Clinical question: Can an algorithm based on risk for multidrug-resistant (MDR) organisms and illness severity guide antibiotic selection in healthcare-associated pneumonia (HCAP)?
Background: The 2005 American Thoracic Society/Infectious Diseases Society of America (ATS/IDSA) guidelines identify patients with HCAP as those with recent contact with a healthcare environment, including nursing homes and hemodialysis; however, previous studies have shown that not all patients with healthcare contact have equal risk for MDR organisms.
Study design: Prospective cohort study.
Setting: Japan, multi-center.
Synopsis: Of the 445 enrolled patients, 124 were diagnosed with community-acquired pneumonia (CAP) and 321 with HCAP. Patients with HCAP were classified based on severity of illness or MDR pathogen risk factors (immune suppression, hospitalization within the last 90 days, poor functional status, and antibiotics within the past six months). Patients with low risk (0-1 factors) for MDR organisms were treated for CAP, and patients with high risk (≥2 factors) or moderate risk (≥1 factor) for severe illness were treated for HCAP.
HCAP patients had a higher 30-day mortality rate (13.7% vs. 5.6%, P=0.017), but mortality rate was less in the patients at low risk for MDR pathogens (8.6% vs. 18.2%, P=0.012). Of the HCAP patients, only 7.1% received inappropriate therapy (pathogen resistant to initial antibiotic regimen), and treatment failure was 19.3%.
Appropriateness of initial empiric therapy was determined not to be a mortality risk; however, this trial might be limited by its location, because Japan appears to have fewer MDR pathogens than the U.S.
Bottom line: A treatment algorithm based on risk for MDR organisms and severity of illness can be used to guide empiric antibiotic therapy in patients with HCAP, and, ideally, to reduce excessive use of broad-spectrum antibiotics.
Citation: Maruyama T, Fujisawa T, Okuno M, et al. A new strategy for healthcare-associated pneumonia: a 2-year prospective multicenter cohort study using risk factors for multidrug-resistant pathogens to select initial empiric therapy. Clin Infect Dis. 2013;57(10):1373-1383.