Survival in patients with nosocomial pneumonia: impact of the severity of illness and the etiologic agent.

Objective: To assess the impact of severity of illness at different times, using the Mortality Probability Models (MPM II), and the impact of etiologic agent on survival in patients with nosocomial pneumonia.

Design: Retrospective, observational study.

Setting: Fourteen-bed medical-surgical intensive care unit (ICU) in a teaching hospital.