Evaluation of a clinical pathway for ventilator-associated pneumonia: changes in bacterial flora and the adequacy of empiric antibiotics over a three-year period.
BACKGROUND
Evaluation of causative pathogens is vital for optimizing empiric antibiotic therapy of ventilator-associated pneumonia (VAP). Based on previous data (Ann Surg 1998;227:743-755), empiric antibiotics for our VAP clinical pathway were modified to target early and late occurring pathogens (ampicillin/sulbactam during the first week of hospitalization; cefepime plus vancomycin afterwards). The objectives of this study were to compare organisms causing VAP over a three-year period to previous data, and to determine the adequacy of the empiric antibiotic regimens.


METHODS
A total of 299 critically ill trauma patients with VAP over a three-year period were studied retrospectively. The incidence of pathogens causing VAP in the study period were compared to a previously published study of a two-year period in our intensive care unit (ICU). Sensitivities of Pseudomonas aeruginosa and Acinetobacter baumannii were evaluated over the study period. The adequacy of empiric antibiotic therapy for each episode of VAP was determined. Therapy was considered to be adequate if one or more antibiotics had in vitro activity against the organism causing VAP.


RESULTS
Statistically significant changes in pathogens included increased Staphylococcus aureus (incidence 17% vs. 11%, p = 0.024) and decreased Acinetobacter baumannii (11% vs. 22%, p < 0.001). Susceptibility patterns were statistically unchanged except for increased resistance of P. aeruginosa to extended-spectrum penicillins (p = 0.016). Empiric therapy was adequate in 76% of VAP episodes.


CONCLUSIONS
The clinical pathway's empiric antibiotic regimen was associated with only modest changes in organisms causing VAP and provided a high rate of adequate empiric coverage.
Wood
G Christopher
GC
Department of Pharmacy, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA. cwood@utmem.edu
Mueller
Eric W
EW
Croce
Martin A
MA
Boucher
Bradley A
BA
Hanes
Scott D
SD
Fabian
Timothy C
TC
D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use*; D001419:Bacteria / Q000187:drug effects* / Q000302:isolation & purification; D001992:Bronchoalveolar Lavage Fluid / Q000382:microbiology; D019091:Critical Pathways; D024901:Drug Resistance, Multiple, Bacterial / Q000187:drug effects*; D005260:Female; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D018410:Pneumonia, Bacterial / Q000188:drug therapy* / Q000209:etiology; D012121:Respiration, Artificial / Q000009:adverse effects*
D000900:Anti-Bacterial Agents