Approach to severity assessment of CAP in adults

Assessment of community-acquired pneumonia (CAP) severity and a review of the adult’s preferences, comorbidities and goals of care is essential to guide empirical antibiotic therapy and the location of careAliberti, 2021.

The severity of CAP is determined by the presence of features that may indicate hospital admission or red flags for intensive care support:

• Low-severity CAP – none of the features that may indicate hospital admission are present.
• Moderate-severity CAP – at least one of the features that may indicate hospital admission is present but none of the red flags for intensive care support are present. These patients have a significant likelihood of deteriorating and need regular observation, so usually require admission to hospital, depending on the patient’s preferences, prognosis and goals of care.
• High-severity CAP – at least one of the red flags for intensive care support is present. This includes adults with signs of sepsis or septic shock (for definitions, see Definition of sepsis and septic shock in adults).

In this topic, the features that may indicate hospital admission and the red flags for intensive care support are based on modified clinical parameters identified in studies of pneumonia severity, as well as the opinion of the Antibiotic Expert Group. They provide a static measure in a dynamic situation; they do not replace clinical judgement. Patients can deteriorate over the initial 24 to 48 hours – it is essential to regularly reassess or provide clear guidance for the patient if they deteriorate.

For an overview of management of CAP in adults, see Management of adults with community-acquired pneumonia (CAP). For residents of an aged-care facility, see also Community-acquired pneumonia in residents of an aged-care facility.