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Pneumonia Severity Index

Enter demographic data, comorbidities, vital signs, and laboratory values to calculate the PSI score and assign a risk class.

Demographics & Comorbidities

Nursing home resident
Neoplastic disease
Liver disease
Congestive heart failure
Cerebrovascular disease
Renal disease

Clinical Findings

Altered mental status

Laboratory Values

Oxygenation & Imaging

Pleural effusion on imaging

Results

Total PSI score

70

Risk class

Class II • ~0.6% mortality

Outpatient treatment usually appropriate.

Score breakdown:

  • Age (adjusted): 70 points
  • Comorbidities: 0 points
  • Examination findings: 0 points
  • Laboratory/Radiography: 0 points

Reference: Fine MJ et al. A prediction rule to identify low-risk patients with community-acquired pneumonia. N Engl J Med. 1997.

How to Use This Calculator

PSI requires demographics, comorbidities, vital signs, ABG, and routine labs. Ensure information reflects current presentation. Use the resulting class to stratify mortality risk and discuss disposition (outpatient vs inpatient vs ICU). PSI complements but does not replace bedside assessment, social considerations, and patient preferences.

Frequently Asked Questions

PSI offers more granular stratification but requires more data. Use CURB-65 when labs are limited or rapid triage is needed. Yes—once labs are available. Many EDs use PSI to identify candidates for outpatient management. Assume normal (≥7.35) or order ABG/VBG. Without pH, PSI may underestimate risk. Age contributes significantly; combine with comorbidities to interpret. Younger patients with severe findings may still accumulate high points. Typically once per admission presentation. Recalculate if clinical status changes dramatically.