PESI Score Calculator
Pulmonary Embolism Severity Index points and risk class from eleven bedside findings.
What it does
The Pulmonary Embolism Severity Index sorts patients with confirmed pulmonary embolism into five risk classes. It was derived from more than 15,000 hospital discharges and then checked in independent groups in Switzerland and France. The appeal is that every input comes from the chart, the bedside exam, or a pulse oximeter, so no special test is needed to score it.
Age dominates the arithmetic. A 40 year old starts at 40 points and an 80 year old starts at 80, before any other finding is counted. That design reflects how strongly age predicts short-term death after a clot. Male sex adds 10, cancer adds 30, and heart failure or chronic lung disease adds 10 each.
The remaining points come from vital signs and mental status. A pulse of 110 or more adds 20, a systolic pressure under 100 adds 30, a breathing rate of 30 or more adds 20, a temperature under 36°C adds 20, and an oxygen saturation under 90% adds 20. Altered mental status carries the largest single weight at 60 points.
The total is then read against five cutoffs: 65 or less is class I, 66 to 85 is class II, 86 to 105 is class III, 106 to 125 is class IV, and above 125 is class V. In the derivation and validation samples, 30-day mortality ran from 0 to 1.6% in class I to 10.0 to 24.5% in class V.
Low-risk does not mean no treatment. The score supports decisions about site of care, early discharge, and monitoring intensity alongside oxygen needs, bleeding risk, social factors, and the ability to take anticoagulation. It was not built to rule out pulmonary embolism in the first place, only to grade severity once the diagnosis is made.
How to use
- Choose metric or imperial units for temperature.
- Enter age in years and sex.
- Enter pulse, systolic blood pressure, and respiratory rate.
- Enter temperature and oxygen saturation.
- Mark cancer, heart failure, chronic lung disease, and altered mental status.
- Read the total, risk class, mortality range, and the point breakdown.
Formula
- age
- Age in whole years, added directly as points.
- male
- 1 for male sex, adding 10 points; 0 for female.
- cancer
- 1 for active cancer, adding 30 points.
- heart failure / lung disease
- 1 each for a history of heart failure or chronic lung disease, adding 10 points each.
- vitals
- Pulse 110 or more, systolic under 100, respiratory rate 30 or more, temperature under 36°C, and saturation under 90% add 20, 30, 20, 20, and 20 points.
- altered mental status
- Disorientation, lethargy, stupor, or coma, adding 60 points.
Temperature below 36°C equals 96.8°F, so the imperial mode converts before scoring. The class boundaries are inclusive at the top: 65 is class I, 85 is class II, 105 is class III, and 125 is class IV. A score of 126 or more is class V. The mortality ranges come from the published derivation and validation cohorts and describe groups, not individual patients.
Worked example
Example: 68 year old woman with stable vitals and no risk factors
Female, age 68, pulse 80, systolic pressure 120, respiratory rate 18, temperature 37°C, oxygen saturation 97%, no cancer, heart failure, lung disease, or altered mental status.
- Age 68 contributes 68 points.
- Female sex adds nothing.
- Pulse 80 is below 110, so no points.
- Systolic pressure 120 is at least 100, so no points.
- Respiratory rate 18 and temperature 37°C are normal, so no points.
- Oxygen saturation 97% is at least 90%, and mental status is normal, so no points.
- The total is 68, which falls in class II (66 to 85) with a 30-day mortality range of 1.7 to 3.5%.
Reference table
| Finding | Points | Class | Score | 30-day mortality |
|---|---|---|---|---|
| Age | 1 per year | I | 65 or less | 0 to 1.6% |
| Male sex | +10 | II | 66 to 85 | 1.7 to 3.5% |
| Cancer | +30 | III | 86 to 105 | 3.2 to 7.1% |
| Heart failure | +10 | IV | 106 to 125 | 4.0 to 11.4% |
| Chronic lung disease | +10 | V | 126 or more | 10.0 to 24.5% |
| Pulse 110 or more | +20 | |||
| Systolic under 100 | +30 | |||
| Respiratory rate 30 or more | +20 | |||
| Temperature under 36°C | +20 | |||
| Altered mental status | +60 | |||
| Oxygen saturation under 90% | +20 |
Limits
- Applies to adults with confirmed pulmonary embolism, not to patients with suspected but unconfirmed disease.
- Does not include troponin, brain natriuretic peptide, right ventricular function, or clot burden.
- Mortality ranges come from cohort data and cannot predict what will happen to one patient.
- A low class does not by itself justify discharge; oxygen needs, bleeding risk, and social support still matter.
Common mistakes
- Capping the age contribution or adding age only above 65.
- Scoring a pulse of exactly 110 as zero when the cutoff includes 110.
- Converting temperature incorrectly and scoring 37°C as hypothermia.
- Using the score to rule out pulmonary embolism instead of grading a confirmed case.
- Treating class II as safe for home care without checking oxygen and social factors.
Try it yourself
Quick checks. Answers sit tucked under each question.
Female, 40, pulse 100, systolic 110, respiratory rate 20, temperature 37°C, saturation 96%, no other findings?
Score 40, class I (very low), mortality 0 to 1.6%, breakdown age 40 = 40.
Male, 85, heart failure, pulse 120, systolic 105, respiratory rate 24, temperature 38°C, saturation 92%?
Score 125, class IV (high), mortality 4.0 to 11.4%. The points are age 85, male 10, heart failure 10, and pulse 20.
Male, 70, cancer, pulse 115, systolic 95, respiratory rate 32, temperature 35.5°C, saturation 88%, altered mental status?
Score 280, class V (very high), mortality 10.0 to 24.5%. Age 70, male 10, cancer 30, pulse 20, pressure 30, breathing 20, temperature 20, mental status 60, and oxygen 20 add up to 280.
Questions
What does PESI stand for?
Pulmonary Embolism Severity Index. It estimates 30-day mortality after a confirmed pulmonary embolism.
How is age scored?
One point for every year of age. A 70 year old starts at 70 points.
What score is low risk?
Classes I and II, meaning 85 points or less, are the low-risk group in the original papers.
Do I need labs to use PESI?
No. The 11 inputs are age, sex, three comorbidities, and six bedside findings.
Does a low PESI mean I can go home?
Not automatically. Outpatient care also depends on oxygen needs, bleeding risk, kidney function, home support, and follow-up.
Is there a simplified version?
Yes, the simplified PESI uses one point for each of six findings and no age weighting. This page implements the original score.
Sources
- Aujesky et al., derivation and validation of the PESI, Am J Respir Crit Care Med 2005
- British Thoracic Society guideline for the management of pulmonary embolism