Severity Assessment and the Immediate and Long-Term Prognosis in Community-Acquired Pneumonia

Severity assessment is a crucial step in the initial management of patients with community-acquired pneumonia (CAP). While approximately half of patients are at low risk of death and can be safely treated as outpatients, around 20% are at increased risk. While CURB-65 (confusion, respiratory rate, blood pressure, urea) and pneumonia severity index (PSI) scores are equally useful as an adjunct to clinical judgment to identify patients at low risk, the so-called minor American Thoracic Society/Infectious Diseases Society of America criteria are predictive of patients in need of intensified treatment (i.e., mechanical ventilation and/or vasopressor treatment). Such patients represent medical emergencies. In elderly patients, CRB-65 (confusion, respiratory rate, blood pressure, age) is no longer predictive of low risk; instead, poor functional status is the best predictor of death. In addition to scores, assessment of oxygenation and unstable cornorbidity, as well as lactate and biomarkers remain important to consider. The added value of combined clinical and biomarker risk stratification strategies should be evaluated in large prospective interventional trials. Survivors of hospitalized CAP have a considerable excess long-term mortality. Risk factors include age, male gender, and nursing home residency, as well as increased PSI and CURB-65 scores. Cardiovascular, pulmonary, renal, and neoplastic comorbidities are prominent causes of long-term mortality. Comorbidities are vulnerable to both the acute and chronic subclinical inflammatory challenge delivered by pulmonary infection and are thereby drivers of mortality. Biomarkers are promising in identifying patients at increased risk of long-term mortality. Future studies should develop consistent strategies of risk stratification and intervention to improve long-term outcomes of patients with CAP.