Nonvalue of the initial microbiological studies in the management of nonsevere community-acquired pneumonia.

STUDY OBJECTIVE To assess the value of the initial microbiological studies (MBS), consisting of sputum Gram's stains, sputum cultures, and blood cultures, in the etiologic diagnosis of community-acquired pneumonia (CAP) without comorbidity. DESIGN A prospective study of 74 adult patients hospitalized with nonsevere CAP empirically treated according to the American Thoracic Society guidelines (ATS-GL) and evaluated with Gram's stains and cultures of valid sputum specimens and blood cultures. SETTING University-affiliated community hospital. RESULTS Gram's stain of a valid sputum specimen failed to identify the etiologic agent in all patients. Sputum cultures identified pathogens in only four patients (5%). The results of all blood cultures were negative. All patients responded to the initial empiric antibiotic coverage selected according to the ATS-GL, and the results of the initial MBS had no clinical impact. CONCLUSION The initial MBS, such as sputum Gram's stains, sputum cultures, and blood cultures, have no value in the management of nonsevere CAP without comorbid factors.