The Diabetic Foot Flashcards
What are the two complications of diabetes that predispose to foot disease?
Diabetic Neuropathy - all 3 of sensory, motor and autonomic neuropathy influence development of foot disease
Peripheral vascular disease - macrovascular complication of diabetes
What is the main cause of diabetic foot disease?
Distal sensory neuropathy
What are the conditions that are associated with development of diabetic foot disease?
1) Sensory neuropathy (microvascular damage to the blood supply to the nerves)
2) Motor neuropathy - develop clawing of the toes due to paralysis of the long extensors/flexors of their feet/toes, indicates that sensation of difference in weight distribution through the foot has been lost as well
3) Limited joint mobility - sugar binding to the collagen in the tendons makes them less flexible reducing joint mobility, patients will be unable to place their hands flat together
4) Autonomic neuropathy - no release of oils into skin so skin breaks down
5) Peripheral vascular disease
6) Trauma - repeated unnoticed minor/discrete events
7) Reduced resistance to infection
8) Other diabetic complications e.g. retinopathy
What can be used to look at the arterial beds and assess macrovascular damage of these beds?
Multi-station contrast-enhanced magnetic resonance angiograph
- shows where large vessels and arterial beds have lost circulation
How does the neuropathic foot present with foot ulceration?
Numb (sensory neuropathy) Dry (autonomic neuropathy) Loss of reflexes Warm Palpable foot pulses - Ulcers occur at points of high pressure loading that haven't been sensed
How does the ischaemic foot present with foot ulceration?
Cold
Pulseless
- Ulcers at the foot margins
Given the features of the neuropathic and ischaemic foot, how does the neuro-ischaemic foot present with foot ulceration?
Numb Dry Cold Pulseless - Ulcers at points of high pressure loading AND at foot margins
Why are the features of a foot with ulceration/s important?
Weighs in on which treatment option is the best - i.e. does the patient need an angioplasty to improve blood flow (ischaemic foot) or just to take weight off the foot and let it heal(neuropathic foot)?
How is the foot of a diabetic patient assessed?
Appearance - how does it look? are there deformities? calluses?
Feel - how does it feel? hot/cold? dry?
Foot pulses - check for dorsalis pedis/posterior tibial pulse to check blood flow to the foot
Neuropathy - vibration sensation, temperature, ankle jerk reflex, fine touch sensation
How is diabetic foot disease managed from a diabetes perspective?
Control blood sugar - reduce hyperglycaemia
Control blood pressure - reduce hypertension
Control dyslipidaemia - try to stop or slow the progression of atheroma
Stop smoking if they do
Education - educate the patient
What are the steps in preventative management of diabetic foot disease?
1) Control diabetes
2) Inspect feet daily
3) Buy bigger and more comfortable shoes
4) Buy shoes with laces and square toe box
5) Inspect inside of shoes for foreign objects
6) Attend chiropodist
7) Cut nails straight across
8) Care with heat and testing heat
9) Never walk barefoot (burning on hot sand, small stones etc)
What is the approach to treatment of diabetic foot disease in terms of personnel and who is involved?
Multidisciplinary team approach - diabetologist - diabetes nurse - chiropodist - orthotist - vascular surgeon - orthopaedic surgeon Potentially a limb fitting centre in cases of disabling amputation
What is the role of the diabetologist and diabetes nurse in management of diabetic foot disease?
Both need to help educate the patient
- diabetes nurse must take them through all the aspects of care the patient must go through and to help control their blood glucose
What is a vascular surgeon needed for in management of diabetic foot disease?
To try and improve blood flow to the foot
- can do a percutaneous angioplasty
- alternative is open bypass surgery
What is an orthopaedic surgeon needed for in management of diabetic foot disease?
Either to
- correct abnormally shaped feet
- or to help amputate lost tissue/toes
What is a chiropodist/podiatrist needed for in management of diabetic foot disease?
To help prevent problems
To remove callus around ulcers to help healing
What is an orthotist needed for in management of diabetic foot disease?
Orthotists design and build specialist footwear for the patient either to prevent ulcers or to prevent worsening of the ulcers while they are healing
What are the options for management of foot ulceration?
Relief of pressure
- bed rest (however, risk of DVT, heel ulceration)
- redistribution of pressure/total contact cast
Antibiotics, possibly long-term (e.g. infection in bone, osteomyelitis)
Debridement (removal of dead tissue/toe/foot)
Revascularisation
- angioplasty
- arterial bypass surgery
Amputation
What is Charcot’s foot?
“Jigsaw of bones all jumbled up”
- Patient has neuropathy and don’t feel their foot and don’t put pressure down appropriately
Results in destruction of joints which then leads to all the bones being totally disturbed producing abnormal pressure in the foot
What is osteomyelitis?
Infection of bone which leads to similar symptoms/signs as Charcot’s foot
What are the features of the foot in osteomyelitis and Charcot’s foot?
Osteomyelitis
- hot red foot with ulcer
- MRI shows marrow oedema in forefoot and hindfoot near the ulcer (inflammation around site of infection)
Active Charcot’s foot
- hot red foot with NO ulcer
- MRI shows marrow oedema in midfoot subchrondral
Both will show abnormal articulation of bones in the foot
- point here is that both diseases are difficult to distinguish between and Charcot’s is a result of diabetic neuropathy over a long period of time where the neuropathy, and resulting uneven distribution of pressure, has been left untreated
What are the conclusions about diabetic foot disease?
- Common and major burden to our patients
- Neuropathy, peripheral vascular disease (PVD), infection and other factors contribute
- Management takes time
What is a new way of predicting risk of blindness and amputation in diabetic patients?
Used risk prediction equations to estimate risk of blindness and amputation
- took into account T1/T2D, yrs since diagnosis, smoking, ethnicity, deprivation, HbA1c levels, sbp, Cholesterol ratio, atrial fibrillation, heart failure, coronary vascular disease, renal disease, rheumatoid arthritis, and presence of retinopathy
All of these showed clear risk prediction conclusions regarding blindness and amputation
