It is presumed that 70% of Community-Acquired Pneumonias (CAP) are caused by bacteria [1], but, in clinical practice, microbial etiology remains unknown in at least 60% of the cases [2]. One of the most important aspects of the treatment of bacterial pneumonia is antibiotic therapy. Precocity has such a decisive impact on prognosis that it is unacceptable to delay the initiation of antibiotics until microbiological results are available [1] [3] [4]. Therefore, virtually all the initial antibiotic regimens are empirical.
