Rotation and restricted use of antibiotics in a medical intensive cave unit - Impact on the incidence of ventilator-associated pneumonia caused by antibiotic-resistant gram-negative bacteria

To test the hypothesis that a new program of antibiotic strategy control ca n minimize the incidence of ventilator-associated pneumonia (VAP) caused by potentially antibiotic-resistant microorganisms, we performed a prospectiv e before-after study in 3,455 patients admitted to a single intensive care unit over a 4-yr period. Regarding the bacterial ecology and the increasing antimicrobial resistance in our medical intensive care unit (MICU), we dec ided to vary our choice of empiric and therapeutic antibiotic treatment, wi th a supervised rotation, and a restricted use of ceftazidime and ciproflox acin, which were widely prescribed before this scheduled change. For all pa tients, VAP was diagnosed based on the results of quantitative culture of b ronchoalveolar lavage specimens (greater than or equal to 10(4) cfu/ml). We studied 1,044 and 1,022 patients requiring more than 48 h of mechanical ve ntilation (MV), respectively, in the before-period (2 yr: 1995-1996) and th e after-period (2 yr: 1997-1998). We observed a decrease from 231 consecuti ve episodes of VAP in the before-period to 161 episodes of VAP in the after -period (p < 0.01), particularly for VAP occurring before 7 d of MV. The to tal number of potentially antibiotic-resistant gram-negative bacilli respon sible for VAP such as Pseudomonas aeruginosa, Burkholderia cepacia, Steno-t rophomonas maltophilia, and Acinetobacter baumanii decreased from 140 to 79 isolated bacilli. The susceptibilities of these bacteria to the antibiotic s regimen increased significantly, especially for P. aeruginosa and B. cepa cia. The percentage of methicillin-sensitive Staphylococcus aureus increase d significantly from 40% to 60% of S. aureus responsible for VAR. These res ults suggest that a new strategy of antibiotics use could be an efficient m eans to reduce the incidence of VAP caused by antibiotic-resistant bacteria . Nevertheless, further studies are needed to validate these data.