Clinical Aspects and Management of Diabetic Foot Wounds - Term Paper Example

Clinical Aspects and Management of Diabetic Foot Wounds Melvina Murphy of New Mexico The prevalence of diabetic foot wounds is increasing, along with the requirement for amputations. There are various significant aspects that impact the incidence of diabetic foot wounds: risk-awareness, prevention, management and treatment of the condition. In this paper, six studies based on different research methods will be reviewed, for improving clinical practice in the management and successful treatment of diabetic foot wounds. Clinical Aspects and Management of Diabetic Foot Wounds Problem Statement and Background This paper proposes to highlight the problems associated with diabetic foot ulcers, and review the management and treatment of this condition, based on research studies. It is well known that diabetic foot ulceration is a significant end-stage complication of diabetes with considerable economic and public health implications. In the United States 5-6% of the population has diabetes, and it is considered one of the most costly diseases (Boulton et al, 1999). The frequency of non-traumatic lower-limb amputations in persons with diabetes has increased in the United States over the last decade, states Reiber (2002). Armstrong et al (2002) predict that by the end of the first quarter of the present millennium, more than 300 million persons world-wide will have diabetes. At any one time, up to 7% of at-risk patients with diabetes have a diabetic wound. With the realization that most ulcerations are entirely avoidable, the concept of prevention takes on a new urgency. According to Akbari and LoGerfo (2002) and Steed et al (2006), problems of the diabetic foot are the most common cause for hospitalization in diabetic patients, with an annual health care cost of over one billion dollars. Currently, two-thirds of all lower limb amputations occur in individuals with diagnosed diabetes, and the relative risk for amputation is forty times greater in people with diabetes. Diabetic foot ulceration will affect 15% of all diabetic individuals during their lifetime and is a significant risk factor for limb loss. Reiber (2002) states that the most consistent risk factors for diabetic foot ulcers are long diabetes duration, measures of peripheral neuropathy, measures of peripheral vascular disease, prior foot ulcer and prior amputation. Amputations reduce patient function and quality of life, and place a heavy burden on individuals, families and health care systems. Foot ulcers result from various etiologic factors and are characterized by an inability to self-repair in a timely and orderly manner (Reiber, 2002). Endothelial dysfunction caused by fundamental alterations of the microcirculation of the diabetic foot contributes to ulceration of the diabetic foot. The main etiologic factors in foot ulceration are diabetic neuropathy and vascular disease; the latter being further classified into macrovascular (that is, atherosclerosis) and microvascular disease. Ultimately, all efforts at prevention and treatment of the diabetic foot should be focused on an understanding of these disease entities (Akbari and LoGerfo, 2002). Guidelines for the diagnosis and treatment of diabetic foot ulcers have been formulated, and their underlying principles enumerated by the National Institutes of Health, 2005 (Steed et al, 2006). The literature review focuses on various aspects of diabetic foot ulcers and their clinical management, by evaluating the following studies based on different research methods: identification of potential risk factors for diabetic foot ulcers, the choice of diabetic foot ulcer classification in relation to the final outcome, patient and podiatrist perspectives on the experience of ulceration and healing, treatment with negative pressure wound therapy on diabetic foot ulcers, treatment with Topical Becaplermin (rhPDGF-BB) gel, and wound therapy with autologous bone marrow stem cells. The databases CINAHL and PUBMED were searched for research articles on wound management related to diabetic foot injuries, using the key words “diabetic foot + wound”, “diabetic foot + injury”. The journals Wounds: A Compendium of Clinical Research and Practice and International Journal of Clinical Practice yielded several quantitative and qualitative research studies on various aspects of diabetic foot injuries and their treatment. Other journals like Wound Repair and Regeneration and Journal of Wound Care were useful for additional background information. Literature Review In order to estimate the prevalence of diabetic chronic sensorimotor neuropathy and foot ulceration in a geographically well-defined diabetic population and to evaluate the potential risk factors, Manes et al (2002) conducted an epidemiological cross-sectional study. It was a large population based study, in a prefecture in Northern Greece. The sample consisted of 821 diabetic patients that included 304 men and 781 type 2 patients (80% of the known diabetic population in the county aged 18 to 70 years). Patients with other diseases known to cause neuropathy, such as pernicious anemia, were excluded from the study. Painful symptoms of neuropathy were assessed using a modified neuropathy symptom score (NSS), a neuropathy disability score (NDS), and a Bio-thesiometer to measure the vibration perception thresholds (VPT). Also, the patients were asked specific questions about their symptoms. The prevalence of neuropathy was 33.5%; it did not differ significantly between men and women (35.2% vs.32.62%) or between current smokers and non-smokers (31.5% vs.35.07%). Patients with any kind of retinopathy had a higher overall prevalence of peripheral neuropathy than patients without (60.6% vs. 29.9%). Mean age and mean known duration of diabetes was significantly higher in neuropathic patients than in non-neuropathic patients. The presence of neuropathy was associated with slightly greater height. The mean fasting glucose was significanty higher in neuropathic patients. No significant differences existed in body weight between the neuropathic and non-neuropathic group. Two hundred and fifty-seven patients (31.3%) had neuropathy symptom score greater than or equal to three, the criterion to diagnose painful neuropathy. The prevalence rate of foot ulcers (FU) was 4.75 percent and of peripheral vascular disease12.7 percent. Patients with foot ulcers had more severe neuropathy than those without FU. The findings of the present study indicate that a large proportion of the diabetic population are neuropathic and, therefore, at risk of foot ulceration. The study also identifies the most important risk factors for diabetic neuropathy (glucose control, age, long duration, height). Strategies to reduce the risk of neuropathy should be developed and involve all the diabetic population (in rural and urban areas). Avoiding risk factors, such as inappropriate blood glucose control could reduce the risk of neuropathy, state Manes et al (2002). Also, proper foot care and education for the total population is of importance for neuropathic patients to reduce the risk of foot ulceration and potential amputation. Van Acker et al (2002) conducted a research study by the method of observation and analysis on the choice of diabetic foot ulcer classification in relation to the final outcome. Several classification systems for diabetic foot ulcers have been proposed. The classification most frequently used analyzes one or more of the following elements: infection, neuropathy, vasculopathy, and the extent (surface and depth) of the ulcer. Among the best known and widely available classifications is the Megit/Wagner. The aim of the study was to present a new classification for diabetic foot ulcers: the two dimensional Van Acker/ Peter classification (VA/ P), and to test its prognostic value in comparison with the one-dimensional Megit/ Wagner classification. The Megit-Wagner classification: This system is based on three features: depth of the ulcer, the degree of infection, and the presence or absence of gangrene and its extent. Grades 1 to 3 are mainly based on neuropathy, while grade 4 and 5 represent mainly ischemic lesions. It is described as very simple and, therefore, often considered to be inconveniently inaccurate. It was noted that the scheme provides insufficient levels to discriminate between wounds that may benefit from nonsurgical rather than surgical management. The Van Acker/Peter classification: This is based upon the Texas Wound Classification, the first bidimensional classification. This new system is established on clinical experience and gives, through different shades of gray, an estimate of the clinical expected risk of amputation in relation to foot pathology. The criteria for the new classification were ease of use by clinicians and clinical investigators and the covering of physiopathology as well as clinical picture, including the depth of ulcers, the degree of infections, and the presence or absence of osteomyelitis. The system includes 25 separate classes. It takes into account not only clinical features, such as depth and grade of infection (horizontal axis), but also the physiopathological background (vertical axis), where ischemic components play a role. Outcome measures studied are healing with or without amputation and the time until healing.The setting was a group of patients visiting the Antwerp Diabetic Foot Clinic between January 1992 and December 1997. 121 patients with a total of 253 ulcers formed the sample for the study. They were analyzed retrospectively. Instruments for the coding of ulcers, clinical descriptions and photographic images were used. A single investigator worked on the study throughout the period of the research, to maintain consistency. Only files with data on healing outcome were included. Both classifications: the Megit/ Wagner and the Van Acker/ Peter were evaluated according to healing with or without amputation and to duration of healing. Results: Of the study population consisting of 121 patients with a total of 253 ulcers 88 percent healed without amputation. About 60 percent of the ulcers were located on the toes, accounting for 83.3 percent of all amputations. Both ulcer classifications (Wagner and VA/P) showed good mutual correlation, but no correlation existed between the two parts of the VA/P classification. Therefore, both classifications deliver additional information and can be used in a complementary way. Furthermore, only in the Wagner classification a significant association was found with duration of healing of the ulcer. From the results, Van Acker et al (2002) concluded that the Wagner classification remains a perfectly usable instrument on the clinical and prognostic levels, in primary health centers. In a multicenter research situation, a more detailed description, such as the VA/P classification, is needed, particularly in case of Wagner 3 ulcers. A qualitative study was conducted by Searle et al (2005), to understand the experience of ulceration and healing in the diabetic foot, from the perspectives of the patient as well as the podiatrist. The aim of the study was to assemble the results of exploratory interviews undertaken with patients and podiatrists by two separate researchers to examine the experience of foot ulceration and treatment from both perspectives. The research study was conducted on 1) Patients with diabetic foot ulcers who were recruited from outpatient podiatry clinics, which they attended as part of their standard foot treatment. They were 13 patients (9 male, 4 female), 45 to 66 years in age. 2) Twelve podiatrists (10 female, 2 male) working in the outpatient clinics from which the patients were recruited. All interviews were tape-recorded, transcribed and coded for emerging themes, using the “constant comparison” approach to qualitative data analysis. In both studies the interview schedules consisted of a series of open-ended questions concerned with examining beliefs about ulcers, causes and treatment of ulcers, and adherence to treatment recommendations. It was found that the experience of having ulcers had a considerable impact on patients’ lifestyles. Both ulcer and treatment affected the patients’ mobility, independence, and social life. These experiences often led to anger, fear, depression, helplessness, boredom, and loss of self-esteem. Podiatrists also perceived that foot ulcers had a negative impact on patients’ lives and their emotional well-being and were aware of factors that may influence adherence to treatment. It is suggested that understanding and addressing the psychosocial aspects of foot ulceration may lead to better adherence and may improve clinical outcomes. It was clear that patients were less likely to adhere to treatment recommendations that conflicted with their usual or preferred lifestyles. For example, despite agreeing that footrest was one of the best remedies for foot ulceration, few felt able to rest as much as recommended. Adherence was generally referred to by the podiatrists as compliance and was perceived to vary from patient to patient over time. The podiatrists believed that the advice they gave patients was very difficult to follow, and consequently, patients would not do so. Podiatrists perceived the main catalyst for changes in adherence to be the provision of information about self-care, the consequences of nonadherence, and stronger, more explicit approaches to communicating such information. The researchers found the results to be of significance for understanding the experience of ulceration and healing in the diabetic foot (Searles et al, 2005). A review of the literature follows, on research related to the treatment of diabetic foot wounds with the help of three different methods: negative pressure wound therapy, Topical Becaplermin (rhPDGF-BB) and autologous bone marrow stem cells. The purpose of the clinical study conducted by Etoz et al (2004), was to evaluate the use of negative pressure wound therapy on diabetic foot ulcers in a preliminary controlled trial. The researchers compared this dressing with traditional moist gauze dressing as a treatment used prior to other wound closure techniques, such as flaps or grafts. The surgical treatment of diabetic wounds with loss of soft tissue usually consists of closure using split-thickness skin grafts or transposition flaps. However, immediate surgical closure often fails because the general conditions of patient and wound may not be appropriate for surgical closure; therefore, the initial step consists of standard wound care (moist gauze dressing) to prepare the wound bed for final closure. Twenty-four diabetic patients were randomly divided into two groups: the negative pressure wound therapy group and control group. Initially, the mean surface area of the diabetic wounds was 109cm2 in the negative pressure wound therapy (NPWT) group and 94.8cm2 in the control group. A medical aspirator system was used to drain the wounds with 125 mm Hg continuous negative pressure and the dressing was changed every 48 hours. Polyurethane ether sponges were used for the NPWT group, and saline moist gauze dressing for the control group. The researchers did not use polyurethane ether sponges in the control group because they wanted to compare NPWT with standard saline moist gauze dressing, which does not require any sponges. However, this difference in the dressing techniques is a flaw in the experimental design of this study. The mean duration of wound care (until the wounds were covered with granulation tissue) was 11.25 days in the NPWT group and 15.75 in the control group. Following NPWT or moist guaze dressing, the mean surface area of the wounds was 88.6cm2 in NPWT group and 85.3cm2 in the control group, showing NPWT reduced the wound surface areas more effectively than moist gauze dressing. From this preliminary controlled trial, the use of negative pressure wound therapy is seen to have strong potential for use as an alternative therapy to achieve a faster granulating wound bed in diabetic foot ulcers, in order to prepare the wound bed for other closure techniques (Etoz et al, 2004). Further studies on a larger cohort of patients for comparing the effects of NPWT on the diabetic nonhealing wounds, are needed to clarify effects and indications and to modify the technique of this treatment. Mannari et al (2002) have conducted an observational research study on the successful treatment of a series of recalcitrant, diabetic heel ulcers with Topical Becaplermin (rhPDGF-BB) Gel. Heel ulcers have the poorest prognosis among diabetic foot ulcers, because flap reconstruction of the heel area is difficult and significant debridement or amputation of the heel rarely leaves a functionally walking patient. Recent advances for the treatment of diabetic foot ulcers have not had much reported success in heel ulcers: growth factors are less effective in ischemic tissue, and bioengineered dressings are difficult to maintain in position on the heel. The setting of the research study was a multidisciplinary wound service facility and in the sample were ten patients (9 men, 1 woman) with neuropathic, diabetic heel ulcers and a mean age of 71 years. All 10 patients were treated with topical becaplermin (rhPDGF-BB) daily. The medication was applied by the patient or home healthcare provider in the morning and left in place for 12 hours. After 12 hours, a normal saline-soaked (0.9% NaCl) gauze was placed on the ulcer for 12 hours. Patients remained as outpatients throughout their treatment periods and were seen in the clinic at weekly intervals. Repeat debridement of necrotic tissue and/or excessive callus was performed as necessary. Ulcer photographs and tracings were performed monthly during clinic visits. The patients were followed to complete healing from one month to twenty-one months (mean 8 months) without recurrence of their heel ulcers (100% wound closure). Eight patients (80%) achieved 100-percent healing at between 13 days and 4 months. Once healed, offloading was converted to orthotic shoes.This series, although small, suggests becaplermin can be effective in treating neuropathic, diabetic, heel ulcers. Although vascular reconstruction should always be performed when feasible in patients with heel ulcers, total healing may not always occur post-reconstruction. In three of the patients in the study the ulcer persisted after vascular reconstruction, but responded to topical growth factor treatment (Mannari et al, 2002). The researchers concluded that, based on experience, Topical Becaplermin (rhPDGF-BB) can be a successful treatment for diabetic heel ulcers. The research conducted by Kirana et al (2007) in the field of autologous stem cell therapy has been focused on the induction of therapeutic angiogenesis and wound healing in patients with peripheral arterial occlusive disease (PAOD). The following is a case report of a patient with Diabetes mellitus (DM) and chronic foot ulcers induced by critical ischaemia, for whom therapeutic angiogenesis and complete wound healing is presented. The patient in this case report takes part in a trial performed at the Heart and Diabetes Center NRW where the researchers seek to induce wound healing through the application of autologous bone marrow stem cells in diabetic patients with ischaemia induced chronic tissue ulcers affecting the lower limbs. This clinical trial is considered to be the first well-controlled study on stem cell therapy that compares bone marrow mononuclear cells (BMMC) to an expanded stem cell product and the standard of care. The case report was of a 60-year-old man, with type 2 DM diagnosed 6 years ago, who presented after amputation with an infected gangrene of the third and fourth toes of the left foot. The ulceration at the site of amputation developed 4 months ago and became progressively worse. The diagnosis at presentation was: infection of forefoot gangrene, necrosis of the second and fifth toe, osteomyelitis of the third and fourth metatarso-phalangeal joint and phlegmone of the forefoot. Co-morbidities of the patient and risk factors of PAOD were: mild hypertension, coronary atherosclerosis, peripheral diabetic polyneuropathy, mild non-proliferative diabetic retinopathy. If one or a combination of the above complications of diabetes is present in the patient, a trigger event can lead to injury. The state of the metabolic system in a diabetic patient is accompanied by a reduced resistance to infections. Local inflammation may lead to necrosis, which often result in amputation. Preclinical studies and previous studies have shown that transplantation of BMMC, including endothelial progenitor cells, into ischaemic limbs promotes collateral vessels formation (angiogenesis). Autologous transplantation of BMMC has been shown to be safe and effective in achieving and in inducing therapeutic angiogenesis. There are two delivery methods for autologous transplantation of BMMC, first, intra-arterial, which use intra-arterial catheter antegrad to deliver the BMMC directly to the distal artery of the affected limb and secondly multiple intramuscular injections. Both methods showed clinical improvements. The impaired wound healing after the amputation was caused by critical limb ischaemia. Based on critical limb ischaemia in combination with foot ulcer and without any options of revascularisation, a treatment with autologous bone marrow stem cells was performed. Before applying this therapy, the study was approved by the local ethics committee. After 20 weeks of therapy clinical improvements were documented. A complete wound healing was achieved and angioneogenesis of the forefoot was demonstrated angiographically. An improvement in microcirculation was also demonstrated; this represents, most probably, a beneficial effect of local application of autologous stem cells and led to an improvement of perfusion and finally to wound healing. For the patient, the most important endpoint is the complete primary wound healing, which has been achieved without any adverse effects. Because of the use of only 40 ml bone marrow, this method is easy to perform and more convenient for the patient compared with other published protocols using 400 ml of bone marrow, state Kirana et al (2007). The researchers conclude that their autologous stem cell therapy worked in this patient and it is a potential new therapeutic option for diabetic patients with chronic foot ulcers induced by critical limb ischaemia. Discussion Epidemiological cross-sectional studies are the most appropriate to draw valid conclusions. The findings (Manes et al, 2002) indicate that a large proportion of the diabetic population are neuropathic and, therefore, at risk of foot ulceration. Avoiding risk factors, such as inappropriate blood glucose control; proper foot care and education for the total population are essential for neuropathic patients to reduce the risk of foot ulceration and potential amputation. The Van Acker/ Peter classification of diabetic foot ulcers is a new system established on clinical experience which gives an estimate through different shades of gray, of the clinical expected risk of amputation in relation to foot pathology; healing with or without amputation and the time until healing. The Megit/ Wagner classification and the Van Acker/ Peter classification when used in a complementary way, were found to give the best results (Van Acker et al, 2002). Classifications can be of great help for the assessment of treatment schemes, and in standardization and analysis of multicenter research. The management of a diabetic foot ulcer requires the patient to change his or her behavior. There is a high potential importance of the qualitative study conducted by Searle et al (2005) to understand the experience of ulceration and healing in the diabetic foot, from the perspectives of the patient as well as the podiatrist. The research yielded significant information on patient compliance to treatment recommendations and their emotions related to the condition, beliefs about diabetic foot ulcers, the causes and treatment. However, a limitation of the study may be the transferability of the findings to another group of diabetic patients with foot ulcers, where the treatment conditions or methods to ensure compliance may be different. Reconstruction of diabetic foot ulcers is often a challenging problem. Research on the treatment of diabetic foot wounds with the help of negative pressure wound therapy, Topical Becaplermin (rhPDGF-BB) and autologous bone marrow stem cells have been reviewed. From the preliminary controlled trial, the use of negative pressure wound therapy by vacuum assisted closure (VAC) is seen to have strong potential to achieve a faster granulating wound bed in diabetic foot ulcers, as compared to saline moist gauze dressing. This helps to prepare the wound bed for other closure techniques (Etoz et al, 2004). The rapid healing of wounds should not only decrease hospital stay, but may avoid extensive plastic surgery flap closure of some wounds The limitation of the study is that the sample size is small, and hence necessitates further studies on a larger cohort of patients. Some contraindications for V.A.C. Therapy include untreated osteomyelitis, non-enteric and unexplored fistula, presence of necrotic tissue, exposed organs or blood vessels, and malignancy in the wound (Andros et al, Suppl. June, 2005). The treatment of a series of recalcitrant, diabetic heel ulcers with Topical Becaplermin (rhPDGF-BB) Gel showed that it is effective and can be successfully used in treating neuropathic diabetic heel ulcers. Mannari et al (2002) found that when ulcers persisted after vascular reconstruction, the use of the topical growth factor treatment was found to be efficacious. This was a giant step in decreasing the morbidity of these lesions. The limitation of this study also, is small sample size. Larger studies are needed to confirm the results. Kirana et al (2007) advocate the use of autologous stem cell therapy as a potential new therapeutic option for diabetic patients with chronic foot ulcers induced by critical limb ischaemia. Their research finding was from the treatment of a single case study with impaired wound healing after amputation. Complete primary wound healing was achieved without any adverse effects. This treatment was also found to be more cost-effective as only 40 ml of bone marrow was used, as against other published protocols using 400 ml. It is observed that the evidence obtained from all the research papers reviewed above can beneficially impact clinical practice related to creating risk-awareness, prevention, management and treatment of diabetic foot ulcers. References Akbari, C. M., LoGerfo, F. W. (2002). Microvascular changes in the diabetic foot. In The diabetic foot: medical and surgical management. (Eds.) Veves, A., LoGerfo, F. W., Giurini, J. M. New Jersey: Humana Press. Andros, G., Armstrong, D. G., Attinger, C., Boulton, A. J. M., Frykberg, R. G. et al (2005). Consensus statement on Negative Pressure Wound Therapy (V.A.C. Therapy) for the management of diabetic foot wounds. Wounds: A Compendium of Clinical Research and Practice, Suppl.to June 2005 issue, 1-33. Armstrong, D. G., Jude, E., Boulton, A. J. M., & Harkless, L. B. (2002). Clinical examination of the diabetic foot and identification of the at-risk patient. In The diabetic foot: medical and surgical management. (Eds.) Veves, A., LoGerfo, F. W., Giurini, J. M. New Jersey: Humana Press. Boulton, A. J., Meneses, P., Ennis, W. J. (1999). Diabetic foot ulcers: a framework for prevention and care. Wound Repair and Regeneration, 7, 7-16. Etöz, A., Özqenel, Y., Özcan, M. (2004). The use of negative pressure wound therapy on diabetic foot ulcers: a preliminary controlled trial. Wounds: A Compendium of Clinical Research and Practice, 16(8), 264-269. Retrieved on August 2, 2007 from http://www.woundsresearch.com/article/2941 Kirana, S., Stratmann, B., Lammers, D., Negrean, M., Stirban, A., Minartz, P., et al (2007). Wound therapy with autologous bone marrow stem cells in diabetic patients with ischaemia-induced tissue ulcers affecting the lower limbs. International Journal of Clinical Practice, 61, 4, 690-694. Manes, C., Papazoqlou, N., Sossidou, E., Soulis, K., Milarakis, D., Satsoqlou, A., Sakallerou, A. (2002). Prevalence of diabetic neuropathy and foot ulceration: identification of potential risk factors – a population based study. Wounds: A Compendium of Clinical Research and Practice, 14(1), 11-15. Retrieved on August 2, 2007 from http://www.medscape.com/viewarticle/430890 Mannari, R. J., Payne, W. G., Ochs, D. E., Walusimbi, M., Blue, M., Robson, M. C. (2002). Successful treatment of recalcitrant, diabetic heel ulcers with topical becaplermin (rhPGDF-BB) gel. Wounds: A Compendium of Clinical Research and Practice, 14(3), 116-121. Retrieved on August 2, 2007 from http://www.woundsresearch.com/article/301 Reiber, G. E. (2002). Epidemiology and health care costs of diabetic foot problems. In The diabetic foot: medical and surgical management. (Eds.) Veves, A., LoGerfo, F. W., Giurini, J. M. New Jersey: Humana Press. Searle, A., Campbell, R., Tallon, D., Fitzgerald, A., Vedhara, K. (2005). A qualitative approach to understanding the experience of ulceration and healing in the diabetic foot: patient and podiatrist perspectives. Wounds: A Compendium of Clinical Research and Practice, 17(1), 16-26. Retrieved on August 2, 2007 from http://www.medscape.com/viewarticle/498844 Steed, D. L., Attinger, C., Colaizzi, T., Crossland, M., Franz, M., Harkless, L., Johnson, A., Moosa, H., Robson, M., Serena, T., Sheehan, P., Veves, A., Wiersma-Bryant, L. (2006). Guidelines for the treatment of diabetic ulcers. Wound Repair and Regeneration, 14, 680-692. Van Acker, K. , Block, C. De, Abrams, P., Bouten, A., Leeuw, D. E., Droste, J., Weyler, J., Peter-Riesch, B. (2002). The choice of diabetic foot ulcer classification in relation to the final outcome. Wounds: A Compendium of Clinical Research and Practice, 14(1), 16-25. Retrieved August 2, 2007, from http://www.woundsresearch.com/article/144 Read More