Community-acquired pneumonia: Determining the appropriate site of treatment in adults

ICU: intensive care unit; ED: emergency department; PSI: Pneumonia Severity Index; PaO₂: partial pressure of oxygen; FiO₂: fraction of inspired oxygen; CURB-65: confusion, uremia, respiratory rate, blood pressure, age ≥65 years; CAP: community-acquired pneumonia.

* Among the available scoring systems for determining the need for admission in patients with CAP, we prefer the PSI because it is the best studied and validated. If a less complex scoring system is desired, the CURB-65 score is a reasonable alternative, although its effectiveness and safety in guiding the initial site of treatment have not been empirically assessed. Refer to the UpToDate topic on assessing severity and determining the appropriate site of care in patients with CAP for additional details and to access PSI and CURB-65 calculators.

¶ Scoring systems, such as the PSI and CURB-65, and clinical criteria are intended to supplement rather than override the judgment of the physician. Factors other than the predictors included in the rules and the clinical criteria may be important when making an admission decision or selecting the site of inpatient care. As examples, patients with early signs of sepsis or rapidly progressive illness are not well represented by severity scores. Patients with these features may warrant hospitalization and/or ICU admission regardless of score. Conversely, older age may be overrepresented in severity scores; this should be taken into account when determining site of care.

Δ Using the CURB-65 score, if the patient has a score of 1 because he or she is ≥65 years of age and he or she has no major comorbidities, hospital admission is not necessarily indicated.

◊ Although a definitive etiologic diagnosis is often not established until after the site of treatment decision has been made, clinical or epidemiologic evidence favoring pathogens associated with rapidly progressive forms of pneumonia (eg, postinfluenza bacterial pneumonias, severe acute respiratory syndrome, Middle East respiratory syndrome, avian influenza [eg, H5N1, H7N9], Legionella pneumonia, coronavirus disease 2019) indicate a need to perform close clinical follow-up to monitor severity of illness particularly for patients initially deemed low risk at presentation and treated outside of the hospital setting.

§ Some PSI class II and III patients may benefit from in-home health care support, also termed "hospital-at-home" (eg, a visiting nurse, intravenous fluids, intravenous antibiotics).

¥ Depending on clinical judgement, such patients may also be managed as outpatients with in-home health care support (eg, visiting nurse, intravenous fluids, intravenous antibiotics), or with a brief (<23 hour) observational stay.