Microbiology and prognostic factors of hospital- and community-acquired aspiration pneumonia in respiratory intensive care unit.

BACKGROUND: Incidence of aspiration pneumonia in hospital-acquired pneumonia and community-acquired pneumonia is high; however, many features of this disease remain imprecise. Our objective was to characterize the microbial etiology and their antibiotic resistance and to determine the prognostic factors in aspiration pneumonia among patients admitted to a respiratory intensive care unit (RICU).

METHODS: A prospective survey was conducted in 112 patients exhibiting hospital-or community-acquired aspiration pneumonia in the RICU of a provincial general hospital from 2010-2012. Bronchoalveolar lavage sampling was collected, and then followed by standard culture and drug-sensitive test. Risk factors were analyzed by multivariate logistic analysis.

RESULTS: One hundred twenty-eight strains were isolated in 94 patients, gram-negative bacilli (57.8%) was the predominant cultured microorganism, followed by fungus (28.9%) and gram-positive cocci (13.3%). The 5 main isolated bacteria demonstrated high and multiantibiotic resistance. The crude overall mortality was 43.8%, 50%, and 40%, respectively, in hospital- and community-acquired aspiration pneumonia group. Multivariate logistic analysis identified age older than 65 years, use of inotropic support, and ineffective initial therapy as independent risk factors of poor outcome.

CONCLUSIONS: The predominant pathogenic bacteria of aspiration pneumonia in patients admitted to an RICU were antibiotic-resistant bacteria, and effective initial supportive management secured better prognosis.