PSI / PORT Pneumonia Severity Index — free guideline decision tool
Pneumonia Severity Index (PSI/PORT), a 20-variable score stratifying community-acquired pneumonia 30-day mortality into classes I–V.
Open guideline tool →Guideline-based
Implements the decision logic from published clinical guidelines.
Runs in your browser
No installation. Enter the patient's values and get a guideline recommendation instantly.
Data stays local
Nothing is uploaded. Results are for licensed clinicians only.
Worked calculation
The values below come from this tool's own example placeholders and are computed server-side with the formula shown on this page, so the arithmetic can be checked quickly. It demonstrates how to substitute values only — it is not clinical advice and not a real case.
| Age | 65 yr |
|---|---|
| Sex | Male |
| Nursing-home resident | Yes |
| History of neoplasm | Yes |
| History of liver disease | Yes |
| History of congestive heart failure | Yes |
| History of cerebrovascular disease | Yes |
| History of renal disease | Yes |
| Altered mental status | Yes |
| Respiratory rate ≥ 30/min | Yes |
| Systolic BP < 90 mmHg | Yes |
| Temperature < 35℃ or ≥ 40℃ | Yes |
| Pulse ≥ 125/min | Yes |
| Arterial pH < 7.35 | Yes |
| BUN ≥ 30 mg/dL (urea ≥ 10.7 mmol/L) | Yes |
| Sodium < 130 mmol/L | Yes |
| Glucose ≥ 250 mg/dL (≥ 13.9 mmol/L) | Yes |
| Hematocrit < 30% | Yes |
| PaO₂ < 60 mmHg | Yes |
| Pleural effusion | Yes |
→PSI risk classClass V
- Total score：350 pts
- 30-day mortality (approx.)：27–31%
- Disposition reference：Inpatient (consider ICU)
| Age | 65 yr |
|---|---|
| Sex | Female |
| Nursing-home resident | No |
| History of neoplasm | No |
| History of liver disease | No |
| History of congestive heart failure | No |
| History of cerebrovascular disease | No |
| History of renal disease | No |
| Altered mental status | No |
| Respiratory rate ≥ 30/min | No |
| Systolic BP < 90 mmHg | No |
| Temperature < 35℃ or ≥ 40℃ | No |
| Pulse ≥ 125/min | No |
| Arterial pH < 7.35 | No |
| BUN ≥ 30 mg/dL (urea ≥ 10.7 mmol/L) | No |
| Sodium < 130 mmol/L | No |
| Glucose ≥ 250 mg/dL (≥ 13.9 mmol/L) | No |
| Hematocrit < 30% | No |
| PaO₂ < 60 mmHg | No |
| Pleural effusion | No |
→PSI risk classClass II
- Total score：55 pts
- 30-day mortality (approx.)：0.6%
- Disposition reference：Outpatient
Common questions
What is 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.
How is PSI / PORT Pneumonia Severity Index calculated? What is the core formula?
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. Compute PSI/PORT points from demographics, nursing-home status, five comorbidities, five exam findings and seven lab/imaging items; assign class I–V.
When is PSI / PORT Pneumonia Severity Index used?
Use to risk-stratify CAP and inform outpatient vs inpatient disposition, preferred by 2019 ATS/IDSA over CURB-65.
How should PSI / PORT Pneumonia Severity Index results be interpreted?
Classes I–III are often low-risk for outpatient care when oxygenation and social factors allow; IV–V favour inpatient care with escalating mortality risk.
What are the key clinical points for PSI / PORT Pneumonia Severity Index?
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.
What are the limits and cautions when using PSI / PORT Pneumonia Severity Index?
More discriminating than CURB-65 but needs labs/ABG variables — do not delay care for missing labs. Hypoxaemia, unstable vitals or unreliable follow-up override a low class. Prefer local CAP pathways (e.g. ATS/IDSA) when they differ. For licensed clinicians and clinical researchers. Interpret results with history, investigations and local protocols; not a diagnosis or prescription, and not a substitute for multidisciplinary decision-making or local guidelines.
Does PSI / PORT Pneumonia Severity Index upload patient data? Where is it calculated?
Calculation runs locally in the browser; inputs and results are not uploaded. For licensed clinicians only; interpret with history, investigations and local protocols — not a diagnosis or prescription.
How is PSI / PORT Pneumonia Severity Index calculated in practice? Can you show a worked example?
Inputs: Age 65 yr, Sex Male, Nursing-home resident Yes, History of neoplasm Yes, History of liver disease Yes, History of congestive heart failure Yes, History of cerebrovascular disease Yes, History of renal disease Yes… → Result: PSI risk class Class V（Total score: 350 pts, 30-day mortality (approx.): 27–31%, Disposition reference: Inpatient (consider ICU)） Inputs: Age 65 yr, Sex Female, Nursing-home resident No, History of neoplasm No, History of liver disease No, History of congestive heart failure No, History of cerebrovascular disease No, History of renal disease No… → Result: PSI risk class Class II（Total score: 55 pts, 30-day mortality (approx.): 0.6%, Disposition reference: Outpatient）
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Pneumonia Severity Index (PSI/PORT), a 20-variable score stratifying community-acquired pneumonia 30-day mortality into classes I–V.
Open guideline tool →For licensed clinicians. Not a substitute for clinical judgement.
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