- Title
- Factors contributing to wound chronicity in diabetic foot ulceration
- Creator
- Tehan, Peta Ellen; Linton, Clare; Norbury, Kate; White, Dianne; Chuter, Vivienne
- Relation
- Wound Practice and Research Vol. 27, Issue 3, p. 111-115
- Publisher Link
- http://dx.doi.org/10.33235/wpr.27.3.111-115
- Publisher
- Cambridge Publishing
- Resource Type
- journal article
- Date
- 2019
- Description
- ABSTRACT: Wound chronicity in diabetic foot ulceration (DFU) presents a significant cost to the healthcare system and also increases the likelihood of infection and amputation. Factors such as dietary intake, smoking, vascular status and infection have been proposed as contributory factors for chronicity. However, there is limited quality evidence to demonstrate the contribution of these factors in delayed healing in DFU. The aims of this research protocol are therefore to assess factors contributing to healing outcomes and wound chronicity in people with DFU, and to measure dietary intake in patients with DFU in an Australian setting. BACKGROUND: Diabetic foot ulceration (DFU) affects 56,000 Australians annually, with 70 Australians undergoing a diabetes-related amputation each week. Diabetes is the leading cause of non-traumatic lower limb amputation, with foot ulcer development preceding amputation in 85% of all lower limb amputation cases1. Recent estimates suggest that DFU and amputations cost the Australian healthcare system over $600 million annually2. A complex pathway leads to the development of a DFU, including the development of peripheral neuropathy (loss of sensation), peripheral arterial disease (PAD)(decreased circulation), and changes to foot shape due to the diabetes disease process3,4. This is further complicated by the increased risk of infection in patients with DFU5. However, whilst the evidence is clear on the risk factors for the development of DFU6, and clinicians can screen and triage patient care appropriately in individuals at high risk of DFU, in relation to risk factors for wound chronicity in DFU the evidence is inconclusive. A number of factors have been proposed to increase the likelihood of chronicity in DFU such as infection, vascular supply and dietary intake (Figure 1); however, there is currently a paucity of good quality, prospective research in this area. For example, a recent systematic review by Lefrancois et al.7 identified that there is currently inadequate or low-quality evidence on a number of factors which have been implicated in wound chronicity in DFU, including dietary intake, smoking, glycaemic control, vascular supply and infection. In particular, a lack of prospective studies investigating detriments to wound healing in DFU was noted. For example, once a patient has an established DFU, it is unclear who will become chronic, defined as >12 weeks' duration8. Chronic DFU patients are more likely to undergo amputation as they are more prone to infection and wound deterioration over time5. AIMS: In order to determine which factors are contributing most to delayed healing in patients with DFU, we need to conduct a prospective cross-sectional study that will measure all of the major factors implicated in wound chronicity in DFU (Figure 1) and determine the effect each of these have on wound Wound Practice and Research 112 healing time and outcomes, including amputation. Therefore the aims of our study are primarily to assess factors contributing to healing outcomes and wound chronicity in people with DFU and secondarily to measure dietary intake in patients with DFU in an Australian setting. METHOD: Participants with diabetes (type 1 and 2) and current DFU attending a public health podiatry clinic will be included and will attend a single testing session. Exclusion criteria will include a contraindication for placement of the toe cuff around the hallux or second digit, previous bilateral mastectomy preventing brachial blood pressure examination, vasospastic disorders, an inability to adhere to the testing protocol, and/or an inability to give informed consent. During a 12-month period it is expected 144 participants will be from across three sites (Hunter New England High Risk Foot Clinic, Wyong High Risk Foot Clinic and Gosford High Risk Foot Clinic), with 60 participants recruited to date. In order to determine which factors are contributing to delayed healing outcomes, a number of variables will bemeasured. A current general medical history will be obtained from the participants’ general practitioner, including current medication, concurrent chronic disease status, overall general medical history and diabetes duration, type (1 or 2), and current HbA1c levels. HbA1c levels are reflective of glycaemia over 2-3 months and are associated with wound healing rates in patients with diabetes. Higher HbA1c levels are associated with poorer healing outcomes – with each 1.0% increase in HbA1c, a daily reduction in wound healing of 0.028 cm2 can be expected9. Demographic data, including age, gender and smoking status, will also be collected. Nicotine is a vasoconstrictor which reduces skin blood flow, resulting in localised tissue ischaemia and impaired healing capability10. Smoking has therefore been clinically associated with general delayed healing; however, extensive controlled studies are yet to be undertaken in DFU. This study will determine if – and to what level – smoking has an effect on healing outcomes in DFU. Lower limb vascular assessment will include systolic toe pressure measurement along with a toe-brachial pressure index, both of which have been demonstrated as accurate indicators of PAD in patients with diabetes11,12. The presence of PAD and its negative impact on healing capacity is frequently underestimated, with the presence of ischaemia within a DFU not always obvious. That is, whilst purely ischaemic ulcers are readily identified by their characteristic appearance, symptoms and location, neuro-ischaemic DFUs can be more subtle in presentation13,14. This study will therefore aim to establish how much impact PAD has on healing outcomes in DFU. An assessment of dietary intake will also be conducted by using the Australian Eating Survey (AES), a valid and reproducible method of quantifying dietary intake15 that assesses usual food and nutrient intake over the preceding 3-6 months. Wound healing requires adequate dietary intake, with poor healing outcomes associated with deficiencies in nutrition16. Nutrition deficiencies can negatively impact Fig 1: Factors influencing wound chronicity in DFU Chronic diabetic foot ulceration Foot deformity/ Offloading Vascular Supply Peripheral neuropathy Glycaemic Control Wound Severity Infection Physical factors including smoking, BMI Dietary IntakeFigure 1. Factors influencing wound chronicity in DFU Tehan et al. Factors contributing to wound chronicity in diabetic foot ulceration 113 Volume 27 Number 3 – September 2019 wound healing by prolonging the inflammatory phase, decreasing fibroblast proliferation, and altering collagen synthesis17. However, dietary intake in patients with DFU has not yet been determined in an Australian cohort. With such variation in regional dietary intake, it is important that this can be established. Presence of infection will be determined by the International Working Group for the Diabetic Foot (IWGDF) guidelines for infection and will be collected by the treating podiatrist. Infection remains the most frequent diabetes complication requiring hospitalisation, and the most common precipitating event leading to lower extremity amputation18. This study will determine how much impact infection has on healing outcomes in DFU. Self-reported physical activity levels will be determined using the International Physical Activity Questionnaire (IPAQ), a validated research tool to determine physical activity levels19. Weight-bearing activity influences the amount of mechanical trauma in the plantar surface of the foot, and is a contributor to DFU20. Presence of foot deformity will also be collected, along with offloading intervention type, and wound education will be given. Current guidelines recommend that patients with DFU reduce their weight-bearing activities, in addition to wearing an offloading device to assist with healing21. Waist circumference will be determined using a tape measure, and weight and height measurements will also be taken to determine patients' body mass index. Obesity is associated with higher rates of post-operative wound infection, with reductions in tissue perfusion proposed as one contributing factor – adipose tissue is poorly vascularised and a reduction in collagen production is also frequently seen22. However, it is currently unclear how obesity impacts wound healing in patients with DFU. Neurological assessment will be performed using a combination of two tests, including a four-site monofilament test and measurement of vibration perception threshold by a neurothesiometer at the hallux. Ascertaining neurological status will help inform the aetiology of the DFU. Wound grade will be determined using University of Texas wound grade classification for DFU which involves assessing the size, depth and duration of the wound. Higher wound grades in chronic DFU are associated with higher rates of non-healing 23. Follow-up with participants regarding their wound healing will be completed at regular intervals through a clinical note audit at 3 and 6 months after the initial assessment, where wound size will be compared to the initial wound measurement.
- Subject
- diabetic foot ulceration; dietary intake; chronic wound; protocol
- Identifier
- http://hdl.handle.net/1959.13/1474431
- Identifier
- uon:49278
- Identifier
- ISSN:1837-6304
- Language
- eng
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