Diagnosis and management of community-acquired pneumonia

Severe community-acquired pneumonia (SCAP) remains the most common infectious reason for admission to the intensive care unit (ICU), reaching a mortality rate of 30–40%. The microbial pattern of the SCAP has changed with S. pneumoniae still the leading pathogen, but a decrease of atypical pathogens, especially Legionella and an increase of viral and polymicrobial pneumonias. IDSA/ATS issued guidelines on the management of CAP including specific criteria to identify patients for ICU admission with good predictive value. The first selection of antimicrobial therapy should be started early covering all likely pathogens, depending on the presence of the risk factors for Pseudomonas aeruginosa infection. Combination therapy may be useful in patients with non-refractory septic shock and severe sepsis pneumococcal bacteraemia as well. The challenges include the emergence of new pathogens as community-acquired methicillin-resistant Staphylococcus aureus, new influenza virus subtypes and the high prevalence of multidrug resistance, mainly from institutionalizing patients.