Diabetic%20foot%20infection Treatment

• Management of diabetic foot ulcer in patients w/ diabetes needs an interdisciplinary approach to address glycemic control, infection, offloading of high-pressure areas, lower extremity vascular status & local wound care
• Mild diabetic foot infections are treated in outpatient setting w/ oral antibiotics, wound care & pressure offloading
• Selected patients w/ moderate diabetic foot infections & all patients w/ severe infections will be given intravenous antibiotics & to be evaluated for possible surgical intervention while staying in the hospital
• For diabetic foot wounds that have no evidence of soft tissue or bone infection, antibiotic therapy is not required
• For infected wounds, obtain a post-debridement specimen (preferably of tissue) for aerobic & anaerobic cultures

• Selection of specific antibiotic therapy should be based on:
  
  • Causative pathogens that are likely or proven
  • Susceptibility to the antibiotic
  • Clinical severity of the infection
  • Evidence of efficacy for diabetic foot infection
  • Costs

• Infected diabetic foot wound that has failed antimicrobial therapy is usually associated w/ progressive tissue destruction & poor wound healing
• The most common pathogens when infection first begins are Staphylococcus aureus, Streptococcus agalactiae, & Streptococcus pyogenes
  
  • Anaerobic & Gram-negative pathogens can play a role in the process w/ time & the presence of devitalized tissue that leads to polymicrobial infections

• Parenteral therapy is initially administered in some moderate infections & most severe infections then switch to oral therapy when the infection is responding
• Empiric antibiotic regimen should cover the most common infecting organisms, usually active against standard strains of staphylococci & streptococci, & then be modified according to infection severity & available clinical or microbiological information
• For mild infections, oral narrow-spectrum antibiotics w/ activity against aerobic gram-positive organisms are preferred to be given for 1-2 weeks
  
  • It is not advisable to give prolonged antibiotic treatment (eg >14 days) in mild soft tissue diabetic foot infection

• Anti-anaerobic empiric therapy is given for necrotic, gangrenous or foul-smelling wounds that also require debridement
• Combination therapy is given when:
  
  • The presumed or proven cause of the infection is >1 microorganism
  • The pathogen has a high potential for developing resistance
  • Selecting an agent to which resistance may quickly develop when used alone

• Once the results of the culture & sensitivity tests are available, consider changing to a more specific regimen that targets just the isolated pathogens
• Generally, antibiotic therapy can be discontinued when signs & symptoms of infection have resolved, even if the wound has not healed

Diabetic Foot Osteomyelitis

• When treating diabetic foot osteomyelitis, the following should be considered:
  • Anatomic site of infection
  • Local vascular supply
  • Soft tissue & bone destruction extent
  • Presence of any systemic signs of infection
  • Patient’s preference for treatment

• Antimicrobial agent should be based on the results of a bone culture, especially because of the need for long-duration therapy
• When empiric therapy is needed, therapy usually covers S. aureus as it is the most common pathogen, but the patient’s history or culture results may suggest a need for broader coverage
• Antibiotic therapy of 6 weeks duration is recommended in patients w/ diabetic foot osteomyelitis that did not undergo resection of the infected foot while 1-week duration for those who have all infected bone resected
• Remission rate does not appear to increase when post-debridement antibiotic therapy is extended beyond 6 weeks or if IV treatment is given longer than a week
• Long-term suppressive therapy or intermittent short courses of treatment of recrudescent symptoms can be the appropriate approach for patients who have apparently incurable infection
• Patients with diabetic foot ulcers may also be given recombinant human epidermal growth factor as data have shown that it enhances wound healing and shortens healing time

Wound Care

• Essentials of wound care in a diabetic patient w/ foot wound include:
  
  • Debridement
  • Offloading
  • Selection of dressings

• Debridement is the removal of debris, eschar, surrounding callus or devitalized tissue that may impede wound healing & foster infection
  
  • It is essential in nonischemic wound to have regular debridement of nonviable tissue
  • Generally, sharp/surgical method of debridement is used but mechanical, autolytic or larval debridement techniques may be appropriate for some wounds

• Offloading is the redistribution of pressure off the wound to the entire weightbearing surface of the foot
  
  • This may be achieved by using temporary footwear until the ulcer heals & foot character stabilizes
  • Pressure-reducing devices (eg removable & irremovable cast walkers & total contact casting) have demonstrated efficacy in plantar surface ulcers
  • Pressure-relief devices that cannot be removed are associated w/ faster healing ulcers than are removable devices as per clinical trials
  • Consultation w/ surgeon skilled in foot surgery is suggested to address bony deformities that prevent the fitting of appropriate footwear &/or offloading of pressure-related ulcers

• Appropriate selection of dressings that allow for moist wound environment & control of excess exudation is necessary in wound care
  
  • In general, dry wound needs topical treatment that adds moisture while diabetic foot ulcers w/ heavy exudate need a dressing that absorbs moisture
  • Dressings should be changed at least daily, both to apply a clean wound covering & to allow careful examination of the wound for infection
  • Povidone iodine impregnated wound dressings may be considered for infected diabetic foot ulcers
• There is mixed evidence supporting the use of hyperbaric oxygen therapy as an adjunctive treatment to standard diabetic foot wound care