义(F=5.763~22.090,均P<0.05),且VAC治疗后的经皮氧分压增大值、溃疡面积缩小值及肉芽组织面积增加值要大于VSD治疗后(P<0.05)。(3)无论采用哪种负压治疗模式,治疗第1周后的2个部位的经皮氧分压增大值均大于治疗第2周后,差异有统计学意义(F=13.254、11.205,均P<0.05)。结论VAC在缩小糖尿病足溃疡面积,增加创面肉芽组织面积及提高溃疡周围组织氧分压方面要优于VSD,VAC治疗模式在治疗糖尿病足溃疡上更具有优势。     

Incidence and characteristics of diabetic foot ulcers in subjects with type 2 diabetes in Catalonian primary care centres: An observational multicentre study

AimsThe main objective was to assess the incidence of diabetic foot ulcers in type 2 diabetes individuals from primary care centres in Catalonia, Spain.MethodsProspective observational study in 36 Primary Care centres in Catalonia during February 2018 and July 2019 was conducted. We included participants with type 2 diabetes and a new foot ulcer. We estimated the annual foot ulcer incidence and described the characteristics: presence of comorbidities, clinical parameters and the characteristics of the diabetic foot ulcers (DFU) at inclusion in the study.ResultsThe incidence of a new DFU during the 12-month recruitment period was 0.42%. The mean age of the participants was 72.2 years (± 12.7), the majority of them were males (n = 178; 69.5%). Overall, 43.8% of DFUs were located on the dorsal aspect of toes or interdigital spaces. A percentage of 43.4% of the participants had ulcers of less than 1 cm2 surface. Further, 44.1% of the participants had a neuroischemic, 20.3% a neuropathic, 20.3% an ischemic ulcer. A 25.3% of ulcers with a concomitant peripheral artery disease were infected.ConclusionsAlthough the incidence found was low, our study shows the great complexity of patients with foot ulcers treated in primary care.     

The effects of applied felted foam on wound healing and healing times in the therapy of neuropathic diabetic foot ulcers.

AIMS: The application of felted foam is a promising method for plantar pressure reduction in the ulcer region of diabetic foot ulcers, but knowledge of its effects on wound healing is sparse. The objective of this study was to evaluate the effects of felted foam on wound healing in diabetic foot ulcers compared with a standard method of plantar pressure relief. MATERIALS AND METHODS: A total of 54 Type 1 or Type 2 diabetic patients with neuropathic diabetic foot ulcers were evaluated in this prospective randomized controlled study. Ulcer healing was assessed by planimetric measurement of the wound area at beginning of the study and after 10 weeks and at least until wound healing. The patients were consecutively enrolled in the study; 24 patients were randomized to the felted foam therapy, and 30 patients were randomized to conventional therapy. RESULTS: In the felted foam group, the initial average wound area was 102.3 +/- 45.3 mm2 (mean +/- sd), and 5.4 +/- 3.1 mm2 after 10 weeks with an average healing time of 75 days [95% confidence interval (CI) 67-84]. In the conventional therapy group, the initial average wound area was 112.5 +/- 50.8 mm2, and 10.6 +/- 4.2 mm2 after 10 weeks with an average healing time of 85 days (95% CI 79-92) (P = 0.03). The mean wound radius decreased by 0.48 mm (95% CI 0.42-0.56) per week in the felted foam group and by 0.39 mm (95% CI 0.35-0.42) per week in the conventional group (P = 0.005). CONCLUSIONS: The felted foam technique appears to be at least as effective as conventional plantar ulcer treatment. It may be a useful alternative in treating neuropathic foot ulceration, especially in patients who are not able to avoid weight-bearing reliably.     

Determinants and estimation of healing times in diabetic foot ulcers

AIMS: To assess the wound size reduction and time course for healing and to establish equations to predict the time course of wound healing in neuropathic, neuroischemic, and ischemic diabetic foot ulcers. METHODS: This prospective study evaluates wound healing over at least a 10-week period in 31 Type 1 or Type 2 diabetic patients with plantar foot ulcers. Thirteen consecutive diabetic patients with neuropathic foot ulceration, 10 consecutive diabetic patients with neuroischemic ulceration, and 8 diabetic patients with peripheral occlusive vascular disease were selected for the study. All patients received identical ulcer wound care including use of proper footwear, non-weight-bearing limb support, use of appropriate antibiotics, debridement, tight control of serum glucose levels, and careful monitoring of the ulcer. Ulcer healing was assessed by planimetric measurement of the wound area every second week until wound healing. The time course of wound healing was calculated by the daily wound radius reduction. RESULTS: The wound area (mean+/-S.E.) in the patients with neuropathic foot ulceration was 61.2+/-17.1 at the beginning and 3.2+/-1.5 mm(2) after 70 days (P=.005). The wound radius decreased by 0.045 mm (95% confidence interval [CI] 0.039-0.055) per day, with most of the wound healing being achieved between the first and seventh week of ulcer care. The average healing time was 77.7 (95% CI 62-93) days. In the neuroischemic group, the initial average wound area was 26.6+/-7.0 mm(2), and 6.25+/-1.7 mm(2) after 10 weeks (P=.007). The wound radius reduction was 0.019 mm/day (95% CI 0.017-0.023) with an average healing time of 123.4 (95% CI 101-145) days. The diabetic patients with peripheral occlusive vascular disease had an average wound size of 32.6+/-13.1 at the beginning and 23.9+/-10.7 mm(2) after 70 days of ulcer care (P=.06). The daily wound radius reduction was 0.0065 mm (95% CI 0.0039-0.0091). Average ulcer duration was 133 (95% CI 116-149) days, but three of eight patients achieved no wound healing. CONCLUSIONS: Providing standard care, the time course of wound healing in diabetic foot ulcers is predominantly determined by etiologic factors, and less by wound size. Taking wound etiology and wound radius into account, the expected healing time can reliably be estimated in neuropathic and neuroischemic ulcers.     

An Automatic Assessment System of Diabetic Foot Ulcers Based on Wound Area Determination,Color Segmentation,and Healing Score Evaluation

Background:

For individuals with type 2 diabetes, foot ulcers represent a significant health issue. The aim of this study is to design and evaluate a wound assessment system to help wound clinics assess patients with foot ulcers in a way that complements their current visual examination and manual measurements of their foot ulcers.

Methods:

The physical components of the system consist of an image capture box, a smartphone for wound image capture and a laptop for analyzing the wound image. The wound image assessment algorithms calculate the overall wound area, color segmented wound areas, and a healing score, to provide a quantitative assessment of the wound healing status both for a single wound image and comparisons of subsequent images to an initial wound image.

Results:

The system was evaluated by assessing foot ulcers for 12 patients in the Wound Clinic at University of Massachusetts Medical School. As performance measures, the Matthews correlation coefficient (MCC) value for the wound area determination algorithm tested on 32 foot ulcer images was .68. The clinical validity of our healing score algorithm relative to the experienced clinicians was measured by Krippendorff’s alpha coefficient (KAC) and ranged from .42 to .81.

Conclusion:

Our system provides a promising real-time method for wound assessment based on image analysis. Clinical comparisons indicate that the optimized mean-shift-based algorithm is well suited for wound area determination. Clinical evaluation of our healing score algorithm shows its potential to provide clinicians with a quantitative method for evaluating wound healing status.     

The effects of ulcer size on the wound radius reductions and healing times in neuropathic diabetic foot ulcers.

The main problems in the treatment of diabetic foot ulcers are prolonged wound healing and not necessary amputations, which may sometimes be caused by the impression that the results of conservative treatment are somewhat unpredictable. The aim of this study was to determine the effects of ulcer size on the wound radius reduction and healing times using a previously established equation for wound healing in neuropathic diabetic foot ulcers. This prospective study evaluates wound healing in 120 diabetic patients with neuropathic foot ulcers who were grouped according to four different ulcer areas (A 100 150 200 mm (2)). Ulcer healing was assessed by planimetric measurement of the wound area every second week until wound healing. The time course of wound healing in the different groups was compared by the weekly wound radius reduction using the equation R = sqrt A/pi. The average healing time in group A was 70 (95 %-CI 64 - 77) days with a wound radius reduction of 0.42 mm/week (95 %-CI 0.28 - 0.56). In group B the average healing time was 79 (95 %-CI 75 - 82) days and the weekly wound radius reduction was 0.47 mm (95 %-CI 0.45 - 0.49). The average healing time in group C was 85 (95 %-CI 80 - 89) days with a wound radius reduction of 0.53 mm/week (95 %-CI 0.42 - 0.56). In group D the average healing time was 97 (95 %-CI 91 - 103) days. The weekly wound radius reduction was 0.57 mm (95 %-CI 0.49 - 0.81). Wound radius reductions and the time needed for healing are affected by the ulcer area, a measure of ulcer size, in neuropathic diabetic foot ulcers. The calculation of the weekly wound radius reduction for different ulcer areas may be a useful tool in daily clinical practice to identify ulcers who do not respond adequately to the treatment.     

A Chinese 2-herb formula (NF3) promotes hindlimb ischemia-induced neovascularization and wound healing of diabetic rats

Diabetic foot ulcer is closely associated with peripheral vascular disease. Enhancement of tissue oxidative stress, reduction of nitric oxide (NO) and angiogenic growth factors, and abnormal matrix metalloproteinase (MMP) activity are pathophysiological factors in post-ischemic neovascularization and diabetic wound healing. Our previous study demonstrated that the Chinese 2-herb formula, NF3, showed significant wound healing effects on diabetic foot ulcer rats. A novel rat diabetic foot ulcer with hindlimb ischemia model was established in order to strengthen our claims on the diabetic wound healing and post-ischemic neovascularization effects of NF3. Our results demonstrate that NF3 can significantly reduce the wound area of the diabetic foot ulcer rat with hindlimb ischemia by 21.6% (p < 0.05) compared with the control group. In addition, flow cytometric analysis revealed that NF3 could boost circulating EPC levels for local wound vessel incorporation. Immunohistochemical analysis showed that NF3 could significantly augment blood vessel density, VEGF and eNOS expression, and attenuate tissue oxidative stress of ischemic muscles (p < 0.001). NF3 significantly stimulated MMP activity involved in angiogenesis. Our study shows, for the first time, the beneficial effects of NF3 in wound healing and post-ischemic neovascularization in diabetes.     

Diabetic foot ulcers—comparison of performance of ankle-brachial index and transcutaneous partial oxygen pressure in predicting outcome

Diabetic foot ulcer (DFU) is the commonest condition for hospital admission and usually the starting point of most diabetic related lower limb amputations. Considering the significant role played by vascularity in the outcome of ulcer healing, we undertook this study to find out the comparative utility of commonly used vascular assessment methods. This study was a single center prospective non-randomized observational study, conducted for a period of 6 months, in diabetic patients presenting with foot ulcers of Wagner Grade II and III. The aim of our study was to compare the performances of ankle-brachial index (ABI) and transcutaneous partial pressure of oxygen (tcPO₂) measurement in predicting wound healing in diabetic ulcers and to define the optimal cut-off value for Indian patients. Five hundred sixty-four patients were included in this study, with the mean age of 58 years. Eighty-seven patients (15%) had peripheral arterial occlusive disease. Four hundred seventy ulcers (83%) healed with the mean healing days of 42.6 days. Age, duration of diabetes, serum creatinine level, and presence of infection were the factors with negative impact in wound healing. In our study, ABI value of 0.6 was found to have 100% sensitivity and 70% specificity, and tcPO₂ value of 22.5 was found to have 75% sensitivity and 100% specificity in predicting wound healing. Both ABI and tcPO₂ are complementary, but tcPO₂ is a better predictor for amputation while ABI is a better predictor for ulcer healing. While assessing the ischemic status of foot ulcer, the cut-off values should be higher in diabetics than non-diabetics.     

An integrative review of therapeutic footwear for neuropathic foot due to diabetes mellitus

BackgroundTherapeutic footwear is built on a model of patient's foot, for people with diabetes suffering with neuropathy. Can the footwear helps to improve plantar pressure in neuropathic foot? This study focussed on available data on therapeutic footwear as an intervention for improving and offloading plantar pressure in neuropathic diabetic foot.MethodsRelevant scientific literature in PubMed, Medline and Google Scholar published between 2000 and 2017 were searched. The keywords searched were therapeutic footwear, plantar pressure, neuropathic foot, rocker sole, ulcer healing and offloading of plantar pressure. Articles on randomized controlled trials, observational, cohort, feasibility and factorial studies were reviewed.ResultsOne hundred and twenty five (125) articles were identified. The article comprised of 6 randomized controlled trials, 2 observational, 1 cohort, 1 feasibility and 1 factorial study met the inclusion criteria and were critiqued with a total enrolment of 1380 study subjects.ConclusionsThe review of the collated literature demonstrated that, therapeutic footwear can improve the healing of neuropathic diabetic foot ulcer by redistributing plantar pressure. However, the efficacy of therapeutic footwear requires the inclusion of technical features that should not be compromised from the design to the production of the footwear.     

羧甲基壳聚糖生物胶液负压滴灌治疗糖尿病足溃疡的疗效

目的:探讨羧甲基壳聚糖生物胶液负压滴灌治疗糖尿病足溃疡的临床疗效。方法:为前瞻性研究。收集2019年2月至2020年3月北京中医药大学东直门医院的60例糖尿病足患者,采用随机数字表法将患者分为试验组和对照组,各30例。对照组在基础治疗的同时采用生理盐水滴灌负压治疗,试验组采用羧甲基壳聚糖生物胶液进行滴灌负压治疗。治疗1...     

Nomogram for prediction of diabetic retinopathy in patients with type 2 diabetes mellitus: A retrospective study

ObjectiveTo develop a nomogram for the risk of diabetic retinopathy (DR) among type 2 diabetes mellitus (T2DM).MethodsQuestionnaires, physical examinations and biochemical tests were performed on 5900 T2DM patients in the Second Hospital of Shijiazhuang. The least absolute shrinkage and selection operator regression was used to optimize feature selection, and the importance of selected features was analyzed by random forest. Logistic regression was performed with selected features, and the nomogram was established based on the results. The Harrell's C-statistic, bootstrap-corrected C-statistic, area under curve (AUC), calibration curve, decision curve analysis (DCA) and clinical impact curve (CIC) were used to validate the discrimination, calibration and clinical usefulness of the nomogram, and further assessment was running by external validation.ResultsPredictors included duration of diabetes, diabetic neuropathy, diabetic kidney disease, diabetic foot, hyperlipidemia, hypoglycemic drugs, glycated albumin, Lactate dehydrogenase. The model displayed medium predictive power with a Harrell's C-statistic of 0.820, bootstrap-corrected C-statistic of 0.813 and AUC of 0.820 in the training set, and which was respectively 0.842, 0.835 and 0.842 in the validation set. The calibration curve displayed good agreement (P > 0.05). The DCA and CIC showed that the nomogram could be applied clinically if the risk threshold is between 2 % and 75 % and 2 %–88 % in validation set.ConclusionsThis nomogram incorporating 8 features is useful to predict the risk of DR in T2DM patients.     

Matrix metalloproteinases and diabetic foot ulcers: the ratio of MMP-1 to TIMP-1 is a predictor of wound healing

Aims Matrix metalloproteinases (MMPs) play a major role in wound healing: they can degrade all components of the extracellular matrix. In diabetic foot ulcers there is an excess of MMPs and a decrease of the tissue inhibitors of MMPs (TIMPs). This imbalance is probably one cause of impaired healing. However, little is known about changes in MMPs during wound healing. Methods Sixteen patients with neuropathic diabetic foot ulcers participated. Wound fluid was collected regularly during the 12-week follow-up period, for measurement of MMP-1, MMP-2, MMP-8, MMP-9 and TIMP-1. Results were analysed by the degree of wound healing: good healers (defined by a reduction of at least 82% in initial wound surface at 4 weeks) and poor healers (reduction of less than 82% in wound surface at 4 weeks). Results In good healers, levels of MMP-8 and -9 secreted by inflammatory cells decreased earlier. The initial levels of MMP-1 were similar in good and poor healers (P = 0.1) but rose significantly at week 2 in good healers (P = 0.039). There was a significant correlation between a high ratio of MMP-1/TIMP-1 and good healing (r = 0.65, P = 0.008). Receiver Operator Curve (ROC) analysis showed that an MMP-1/TIMP-1 ratio of 0.39 best predicted wound healing (sensitivity = 71%, specificity = 87.5%). Conclusions A high level of MMP-1 seems essential to wound healing, while an excess of MMP-8 and -9 is deleterious, and could be a target for new topical treatments. The MMP-1/TIMP-1 ratio is a predictor of wound healing in diabetic foot ulcers.     

Risk factors associated with healing chronic diabetic foot ulcers: the importance of hyperglycemia

Diabetic foot ulcer management presents a significant challenge for wound care clinicians; numerous approaches to encourage healing in these difficult wounds have been explored. To determine risk factors related to diabetic foot ulcer time to healing and closure, a secondary analysis of data from a prospective randomized study involving 245 patients treated with a bioengineered human dermal substitute (n = 130) or control treatment (n = 115) was conducted. Analyzed variables included age, race, gender, ulcer duration, initial ulcer size, initial hemoglobin (HgbA1c), average HgbA1c, change in HgbA1c, diabetes type, average hours of weight-bearing, study ulcer infection, history of smoking or alcohol use, and laboratory values. Time to healing was significantly affected by initial ulcer size (risk ratio 0.75, confidence interval 0.59-0.96), gender (risk ratio 2.01, confidence interval 1.20-3.40), and wound infection during the study (risk ratio 2.9, confidence interval 1.45-4.22). Initial ulcer size (>2 cm2), male gender, and an episode of infection during the study were associated with an increased risk of nonclosure after 12 weeks of care (P <0.05). In patients whose HgbA1C increased during the study (n = 101), 20.7% of all wounds and 21% of dermal substitute-managed wounds (n = 105) healed; whereas, in patients whose HgbA1C levels remained stable or decreased, 26.3% of all wounds and 47% of dermal substitute-managed wounds healed (P <0.05). Female gender, small ulcer size, and the absence of infection were found to have a positive effect on healing all diabetic foot ulcers; improved glucose control had a significant effect on healing wounds managed with the dermal substitute only. This is the first diabetic foot ulcer study to find a relationship between hyperglycemia and wound healing. Further research into factors that improve healing of wounds, including diabetic foot ulcers, is warranted.     

糖尿病足Wagner分级方法和TEXAS大学分类法临床应用价值比较

目的评价两种糖尿病足分类方法：Wagner分级方法和TEXAS大学分类法对糖尿病足溃疡预后的影响。方法入选1999年3月至2009年9月新诊断的糖尿病足患者242例,其中男145例,女97例,年龄19～78岁,糖尿病病程0．5～27．0年,足部溃疡病程3d～2周。记录患者溃疡面积、有无感染、缺血、神经病变等,分别应用Wagner分级法和TEXAS大学分类法分类,采用回顾性队列研究设计,随访6个月,痊愈、截肢及死亡为终点事件。应用趋势卡方、生存分析Kaplan—Meier法及log—rank检验等统计方法,比较两种分类法对溃疡痊愈和截肢（趾）风险的预测价值。结果242例糖尿病足患者中,神经性溃疡133例（54．9％）,神经缺血性溃疡83例（34．3％）,缺血性溃疡5例（2．1％）,非神经非缺血性溃疡21例（8．7％）。在观察期内,痊愈147例（60．7％）,截肢（趾）50例（20．7％）,至6个月时溃疡仍未愈者34例（14％）,死亡3例（5．4％）。随着Wagner分级、TEXAS大学分期和分级的升高,截肢（趾）率升高（X^2=79．6420、32．8046、39．2448,均P〈0．01）。单纯感染性溃疡截肢（趾）的风险是无感染无缺血性溃疡的29倍（RR=29．237,95％CI：3．845～222．341,P〈0．01）,合并感染和缺血的溃疡则较无感染无缺血性溃疡的截肢（趾）风险增加48倍（RR=48．300,95％CI：6．209～375．703,P〈0．01）。单纯缺血性溃疡与无感染无缺血性溃疡相比,其截肢（趾）风险增加8倍,但差异无统计学意义（RR=8．364,95％CI：0．899～77．798,P〉0．05）。经log—rank检验,随TEXAS大学分类法的分期升高,溃疡愈合时间延长（X^2=11．234,df=3,P〈0．05）,而分级变化对溃疡愈合时间的影响无统计学意义（X^2=5．452,Jf=2,P〉0．05）;Wagner不同分级对溃疡愈合时间的影响亦无统计学意义（X^2=4．761,df=2,P〉0．05）。结论与Wagner分级法相比,TEXAS大学分类法与糖尿病足溃疡的截肢（趾）率及溃疡愈合时间均有较强的相关性,有更强的预测价值。     

Efficacy of shock wave therapy on chronic diabetic foot ulcer: A single-blinded randomized controlled clinical trial

ObjectiveThis study was conducted to evaluate the efficacy of extracorporeal shock wave therapy (ESWT) on the healing rate, wound surface area and wound bed preparation in chronic diabetic foot ulcers (DFU).MethodsThirty eight patients with 45 chronic DFU were randomly assigned into; the ESWT-group (19 patients/24 ulcers) and the control-group (19 patients/21 ulcers). Blinded therapist measured wound surface area (WSA), the percentage of reduction in the WSA, rate of healing and wound bed preparation at baseline, after the end of the interventions (W8), and at 20-week follow-up (W20). The ESWT group received shock wave therapy twice per week for a total of eight treatments. Each ulcer was received ESWT at a frequency of 100 pulse/cm², and energy flux density of 0.11 mJ/cm². All patients received standardized wound care consisting of debridement, blood-glucose control agents, and footwear modification for pressure reduction.ResultsThe overall clinical results showed completely healed ulcers in 33.3% and 54% in ESWT-groups and 14.28% and 28.5% in the control group after intervention (W8), and at follow-up (W20) respectively. The average healing time was significantly lower (64.5 ± 8.06 days vs 81.17 ± 4.35 days, p < 0.05) in the ESWT-group compared with the control group.ConclusionESWT-treated ulcers had a significant reduction in wound size and median time required for ulcer healing, with no adverse reactions. So, the ESWT is advocated as an adjunctive therapy in chronic diabetic wound.