Australian Diabetes Foot Network: management of diabetes-related foot ulceration — a clinical update

Debridement of DRFUs is an essential component of wound bed preparation, as it removes non-viable tissue, allows comprehensive examination of the wound bed and assessment of actual wound size, has the potential to convert a chronic wound to an acute wound, and reduces local pressure on the ulcer.10,11 Surgical sharp debridement is required for management of deep necrotic tissue, gangrene, drainage of collections, deep infections or when pain necessitates the use of an anaesthetic.12,13 Non-surgical sharp debridement is generally required every 1–2 weeks to remove non-viable tissue, including the surrounding callus.12 Non-sharp debridement (enzymatic, autolytic and biological) can be used as an adjunct to sharp debridement and can be especially helpful for adherent slough, or when pain limits non-surgical sharp debridement.14

In the presence of PAD, debridement could potentially create a larger non-healing wound, therefore vascular investigations are indicated before debridement. One exception is for an abscess, which requires immediate drainage to reduce tissue pressures, control infection and prevent further tissue loss. Same-day vascular review is then recommended.

Ulcers should be regularly inspected and cleaned with saline or clean water.7 Cleaning with surface antiseptics (eg, chlorhexadine) is not recommended, as this may be harmful to granulation tissue.11

There is no evidence showing that one type of dressing is better than another, or that one type of dressing can be used on all wounds. Dressing choice will generally change as the wound characteristics change during healing. Dressing selection is based on the principles of “moist wound healing”, where inflammation, infection and exudate are controlled while maintaining an adequate moisture balance at the wound bed.7,11 In general, foam dressings meet the objectives of moist wound healing and will suit a wide variety of wounds.

An exception to the creation of a moist wound environment is when a dry, non-infected ulcer is present in the setting of ischaemia. These ulcers should be kept dry and covered with a non-adherent, non-occlusive dressing until a vascular referral and management plan is arranged.

There is some evidence supporting the use of new technologies such as negative pressure wound therapy and hyperbaric oxygen for healing DRFUs. However, the specific knowledge and skills required for these technologies generally limits their use to MFCTs,15 and they would form only a part of the comprehensive wound management plan.

Pressure off-loading is an essential component of DRFU management, particularly in the case of plantar neuropathic ulcers.11,16 Total contact casting has been shown to heal more plantar wounds, but it requires proficient staff for safe application and removal, and is contraindicated with significant PAD and spreading infection. Casting is not always appropriate, and has the potential to cause iatrogenic ulcers, muscle wasting and increase the risk of falls.17

Removable ambulatory walkers (eg, controlled ankle movement walkers and air casts) have been shown to off-load pressure from ulcers by an equivalent amount to total contact casting.16 However, their efficacy in healing wounds is generally less than total contact casting, as they can be removed. An individual’s compliance can be improved by making an ambulatory walker irremovable by applying a cable tie or adhesive bandage around it.18 Other pressure off-loading devices, such as postoperative shoes and felt padding, should be considered when total contact casts and ambulatory walkers are either unavailable or contraindicated.17

In the presence of significant underlying deformity, people with ulcers that fail to heal using conservative pressure off-loading techniques should be assessed by an orthopaedic surgeon and/or an MFCT to determine if they would benefit from surgical intervention. Procedures such as tendoachilles lengthening, arthroplasties, metatarsal head resection and tenotomies may improve healing time and reduce the risk of ulcer recurrence.19 Surgery of this type should not be considered in the presence of PAD without input from a vascular specialist.

Ongoing relief of pressure is important for secondary prevention in people with healed foot ulceration, particularly in the presence of a foot deformity. In the absence of a foot deformity, most individuals with a healed ulcer can be accommodated in off-the-shelf footwear (unmodified comfort or sports shoes). Medical-grade footwear is generally required for people with a foot deformity as it provides extra depth, multiple-width fittings and features designed for a broader range of foot types. Medical-grade footwear may also be fitted with custom-made orthoses to redistribute plantar pressure and reduce the risk of future foot ulceration. Medical-grade footwear should be purchased from suppliers with trained staff. Medical-grade footwear can be expensive, so health professionals should be aware of government-funded schemes to support such purchases (eg, the Department of Veterans Affairs “gold cards”).

If pedal pulses are absent in either foot, if there is gangrene or if there is no improvement in the ulcer healing despite appropriate wound management for 4 weeks, the person should be referred to a vascular specialist or an MFCT. Vascular specialists and MFCT members are the most appropriate individuals for selecting advanced investigations (eg, arterial Doppler ultrasound, computed tomography angiogram, magnetic resonance angiogram and catheter angiogram). Revascularisation by either percutaneous angioplasty or operative bypass is recommended whenever possible.27

As well as specific treatment for a DRFU, it is important to undertake a general assessment of the individual’s diabetes and other cardiovascular comorbidities.28 This is aimed at preventing the development or progression of other diabetes-related complications (which may further affect foot health), and at reducing mortality through modification of cardiovascular risk factors. Lipid and blood pressure control should be maximised, cessation of smoking encouraged and aspirin therapy considered.29 There is no study addressing the role of glycaemic control in the acute management of diabetes-related foot complications, but it is prudent to optimise glycaemic control at the time of acute illness, when there is infection and perioperatively. Metformin should be withdrawn when there is significant infection and/or ischaemia, when an individual is fasting for procedures and with administration of angiographic contrast.29

It is well documented that best-practice management of complex DRFUs need coordinated, expert interdisciplinary input in both inpatient and outpatient settings.30,31 Management by MFCTs, comprising medical, surgical, nursing, podiatry and other allied health professionals with appropriate skills and knowledge, increases the percentage of healed ulcers and reduces wound healing times, hospitalisation and amputations.32,33