Investigations

Not all patients admitted with CAP require extensive microbiologic workup. Blood and sputum cultures should be reserved for patients with severe presentations, suspected resistant organisms, recent antimicrobial exposure, or failure of therapy

During respiratory virus season, consider a nasopharyngeal swab for respiratory virus testing:

• If positive: consider discontinuation of antibacterial agents

• If negative: discontinue antiviral agent (if started)

Rarely, patients admitted with pneumonia may have a negative initial chest x-ray. If clinical features are highly suggestive, it may be reasonable to treat presumptively and repeat imaging after 24-48 hrs. Lack of infiltrate after 48 hrs suggests an alternative diagnosis other than bacterial CAP and may allow early discontinuation of antimicrobials