Pneumonia Severity Index (PSI/PORT) Calculator

Step 1: class I

A patient is in class I, with no points needed, if they are 50 or younger and have none of these: neoplastic disease, congestive heart failure, cerebrovascular disease, renal disease, liver disease, altered mental status, pulse 125/min or higher, respiratory rate 30/min or higher, systolic blood pressure under 90 mm Hg, or temperature under 35 °C or 40 °C or higher (Allena 2023). Anyone else goes to step 2.

Step 2: points

Start with the age in years (age minus 10 for women), then add points for each finding present (Noguchi 2024) (Allena 2023):

• Nursing home resident: +10
• Neoplastic disease: +30
• Liver disease: +20
• Congestive heart failure: +10
• Cerebrovascular disease: +10
• Renal disease: +10
• Altered mental status: +20
• Respiratory rate 30/min or higher: +20
• Systolic blood pressure under 90 mm Hg: +20
• Temperature under 35 °C or 40 °C or higher: +15
• Pulse 125/min or higher: +10
• Arterial pH under 7.35: +30
• Blood urea nitrogen 30 mg/dL or higher: +20
• Sodium under 130 mmol/L: +20
• Glucose 250 mg/dL or higher: +10
• Hematocrit under 30%: +10
• PaO2 under 60 mm Hg (or SpO2 under 90%): +10
• Pleural effusion on chest imaging: +10

Noguchi and colleagues print the oxygen item as PaO2 under 60 mm Hg (SpO2 under 90%), and the respiratory rate item as 30/min or higher; Allena and colleagues print the rate as over 30/min. This tool uses 30/min or higher, as in Noguchi 2024 (Noguchi 2024).

Risk classes

Points give the class for anyone not in class I (Hu 2015) (Noguchi 2024). The mortality column is the figure reported for community-acquired pneumonia by Fine and colleagues, as printed by Hu and colleagues (Hu 2015) (Fine 1997).

• Class I: step 1 only, the lowest risk class.
• Class II: 70 points or fewer; mortality 0.6%.
• Class III: 71 to 90 points; mortality 0.9%.
• Class IV: 91 to 130 points; mortality 9.3%.
• Class V: over 130 points; mortality 27%.

Allena and colleagues describe classes I and II as low risk and suitable for outpatient care, class III as outpatient care or a short observation stay by clinical judgment, and classes IV and V as needing admission (Allena 2023).

Worked example: a 72-year-old woman with congestive heart failure, a respiratory rate of 30/min and a blood urea nitrogen of 30 mg/dL scores 62 + 10 + 20 + 20 = 112 points, class IV.

What the studies found

In 752 patients hospitalized with a COPD exacerbation, the PSI had an area under the curve of 0.847 for in-hospital death; a cut-off of 116.5 points gave a sensitivity of 82.2% and a specificity of 77.6% (Hu 2015). In a meta-analysis of 21 studies of healthcare-associated pneumonia, the PSI, A-DROP, I-ROAD and CURB-65 at a moderate cut-off had pooled sensitivities of 0.91 to 0.97 and specificities of 0.15 to 0.44 for death, and A-DROP and CURB-65 predicted about as well as the PSI (Noguchi 2024).

Related tools

The A-a gradient calculator works from the same arterial blood gas. The CURB-65 calculator is a shorter pneumonia severity score that needs only one blood test. For suspected sepsis, see the qSOFA calculator. For a pleural effusion, Light's criteria separate an exudate from a transudate. Other bedside scores are listed under For healthcare professionals.