229Original Article Outcome Analysis of Patients Requiring Mechanical Ventilation with Severe Community-Acquired Pneumonia and Identified Bacterial Pathogens

Background: Severe community-acquired pneumonia (CAP) is associated with high mor-tality. The choice of antibiotics should be guided by the distribution of bacte-rial pathogens. The purpose of this study was to analyze the causative bacte-ria and outcomes of patients with severe CAP in a medical intensive care unit (MICU) in Taiwan. The results may provide a basis of guidance for future empirical antibiotic treatments. Methods: We enrolled patients with severe CAP who were intubated and who required mechanical ventilation in an MICU in 2001. Only patients with identified bacterial pathogens were included. The bacterial distribution was deter-mined, while differences in age, acute physiology and chronic health evalua-tion (APACHE) II scores, and initial PaO2/FiO2 ratio between surviving and expired patients were compared. Results: Fifty-nine patients were enrolled and 75 isolates were obtained. Klebsiella pneumoniae was the most common bacteria (21.3%), followed by Pseudomonas aeruginosa and Acinetobacter baumannii. Staphylococcu