Download Diabetic foot infection

Meeting of the Lebanese Society
of Rheumatology
6th of November 2009, Beyruth
Diabetic foot infection
Dr Aurélien DINH, MD
Pr Louis BERNARD, MD, PhD
Infectious Diseases, University Hospital Tours, France
Corresponding author: [email protected]
Definition
• Infection is due
– to tissue infestation
– by micro organisms
– with inflammatory response
• Diabetic foot infection (DFI) is due to foot
ulceration
• Colonization should be distinguish from
infection
• Colonization is continuous on wound
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No infection !
Infection !
Diagnosis
• Diagnosis of infection is clinical (not
bacteriological):
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Induration
Warmth
Erythema
Local tenderness
Purulence discharge
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• DFI involve soft tissue with or wthout bone
tissue (osteitis)
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Are all diabetics equal for foot
infection ?
• NO !!
• Diabetic foot infection is mostly due to
peripheral neuropathy
• Mainly because of
– deformation (neuroarhropathy)
– insensitiveness
Deformation
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Sensitive neuropathy
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Peripheral neuropathy
• Lack of protective sensation
• Cracking skin
>>Neuropathy is favourable to wound
• Neuropathy delays diagnosis and
treatment of wound
• Neuropathy does’nt help to take care
(no pain, no care)
Physiopathology of DFI
• Foot wound and infection are more frequent in
diabetic population
• Risks factors are subject to debate but :
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Deficit of cellular mechanism of defense (hyperglycemia)
Peripheral neuropathy
Hyperpressure
No off-loading
Chronicity of wound
Hypoxy
Vascular disease
Anatomic deformation
Predictive factors of outcome
• Peripheral vascular disease
– restrict debridment
– Reduce antibiotic efficacy
– Encourage gangrene
• No off-loading
– Encourage by insensitivity to pain
– Refrain from wound healing
– Encourage infection and osteitis
Clinical classification
(staging in DFI)
• UT (University of Texas) Classification
– Easy to use, based on : depth of wound/ infection/
vascular disease
• IWGDF-IDSA classification (International
working group on the diabetic foot
classification) focus on infection stage
• Others classifications : Wagner, Lipsky,
PEDIS
UT Classification
Wound prevalence
by grade and
stage
Prevalence
of
amputation
within each
wound
category
IDSA-IWGDF classification
Lavery, CID 2007
How to collect specimens
for microbiological
diagnosis ?
• Bacteriological samples :
– should be performed
• Only in case of clinical infection
• Before antibiotic therapy
– Several methods exists
How to get reliable
microbiological data ?
• How to get bacteriological specimens ?
• There is no consensus to distinguish the best method
• Local protocols should be done by clinicians and
microbiologists
• They should specify: objective of analysis, method of
taking specimens, transport, culture…
• The goal is to identify micro organisms involve in
bacterial invasion and to avoid colonization
General principles
• Wound should be cleanse and debride
before obtaining specimens for culture
• Samples should
– be clearly identified
– and promtly send to laboratory
Microbiological evaluation
• Generally : blood cultures or cultures of deep
tissue biopsy specimen>>more clinically
significant
• Superficial swab: easy to perform, not
invasive
• Scraping with a curette
• Needle Aspiration
• Soft tissue biopsy
• Bone biopsy (osteomyelitis)
Superficial swab
Needle aspiration
Soft tissue biopsy
Bone biopsy
Microbiological correlation between
superficial sample and deep tissue
biopsy (from E. Senneville)
62
65
69
30
68
???
24
Sapico 1984, Lavery 1995, Slater 2004, Kessler 2006, Senneville 2006
Microbiological correlation
(between kind of wound and germs involved)
Lipsky CID 2004
Bone biopsy
• Gold-standard test for diagnosis osteo
myelitis (histological analysis should be
performed)
• Usefulness reliably recovering the
pathogens responsible for bone
infection
• It should be performed passing through
a clean zone
Concordance between superficial
swabs and bone biopsy
Senneville CID 2006
Recommanded wash out period
before bone biopsy : +15 days
7
pénicilline
céfalotine
netilmycine
clindamycine
ciprofloxacine
rifampicine
6
5
4
3
2
1
0
1
5
9
13
17
21
Witso et al. Acta Orthop Scand, 1999
Bone biopsy
Which relevance for other
laboratory investigations ?
• Limited interest
• No biological markers can help to make
difference between infection and
colonization
• Kinetic of the value of C Reactive
protein could be interesting to estimate
response to treatment
Assess risk factors
• Mechanical factors
• Vascular factors
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Clinical data
Systolic index pressure
Doppler
Transcutaneous oxygen pressure
others
© Copyright Pr Louis BERNARD
DFI management
• Multidiscplinary team
• Management
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Strict glycemic control
Strict off-loading
Medical debridment
Wound care plan
Edema controll
Tetanos vacinal status
Glycemia/off loading
• Glycemia
– should be strictly controlled:
• close monitoring,
• insulinotherapy
• Off loading :
– The major factor !!
– It should be total and continuous
Atherosclerosis/Debridment
• Seek for vascular disease to correct
• Mechanical debridment to clean tissue
– Physically excise dead and unhealthy
tissues
– Reduces bacterial burden
– Removes reservoir of potential pathogens
>> help to heal
Local therapy
• Local antiseptic :
– No Proof of effectiveness !!
• Local antibiotherapy :
– No Proof of effectiveness !!
Wound care
• Wound dressing
– should be performed daily,
– no adhesive or occlusive devices
• But there is:
– No good trials
– No consensus
– No study cost/effectiveness
Others
• Tetanos vaccine status : YES
• Hyperbaric oxygenia : no proof of
effectiveness
• Growth factors: no proof of
effectiveness
Antibiotherapy
• Indication: when there is infection and after
microbiological sample performed
• Empirical antibiotic regimen:
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Effective against staphylococcus aureus
Decrease with bacteriological results
Depending on severity of infection
Depending of diagnosis of osteitis
Mostly parenteral at the beginning
With good biodisponibility and penetration
Complex choice of
antibiotherapy
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Bacterial spectra >> effective on Staphylococcus
Biodisponibility >> intra veinous ?
Penetration >> high dose ?
Tolerance >> visceral failure
Interaction
Bitherapy >> to prevent resistance
High dose >> because of atherosclerosis
Treatment duration
Lipsky, CID 2004
Surgical strategies
• Vascular surgery
– by pass
– Percutaneous transluminal angioplasty
• Orthopedic surgery
– To control infection
– To attempt to salvage limb
Vascular surgery (1)
• Vascular disease exacerbate
infection>> revascularization
• Revascularisation can be realise
– to save the limb
– or to help healing
Vascular surgery (2)
• In case of critical ischemia
– revascularization should be perform when
sepsis is controlled
– In case of emergency: revascularization
should be performed close or at the same
time
• When ischemia is less critical:
revascularization should always be
discussed
Before
After
Benefit of revascularization (1)
Jacqueminet Diabetes care 2005
Benefit of revascularization (2)
Jacqueminet Diabetes care 2005
Methods for local treatment
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•
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Most important !!
Excision of infected tissues
Limited debridment of necrotic tissues
Drainage of deep abscess and deep space
infection
• In some cases : amputation = the only option
• Surgery should attempt to preserve the
integrity of walking surface
Indications for surgery
• Urgent surgical consultation:
– Fasciitis and necrosis
– Gangrene/abscess
• Delay surgery :
– cellulitis not responding after 3 days of efficient
antibiotic therapy
• Indications for amputation:
– If vascular disease: state on vascularization
possible procedure
– If non vascular disease: if extensive soft tissue lost
or fasciitis with life or limb-threatening infection
Osteitis in DFI
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•
•
•
When think about it ?
Which imagery ?
Surgery management
Which antibiotic therapy ?
Physical examination
• No healing despite appropriate care
• Positive probe to bone test
– (PPV:50-89% ; NPV>95%)
• Sausage deformity
Accuracy of probe to bone test
Lavery Diabete care 2007
Ulcers not healing
CRP and osteitis
Enderle et al. Diabetes Care 1999
Radiological diagnosis of osteitis (1)
Dinh MT CID 2008
Radiological diagnosis of osteitis (2)
Kapoor et al. Arch Int Med 2007
Radiological diagnosis of osteitis (3)
Termaat JBJS 2008
Surgery for osteitis
• Conservative surgery
– Limited resection
– No osteo synthesis
– Antibiotherapy from 4 to 6 weeks
(parenteral then oral)
• Different from acute Charcot foot
Hartemann-heurtier,
Senneville,
Diabetes metabolism 2008
Microbiology in osteitis of DFI
Hartemann-heurtier, Senneville, Diabetes metabolism 2008
Antibiotic treatment for osteitis in
DFI
Hartemann-heurtier, Senneville, Diabetes metabolism 2008
Preventive actions
• Education:
– risks of neuropathy and vascular disease,
self management and examination
• Pedicure:
– nails care, managing hyperkeratosis
• Shoes:
– should fit, trauma due to shoes are the
first cause of diabetic ulcers
• Preventive surgery:
– if major deformation to avoid futur
hyperpressure
Take home messages
• Diabetic foot ulcers are
– Coming on insensitive
foot
– Always colonized
– Infection diagnosis is
clinical
– Outcome depending
mostly on
atherosclerosis and
tipping off
• Management need
– Precise wound care
– Assess risks factors
– Microbiological
specimens
– Antibiotherapy
– Surgery some times
Thank you for your attention !
• Thanks to
– french infectious disease society,
– french society of vascular surgery,
– french society of microbiology
• Pr Agnès Hartmann-Heurtier (Endocrinology,
Pitié Salpétrière)
• Dr Eric Senneville (Infectious disease, Lille)