Comparing a Brazilian guideline to treat nosocomial pneumonia with the ATS guideline in a tertiary hospital in Brazil

Introduction

The medical literature shows that the most important prognosis factor in nosocomial pneumonia is the correct empirical antimicrobial therapy. Recently the microorganisms have been becoming more resistant to the usual antibiotics and there are many reports of Gram-negative bacilli (GNB) only susceptible to Polimixyn b (PB). The ATS guideline does not suggest the use of PB as an empirical therapy, while the Brazilian Sepsis Guideline (BG) allows the use of this antibiotic in special circumstances. The aim of this study was to compare the efficacy of both guidelines, based on the microbiological data.

Methods

This is a retrospective study with 93 cases of nosocomial pneumonia diagnosed according to the ATS criteria, managed in our ICU from 1 February 2005 to 16 September 2006. We analyzed the efficacy of both guidelines, using them during all the study period or stratifying the patients into two groups according to the research median period (24 November 2005).

Results

There were 67 cases of ventilator-associated pneumonia (VAP) and 26 cases of non-VAP. The overall result shows that the ATS would be effective in 76% (CI 67–85%) and the BG in 87.9% (CI 81–94.7%) of the cases. This difference was statistically significant (P = 0.035). The most prevalent bacteria were Acinetobacter sp. and Pseudomonas aeruginosa. From February to August 2005 there were a burden of multiresistant (MR) GNB, only susceptible to PB. Using the ATS or the BG in this period, the guidelines would be effective in 64% (CI 51–77%) and 84.4% (CI 74.8–94%) respectively (P = 0.017). In the second half of the study we controlled the MR GNB, and the efficacy of both guidelines were similar between ATS and BG (97% vs 93.9%; P = 1).

Conclusion

Our data show that the more restrictive ATS guideline can significantly lead to a wrong empirical therapy in MR GNB high-prevalence situations. The use of the BG can lead to a better empirical treatment in this situation. This information enhances the need for ICU flora knowledge, which are seasonal, so there is no 'all time and place perfect guideline', although the BG was a better option in our ICU than the ATS guideline.