title: Outcome analysis of patients requiring mechanical ventilation with severe community-acquired pneumonia and identified bacterial pathogens.
abstract: BACKGROUND
  Severe community-acquired pneumonia (CAP) is associated with high mortality. The choice of antibiotics should be guided by the distribution of bacterial pathogens. The purpose of this study was to analyze the causative bacteria 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 determined, while differences in age, acute physiology and chronic health evaluation (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. Staphylococcus aureus (8%) was the most-commonly isolated gram-positive organism, and half of its isolates were oxacillin-resistant (ORSA). The overall mortality was 55.9%. Multiple logistic regression analysis revealed that survivors had a significantly younger age and lower APACHE II scores.
  
  
  CONCLUSIONS
  Gram-negative bacilli were the most-common causative pathogens among patients with severe CAP requiring mechanical ventilation. Antipseudomonal antibiotics or a carbapenem should be considered to cover Pseudomonas species, extended-spectrum beta-lactamase-producing strains, and Acinetobacter species. If the isolated bacteria are gram-positive, care should be taken to cover the possibility of ORSA. Old age and higher APACHE II scores were associated with higher mortality.
authors: Department of Pulmonary and Critical Care Medicine, Chang Gung Memorial Hospital, Taipei.
authors: Han-Chung
authors: HC
authors: Hu
authors: Chung-Chi
authors: CC
authors: Huang
authors: Ying-Huang
authors: YH
authors: Tsai
authors: Cheng-Huei
authors: CH
authors: Lee
authors: Meng-Jer
authors: MJ
authors: Hsieh
mesh_terms: D018806:APACHE; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D017714:Community-Acquired Infections / Q000209:etiology / Q000401:mortality / Q000628:therapy*; D005260:Female; D006090:Gram-Negative Bacteria / Q000302:isolation & purification; D016905:Gram-Negative Bacterial Infections / Q000209:etiology / Q000401:mortality / Q000628:therapy*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D018410:Pneumonia, Bacterial / Q000209:etiology / Q000401:mortality / Q000628:therapy*; D012121:Respiration, Artificial
chemical_list: D000900:Anti-Bacterial Agents