Definition of soft tissue wound infection
Must meet at least 1 of the following criteria:
- Organisms cultured from tissue/drainage site
- Purulent drainage
- Abscess or other evidence of infection
- At least 2 of the following:
- Localized pain/tenderness
- Redness
- Swelling
- Heat
What 3 major organisms are found in the majority of wounds?
Acinetobacter
E. Coli
Pseudomonas
(Think “guerilla warfare”… gorilla = A.P.E)
What happens to the type of bacteria that infect a wound as time goes on?
As the injury progresses, it goes from a gram (+) problem to a gram (-) one
Exception = recurrent MRSA infections
What did widespread treatment of Acinetobacter do?
Lead to the development of multi-drug resistant strains
Early lessons from Iraq
aka Microbiology take home points
- Organisms change over time
- Gram (-) rods are the predominant problem
- Appear to travel w/ wounded patients
- Result in nosocomial spread
- No indication for pre/post procedure cultures
- If something doesn’t look infected, don’t culture it
- 30% of wounds become infected
- 20% of these patients experience multiple repeat infections after discharge
- Recent appreciation for invasive fungal infections
Comparative toxicities of antifungal agents (mainly Amphotericin B vs Fluconazole)
AmB is highly nephrotoxic
Flu is slightly hepatotoxic
Recent trends in war wounds
- Atypical mycobacterial wound infections
- requires months of triple drug therapy
- all from blast patients during OEF (operation enduring freedom)
- Colistin resistant Acinetobacter
- most strains have been sensitive to minocycline
- fortunately, colistin-resistance acinetobacter are not very virulent
Difference between OIF and OEF
Iraq:
hot, arid desert
blast injuries inside vehicles
acinetobacter largest concern
Afghanistan:
lush, heavy vegetation in some regions
blast injuries while walking
invasive fungal infections were significant concern
Empiric Treatment Options when Wounds Appear Infected
Meropenem
Vancomycin
Antifungals
Always send tissue or pus for culture (swab is not as good); send tissue for histopathology if fungi are a concern
Measures to prevent infection
- Adequate debridement
- fluid lavage of open wounds
- repeat washouts critical
- Negative Pressure Wound Therapy
When to consult ID
- what you’re doing isn’t working
- renal problems or drug allergies limit selection of Abx
- you’re thinking of starting an Abx or Antifungal you’re not familiar with
How did nosocomial spread of acinetobactor kill people?
Gave elderly people pneumonia
