DFI and Pressure Ulcers Flashcards
What is Diabetic Foot Infection?
Soft tissue or bone infection below the malleolus
Areas of DFI:
- skin ulceration (peripheral neuropathy)
- wound (trauma)
Complications:
- hospitalization
- osteomyelitis => amputation
What is the pathophysiology of DFI?
- Neuropathy
- Peripheral: decrease pain sensation and altered pain response
- Motor: muscle imbalance
- Autonomic: increase dryness, cracks, and fissures - Vasculopathy
- Early atherosclerosis
- Peripheral vascular disease
- Worsened by hyperglycemia and hyperlipidemia - Immunopathy
- Impaired immune response
- Increase susceptibility to infections
- Worsened by hyperglycemia
=> Ulcer formation and wounds
=> Bacterial colonization, penetration and proliferation
=> DFI
Definition of DFI (INFECTED)
Purulent discharge
OR
> = 2 signs or symptoms of inflammation (PWETI)
- Erythema
- Warmth
- Tenderness
- Pain
- Induration (hardness)
What are the causative organisms of DFI?
*Typically polymicrobial
Staphyloccous Aureus
Streptococcus
Gram-negative bacilli - Particularly in chronic wounds or previously treated with antibiotics
- E. coli, Klebsiella, Proteus
- Pseudomonas (less common)
Anaerobes - ischemic or necrotic wounds
- Peptostreptococcus, Veillonella, Bacteroides
When should culture be obtained for DFI?
Mild DFI - optional
Moderate-severe DFI - deep tissue cultures after cleansing and before starting antibiotics (if possible), avoid skin swabs
*Do not culture uninfected wounds
DFI treatment is dependent on _____ and ______
Severity of infection
- based on IDSA (mild, moderate, severe definition)
- account for SIRS criteria (systemic signs)
- account for extent of tissue involvement
AND
Patient specific factors
- allergies
- MRSA risk factors
- pseudomonal risk factors (water exposure, warm climate)
When should Pseudomonas cover be considered in DFI?
*Pseudomonas should be covered when:
- severe infection
- failure of antibiotics not active against pseudomonas
What constitutes a MILD IDSA Infection Severity (DFI)
Mild
- Infection of skin and sc tissue +
- If erythema =<2cm around ulcer +
- No signs of systemic infection
What organisms should be covered in MILD DFI?
Staph
Strep
What are the empiric antibiotic options for MILD DFI?
PO Cephalexin 500mg q6h
PO Cloxacillin 500mg-1g q6h
PO Clindamycin 300-450mg q6h (penicillin allergy)
What are the empiric antibiotic options for MILD DFI?
(If there are MRSA risk factors, use what instead?)
If MRSA risk factors
- PO Cotrimoxazole 960mg bid
- PO Clindamycin 300-450mg q6h
- PO Doxycyline 100mg bid
What is the duration of therapy for MILD DFI?
1-2 weeks
What constitutes a MODERATE IDSA Infection Severity (DFI)?
Moderate
- Infection of deeper tissue (e.g., joints, bones)
or
- If erythema >2cm +
- No signs of systemic infection
What organisms should be covered in MODERATE DFI?
Staph
Strep
Gram-negative
Anaerobic
What are the empiric antibiotic options for MODERATE DFI?
IV Amoxicillin-Clavulanate 1.2g q6-8h
IV Cefazolin 1-2g q8h + Metronidazole 500mg q8h
IV Ceftriaxone 1-2g q12-24h + Metronidazole 500mg q8h
What are the empiric antibiotic options for MODERATE DFI?
(What to ADD if there are MRSA risk factors)
If MRSA risk factors: add
- IV Vancomycin 15mg/kg q8-12h
- IV Daptomycin 4-6mg/kg q24h
- IV Linezolid 600mg q12h
*Reserve Daptomycin and Linezolid for vancomycin resistance, more ex as well
What is the duration of therapy for MODERATE DFI (no bone involvement)?
1-3 weeks
What constitutes a SEVERE IDSA Infection Severity (DFI)?
Moderate
- Infection of deeper tissue (e.g., joints, bones)
or
- If erythema >2cm +
- Signs of systemic infection
What organisms should be covered in SEVERE DFI?
Staph
Strep
Gram negative
Anaerobe
Pseudomonas
What are the empiric antibiotic options for SEVERE DFI?
IV Piperacillin-Tazobactam 4.5g q6-8h
IV Cefepime 2g q8h + Metronidazole 500mg q8h
IV Meropenem 1-2g q8h
IV Ciprofloxacin 400mg q8-12h + Clindamycin 600mg q8h
IV Ceftazidime 1-2g q8h + Clindamycin 600mg q8h
What are the empiric antibiotic options for SEVERE DFI?
(What to ADD if there are MRSA risk factors)
If MRSA risk factors add:
IV Vancomycin 15mg/kg q8-12h
IV Daptomycin 4-6mg/kg q24h
IV Linezolid 600mg q12h
What is the duration of therapy for SEVERE DFI (no bone involvement)?
2-4 weeks
What is the duration of therapy for DFI with bone involvement?
Surgery - all infected bone and tissue removed
Surgery - all infected bone and tissue removed (e.g., amputation): 2-5 days
What is the duration of therapy for DFI with bone involvement?
Surgery - residual infected soft tissue
Surgery - residual infected soft tissue: 1-3 weeks
What is the duration of therapy for DFI with bone involvement?
Surgery - residual viable bone
Surgery - residual viable bone: 4-6 weeks
What is the duration of therapy for DFI with bone involvement?
No surgery or Surgery - residual dead bone
No surgery or Surgery - residual dead bone: >= 3months
When should antibiotics for DFI be stopped/changed?
Do not continue Abx until complete wound healing (bacteria cleared faster than wound heals)
Streamline choice of Abx based on culture and AST (impt as the empiric choices are broad spectrum => selection pressure)
Switch to oral therapy when patient improved
What are the adjunctive measures for DFI?
Wound care
- debridement
- “off-loading” - relieve pressure on ulcer
- apply dressings that promote a healing environment and control excess exudation
Foot care
- daily inspection
- prevent wounds and ulcers
Optimal glycemic control
What are Pressure Ulcers?
Pressure ulcers = Decubitus ulcers = Bed sores
Synergistic interaction between 4 factors:
Moisture
Pressure (amount of time and duration)
Shearing force
Friction
What are the risk factors for Pressure Ulcers?
Reduced mobility
Debilitated by severe chronic diseases
Reduced consciousness
Sensory and autonomic impairment
- incontinence (moisture)
Extremes of age - mobility issue
Malnutrition
What are the 4 stages of clinical presentation of Pressure Ulcers?
Stage 1: abrasion of epidermis, irregular area of tissue swelling, no open wound
Stage 2: extends through dermis, open wound
Stage 3: extends deep into s/c fat, open sore or ulcer
Stage 4: involves muscle and bone, deep sore or ulcer
*Similar criteria for INFECTION applies:
- Purulent OR
- > = 2 signs and symptoms of inflammation: erythema, warmth, tenderness, pain, induration
What are the causative organisms of Pressure Ulcers?
Identical to DFIs, polymicrobial
Staphyloccous Aureus
Streptococcus
Gram-negative bacilli - Particularly in chronic wounds or previously treated with antibiotics
- E. coli, Klebsiella, Proteus
- Pseudomonas (less common)
Anaerobes - ischemic or necrotic wounds
- Peptostreptococcus, Veillonella, Bacteroides
Treatment of Pressure Ulcers?
same as DFI
What are the adjunctive measures for Pressure Ulcers?
Wound care
- debridement of infected or necrotic tissue
- local wound care: normal saline, avoid harsh chemicals
Relief of pressure
- turn/reposition every 2h
Barrier creams/dressings
