🫁 PSI / PORT Pneumonia Severity Index
Pneumonia Severity Index (PSI/PORT), a 20-variable score stratifying community-acquired pneumonia 30-day mortality into classes I–V.
PSI / PORT Pneumonia Severity Index
Age (yr)
Sex
Nursing-home resident
History of neoplasm
History of liver disease
History of congestive heart failure
History of cerebrovascular disease
History of renal disease
Altered mental status
Respiratory rate ≥ 30/min
Systolic BP < 90 mmHg
Temperature < 35℃ or ≥ 40℃
Pulse ≥ 125/min
Arterial pH < 7.35
BUN ≥ 30 mg/dL (urea ≥ 10.7 mmol/L)
Sodium < 130 mmol/L
Glucose ≥ 250 mg/dL (≥ 13.9 mmol/L)
Hematocrit < 30%
PaO₂ < 60 mmHg
Pleural effusion
When to use
Use to risk-stratify CAP and inform outpatient vs inpatient disposition, preferred by 2019 ATS/IDSA over CURB-65.
How it works
Points from age (minus 10 if female), nursing-home residence, five comorbidities, five exam findings, and seven lab/imaging findings; class I requires age ≤ 50 with no comorbidity/exam abnormality, then II ≤ 70, III 71–90, IV 91–130, V ≥ 131.
Key points
- PSI identifies low-risk patients (classes I–III) who can often be treated as outpatients, reducing unnecessary admissions (original synthesis · not guideline verbatim).
- It is more discriminating than CURB-65 but more complex, requiring labs and arterial gas variables.
- Override the score with clinical judgment for hypoxemia, unstable comorbidity, or social barriers to outpatient care.
References
- Fine MJ, et al. PSI derivation. N Engl J Med 1997.
- Metlay JP, et al. ATS/IDSA CAP guideline. Am J Respir Crit Care Med 2019.
Decision support for licensed clinicians only; not a substitute for clinical judgement, diagnosis or local protocols.