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IDSA/ATS ICU Criteria for CAP

Helps determine the need for the ICU in patients with community-acquired pneumonia (CAP), as outlined by the American Thoracic Society (ATS) / IDSA. Meeting ≥3 minor criteria suggests ICU-level care.

Antibiotic guideCommunity-Acquired Pneumonia
Below ICU threshold
0–2 minor criteria
ICU not indicated by this rule; floor admission reasonable
0pts
Vitals & mental status
Confusion / disorientation
Hypothermia (core temp <36°C / <96.8°F)
Hypotension requiring aggressive fluid resuscitation
Respiratory rate ≥30 breaths/min
Oxygenation & imaging
PaO₂/FiO₂ ratio <250
Multilobar infiltrates
Labs
Leukopenia (WBC <4,000/mm³, not from chemotherapy)
Thrombocytopenia (platelets <100,000/mm³)
Uremia (BUN >20 mg/dL)
IDSA/ATS minor criteria: Mandell LA, et al. Clin Infect Dis. 2007;44(Suppl 2):S27–S72 (reaffirmed 2019). Major criteria — either one alone = ICU: invasive mechanical ventilation; septic shock requiring vasopressors. This tool scores the 9 MINOR criteria only.

More CAP tools

CURB-65Estimates the mortality of community-acquired pneumonia (CAP) and suggests inpatient vs. outpatient treatment. PSI is favored over CURB-65 by ATS/IDSA, but PSI is cumbersome to use — so many prefer CURB-65.DRIP — Drug Resistance in PneumoniaAttempts to predict the risk of drug-resistant organisms (DRPs) in community-acquired pneumonia (CAP).Pneumonia Severity Index (PSI)Helps determine risk of mortality from Community-Acquired Pneumonia (CAP) and guides home vs. admit; PSI is favored over CURB-65 by ATS/IDSA but is cumbersome to use, resulting in many preferring CURB-65.