Development of a guideline for the management of ventilator-associated pneumonia based on local microbiologic findings and impact of the guideline on antimicrobial use practices

OBJECTIVE. To describe the development of a guideline for the management of ventilator-associated pneumonia (VAP) based on local microbiologic findings and to evaluate the impact of the guideline on antimicrobial use practices. DESIGN. Retrospective comparison of antimicrobial use practices before and after implementation of the guideline. SETTING. Intensive care units at Harborview Medical Center, Seattle, Washington, a university-affiliated urban teaching hospital. PATIENTS. A total of 819 patients who received mechanical ventilation and who underwent quantitative bronchoscopy between July 1, 2003, and June 30, 2005, for suspected VAP. INTERVENTIONS. Implementation of an evidence-based VAP guideline that focused on the use of quantitative bronchoscopy for diagnosis, administration of empirical antimicrobial therapy based on local microbiologic findings and resistance patterns, tailoring definitive antimicrobial therapy on the basis of culture results, and appropriate duration of therapy. RESULTS. During the baseline period, 168 (46.7%) of 360 patients had quantitative cultures that met the diagnostic criteria for VAP, compared with 216 (47.1%) of 459 patients in the period after the guideline was implemented. The pathogens responsible for VAP remained similar between the 2 periods, except that the prevalence of VAP due to carbapenem-resistant Acinetobacter species increased from 1.8% to 15.3% (P <.001), particularly in late-onset VAP. Compared with the baseline period, there was an improvement in antimicrobial use practices after implementation of the guideline: antimicrobial therapy was more frequently tailored on the basis of quantitative culture results (103 [61.3%] of 168 vs 150 [69.4%] of 216 patients; P = .034), there was an increase in the use of appropriate definitive therapy (135 [80.4%] of 168 vs 193 [89.4%] of 216 patients; P =. 001), and there was a decrease in the mean duration of therapy (12.0 vs 10.7 days; P =. 0014). The all-cause mortality rate was similar in the periods before and after the guideline was implemented (38 [22.6%] of 168 vs 46 [21.3%] of 216 patients; P = .756). CONCLUSIONS. Implementation of a guideline for the management of VAP that incorporated the use of quantitative bronchoscopy, the use of empirical therapy based on local microbiologic findings, tailoring of therapy on the basis of culture results, and use of shortened durations of therapy led to significant improvements in antimicrobial use practices without adversely affecting the all-cause mortality rate.