Virulent Gram-Negative Bacilli Isolated in Sputum Culture Predict Length of Hospital Stay in Patients with Community-Acquired Pneumonia

Abstract

Background: The role of sputum culture in identifying infectious pathogens and in guiding initial empiric antibiotic treatment for community-acquired pneumonia (CAP) is limited. However, sputum culture is still widely used clinically in Taiwan. The aim of this retrospective study was to examine the value of sputum culture in terms of the clinical outcome. Methods and patients: From January 1, 2002 to December 31, 2002, CAP patients who were admitted to our hospital and had a sputum culture on admission day were enrolled. Patients were divided into 2 groups: one, a Gram-negative bacilli (GNB) group, for those with a presence of Klebsiella pneumoniae and/or Pseudomonas aeruginosa, and the other, a non-GNB group. Both groups were stratified by means of the modified Fine's pneumonia severity index into low-and high-risk patients. We determined the impact of virulent GNB isolated in the sputum culture on in-hospital mortality and length of stay (LOS) in the hospital. Results: One hundred and forty-eight patients were enrolled. Thirty-eight patients (25.7%) were in the virulent GNB group. The demographic characteristics were similar in both groups. In terms of in-hospital mortality, there was no significant difference between the 2 groups. LOS was significantly longer in the virulent group (18.89±14.85 vs. 12.74±11.35 days; P=0.024), especially for high-risk patients (27.24±15.67 vs. 17.50±13.07 days; P=0.019). The possible explanation for this is that more patients were admitted to the ICU. Conclusion: We conclude that virulent GNB isolated in sputum culture, especially in a high- risk patient group, could result in a significant increase in LOS in the hospital.