Diabetic Foot Flashcards
Diabetic foot is caused by a range of diabetic complications.
(1) Neuropathy - what does this cause? - 3
(2) PVD:
- What is the main symptom?
- Why might it be painless?
(3) Infection:
- How does hyperglycaemia lead to cellulitis?
- Why do they get osteomyelitis eventually?
- What may be seen on XR in terms of the bone?
(4) What 3 deformities do they get?
(5) What 3 mechanisms lead to ulcer formation?
Intermittent claudication - may be painless due to neuropathy
Sensory loss (painful/painless)
Motor loss
Autonomic loss
Hyperglycemia impairs WBC function + neuropathy and ischaemia impair normal inflammatory and immune response.
Diabetic foot osteomyelitis (DFO) is mostly the consequence of a soft tissue infection that spreads into the bone, involving the cortex first and then the marrow.
Bone destruction and cortical thinning ====== Charcot's foot Toe clawing High arched foot
Neuropathy and arterial disease leading to ischaemia
Ulcers:
- How does neuropathy cause ulcers?
- How does arterial disease cause ulcers?
They happen in combination in most patients
- What do they look like?
- Why does impaired proprioception (neuropathy) increase the risk of?
Where do neuropathic ulcers form?
Where do neuroischaemic ulcers form?
What are the signs of an infected ulcer?
Poor perfusion (delivery of nutrient-rich blood) to the lower extremities. The overlying skin and tissues are then deprived of oxygen, killing these tissues and causing the area to form an open wound.
Local paresthesias, or lack of sensation, over pressure points on the foot leads to extended microtrauma, breakdown of overlying tissue, and eventual ulceration.
Punched out
Callus base/border - look up
Toes or malleoli - look up ======= Cellulitis on margin Increased pain Smell Fever
Skin changes:
Autonomic neuropathy:
- How may the skin feel?
- What will the skin not be able to produce?
- Why do they get a bounding pulse?
If there is arterial ischaemia, PVD May develop. What are the 5 signs of PVD?
Dry
Lack of sweat
DM causes tachycardia
Pale Painful/painless Pulseless Cool Hairless
pain, paralysis, pallor, paresthesia, and pulselessness
Stages of ulceration:
What are the 4 stages?
Neuropathy (diagnosed clinically)
Ischaemia (diagnosed clinically + doppler +/- angio)
Bony deformity (e.g. Charcot joint)
Infection (swabs, culture, x-ray for osteomyelitis, probe ulcer to see depth)
Charcot foot (aka neuropathic joint)
Presentation?
What may happen to the joint itself?
What does it usually present after?
Why does neuropathy cause this?
Acute swelling
Red and hot
Deformity
Joint subluxation
Minor trauma - increased risk due to lost proprioception
Bone damage due to (insensate) fracturing, inflammation, and/or increased osteoclast activity
Foot deformities:
Why does toe clawing occur?
Why does a high arched foot (pes cavus) occur?
Due to motor neuropathy - MPJ hyperextension and interphalangeal flexion
Due to motor neuropathy
Management - Patient education:
What should be done daily?
What should patients avoid?
Why should they wear slippers indoors?
Toenail care:
- What does this prevent?
- Why may a podiatrist need to be used?
What type of shoes should they wear?
Inspection and washing of feet
Fires
Hot water bottles
Very hot baths
To prevent trauma
To prevent ingrown toenails
Those with poor vision or problems bending
Comfortable, spacious shoes
Management - Monitoring:
How often is a review done?
What type of examination is done to determine ulcer risk?
Annually
Neurovascular examination
Management - Treatments:
When should they be referred to a podiatrist or diabetic foot MDT?
5 members of the diabetic foot MDT?
When new diabetic foot problems
Diabetologist Surgeon Specialist nurse Podiatrist Tissue viability nurse
Management - Treatments:
What is given for infections?
What must be done for investigations before Rx is given?
What is done for the ulcers?
Painful neuropathy:
- What antidepressant can be used?
- What meds are used as second-line for nerve pain?
ABs - flucloxacillin
Swabbing first
Debridement (removes dead tissue, allows wound healing)
Wound dressings
Offloading
TCA’s - tricyclic antidepressants - amitriptyline
Gabapentin or carbamazepine
Management - Treatments:
Charcot foot:
- What is done?
- What can be prescribed for them?
Immobilisation with a cast 3-6 months
Offloading - they stop weight-bearing on the foot
Prescription shoes
