Assessment of Severe Extremity Wound Bioburden at the Time of Definitive Wound Closure or Coverage
Condition: Open Fracture
MeSH terms: Fractures, Open
Study type: Observational

Summary: 
      The purpose of this study is to characterize the bacteria in the wound "bioburden" at the
      time of definitive wound coverage/closure of severe tibia fractures in both the military and
      civilian populations.
    

Detailed description: 
      Infection remains the most common and significant complication following high energy
      fractures. The strategies used in the prevention of deep infection following severe open
      fracture wounds have remained constant for the past 20 years.

      This project is designed to analyze the microbiology profiles of wounds from severe tibia
      fractures at closure by comparing two methods: routine microbiology techniques and PCR
      methods using the Ibis T5000 Biosensor System. The results from both identification methods
      will be compared to the pathogens associated with deep surgical site infections that occur
      post closure of the wound. Currently it is unknown which of these methods will yield
      information that can lower complication rates and better function of the leg. Our goal is to
      perform a multi-center, prospective cohort study of wound bacterial bioburden and associated
      antibiotic care in severe open lower extremity fractures.

      Primary Aim: In a subset of 60 patients, compare the bioburden, as detected by Ibis
      technology, from each of three sampling techniques (deep tissue; soft tissue composite;
      composite of tissue from the length and depth of the wound). Samples obtained using the most
      effective technique identified in this step will be processed using Ibis in subsequent tissue
      analysis. Effectiveness is defined as the ability to identify key wound infection-causing
      pathogens.

      Primary Hypothesis: The composite sampling approach will be the most effective technique.

      Secondary Aim: Characterize the wound bioburden at the time of definitive wound closure or
      coverage using the Ibis T5000 Biosensor System PCR technology as compared to standard
      microbiology techniques.

      Hypothesis 2: The Ibis technology will detect more species of pathogens than standard
      microbiology techniques. The percent of patients for whom Ibis will detect all species
      identified by standard microbiology will be greater than 95%.

      Specific Aim 3: Characterize the wound bioburden in the patients who develop deep infection
      within one year of wound closure, and determine the association between infecting pathogens
      with initial wound closure bioburden as measured jointly by Ibis and standard microbiology
      techniques.

      Specific Aim 4: Document the variability in antibiotic selection and duration, and examine
      the impact of this selection on subsequent deep infection.

      Hypothesis 4a: Among patients treated with antibiotic regimens that are appropriate for the
      pathogens identified by standard microbiology, there will be a lower probability of deep
      infection than among those patients who received inappropriate antibiotic regimens.

      Hypothesis 4b: Among patients treated with antibiotic regimens that are appropriate for the
      pathogens identified by Ibis, there will be a lower probability of deep infection than among
      those patients who received inappropriate antibiotic regimens.
    

Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Particiapting METRC Trauma Centers across the country.
      
Biospecimen description: 
      Tissue
    
Keywords: open fracture wounds; infections; tibia fractures; antibiotic therapies in severe fractures; All severe open fracture of the tibia bone