ILE XI Diabetic Foot Infection Objectives

What type of diabetic foot infection involves the central plantar space (arch) and are typically caused by minor penetrating trauma or an extension of infection of a nail or web space of toes?

Deep Abscesses

What type of diabetic foot infection arises from infections in the toes that are related to routine care of the nails, nail beds, and calluses of the toes?

Dorsum Cellulitis

What type of diabetic foot infection is a chronic ulcer of the sole of the foot that develops due to neuropathic changes, which are responsible for misalignment of weight-bearing bones?

Mal perforans ulcers

What infection is one of the most serious complications of diabetic foot infections?

Osteomyelitis

Although patients do not typically experience pain, what symptoms are most common with DFI?

Swelling, Edema

What type of organisms are most likely with patients presenting with foul-smell odor associated with the infection site?

Anaerobic

What two microorganisms are most common in DFI?

Staph and Strep

What symptom criteria indicates a severe DFI?

SIRS criteria

What labs should be initially taken for treatment of DFI?

Inflammatory serum biomarkers (ex. CRP, ESR, procalcitonin)

– WBC, A1C, BG

Local infection only; erythema <2 cm

Classification 2- Mild

Local infection with erythema >2 cm or involving deeper structures

No system inflammatory response

Classification 3-Moderate

Local infection with 2 or more signs of SIRS

Classification 4-severe

Infection involving bone (osteomyelitis)

Add (O)

MRSA risk factors:

prolonged hospitalization, intensive care admission, recent hospitalization, recent _ use (<90 days) , invasive procedures, _ infection, admission to nursing homes, hemodialysis, discharge with central venous access

antibiotic, HIV

P. aeruginosa risk factors:

isolation of P. aeruginosa from cultures of the affected site within previous few weeks, _ ulcers, person with moderate to severe infection who resides in Asia or North Africa.

macerated

Mild infection, no risk factors for MRSA/Pseudomonas, GPC

empiric tx?

cephalexin

Mild infection, no risk factors for MRSA/Pseudomonas, GPC, but has B-lactam allergy

empiric tx?

Doxycycline, TMP-SMX, clindamycin

Mild infection, risk factors for MRSA, GPC

empiric tx?

Doxycycline, TMP-SMX, clindamycin,

linezolid

Moderate/severe infection, no risk factors for MRSA/Pseudomonas, GPC + GNR

empiric tx?

IV: ampicillin/sulbactam, ceftriaxone

PO: amoxicillin/clavulanate

Moderate/severe infection, macerated ulcer/warm climate, GPC + GNR

empiric tx?

Piperacillin/tazobactam, cefepime, ceftazidime

Moderate/severe infection, MRSA risk factors, GPC + GNR

empiric tx?

Vancomycin, linezolid, daptomycin,

TMP-SMX, doxycycline PLUS ceftriaxone

Moderate/severe infection, ischemic limb/necrosis, GPC + GNR +anaerobes

empiric tx?

Ceftriaxone PLUS metronidazole

Piperacillin/tazobactam

Ampicillin/sulbactam

Duration of tx

Mild

1-2 weeks

Duration of tx

Mod-severe

2-4 weeks (10 days following surgical debridement)

Duration of tx

Bone involvement: resected

2-5 days

Duration of tx

Bone involvement: debrided

1-2 weeks

Duration of tx

Bone involvement: no surgery

6 weeks

What are the treatment goals?

- Treat infected wounds
- Prevent additional complications
- Preserve normal limb function
- Avoid unnecessary antibiotics
- Minimize toxicities/cost and increase patient quality of life

When to cover for anerobes?

In severe infections with chronic foot ischemia