Severe community-acquired pneumonia: current concepts and controversies.

Community-acquired pneumonia, particularly in its severe forms (sCAP), remains a major public health problem due to its frequency, immediate and delayed complications, and the cost of treatment. Although rare, resistant pathogens could make it increasingly difficult to choose an empirical antibiotic treatment. Rapid molecular microbiological diagnostic techniques could help guide this choice, but their role needs to be better evaluated and their cost may be an obstacle to their widespread use. The duration of treatment tends to be decreasing, but could be guided by clinical progression and possibly biomarkers. As a disorder of dysregulated systemic inflammation, sCAP is potentially eligible for immunomodulatory treatment. Three recent high-powered randomized trials on corticosteroids have yielded conflicting results. There is a need to better define which patients are likely to benefit, perhaps those with a marked inflammatory syndrome, and in any case not those with influenza. Some macrolides also have a potential immunomodulatory effect. Other treatments are currently being investigated. Supportive care, particularly respiratory support, remains essential. It is not specific to sCAP and must be tailored to the severity of the patient's condition.