Risk factors and prognostic factors in nosocomial pneumonia outside the intensive care units setting

INTRODUCTION. Nosocomial pneumonia (NP) is the second most frequent cause of hospital-acquired infection and is associated with elevated morbidity and mortality rates, particularly in intensive care units (ICU). The objectives of this study were to determine the incidence, risk factors and prognostic factors of NP acquired outside the ICU. METHODS. A prospective case-control study was performed. All NP cases were acquired outside the ICU, and each case was paired with a control subject matched for gender, age, date of admission and hospitalization area. Epidemiological, clinical and microbiological data were obtained from cases and controls, and the risk factors and prognostic factors for NP were established. RESULTS. During the study period a total of 67 cases of NP outside the ICU were diagnosed. Estimated incidence was 3.35 cases/1,000 admissions. Mean age of the patients was 70 +/- 13 years and 48 of them were men. On multivariate analysis adjusted for confounding factors, bronchoaspiration, previous surgery and steroids were significantly associated with the development of NP. Mortality attributable to NP was 27%. The existence of an ultimately or rapidly fatal underlying condition and the presence of leukocytosis or leukopenia were associated with poor prognosis. CONCLUSION. The incidence of NP outside the ICU setting is low. Measures to reduce bronchoaspiration and judicial steroid use are necessary to decrease the risk of acquiring NP and to improve the prognosis.