23 - Diabetic Foot Ulcer Flashcards
Describe peripheral vascular disease
- 4 times more prevalent in diabetics
- Arterial occlusion typically involves the tibial and peroneal arteries, but spares the dorsalis pedis artery
What are the contributing factors to peripheral vascular disease?
- Smoking
- Hypertension
- Hyperlipidemia
- Elevated cholesterol or decreased HDL
- Obesity
- Age
What are the signs and symptoms of arterial occlusive disease?
- Claudicaion
- Rest pain
- Atrophic, shiny skin
- Diminished hair growth
- Dependent rubor (red coloration visible when the leg is in a dependent position but not when it’s elevated above the heart)
- Pallor on elevation (pale appearance)
What are the three categories of complications of peripheral neuropathy?
- Sensory
- Motor
- Autonomic
What are the sensory complications of peripheral neuropathy?
- Loss of protective sensation
- Pain, pressure and temperature sensation loss
What are the motor complications of peripheral neuropathy?
- Atrophy of the intrinsic muscles
- Flexion deformity
- Pressure at metatarsal heads and toes
What are the autonomic complications of peripheral neuropathy?
- Dyshidrosis and dry skin
- AV shunting (increase in bone and skin perfusion)
How does arterial occlusion and peripheral neuropathy lead to ulceration and amputation?
Associated with an increased risk of ulceration and amputation
- Increased plantar pressure
- Bony prominence
- Limited joint mobility
Describe a neuropathic wound
Neuropathic wound
- Someone with diabetes or lack of sensation
- This is pretty typical, usually on the bottom of the foot, common on metatarsal heads
- Beefy red tissue centrally
- Necrotic = black, brown, dark
- Fibrotic = white
What types of factors can delay wound healing?
Both systemic factors and local factors
What are the systemic factors that can delay wound healing?
Systemic factors
- Old age
- Obesity
- Chronic diseases (diabetes, anemia, etc.)
- Malnutrition
- Vascular insufficiency
- Immunodeficiency
- Poor health
- Stress
What are the local factors that can delay wound healing?
Local factors
- Continued pressure
- Dessication and dehydration
- Trauma and edema
- Colonization or infection
- Lack of oxygen delivery
- poor hygiene
What are the stages of normal cutaneous wound healing?
Day 0 - Trauma
Day 0-3 - Haemostasis, inflammation, cell migration
Day 3-7 - Cell proliferation, ECM synthesis, granulation tissue, angiogenesis, re-epithelialization
Day 10-14 - Remodelling, wound closure, contraction
What cell types will be present throughout the wound healing cycle?
Day 0-3 - Platelets, neutrophils, lymphocytes, macrophages, EPCs
Day 3-7 - keratinocytes, endothelial cells, fibroblasts, macrophages, EPCs
Day 7-14 - myofibroblasts, macrophages
What are all the factors that can lead to stalled wound healing?
- No “trigger” of acute tissue damage
- Exaggerated inflammation and PAIN
- Increased MMPs and decreased TMPs
- Deficiency of GF receptors and destruction of GFs y MMPs
- Senescent fibroblasts
- Increased bioburden or biofilm
- Loss of moisture control
- Altered nitric oxide levels
What are MMPs?
Matrix metalloproteinases (MMPs) are a group of enzymes that in concert are responsible for the degradation of most extracellular matrix proteins during organogenesis, growth and normal tissue turnover.
They are a GOOD thing for the wound because it “kicks it into high gear” to a point, bu when it gets too high it is no longer beneficial
What are the two ulcer grading systems we covered?
- Wagner’s grading system for diabetic feet
- University of Texas wound classification system
** NEED to know these **
What is Wagner’s grading system for diabetic feet useful for?
Useful for expressing the severity of a diabetic foot ulcer or infection
What is the scale for Wagner’s?
Grade 0, 1, 2, 3, 4, 5
Describe a grade 0 ulcer
Grade 0: no evidence of ulcer or infection.
Describe a grade 1 ulcer
Grade 1: ulcers are superficial lesions, but suggest full thickness erosions of the epidermis; the dimensions of these, and all, lesions should be noted.
Describe a grade 2 ulcer
Grade 2: ulcers may simply be considered deeper lesions that have penetrated to bone or a fascial plane (tracking).
Describe a grade 3 ulcer
Grade 3: ulcers extend to bone, or have invaded a fascial plane and may be associated with abscess formation. (Osteomyelitis is very likely. Such lesions, almost by definition, represent surgical problems because infected bone needs to be debrided and deep abscesses need to be drained.)
Must have extension to bone AND sign of infection or abscess ***
Describe a grade 4 ulcer
Grade 4: feet have gangrene of the forefoot, frequently requiring debridement or amputation.
Describe a grade 5 ulcer
Grade 5: implies gangrene of the entire foot that will likely require amputation.
Describe the University of Texas wound classification system
Combines a number indicating the depth of an ulcer with a letter which indicates the comorbidities
What are the scales
Depth
- Grade 0, I, II, III
Comorbidities
- Stage A, B, C, D
Describe grade 0
Grade O – Intact Skin, Pre or post ulcerative site
Describe grade I
Grade I – Ulcers are superficial wound through the epidermis/dermis
Describe grade II
Grade II – Through tendon or capsule
Describe grade III
Grade III – Through bone or into joints
Describe all the stages of comorbidities
Stage A – Clean
Stage B –Infection
Stage C – Ischemic
Stage D – Ischemic and infected
What are the principles of ulcer management?
1 - Vascular Supply 2 - Debridement 3 - Infection 4 - Offloading 5 - Wound Management 6 - Wound Closure 7 - Management of medical comorbidities 8 - Nutrition status
What are the MOST common diabetic foot infections?
Bacterial and fungal infections of the skin
Describe how a foot infection is different in a diabetic patient
Authors disagree about an increased susceptibility to staphylococcal skin infections, but there is general accord that once an infection of the foot or lower leg has been established, it is generally more severe and refractory in the diabetic patient
Need to treat with a broad spectrum antibiotic because it may be multi-organism
What is osteomyelitis?
- Osteomyelitis is one of the most serious problems of foot care in diabetic patients.
What is possible with diabetic foot infections?
Few have systemic manifestations of infection (fever, malaise, leukocytosis), but most patients have long-standing indolent ulcers with swelling and erythema.
What type of infections are common in diabetic feet?
- Mixed infections are common; staphylococci are usually associated with anaerobic or aerobic streptococci (not group A) or with one of the enterobacteriacae (E. coli, Klebsiella, Proteus, Enterobacter, etc.).
- Conservative treatment with antimicrobial drugs, incision, and the drainage is frequently unsuccessful, especially in the presence of vascular insufficiency; amputation may be required for cure.
What accounts for 45-70% of all lower extremity amputations?
Complications resulting from diabetes mellitus, which includes peripheral vascular disease, neuropathy, and infection, account for 45% to 70% of all lower-extremity amputations.
How can imaging be used in an infected foot?
The surgeon should use imaging techniques as a road map to point out the pathologic condition that requires debridement or drainage.
How can plain radiographs be utilized?
Plain radiographs can help identify bone destruction and gas in the soft tissues.
How can CT be utilized?
Bone destruction seen on plain films or a computerized tomography scan (CT) may indicate osteomyelitis, but questionable cases may be resolved by nuclear imaging techniques such as bone scanning or leukocyte Indium scanning.
How can MRI be utilized?
Magnetic resonance imagine (MRI) may help evaluate for osteomyelitis, Charcot foot, or deep abscess formation in questionable cases.
What is the rule of thumb when ordering imaging?
Because sophisticated imaging techniques are expensive, they should not be ordered routinely unless the diagnosis, or need for surgery, cannot be established by physical exam or plain radiographs alone.
What are three bone scans you can use?
- Technetium-99m scan
- Gallium 67 scan
- Indium scan
Describe a Gallium 67 scan
a type of nuclear medicine study that uses a radioactive tracer to obtain images of a specific type of tissue, or disease state of tissue
Gallium is taken up by tumors, inflammation, and both acute and chronic infection, allowing these pathological processes to be imaged by nuclear scan techniques
Describe a indium scan
A bone scan with WBC indication, so it is specific for an inflammatory process
Describe a Tech 99 scan
A true bone scan
Evaluates bone turnover (recognizes fracture, Charcot foot, bone infection, bone tumor, etc.)
What will you see on these scans in acute osteomyelitis?
- Tech 99 scan: positive
- Ga 67 scan: positive for “focal” uptake
- Indium scan: positive
What will you see on these scans in inactive chronic osteomyelitis?
- Tech 99 scan: positive
- Ga 67 scan: negative
- Indium scan: negative
What will you see on these scans in Charcot joint?
- Tech 99 scan: positive
- Ga 67 scan: negative
- Indium scan: negative
What is the gold standard for diagnosing bone infection pathology?
Gold standard = bone biopsy, we need to send specimen to pathology and a specimen to micro –> will tell you what the organisms are so you can tailor your antibiotics
What is the case study we discussed?
52 year old NIDDM male presents with a non-healing ulcer sub 5th secondary to spider bite
Hallux limitis with an equinus
Limited motion of big toe (use this part of the foot while walking)
Equinus, limited dorsiflexion of ankle, also contributing to this
The wound was debrieded
What did the patient present with one month post op?
- Diffuse swelling
- Bone marrow inflammation
- No organisms found
- No osteomyelitis (infection in a bone)
This was diagnosed as a charcot episode (a condition causing weakening of the bones in the foot that can occur in people who have significant nerve damage)
What is the treatment for Charcot foot?
Immobilization or external fixation
Both of these can work to stabilize the bone
What is found 6 months post-op in this patient?
Extra bone is found in the foot
This is part of the healing process - fibrosis and bone formation of a previously inflammed joint
What does extra bone cause in the foot?
Extra pressure
What did the patient present with 6 years later?
- Patient developed an ulcer stub on the first MPJ (metatarsal phalangeal joint)
- Ulceration is due to excess bone formation
What is the treatment for this ulcer?
- Skin flap rotation to cover wound with skin from foot
Called a bilobed rotational flap
What happened after this procedure?
Patient formed an ulcer on the 4th metatarsal while the rest of the foot was healing
This eventually lead to a partial 4th ray resection
An orthotic is used to help a patient with a 4th and 5th toe amputation to maintain stability and support while walking
