DF, Gangrene, Leg Ulcers Flashcards
What are the pathologies associated with diabetic foot?
- neuropathy
- vasculopathy
- diabetic (neuropathic) ulcer
- diabetic foot infections
- gangrene
What causes the glove & socks hypothesia?
interacting metabolic abnormalities worsened by injury of vasa nervorum:
Sensory neuropathy in distal nerve fibers (loss of protective sensation leads to lack of awareness of incipient or ulceration)
What are the affects of motor neuropathy?
1- alteration of distribution of forces during walking
2- reactive thickening of skin (callus) at sites of abnormal load
3- ischemic necrosis of tissues beneath callus
4- neuropathic ulcer
How does Charcot foot of diabetes develop?
AUTONOMIC NEUROPATHY
osteoporosis
What are the types of vasculopathy?
Macrovascular disease (due to atherosclerosis) Microvascular disease
What is the pathophysiology of microvascular disease?
STRUCTURAL
- thickened basement membrane
- capillary wall fragility
- thrombosis
FUNCTIONAL (vasomotor neuropathy)
- defective microcirculation
- abnormal endothelial function
How is vasculopathy managed?
- antiplatelet
- vasodilators
- pentoxyphylline
What are the routes of infection entry leading to DF?
- skin fissuring & cracks
- fungal infection (tinea pedis)
- ulcers
What are the predisposing factors to Diabetic foot?
- hyperglycemia
- ischemic tissues
- neuropathy
- poor immune system
What is the clinical picture of DF?
- general: from mild to septic shock
- local: hot, red, tender swelling, may have pus
- due to peripheral neuropathy the presentation may be offensive odor or tissue destruction (sloughing & ulcers)
What is the most important laboratory investigation in case of DF?
SWAB & CULTURE/SENSITIVITY (to use appropriate antibiotic)
What radiological investigations are used in case of diabetic foot?
XRAY: to detect chronic osteomyelitis & joint destruction (Charcot’s joint)
DUPLEX: to assess vascularity
MRI: to assess extent of soft tissue involvement
What is the investigation of choice to see soft tissue involvement?
MRI
What is Wagner’s classification system?
0: pre ulcerative area
1: superficial ulcer (partial/full thickness)
2: ulcer deep to tendon, capsule, bone
3: 2 + abscess, osteomyelitis or joint sepsis
4: localized gangrene
5: global foot gangrene
What is the first & most important line of prophylaxis against DF?
proper control of blood glucose
How should DF be prevented?
- control of blood glucose
- care of foot
- establishment of good vascularity (vasodilators, antiplatelets, vitamins)
- regular exercise
What is the medical treatment for diabetic foot?
1- limb elevation
2- hot fomentation
3- correction of hyperglycemia: shift to insulin
4- antibiotics (PARENTERAL ROUTE)
- start with broad-spectrum empirical then according to C&S
What is the medical treatment for diabetic foot?
1- limb elevation
2- hot fomentation
3- correction of hyperglycemia: shift to insulin
4- antibiotics (PARENTERAL ROUTE)
- start with broad-spectrum empirical then according to C&S
What is the surgical treatment of DF?
- GENEROUS DEBRIDEMENT
- under general anesthesia
- adequate incision & drainage of any pus
- excise any necrotic tissue
- removal of all callus (sequestrum)
How should a wound or ulcer be managed in a diabetic patient?
- daily irrigation of exudation with saline
- daily dressing with topical antiseptic
- avoid excessive packing
- remove any new necrotic tissue & incise any new pus collection
- off-loading measures (eliminate any plantar pressure on the wound/ulcer)
- total contact casting
- removable cast walkers
- ankle foot orthosis
- custom & surgical shoes
What is gangrene & what are its types?
macroscopic necrosis (tissue death) + putrefaction
types:
- dry
- moist
- special: gas gangrene, bed sores, Fournier’s gangrene, necrotizing fasciitis
What is the difference between dry & moist gangrene?
DRY MOIST
- chronic ischemia - acute ischemia or chronic ischemia with underlying edema or infection
- minimal putrefaction - marked
- minimal odor - very offensive
- line of demarcation - no line (severe toxemia)
- absent skipped lesions - present
- if small: autoseparation - amputation until level of good vascularity
- if large: amputation
What is Fournier’s gangrene?
- idiopathic gangrene (necrotizing fasciitis) of the scrotum
- due to synergistic infection
- affects scrotum but spares testis
How is Fournier’s gangrene treated?
debridement & scrotal reconstruction
What is an ulcer?
loss of epithelial cover
How should an ulcer be inspected?
- site
- size
- shape
- number
- floor
- edge
- margin & surrounding skin
- discharge
What are the different sites of ulcers & their causes?
- UPPER FACE: basal cell carcinoma
- LOWER LIP: squamous cell carcinoma
- ABOVE MEDIAL MALLEOLUS: venous ulcer
- DISTAL PART OF LOWER LIMB: ischemic ulcer
- PRESSURE POINTS: neuropathic ulcer
What can be inspected in the floor of an ulcer?
- red granulation tissue: healthy ulcer
- white necrotic material/pyogenic membrane: unhealthy ulcer
- wash-leather slough: syphilitic gumma
- caseating material: TB
What are the different edges of an ulcer?
- Shelving (sloping): healing ulcer
- Punched out:
- Undermined: TB
- raised & everted: SCC
- rolled in & beaded: BCC
What could be seen around the margin of an ulcer?
- pigmentation & eczema: venous ulcer
- trophic changes: ischemic ulcer
- cyanotic: TB
What does discharge indicate in an ulcer?
- purulent: active infection
- green: pseudomonas
- casious: TB
- serous: healthy healing ulcer
What are the causes of tender ulcers?
- ischemic ulcer
- venous ulcer
- any inflamed or infected ulcer
What are the causes of non tender ulcers?
non-infected ulcers
- neuropathic
- malignant
- TB
- syphilitic
Why is the base tested?
- for presence of induration (underlying fibrosis)
most of chronic ulcers are indurated especially venous & malignant ulcers
describe an ischemic ulcer.
vascular insufficiency causing sloughing of ischemic tissues
- at most distal parts like toes, dorsum of foot, or around maleoli
- pale or blackened or mummified margins
- extremely tender
describe a venous ulcer.
incompetent lower perforators leading to deposition of hemosiderin & release of proteolytic enzymes
- first sign is itching & eczema
- usually in Gaiter’s area
- margin is pigmented & contains eczema
- extremely tender
describe a neuropathic ulcer.
shin denervation (autonomic neuropathy) -> trophic ulcer
- at pressure sites or any friction site (ball of toes & heel)
- hypertrophied skin (hyperkeratotic) margin
- not tender unless there’s an infection
