Diabetic Foot PPT

Diabetic Foot

Two main Complications of Hyperglycemia Ischemia Neuropathy

 Predisposing peripheral vascular disease Atherosclerosis (medium-sized vessels below the knee)

Compromised blood supply

Ischemia

Coagulative necrosis

Ulcer Ischaemic toes due to artherosclerosis

Infection

Dry gangrene

Wet gangrene

Neuropathy Neuropathy

Sensory

Motor

Muscle wasting Foot weakness Postural deviation

↓ nociception

Deformities, stress and shear pressures

Trauma

↓ Proprioception, Unawareness of foot position

Stress on bones & joints Plantar pressure

Callus formation

Ulcer

Autonomic

Reduced sweating

Dry skin

Fissures and cracks

Infection

Activation of Protein Kinase C Intracellular hyperglycaemia 

Stimulates de novo synthesis for diacylglycerol (DAG) 

Activates PKC

Downstream effects: •Production of vascular endothelial growth factor •Increased vasoconstriction •increased deposition of extracellular matrix and basement membrane material •Production of plasminogen activator inhibitor •Production of proinflammatory cytokines

Disturbance in polyol pathway Hyperglycemia 

increase IC glucose (eg: nerves, lens, kidney, blood vessels) 

metabolize by aldose reductase 

sorbitol (polyol) 

Fructose  Accumulated sorbitol & fructose

NADPH used up during polyol pathway

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Increase IC osmolarity

Decreased GSH (Reduced glutathione)

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Influx of water

Cells susceptible to oxidative stress

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Osmotic cell injury

Oxidative cell injury

 Nerve Da

Diffentiation of Ischaemic and Neuropathy Ulcer

Symptoms

Inspection

Palpation Ulceration

Ischaemia

Neuropathy

Claudication

Usually painless

Rest pain

Or painful neuropathy

Dependent rubor

High arch + clawing of toes

Trophic changes

No trophic changes

Gangrenous digits

Surrounded by callus

Cold

Warm

Pulseless

palpable pulses

Painful

Painless

At the distal and over

Sites of pressures

Claw toe

Severe atrophy of the intrinsic foot muscles (lumbrical & interossei) d/t motor neuropathy resulted in imbalance of foot muscles & cocked-up toes.

Neuropathic foot ulcer

Callus formation on its surrounding ulcer lesion.

Infection • Individuals with DM have a greater frequency and severity of infection. • Reasons:  – abnormalities in cell-mediated immunity and phagocyte

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function  – diminished vascularization  – Hyperglycaemia aids the colonization and growth of a variety of organisms (Candida and other fungal species). Common pathogens:

• Combined with local ischemia, insensitivity to skin injury and localized pressure d/t deformity, more susceptible to infection

Clinical presentation of diabetic foot

Ischemic foot ulcer

Foot ulcers

Charcot Joint • Diabetic neuropathy is the most common cause.

• An acute Charcot’s foot will have swelling, erythema, raised skin temperature, joint effusion and bone resorption in an insensate foot

Charcot Joint

Rocker bottom charcot foot

Dry Gangrene

Wet Gangrene

Gangrene • Gangrene is a condition that involves the death and decay of tissue, usually in the extremities due to loss of blood supply. Dry gangrene

Wet gangrene

• no infection • little tissue liquefaction • In early stages, dull, aching pain, extremely painful to palpate, cold, dry and wrinkled. • In later stages, skin gradually changes in color to

• Bacterial infection

 – dark brown, then  – dark purplish-blue, then  – completely black

• copious tissue liquefaction • offensive odor • swollen, red and warm. • usually develops rapidly due to blockage of venous and/or arterial blood flow

• Treatment is surgical debridement and amputation.