Optimal treatment of infected diabetic foot ulcers

Developing a Practical Tool for Predicting Wound Healing Outcomes of Patients with Diabetic Forefoot Ulcers: Focus on Vasculopathy and Infection

OBJECTIVE

To develop a preliminary risk scoring system to predict the prognosis of patients with diabetic forefoot ulcers based on the severity of vasculopathy and infection, which are the major risk factors for amputation.

METHODS

Forefoot was defined as the distal part of the foot composed of the metatarsal bones and phalanges and associated soft tissue structures. The degree of vasculopathy was graded as V0, V1, or V2 according to transcutaneous partial oxygen tension values and toe pressure. The degree of infection was graded as I0, I1, or I2 according to tissue and bone biopsy culture results. The risk scores were calculated by adding the scores for the degree of vasculopathy and infection and ranged from 0 to 4. Wound healing outcomes were graded as healed without amputation, minor amputation, or major amputation. The authors evaluated wound healing outcomes according to risk scores.

RESULTS

As the risk score increased, the proportion of patients who underwent both major and minor amputations increased (P < .001). In the multivariate logistic analysis, the odds ratios of amputation also increased as the risk score increased. Patients with a risk score of 4 were 75- and 19-fold more likely to undergo major and minor amputations, respectively, than patients with a risk score of 0 (P = .006 and P < .001).

CONCLUSIONS

The risk score can be used as an indicator to predict the probability of amputation in patients with diabetic forefoot ulcers.

Skin hydration level cutoff value to predict wound healing potential in diabetic foot ulcers

AIMS

Transcutaneous oxygen pressure (TcPO₂) is a reliable predictor of wound healing in diabetes patients; however, measurements are cumbersome. Previously, we demonstrated that skin hydration in the feet of patients with diabetic foot ulcers (DFU) is influenced by microcirculation rather than peripheral nerve function. Furthermore, skin hydration level before recanalization can predict wound healing better than TcPO₂. This study investigated the skin hydration level cutoff value to predict DFU healing.

METHODS

We retrospectively enrolled 834 patients with DFU. Wound healing outcomes were graded as healed without amputation or with minor/major amputation. Receiver operating characteristic analysis was used to evaluate the ability of skin hydration to predict wound healing outcomes and determine the optimal cutoff value for subsequent analyses.

RESULTS

Average skin hydration values in the healed without and with amputation groups were 25.0 ± 7.4 arbitrary units (a.u.) and 17.5 ± 5.7 a.u., respectively (P < 0.001). The healing rate without amputation increased with skin hydration. A skin hydration value ≥ 21 a.u. significantly lowered the incidence of amputation. The cutoff value was 21 a.u. [(Youden's index, sensitivity, specificity, P-value) = (1.6, 92, 69.6, P < 0.001)].

CONCLUSIONS

A minimal skin hydration value of 21 a.u. is required for diabetic wound healing.

Tswana traditional health practitioners' perspectives on the management of diabetes and hypertension: a qualitative study using focus group discussions

INTRODUCTION

The literature suggests the involvement of Traditional Health Practitioners (THPs) perspectives in treating diabetes and hypertension in Africa. This study sought the perspectives of Tswana THPs in the management of both diabetes and hypertension.

METHODS

Using a semi-structured interview guide, four Focus Group Discussions (FGDs) sessions were held with 40 THPs; FGD1 (12) FGD2 (6); FGD3 (13) and FGD4 (9) who were purposely selected from Bojanala and Dr. Ruth Sekgopomati Districts in the North-West Province of South Africa.

RESULTS

Tswana THPs perceived diabetes as a "sugar" disease and described hypertension as a disease associated with the abnormal flow of blood in a patient's body. In addition, some of the signs and symptoms of both diabetes and hypertension mentioned by Tswana THPs agreed with scientific literature. Tswana THPs employed the use of the following plants: borago officinalis, ziziphus mucronata, hypoxis hemerocallidea, sutherlandia frutescens, senna italica, urginea sanguinea and eucalyptus globulus in the management of diabetes and hypertension.

CONCLUSION

Some of the medicinal plants employed by THPs in the management of both diabetes and hypertension has been proven scientifically to be effective against these chronic conditions.

Skin Hydration Level as a Predictor for Diabetic Wound Healing: A Retrospective Study

BACKGROUND

In the diabetic foot, the skin may crack and develop fissures, potentially increasing vulnerability to ulceration and infection. Therefore, maintaining adequate skin hydration may be crucial for diabetic wound healing. However, no clinical study has addressed this issue. This study aimed to determine and compare the effect of the skin hydration level on diabetic wound healing with that of the tissue oxygenation level, which is recognized as the most reliable parameter in predicting diabetic wound healing.

METHODS

This retrospective study included 263 diabetic patients with forefoot ulcers. Skin hydration and transcutaneous oxygen pressure data collected before and after percutaneous transluminal angioplasty were analyzed. Skin hydration and tissue oxygenation were graded as poor, moderate, or acceptable. Wound healing outcomes were graded as healed without amputation, minor amputation, or major amputation. Wound healing outcomes were compared using four parameters: skin hydration at baseline, transcutaneous oxygen pressure at baseline, post-percutaneous transluminal angioplasty skin hydration, and post-percutaneous transluminal angioplasty transcutaneous oxygen pressure.

RESULTS

Each of the four parameters exhibited statistically significant correlations with wound healing outcomes. In the concurrent analysis of both skin hydration and transcutaneous oxygen pressure, skin hydration was a dominant parameter (p = 0.0018) at baseline, whereas transcutaneous oxygen pressure was a dominant parameter (p < 0.0001) following percutaneous transluminal angioplasty.

CONCLUSIONS

Skin hydration level might be a useful predictor for diabetic wound healing. In particular, the skin hydration level before recanalization was found to be superior to transcutaneous oxygen pressure in predicting wound healing.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Comparison of perfusion values after percutaneous transluminal angioplasty according to the severity of ischaemia in the diabetic foot

Percutaneous transluminal angioplasty (PTA) is now more frequently used to improve tissue perfusion in ischemic diabetic feet. However, there are concerns about its feasibility and effectiveness in severely ischaemic feet. This study aimed to compare the perfusion values after PTA according to the ischaemic degree of diabetic feet. This study included 133 ischaemic diabetic feet. The foot transcutaneous oxygen pressure (TcPO₂ ) and toe pressure were measured before the procedure and every second postoperative week for 6 weeks. The patients were divided into three groups according to ischaemic severity on the basis of TcPO₂ and toe pressures. In the "severely ischaemic" group, the TcPO₂ increased from 7.5 ± 4.9 to 40.3 ± 11.3 mm Hg (5.4-fold) 6 weeks after the PTA (P < 0.001). The toe pressure increased from 8.5 ± 8.8 to 42.2 ± 19.3 mm Hg (5.0-fold, P < 0.001). In the "mild" group, the TcPO₂ increased from 35.4 ± 2.5 to 41.8 ± 12.4 mm Hg (1.2-fold, P = 0.003), and the toe pressure increased from 45.7 ± 12.3 to 54.3 ± 31.3 mm Hg (1.2-fold, P > 0.05). Results of the "intermediate" group were in between. The most severely ischaemic group had the most dramatic increase of tissue perfusion after PTA. As such, PTA can be an effective method for increasing tissue perfusion even in the severely ischaemic diabetic feet.

Diabetic Foot Infections: Update on Management

PURPOSE OF REVIEW

Diabetic foot infections (DFIs) are common in patients with diabetes mellitus complicated by foot ulcers and can be classified in different categories based on their severity. In this report, we present the diagnosis and management of DFIs according to their classification.

RECENT FINDINGS

While appropriate antibiotic regiments and surgical techniques for the treatment of DFIs are well established, new technologies and techniques for example in medical imaging, wound care modalities, and supplementary therapy approaches show potentially promising results in preventing DFIs. As with every complex disease, fine tuning DFI management can be challenging as it requires careful evaluation of different parameters. It demands timely action, close collaboration of different specialties, and patient cooperation.

Diabetic Foot Infections: an Update in Diagnosis and Management

Foot infections are a common problem in patients with diabetes and a risk factor for limb amputation. They occur as a result of skin ulceration, which facilitates penetration of pathogens to deeper tissues. The diagnosis of infection is clinical. Aerobic gram-positive cocci are the most common pathogens. Ulcers which are chronic, preceded by administration of antibiotics and hospitalization or complicated by severe infection are polymicrobial. Antibiotic therapy is initially empiric based on the severity of the infection. Definitive therapy is modified according to the results of the microbiological culture and the response to empiric treatment. The optimal duration of antibiotic therapy ranges from 1-2 weeks for mild infections to 2-4 weeks and even longer for severe infections and osteomyelitis. Surgical consultation should be sought for infections complicated with abscesses, necrotizing fasciitis or osteomyelitis. With appropriate care, infection resolves in about 80-90% of non-limb threatening and in about 60% of severe infections.

Lower extremity amputation in peripheral artery disease: improving patient outcomes

Peripheral artery disease affects over eight million Americans and is associated with an increased risk of mortality, cardiovascular disease, functional limitation, and limb loss. In its most severe form, critical limb ischemia, patients are often treated with lower extremity (LE) amputation (LEA), although the overall incidence of LEA is declining. In the US, there is significant geographic variation in the performing of major LEA. The rate of death after major LEA in the US is approximately 48% at 1 year and 71% at 3 years. Despite this significant morbidity and mortality, the use of diagnostic testing (both noninvasive and invasive testing) in the year prior to LEA is low and varies based on patient, provider, and regional factors. In this review we discuss the significance of LEA and methods to reduce its occurrence. These methods include improved recognition of the risk factors for LEA by clinicians and patients, strong advocacy for noninvasive and/or invasive imaging prior to LEA, improved endovascular revascularization techniques, and novel therapies.

Temporal trends and geographic variation of lower-extremity amputation in patients with peripheral artery disease: results from U.S. Medicare 2000-2008

OBJECTIVES

This study sought to characterize temporal trends, patient-specific factors, and geographic variation associated with amputation in patients with lower-extremity peripheral artery disease (LE PAD) during the study period.

BACKGROUND

Amputation represents the end-stage failure for those with LE PAD, and little is known about the rates and geographic variation in the use of LE amputation.

METHODS

By using data from the Centers for Medicare & Medicaid Services (CMS) from January 1, 2000, to December 31, 2008, we examined national patterns of LE amputation among patients age 65 years or more with PAD. Multivariable logistic regression was used to adjust regional results for other patient demographic and clinical factors.

RESULTS

Among 2,730,742 older patients with identified PAD, the overall rate of LE amputation decreased from 7,258 per 100,000 patients with PAD to 5,790 per 100,000 (p < 0.001 for trend). Male sex, black race, diabetes mellitus, and renal disease were all independent predictors of LE amputation. The adjusted odds ratio of LE amputation per year between 2000 and 2008 was 0.95 (95% CI: 0.95-0.95, p < 0.001).

CONCLUSIONS

From 2000 to 2008, LE amputation rates decreased significantly among patients with PAD. However, there remains significant patient and geographic variation in amputation rates across the United States.

Methicillin-resistant Staphylococcus aureus in diabetic foot infections

Diabetic foot ulcers are often complicated by infection. Among pathogens, Staphylococcus aureus predominates. The prevalence of methicillin-resistant S. aureus (MRSA) in infected foot ulcers is 15-30% and there is an alarming trend for increase in many countries. There are also data that recognize new strains of MRSA that are resistant to vancomycin. The risk for MRSA isolation increases in the presence of osteomyelitis, nasal carriage of MRSA, prior use of antibacterials or hospitalization, larger ulcer size and longer duration of the ulcer. The need for amputation and surgical debridement increases in patients infected with MRSA. Infections of mild or moderate severity caused by community-acquired MRSA can be treated with cotrimoxazole (trimethoprim/sulfamethoxazole), doxycycline or clindamycin when susceptibility results are available, while severe community-acquired or hospital-acquired MRSA infections should be managed with glycopeptides, linezolide or daptomycin. Dalbavancin, tigecycline and ceftobiprole are newer promising antimicrobial agents active against MRSA that may also have a role in the treatment of foot infections if more data on their efficacy and safety become available.

Effect of percutaneous transluminal angioplasty on tissue oxygenation in ischemic diabetic feet

Percutaneous transluminal angioplasty (PTA) has been performed as an alternative to bypass surgery for improving tissue oxygenation in ischemic diabetic feet because the former is less invasive than the latter. The purpose of this study was to evaluate the effect of PTA on tissue oxygenation in ischemic diabetic feet. This study included 29 ischemic diabetic feet, as determined by a transcutaneous oxygen pressure (TcPO(2) )<30 mmHg. The PTA was carried out in 29 limbs. The PTA procedure was considered successful, acceptable, and failed when residual stenosis was<30%, between 30 and 50%, and>50%, respectively. For evaluation of tissue oxygenation, the foot TcPO(2) was measured before PTA and weekly for 6 weeks after PTA. Immediately after PTA, 26 feet were evaluated as being successful and the remaining three as acceptable. Before PTA, the average foot TcPO(2) was 12.7 ± 8.9 mmHg. The TcPO(2) values were increased to 43.6 ± 24.1, 51.0 ± 22.6, 58.3 ± 23.0, 61.3 ± 24.2, 59.0 ± 22.2, and 53.8 ± 21.0 mmHg 1, 2, 3, 4, 5, and 6 weeks after PTA, respectively (p<0.01). The PTA procedure significantly increases tissue oxygenation in ischemic diabetic feet. The maximal level of tissue oxygenation was measured on the fourth week following PTA.

A case report of an effective treatment for diabetic foot ulcers with integration of traditional Chinese medicine and Western medicine

Diabetes contributes 75-85% of the factors predisposing to foot amputations, usually in association with infection and gangrene. The treatment of foot ulcers is expensive, and the effectiveness of treatment varies. We report herein a case of a diabetic foot ulcer that was treated with integrated traditional Chinese and Western medicine, with desirable cost-effective results. Traditional Chinese medicine (TCM) therapeutic principles include improving the spleen, nourishing yin, regulating qi, and resolving dampness, as well as activating stagnant blood. Western medicine includes wound debridement, skin grafting, and use of insulin, antibiotics, and vasodilators. The patient was treated with a holistic multidisciplinary approach (i.e., a combination of TCM and Western medicine, surgical management, education for diabetic foot care, and psychological counseling). Without this approach, the patient might have ended up with foot amputation and/or sepsis.

Is the foot elevation the optimal position for wound healing of a diabetic foot?

In managing diabetic foot ulcers, foot elevation has generally been recommended to reduce oedema and prevent other sequential problems. However, foot elevation may decrease tissue oxygenation of the foot more than the dependent position since the dependent position is known to increase blood flow within the arterial system. In addition, diabetic foot ulcers, which have peripheral vascular insufficiency, generally have less oedema than other wounds. Therefore, we argue that foot elevation may not be helpful for healing of vascularly compromised diabetic foot ulcers since adequate tissue oxygenation is an essential factor in diabetic wound healing. The purpose of this study was to evaluate the influence of foot height on tissue oxygenation and to determine the optimal foot position to accelerate wound healing of diabetic foot ulcers. This study included 122 cases (73 males and 47 females; two males had bilateral disease) of diabetic foot ulcer patients aged 40-93 years. Trans-cutaneous partial oxygen tension (TcpO(2)) values of diabetic feet were measured before and after foot elevation (n=21). Elevation was achieved by placing a foot over four cushions. We also measured foot TcpO(2) values before and after lowering the feet (n=122). Feet were lowered to the patient's tibial height, approximately 30-35 cm, beside a bed handrail. Due to the large number of lowering measurements, we divided them into five sub-groups according to initial TcpO(2.) Tissue oxygenation values were compared. Foot-elevation-lowered TcpO(2) values before and after elevation were 32.5+/-22.2 and 23.8+/-23.1 mmHg (p<0.01), respectively. Foot-lowering-augmented TcpO(2) values before and after lowering were 44.6+/-23.8 and 58.0+/-25.9 mmHg (p<0.01), respectively. The lower the initial TcpO(2) level, the more the TcpO(2) level increased. The foot lowering, rather than elevation, significantly augments TcpO(2) and may stimulate healing of diabetic foot ulcers.

The treatment of diabetic foot ulcers: reviewing the literature and a surgical algorithm

PURPOSE

To provide an overview of the literature related to the treatment of diabetic foot ulcers.

TARGET AUDIENCE

This continuing education activity is intended for physicians and nurses with an interest in wound care.

OBJECTIVES

After reading this article and taking this test, the reader should be able to:

Emergency Management of Chronic Wounds

As America's emergency departments witness an increase in care provided to an aging population, the emergency physician increasingly evaluates and treats manifestations of chronic disease. Nonhealing wounds are often a presenting manifestation of chronic disease. They are a source of pain and disability for this population. Emergency physicians should possess a fundamental knowledge in the management of chronic wounds. This article familiarizes the emergency physician with the epidemiology of chronic wounds, the physiology of tissue repair, the pathophysiology involved in wound healing failure, the common types of chronic wounds, and specific management strategies.

The role of early surgical debridement and revascularization in patients with diabetes and deep foot space abscess: retrospective review of 106 patients with diabetes

One hundred-six patients underwent emergency debridement of a deep foot space abscess. While 43 patients were admitted after an outpatient visit with immediate surgical debridement (group A), 63 patients were transferred from other hospitals after a mean stay of 6.2+/-7.5 days without debridement (group B). No significant differences were observed in the demographic and clinical features between the 2 groups, except for the following differences in group B: higher blood glucose level on admission (P=.015), lower serum albumin level (P=.005), and a more frequent extension of the infection to the heel (P=.005). Eradication of the infection was obtained in group A without amputation in 9 patients, with an amputation of 1 or more rays in 21, with metatarsal amputations in 12, and with a Chopart amputation in 1. In group B, incision and drainage alone were performed in 4 patients, amputation of 1 or more rays in 21, metatarsal amputations in 10, Chopart amputations in 23, and an above-the-ankle amputation in 5. The amputation level was significantly more proximal in group B (chi2=24.4, P<.001). There was no significant difference in the presence of peripheral arterial occlusive disease between the 2 groups (P=.841). Regression logistic analysis showed a significant relationship between the amputation level and the number of days elapsed before debridement (odds ratio, 1.61; P=.015; confidence interval, 1.10-2.36), but not with the presence of peripheral occlusive disease (odds ratio, 1.73; P=.376; confidence interval, 0.29-15.3). These data show that a delay in the surgical debridement of a deep space abscess increases the amputation level. Accuracy in the diagnosis of peripheral occlusive disease and immediate revascularization yield similar outcomes in patients with or without peripheral occlusive disease.

Treatment for diabetic foot ulcers

People with diabetes develop foot ulcers because of neuropathy (sensory, motor, and autonomic deficits), ischaemia, or both. The initiating injury may be from acute mechanical or thermal trauma or from repetitively or continuously applied mechanical stress. Patients with clinically significant limb ischaemia should be assessed by a vascular surgeon to determine the need for angioplasty, stenting, or femorodistal bypass. When infection complicates a foot ulcer, the combination can be limb or life-threatening. Infection is defined clinically, but wound cultures reveal the causative pathogens. Tissue specimens are strongly preferred to wound swabs for wound cultures. Antimicrobial therapy should be guided by culture results, and should aim to cure the infection, not to heal the wound. Alleviation of the mechanical load on ulcers (off-loading) should always be a part of treatment. Neuropathic ulcers typically heal in 6 weeks with total contact casting, because it effectively relieves pressure at the ulcer site and enforces patient compliance. The success of other approaches to off-loading similarly depends on the patients' adherence to the effectiveness of pressure relief. Surgery to heal ulcers and prevent recurrence can include tenotomy, tendon lengthening, reconstruction, or removal of bony prominences. However, these procedures may result in secondary ulceration and other complications. Ulcer recurrence rates are high, but appropriate education for patients, the provision of posthealing footwear, and regular foot care can reduce rates of re-ulceration.