The initial step of the management plan of a patient with community acquired pneumonia is the decision on hospital admission (inpatient vs. outpatient treatment). If the patient is to be admitted to the hospital, a decision should be made as to whether there should be an admission to the general medical floor or to the intensive care unit (ICU).

Patients with high-risk community-acquired pneumonia should be admitted to the hospital for treatment. Severity of illness scores, such as CURB 65 and Pneumonia Severity Index (PSI), are used to stratify patients.

Admission to the hospital is warranted in the following cases:^[1]

• CURB 65 ≥2, OR
• High PSI score: There is no cut-off value for the PSI score; a higher score is associated with a higher risk of morbidity and mortality. A Risk Class I pneumonia patient can be sent home on oral antibiotics. A Risk Class II-III pneumonia patient may be sent home with IV antibiotics or treated and monitored for 24 hours in hospital. Patients with Risk Class IV-V pneumonia patient should be hospitalized for treatment.

Patients with severe community-acquired pneumonia should be admitted to the ICU if any of the following is present:^[1]

• Invasive mechanical ventilation (major criteria), OR

• Septic shock with need for vasopressors (major criteria), OR

• At least 3 of the following minor criteria:
  • Respiratory rate >30 breaths/min
  • PaO2/FiO2 ratio <250
  • Multilobar infiltrates
  • Confusion/disorientation
  • Uremia (BUN >20 mg/dL)
  • Leukopenia (WBC <4000 cells/mm3)
  • Thrombocytopenia (platelets <100,000 cells/mm3)
  • Hypothermia (temperature <36 degrees C)
  • Hypotension that requires aggressive fluid resuscitation