ASSESSMENT AND MANAGEMENT OF THE DIABETIC FOOT

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ASSESSMENT AND MANAGEMENT OF THE DIABETIC FOOT

• MS Shan Bergin
• Research Fellow
• Diabetes and Endocrinology, The Royal Melbourne
  Hospital
• Monash Institute of Health Services Research
• Clinical Podiatrist, Caulfield Community Health

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BACKGROUND

• 4 of Australian population has diabetes
• 20 of these will experience foot ulceration
• Foot complication highly likely to result in
  hospital admission
• 2,800 lower limb amputations p / year in Aust.
• Cost of foot complications is high
• health care (US gt1 billion p/y, UK gt8,000 p/
  amp)
• quality of life

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WHO IS MOST AT RISK?

• Type 2 or IR Type 2
• Males gt Females
• gt 60 years
• Diabetes Duration gt10 years
• HbA1c gt 7.5
• Past history of ulcer / amputation
• OTHER smoking, social isolation, CALD and
  indigenous groups, socioeconomics

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MAKING AN IMPACT

• THE KEY IS PREVENTION
• VIGILANCE
• EARLY INTERVENTION
• EDUCATION

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ASSESSMENT

• WHO, WHEN, WHAT, HOW..?
• WHO - GP, podiatrist, nurse, diabetes educator.
• WHEN
• formal assessment
• - no complications - every 12 months
• - complications - every 3-6 months
• CHECK THEM AT EVERY OPPORTUNITY

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WHAT..

• Neuropathy
• Peripheral Vascular Disease
• Pressure areas (corns, callous, redness etc)
• Footwear
• Education / awareness of individual
• Need for referral

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NEUROPATHY

• Motor
• Shortening of small muscles
• Change in foot shape, structure and function
• Autonomic
• Loss of sweating
• Altered small vessel flow
• Sensory
• Loss of pain, vibration sensation

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CONSEQUENCES OF NEUROPATHY

• - Motor increased pressure areas
• - Autonomic more prone to injury / trauma
• - Sensory no warning about impending trauma
• Irreversible once established.
• Significant precursor to ulceration.
• Implicated in 80 of ulcers.

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ASSESSMENT OF NEUROPATHY

• Nerve conduction studies - little value
• Motor - visual assessment or muscle testing
• Autonomic - visual assessment
• Sensory - 10g Semmes Weinstein Monofilament
• Other - tuning fork, reflexes - both ? with age
• Symptoms - burning, tingling, numb, tightness

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MANAGEMENT OF NEUROPATHY

• Reduce risk factors
• BSLs
• avoid extreme temperatures
• Check feet regularly
• Footwear - appropriate
• daily checks
• wear at all times
• Protect vulnerable areas
• pressure spots - treatment
• insoles / shoes
• Skin care - moisturise

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PERIPHERAL VASCULAR DISEASE

• 2-3 times more likely in those with diabetes
• Largely affecting peroneal and tibial vessels
• Most significant factor in 60 of amputations
• Detection relies on - Clinical Assessment
• Appropriate
  Investigations
• PVD is highly suggestive of coronary artery
  disease and
• appropriate investigations should be initiated in
  the
• presence of PVD.

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ASSESSING FOR PVD

• MOST RELIABLE
• Palpation of pedal pulses
• dorsalis pedis
• posterior tibial
• femoral bruit
• Other
• non-healing wound
• Always be suspicious..

• LESS RELIABLE
• Ankle Brachial Index
• unless you can interpret
• Temperature
• Filling time
• Colour change

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ASSESSING FOR PVD

• Gold standard
• angiogram
• duplex ultrasound
• doppler studies
• toe pressures
• TCPO2

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MANAGEMENT OF PVD

• Mild to Moderate
• Reduce risk factors
• BSLs
• Smoking
• Diet / Lipids
• Medication
• Exercise - walking
• Protect the vulnerable foot

• Severe
• refer for vascular studies
• surgery requires gt70 stenosis
• OR
• presence of infection / gangrene
• Suspect PVD / non-healing wound
• refer for vascular review

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PRESSURE

• Causes of ? pressure
• Biomechanics
• motor neuropathy
• Limited Joint Mobility
• stiffening of soft tissue
• Footwear
• Lifestyle
• bed or chair

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CONSEQUENCE OF INCREASED PRESSURE

• Blisters
• Corns
• Callous
• Extravasation
• Tissue necrosis
• Tissue breakdown
• Ulceration

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FOOTWEAR

• Major contributor to ulceration!
• Should be worn at all times
• Should be appropriate
• Professionally fitted
• Should protect all areas
• pressure areas
• Does not need to cost
• Shop for features not brands

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SHOE FEATURES

• Rubber sole
• flexible across met heads
• Soft inner sole SHOPPING TIPS
• Rounded, Deep toe box 1.Buy in the afternoon
• Fastening 2.Wear in slowly
• laces 3.Check feet regularly
• buckle
• Firm, deep heel cup
• No seams and soft upper

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EDUCATIONWhat they DO know and what they SHOULD
know

• LEVEL OF KNOWLEDGE
• Do they know
• at risk for PVD, neuropathy, ulceration and
  amputation
• link between BSLs and complications
• how to care for their feet on a daily basis
• how to purchase appropriate footwear
• basic first aid for feet
• when to seek professional attention

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BASIC FOOTCARE

• DO
• Check feet daily
• colour
• temperature
• sores, cracks, blisters etc
• Check shoes before wearing
• Wash feet daily
• Dry well between toes
• no powder please
• spirits if very wet
• Moisturise daily

• Cut nails to shape of toe
• Check nails for changes
• See Podiatrist for Tx of corns and callous
• Pumice stone
• Dress cuts or cracks
• Have regular foot checks
• NB If patient cant see feet they cant check
  them!!!!!!

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BASIC FOOTCARE

• DONT
• Soak feet
• Walk barefoot
• Place feet near heat
• Cut nails down the side
• Use corn pads / cures
• Use a blade or sharp tool
• Ignore warning signs

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FIRST AID

• Wash and dry area
• Apply an antiseptic
• Betadine cream
• Re-dress daily for 7 days
• Monitor
• redness, swelling, pus, pain
• Seek professional advice if
• still present gt 7 days
• worsens (as above)

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WHEN TO REFER

• Everyone at least once
• annual check with podiatrist
• Complications
• PN, PVD, pressure areas
• tinea, nail / skin problems
• 2-6 monthly
• Poor eyesight
• Poor mobility
• Cognitive dysfunction

• Any non-healing injury
• Any ulcer
• Any signs of infection
• dont need an ulcer
• Any swelling, heat etc
• Better to refer and get a positive result than
  not refer at all and get a negative result

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RECOMMENDED READING

• 1. International consensus on the diabetic foot
  - guidelines for prevention
• and management.
• 2. National Centre for Diabetes Strategies -
  Type 2 guidelines
• 3. The Foot in Diabetes 3rd Edition (Boulton,
  Connor, Cavanagh)
• 1. Australasian Podiatry Council website
• 2. Diabetes Australia, Victoria website
• 3. Australian Diabetes Society website

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BACKGROUNDFOOT ULCERS AND DIABETES

• 20 will ulcerate
• 70 will re-ulcerate within 5 years
• 85 of amputations preceded by ulceration
• Cost is in millions p/a
• Immeasurable costs
• Carers, employment, QoL

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WHY DO PEOPLE WITH DIABETES ULCERATE?

• Neuropathy sensorimotor and autonomic
• loss of protective sensation
• pressure and trauma
• dry and poorly nourished skin
• Impaired response to injury
• blood platelets, macrophages, fibroblasts
• essential to regeneration of healthy tissue

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WHY DO PEOPLE WITH DIABETES ULCERATE?

• Rarely - as a result of deeper infection
• Cellulitis, abscess, osteomyelitis
• Peripheral Vascular Disease?
• Contentious - ? Precursor to ulceration
• Not in doubt is role of PVD in delayed healing
  and amputation.

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Why is healing a diabetic foot ulcer so
complicated?
Aetiology and management are multifactorial. AET
IOLOGY MANAGEMENT neuropathy pressure
relief pressure max blood flow
blood supply debridement trauma
infection cellular responses
glycaemic control SELECTION OF APPROPRIATE
DRESSINGS
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PHYSIOLOGY OF WOUND MANAGEMENT

• Proliferation
• newly formed granulation
• fibroblasts
• collagen
• angiogenesis
• epithelialisation
• Remodelling
• more organised
• increased tensile strength

ACUTE Well defined sequence. Overlap but well
regulated. Haemostasis - early matrix for
cells Inflammation - infiltration of essential
cells - prevent infection - release of growth
factors
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PHYSIOLOGY OF WOUND MANAGEMENT

• CHRONIC
• Stuck in inflammatory or proliferative phase.
• Altered are functions of
• - Fibroblasts
• - Proteases
• - Cytokines
• Healing is delayed or stops altogether.

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PHYSIOLOGY OF WOUND MANAGEMENT

• Points to consider
• normal wound healing process takes 2/52
• (with remodelling continuing beyond this)
• diabetes can slow this espec in presence of PVD
• However,
• if healing is not progressing
  within 2-4 weeks review management including
  dressings.

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BASIC WOUND DRESSINGS

• Aims
• Maintain a moist environment
• Provide a barrier against infection
• Reduce pain
• Promote rapid healing

• Dressings should also
• Be user friendly
• (removing and applying)
• Be cost effective
• Have no adverse effects
• Where possible have some evidence of effect

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BASIC WOUND DRESSINGS

• 5 generic groups
• Hydrogels (Solosite, Intrasite, Purilon)
• Hydrocolloids (Cutinova Hydro, Comfeel)
• Foams (Allevyn, Lyofoam, Biatain)
• Alginates (Kaltostat, Algoderm)
• Films (Opsite, Tegaderm)
• Miscellaneous Antimicrobials (Silvazine)
• Inert (paraffin gauze)
• Silicone based (Mepitel)

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MODERN ADVANCES IN WOUND MANAGEMENT

• Basic wound dressings dont address
• Cellular abnormalities associated with diabetes
• Possible influence of bacteria on healing
• Modern research and dressings seek to address
  these issues.

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MODERN ADVANCES IN WOUND MANAGEMENT

• Bacterial Burden
• Levels of bacteria referred to as
• Contaminated
• Colonised
• Infected
• Infection diagnosed at 105 or 100,000 or more
  bacterial cells.

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ADVANCES IN WOUND MANAGEMENT

• Bacterial load not significant enough to cause
  infection can impede healing?
• Known as critical colonisation there are no
  signs or symptoms of infection.
• Exact bacterial level at which healing is delayed
  is not yet known.
• Modern wound dressings attempt to address this
  issue.

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ADVANCES IN WOUND MANAGEMENT
MODERN WOUND DRESSINGS Silver based
dressings Acticoat, Avance, Contreet Biotechnolog
ies / cellular modulators Dermagraft,
Promogran Other Growth factors, honey
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USE OF SILVER IN MODERN WOUND DRESSINGS

• Inert metal that does not react with human tissue
  in its pure form.
• moisture (wound fluid) releases active ions.
• Biologically active ions bind with cell proteins.
  
• Impairs cell walls, disrupts cellular function,
• inhibits respiration, inactivates DNA / RNA
• Some release silver onto wound surface and some
  dont.

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USE OF SILVER IN MODERN WOUND DRESSINGS

• Effective against broad spectrum of bacteria
• MRSA
• VRE
• Fungi
• In low concentrations.
• Not thought to accumulate in the body excreted
  via liver or kidneys.

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USE OF SILVER IN MODERN WOUND DRESSINGS

• Early work conducted on animal models and
  in-vitro studies on affect of silver on bacteria
  demonstrate good results.
• Whilst both promising treat with caution
• human skin is unique
• in-vitro tests are tightly controlled

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USE OF SILVER IN MODERN WOUND DRESSINGS
In summary Little research evidence supporting
use in DFU. Other studies and anecdotal evidence
promising. Insufficient evidence on toxicity with
use of silver. Cost is an issue in light of lack
of evidence. More research is required
especially in the areas of adverse events an cost
effectiveness.
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BIOTECHNOLOGIES AND CELLULAR MODULATORS

• AIMS
• To overcome cellular deficiencies occurring as a
  result of diabetes
• Dermagraft
• Promogran

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DERMAGRAFT HUMAN DERMAL REPLACEMENT

• Manufactured in the USA, designed to replace
  damaged dermis (or parts of) to facilitate or
  kick start healing.
• Comprised of
• Biodegradable mesh
• Dermal fibroblasts (cultured in-vitro)
• Metabolically active
• Delivers matrix proteins and essential cytokines
  to wound bed

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BIOTECHNOLOGIES
PROMOGRAN Aim Address issues with
MMPs. Proteases destroy non-viable
tissue. Regulated and mediated when and
where. In DFU appears that this regulation is
faulty and proteases destroy health tissue as
well.
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OTHER ADVANCES IN WOUND CARE
HONEY No robust studies on use espec in DFU. Aim
is to address bacterial burden. Evidence is
mostly anecdotal. ps honey from the
supermarket doesnt work!!!!!
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RECOMMEDED READING

• Systematic reviews of wound care management (2 -
  1999) dressings and topical agents used in the
  healing of chronic wounds, (4 - 2000) diabetic
  foot ulceration.
• Health Technology Assessment
• World Wide Wounds
• www.worldwidewounds.com
• Wound Management Association (Vic)
• Learn to assess evidence presented in order to
  judge information.