title: The pathogen of ventilator-associated pneumonia does not influence the mortality rate of surgical intensive care unit patients treated with a rotational antibiotic system.
abstract: BACKGROUND
  Ventilator-associated pneumonia (VAP) is one of the leading causes of morbidity in critically ill surgical patients. Certain pathogens (e.g., methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa) have been associated with an excess mortality rate from sepsis in several studies, but not in the surgical setting specifically or when protocol-driven antibiotic therapy is administered.
  
  
  OBJECTIVE
  We sought to determine which factors and, in particular, whether the individual pathogen affected the mortality rate in our surgical intensive care unit (ICU), where a rotational antibiotic system has been employed continuously since 1997. We hypothesized that the type of pathogen and illness severity were the primary influences on the mortality rate of patients with VAP.
  
  
  METHODS
  A total of 198 consecutive patients from a university surgical ICU, with clinical signs of VAP confirmed by quantified isolation of significant numbers of a pathogen (> or =10(4) colony-forming units [cfu]/mL) from bronchoalveolar (BAL) fluid obtained by fiberoptic bronchoscopy, were identified prospectively from January 2001 to November 2004. The data collected were age, sex, Acute Physiology and Chronic Health Evaluation (APACHE) III score, multiple organ dysfunction score, unit day of diagnosis, time (h) to antibiotic administration (TTA), appropriateness of initial therapy (AIT), unit and hospital length of stay, and mortality rate. Pathogens were classified as non-lactose-fermenting gram-negative bacilli (NGNB), lactose-fermenting gram-negative bacilli (LGNB), methicillin-sensitive Staphylococcus aureus, methicillin-resistant S. aureus, yeast, community-acquired pneumonia (e.g., Streptococcus pneumoniae), or other pathogens. Patients with a polymicrobial isolate were placed in the "other" category.
  
  
  RESULTS
  The overall mortality rate was 32.3% vs. 55% as predicted by APACHE III normative data. The overall AIT was 92%. The mortality rate for NGNB infections was 35.6% vs. 29.4% for LGNB infections (p = NS). By logistic regression, neither TTA, AIT, nor pathogen influenced the mortality rate.
  
  
  CONCLUSIONS
  The type of pathogen does not influence death in surgical ICU patients with VAP diagnosed rigorously and treated by a rotational antibiotic system. The high proportion of AIT as a result of the rotational antibiotic administration system optimizes bacterial killing and negates the impact of bacterial resistance, contributing to better outcomes.
authors.affiliation: Department of Surgery, Weill Medical College of Cornell University, 525 E. 68th St., New York, NY 10021, USA. sre2003@med.cornell.edu
authors.forename: Soumitra R
authors.initials: SR
authors.lastname: Eachempati
authors.forename: Lynn J
authors.initials: LJ
authors.lastname: Hydo
authors.forename: Jian
authors.initials: J
authors.lastname: Shou
authors.forename: Philip S
authors.initials: PS
authors.lastname: Barie
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001424:Bacterial Infections / Q000188:drug therapy / Q000401:mortality*; D001992:Bronchoalveolar Lavage Fluid / Q000382:microbiology; D003422:Critical Care; D004358:Drug Therapy / Q000379:methods*; D005260:Female; D006090:Gram-Negative Bacteria / Q000302:isolation & purification; D006094:Gram-Positive Bacteria / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008875:Middle Aged; D009181:Mycoses / Q000188:drug therapy / Q000401:mortality*; D053717:Pneumonia, Ventilator-Associated / Q000188:drug therapy / Q000401:mortality*; D016896:Treatment Outcome; D015003:Yeasts / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents