title: Empyema management: A cohort study evaluating antimicrobial therapy.
abstract: OBJECTIVE
  Empyemas require aggressive antimicrobial and surgical management. However, the specifics of antimicrobial therapy have not been studied in clinical trials. The present study examines management and outcomes among a cohort of patients with empyema cared for in a tertiary-care referral hospital over a decade.
  
  
  METHODS
  We retrospectively identified patients hospitalized with empyema from January 2000 through December 2010 at one institution. Patient demographics, laboratory findings, treatments, and patient outcomes were abstracted using a standard form. Data were summarized with standard descriptive statistics.
  
  
  RESULTS
  A total of 91 patients were identified. The predominant organisms were viridans group streptococci, which were isolated in 64% of cases with cultures. The median length of hospitalization was 9 days. Length of antimicrobial therapy from time of source control was variable, with a median (interquartile range) duration of 27 (15-31) days. Of note, longer courses of parenteral, but not oral, therapy were associated with fewer cases of clinical failure.
  
  
  CONCLUSIONS
  This descriptive analysis demonstrated a higher rate of viridans group streptococci than expected. Three weeks of therapy was generally adequate and prevented clinical failure, but further study is needed with a much larger cohort to better define the optimal drug regimen, route, and duration of antimicrobial therapy for empyema.
authors.affiliation: Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: Kate
authors.initials: K
authors.lastname: Birkenkamp
authors.affiliation: Division of Infectious Diseases, Mayo Clinic, Rochester, MN, USA. Electronic address: OHoro.John@mayo.edu.
authors.forename: John C
authors.initials: JC
authors.lastname: O'Horo
authors.affiliation: Department of Anesthesiology, Mayo Clinic, Rochester, MN, USA.
authors.forename: Rahul
authors.initials: R
authors.lastname: Kashyap
authors.affiliation: Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: Ben
authors.initials: B
authors.lastname: Kloesel
authors.affiliation: Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, MN, USA.
authors.forename: Brian D
authors.initials: BD
authors.lastname: Lahr
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: Craig E
authors.initials: CE
authors.lastname: Daniels
authors.affiliation: Division of General Thoracic Surgery, Mayo Clinic, Rochester, MN, USA.
authors.forename: Francis C
authors.initials: FC
authors.lastname: Nichols
authors.affiliation: Division of Infectious Diseases, Mayo Clinic, Rochester, MN, USA; Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN, USA.
authors.forename: Larry M
authors.initials: LM
authors.lastname: Baddour
mesh_terms: D000368:Aged; D000890:Anti-Infective Agents / Q000627:therapeutic use*; D015331:Cohort Studies; D016724:Empyema, Pleural / Q000188:drug therapy*; D005260:Female; D006801:Humans; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D062606:Tertiary Care Centers; D016896:Treatment Outcome
chemical_list: D000890:Anti-Infective Agents
keywords: Empyema; Parapneumonic effusion; Pleural effusion; Pleural infection