🫁 PSI / PORT Pneumonia Severity Index
UseUse to risk-stratify CAP and inform outpatient vs inpatient disposition, preferred by 2019 ATS/IDSA over CURB…
StrataClasses I–III are often low-risk for outpatient care when oxygenation and social factors allow; IV–V favour i…
LimitsMore discriminating than CURB-65 but needs labs/ABG variables — do no… · Hypoxaemia, unstable vitals or unreliable follow-up override a low cl… · Prefer local CAP pathways (e.g. ATS/IDSA) when they differ.
SourceMetlay JP, et al. ATS/IDSA CAP guideline. Am J Respir Crit Care Med 2019.
This-shift next steps
After scoring: open the scene pack, peer scores, and the matching pathway. Local reference — no HIS write.
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Methodology · worked example, guidelines & full notes
PSI identifies low-risk patients (classes I–III) who can often be treated as outpatients, reducing unnecessary admissions (original synthesis · not guideline verbatim).
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
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
Verification & sources · governance
FAQ
Frequently asked questions
- 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）