Diabetic Foot Infections ( Adult )

Publication: 31/07/2010  --
Last review: 12/10/2017  
Next review: 01/10/2020  
Clinical Guideline
CURRENT 
ID: 1947 
Approved By: Improving Antimicrobial Prescribing Group 
Copyright© Leeds Teaching Hospitals NHS Trust 2017  

 

This Clinical Guideline is intended for use by healthcare professionals within Leeds unless otherwise stated.
For healthcare professionals in other trusts, please ensure that you consult relevant local and national guidance.

Update on aztreonam injection shortage - now only restricted outside of CF and UTI (protected antibiotic codes no longer required for these indications). See alternatives - 22 August 2018

Clinical Guidelines for the Management of Adult Diabetic Foot Infections

Summary
Diabetic Foot Infections ( Adult )

Scope of the guideline

The guideline should be used Trust wide by medical, surgical, podiatrist and nursing staff for the management of patients presenting acutely with diabetic foot infections. The guideline may be used as guidance for primary care and community teams.

Criteria for use of guidelines

This guideline has been produced to promote consistent care of patients with diabetic foot infections. It outlines the actions necessary for managing these conditions and thereby reduces the risk to patients as much as possible. Whilst based on scientific evidence or professional consensus these guidelines are not intended to replace clinical judgement.

There are screening and referral pathways for diabetic feet, incorporating risk assessment for annual review on Leeds Health Pathways for primary care to access

All patients with diabetic foot infection should be assessed by the specialist diabetic foot care team.

Please refer urgently via the Hot Foot Phone 07786250788 (Monday – Friday 08.00 – 17.00), out of hours refer to the medical SpR on call.
See main guideline below for: Diagnosis
Investigations required
Non-Antimicrobial Management
Antimicrobial treatment

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Background
  • Diabetic foot infections (infected foot ulcers, gangrene and osteomyelitis) are a major cause for admission for patients with diabetes mellitus.
  • Diagnosing infection in the diabetic foot can be difficult and should be done in conjunction with a specialist team if in doubt.
  • Infections may present with few of the classic signs of infection with deranged glycaemic control often being the only clue
  • Conversely erythema in the diabetic foot may indicate other pathology such as trauma, inflammation/charcot arthropathy or ischaemia.
  • If not treated appropriately, foot infections can lead to septicaemia, amputation and death.
  • A multidisciplinary team approach (podiatrists, diabetologists, microbiologists, radiologists, vascular and orthopaedic surgeons, nursing staff and diabetes nurse specialists) is required to reduce morbidity and mortality for affected patients. (EL-A)

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Clinical Diagnosis

A “Hot Foot” in a patient with diabetes is a medical emergency and should be:

  • assessed immediately by a clinician with the skills and resources available to manage such problems
  • referred to and reviewed by a member of the Multidisciplinary Foot Care Team (MDFCT) with 24 hours

Foot Assessment
Remove all bandages and dressings on both feet to ensure a thorough assessment

  • Is there evidence of infection?
    • Locally (in the foot):  Hot, red (erythema), indurated, swelling, pain (although the absence of pain in a neuropathic patient does not exclude infection)
    • Systemically: Shivers/Shakes, arthralgia/myalgia, headaches, poor appetite, lethargy, deranged Blood Sugars (when previously well controlled)
  • Does the foot have normal perfusion?
    • Is it cool, pale and pulseless? Is there any necrosis (dead tissue)?

Severity of Infection Assessment(see Table 1- Severity Assessment for Diabetic Foot Infection)

Table 1- Severity Assessment for Diabetic Foot Infection (based on IDSA criteria)

Superficial / Mild

Moderate

Severe

  • Pus or 2 or more of: Erythema, warmth, pain, tenderness, induration
  • Any cellulitis <2cm around wound confined to skin or subcutaneous tissue, and
  • No evidence of systemic infection
  • Lymphatic streaking, deep tissue infection involving subcutaneous tissue, tendon, fascia, bone or abscess, or
  • Cellulitis > 2cm, and,
  • No evidence of systemic infection
  • Any infection accompanied by systemic toxicity (fever, chills, shock, vomiting, confusion, metabolic instability). The presence of critical ischaemia of the involved limb may make the infection severe
  • See Sepsis Guideline

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Investigation

Investigations are required to help determine the depth of the wound, the infecting microorganism and the general health/fitness of the patient (EL-A).

  • Blood tests: FBC, U&E, plasma & capillary Glucose, CRP, Blood cultures. Add venous blood gases in patients who take insulin for their diabetes if capillary blood glucose > 14 mmol/L, to exclude Diabetic Ketoacidosis. Lactate should be requested (from laboratory or by Blood Gas) to assess sepsis if present
  • Urine tests: Check for ketones in hyperglycaemic patients who take insulin for their diabetes.
  • Microbiological tests:
    • Blood Cultures: should be collected if severe infection suspected.
    • Wound Swabs: are not ideal and should only be collected if no other sampling is possible. They grow a range of organisms, many of which may simply be colonising the wound rather than causing the infection
    • Tissue sample (bone or soft tissue): collected from the base of the ulcer following thorough debridement and cleaning to reduce contamination. This should be done by an operator skilled at debridement (usually a member of the MDFCT.
    • Tissue Sample Collection SOP
  • Radiological:
    • Plain X ray: to look for evidence of gas in soft tissues / bony destruction / or fracture. Osteomyelitis cannot be excluded on the basis of plane radiography.
    • Magnetic resonance imaging (MRI): may be helpful to exclude osteomyelitis or abscess or determine if surgery is required
    • Magnetic resonance angiography (MRA): may be helpful to assess the vascular supply to the limb. This should only be requested following discussion with a Vascular Surgeon and MDFCT

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Treatment
Non-Antimicrobial Treatment

Having performed your clinical evaluation you may be able to assess the depth and severity of the infection. The assessment of diabetic foot infection can be difficult, the true depth of infection is not always apparent and the rate of spread can be alarming (EL-A). Frequent assessment by a suitably qualified health care provider is essential (frequency dictated by patient need and should be specified in the patients care plan).

All patients with diabetic foot infection should be assessed by the Multi-Disciplinary Foot Care Team urgently.

Please refer urgently via the Hot Foot Phone 07786 250788 (Monday – Friday 08.00 – 15.00), out of hours refer to the Leeds Teaching Hospitals Medical SpR on call.

  • Superficial/Mild infections may often be treated with oral antibiotics on an out patient basis under the close supervision of the Multi-Disciplinary Foot Care Team (see guidance below). (EL-A)
  • Most other infections will require:
    • Admission
    • Specialist assessment
    • Intravenous antibiotics (see antibiotic guidelines)
    • Rehydration
    • Pumped insulin therapy and regular capillary glucose monitoring
    • DVT prophylaxis
  • An urgent Vascular Surgical opinion (on call registrar, via LGI switchboard) is recommended for Moderate/Severe infections requiring admission if the need for surgical debridement is suspected. (EL-D) This would include patients with a clinical suspicion of abscess formation, evidence of rapidly progressing or penetrating infection or any other case that causes concern after discussion with the on call Consultant Physician.
  • Removal of infected tissue and abscess drainage may be urgently required so the patient must be fasted until the need for surgery is excluded.
  • A less urgent vascular surgical opinion may also be indicated to assess the need for revascularisation once the acute infection is controlled.

General wound care, dressings and diabetic foot ulcers (EL-D)

  • Patients should be non-weight bearing to aid healing of their ulcers
  • Sterile, non-adhesive dressings should be used to cover ulcers to protect them from trauma, absorb exudates, reduce infection and promote healing
  • Wound with low levels exudate - use Inadine® (unless iodine allergy) and a dry dressing
  • Wound with high levels exudate - use Aquacel Ag® and a foam dressing
For dressings advice please liaise with specialist diabetes podiatrist via Hot Foot Phone - 07786 250788

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Empirical Antimicrobial Treatment

Notes (and Key to symbols)

  • All treatment should be amended to directed therapy based on microbiology results from bone or tissue samples. Results from superficial swabbing should be viewed with caution.
  • Treatment durations should be individualised based on the extent of infection and the interventions performed.
  • Antibiotics should be reviewed 24 hours after major amputation and can usually be stopped (except if the patient remains systemically unwell or the patient has sustained a bacteraemia). All doses should be adjusted to account for the patient’s renal function
  • For Teicoplanin, does at 12mg/kg (actual body weight) 12-hourly for 3 doses then 12mg/kg daily
  • Teicoplanin levels should be monitored
  • It is the opinion of the guideline group that oral Co-amoxiclav electronic Medicines Compendium information on Co-amoxiclav 625mg (half the dose of the IV preparation) may be insufficient to treat bone infection. The dose cannot be increased due to toxicity from the clavulanic acid component. A compromise solution to optimise the therapy for penicillin susceptible organisms (such as B-haemolytic Streptococci) is to add 500mg of oral amoxicillin to the Co-amoxiclav electronic Medicines Compendium information on Co-amoxiclav 625mg. When the approach was discussed at the Microbiology Clinical Governance Group the consensus was for clinical equipoise but not considered harmful.
  • Many antimicrobial agents can precipitate Clostridium difficile infection. Test all cases of diarrhoea for CDI and contact a Microbiologist to discuss alternative antimicrobial options
  • Given the frequency of antibiotics required in this population and problems encountered with antimicrobial resistance, consideration should be given to testing patients alleging penicillin allergy by Clinical Immunology & Allergy service to inform the antibiotic choices. See also Management of Patient with Penicillin allergy Guideline

* Decision whether to treat with metronidazole IV or PO should be based on the GIT function and likely absorption of the septic patient

 

Targeted Antimicrobial Therapy

  • Empiric antimicrobial therapy should be reviewed in light of appropriate culture and sensitivity results.
  • Other antimicrobials with special considerations which may be used for empiric and targeted therapy include:
  • Linezolid electronic Medicines Compendium information on Linezolid: can rarely cause optic neuritis, thrombocytopaenia (and other blood dyscrasias). Licence is limited to a max. treatment duration of 28 days. Visual acuity and FBC should be checked before starting treatment and FBC should be checked weekly. Linezolid electronic Medicines Compendium information on Linezolid should not be given to patients taking medication with MAOI activity due to the risk of serotonin syndrome.
  • Daptomycin electronic Medicines Compendium information on Daptomycin: IV only but can be offered as a once-daily preparation through the CIVAS service. Can rarely cause myositis. Statins should be stopped temporarily while on treatment and patients should be monitored with baseline and weekly CK testing.
  • Co-trimoxazole electronic Medicines Compendium information on Co-trimoxazole: Can cause GI upset and more rarely blood dyscrasias especially in the elderly. Consider concurrent administration of folic acid on treatment and monitor patients with weekly FBC’s.

These agents should be used only after consultation with an Infection Specialist.
Discharge from hospital and out-patient follow-up

  • All patients should have a clear diagnosis and management plan (including planned duration of therapy) prior to discharge
  • No patient should be discharged with penetrating / deep infection (EL-D). Patients with superficial infection may be discharged after liaison with the Multi-Disciplinary Foot Care Team (Hot Foot Phone- 07786 250788)
  • All foot lesions must be inspected on the day of discharge (EL-D)
  • All patients on discharge should be referred to the Multi-Disciplinary Foot Care Team for out-patient follow-up, using appropriate referral forms

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Provenance

Record: 1947
Objective:

Aims
To improve the diagnosis and management of diabetic foot infections in adults

Objectives
To set-out criteria for referral to specialists

To provide evidence-based recommendations for appropriate investigation of diabetic foot infections

To provide evidence-based recommendations for appropriate empirical or directed antimicrobial therapy of diabetic foot infections

To recommend appropriate dose, route of administration and duration of antimicrobial agents.

To improve the diagnosis and management of diabetic foot infections in adults
Clinical condition: Diabetic Foot Infections
Target patient group: All adult patients with diabetic foot infections
Target professional group(s): Secondary Care Doctors
Secondary Care Nurses
Pharmacists
Adapted from:

Evidence base

Armstrong DG, Lavery LA, Harkless LB. Validation of a Diabetic Wound Classification System. The Contribution of depth, infection and Ischaemia to risk of amputation. 1998. Diabetes Care 21; 5: 855-859.

Boulton AJM, Connor H, Cavanagh PR. The Foot in Diabetes. 2000. John Wiley and Sons, New York.

Edmonds ME, Foster AVM, Sanders LJ. A Practical Manual of Diabetic Footcare,2004. Blackwell Publishing, Oxford.

Leese G, Nathwani D, Young M et al. Use of antibiotics in people with diabetic foot disease: A consensus statement. 2009. Diabetic Foot J 12; 1-10.

Lipsky, Benjamin A., Anthony R. Berendt, et al. (2004). "Diagnosis and Treatment of Diabetic Foot Infections." Clinical Infectious Diseases 39(7): 885-910.

Evidence levels:
A. Meta-analyses, randomised controlled trials/systematic reviews of RCTs
B. Robust experimental or observational studies
C. Expert consensus.
D. Leeds consensus. (where no national guidance exists or there is wide disagreement with a level C recommendation or where national guidance documents contradict each other)

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Approved By

Improving Antimicrobial Prescribing Group

Document history

LHP version 1.0

Related information

Appendix 1 Diabetic Foot Infection Pathway for A&E

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Equity and Diversity

The Leeds Teaching Hospitals NHS Trust is committed to ensuring that the way that we provide services and the way we recruit and treat staff reflects individual needs, promotes equality and does not discriminate unfairly against any particular individual or group.