L6: Diabetic Foot Flashcards
Def of Diabetic Foot
- Infection, ulceration or destruction of deep tissues associated with neurological abnormalities & various degrees of peripheral vascular diseases in the
lower limb (based on WHO definition)
Epidemeology of Diabetic Foot
Pathophysiology of Diabetic Foot
Pathogenesis of Neuropathy
- Changes in the vasa nervosa
- Metabolic disorders with release of nerve toxic substance ( e.g. end glycation product)
what types of nerves does neuropathy affect?
- Motor Nerves
- Autonomic nerves
- Sensory nerves (most important)
Motor nerves affection in neuropathy (Diabetic Foot)
wasting of small muscles of the foot ——> foot deformities —–> abnormal pressure area
Autonomic nerves affection in neuropathy (Diabetic Foot)
- Dryness of the skin and loss of sweat and oil secretion which leads to excessive callus formation and skin cracks.
- Loss of neurogenic component of inflammatory response blunted inflammatory response and less severe signs of a severe infections.
Sensory nerves affection in neuropathy (Diabetic Foot)
- Sensory loss of superficial and deep sensation is the
most important part of sensory affection - Patients are unaware of trauma to the foot (loss of
protective mechanism) pressure sores over weight bearing points of the foo
Pathogenesis of Ischemia in DM
- Accelerating atherosclerosis in diabetic patients
- Usually atherosclerosis affects small size arteries (anterior tibial, posterior tibial and dorsalis pedis)
Pathophysiology of infection in DM
Peripheral Neuropathy
- Sensory and autonomic neuropathy provides site of
entry of organisms and blunt neurogenic immune
response.
Metabolic
- Hyperglycemia a state of immuno-suppression
Diabetic foot microbiology
- Usually in limb threatening diabetic foot infections there is polymicrobial bacterial infection with gram positive, gram negative, and anaerobic bacterial
infection .
Clinical Picture of Diabetic Foot
- Trophic ulcers (either ischemic or neuropathic)
- Dystrophic changes
- Gangrene & previously amputated toes or foot
Compare between Ischemic & Neuropathic Ulcers in terms of:
- Site
- Temperature
- Sensation
- Pulse
- Pain
- Deformity
Examination of Diabetic Foot
- Dermatological
- Neurological
- Vascular
Dermatological assessment of Diabetic Foot
Neurological assessment of Diabetic Foot