Severity assessment in community-acquired pneumonia

In current guidelines for the management of adults with community-acquired pneumonia (CAP), the triaging decision about hospitalization or intensive care unit (ICU) admission, and, as a consequence, selection of initial antimicrobial treatment is largely based on the assessment of pneumonia severity. The proposed severity criteria are mainly derived from studies determining predictors of adverse outcome. These include age, male sex, comorbidity, acute respiratory failure, severe sepsis and septic shock, extension of radiographic infiltrates, bacteraemia and CAP through several different pathogens such as Streptococcus pneumoniae, Staphylococcus aureus, Gram-negative enteric bacilli (GNEB), and signs of disease progression within the first 48-72 h. In addition, prediction rules and need for a complicated course in ambulatory and hospitalized patients, for the individual risk of death have been developed which may be helpful in determining the patient who might require hospitalization or intensive care, respectively. Risk classifications such as the scores developed by FINE et al. [40] are not only useful for identifying low risk patients who might safely be treated as outpatients, but apparently they will also play a major role in the evaluation of processes and outcomes of care for patients with CAP. Recent investigations have provided objective criteria for the definition of severe CAP requiring ICU admission. Whether the detection of infiltrates in the chest radiographs of patients with acute lower respiratory tract infection (LRTI) suggestive of mild pneumonia has an independent prognostic impact which fundamentally affects the concept of mild LRTI remains to be seen. Based on objective criteria for severity assessment it will be possible to define interventions aimed at reducing hospital admission rates, define a risk-adapted antimicrobial treatment regimen, reduce costs for antimicrobial treatment and supportive measures, shorten hospital stay, and, thereby, improve the quality of care for patients with community-acquired pneumonia.