Diabetic Foot Infection, Severe
It is essential that cases of severe diabetic foot infection are managed in conjunction with the Diabetic Foot MDT. Refer to OUH Acute Foot Pathway (Acute Foot Pathway)
Severe diabetic foot infection is defined as: 2 or more of the following
- local swelling or induration
- erythema
- local tenderness or pain
- local warmth
- purulent discharge
WITH signs of sepsis/systemic inflammatory response syndrome (SIRS) - see also guideline Sepsis identification and management
Particular attention should be paid to the potential need for urgent surgery (source control), discuss with on-call Vascular team.
A wound sample should be taken prior to/as soon as possible after starting antibiotics. Superficial swabs have limited diagnostic value, so preference should be made for a deep swab, collection of pus, tissue sample (by an appropriately trained clinician) or surgical cultures.
Cases of severe infection are typically commenced on broad spectrum intravenous antibiotics:
- Give IV for at least 48 hours (until stabilised).
- Review empirical treatment within 48-72 hours.
- Switch to oral antibiotics should be encouraged when clinically appropriate. Tailor according to culture and sensitivity.
- Course length is based on clinical assessment: minimum 7 days and up to 6 weeks for osteomyelitis (use oral antibiotics for prolonged treatment).
- Metronidazole should not be given for longer than 14 days.
Consider if there are risk factors for Pseudomonas, which include: previous isolation of Pseudomonas from wound swab or tissue; recent/frequent exposure to broad spectrum antibiotics.
If no risk factors for Pseudomonas
Preferred:
flucloxacillin 500mg-1g iv qds AND metronidazole 400mg po tds (500mg iv tds if NBM)
If haemodynamically unstable: ADD gentamicin 5mg/kg IV single dose. If creatinine clearance less than 30 ml/min reduce dose to 3mg/kg.
Oral follow-on: flucloxacillin 500mg – 1g po qds AND metronidazole 400mg po tds
Penicillin allergy non-severe:
cefazolin 1g-2g iv tds AND metronidazole 400mg po tds (500mg iv tds if NBM)
If haemodynamically unstable: ADD gentamicin 5mg/kg IV single dose. If creatinine clearance less than 30 ml/min reduce dose to 3mg/kg.
Oral follow-on: cefalexin 1g po tds AND metronidazole 400mg po tds
Penicillin allergy severe and/or MRSA positive:
co-trimoxazole 960mg po bd (iv if NBM) AND metronidazole 400mg po tds (500mg iv tds if NBM)
OR
teicoplanin 6mg/kg iv (see teicoplanin monograph for dose banding, dose frequency and monitoring) AND metronidazole 400mg po tds (500mg iv tds if NBM)
If haemodynamically unstable: ADD gentamicin 5mg/kg IV single dose. If creatinine clearance less than 30 ml/min reduce dose to 3mg/kg.
Oral follow-on:
co-trimoxazole 960mg po bd AND metronidazole 400mg po tds
OR
doxycycline 100mg po bd AND metronidazole 400mg po tds
If risk factors for Pseudomonas or Pseudomonas isolated
Includes severe and moderate DFI where Pseudomonas is suspected/confirmed
piperacillin-tazobactam 4.5g iv qds
OR
ceftazidime 2g iv tds AND metronidazole 400mg po tds (500mg iv tds if NMB)
MRSA positive: ADD linezolid 600mg po bd OR if unable to tolerate, teicoplanin 6mg/kg IV (see teicoplanin monograph for dose banding, dose frequency and monitoring).
If haemodynamically unstable: ADD gentamicin 5mg/kg IV single dose. If creatinine clearance less than 30 ml/min reduce dose to 3mg/kg.
Oral option:
clindamycin 450mg po tds AND ciprofloxacin* 500mg–750mg po bd (note: High risk of developing c-diff.)
*Ensure that the patient is given the Fluoroquinolone MHRA patient information leaflet.
Fluoroquinolones, including ciprofloxacin are associated with disabling and potentially long-lasting or irreversible side effects. See Fluoroquinolone antibiotics - severe adverse effects.