This Pulmonary embolism severity index (PESI score) calculator predicts 30 day mortality risk PE based on patient clinical data and offers a risk classification prognostic. Discover below the form the criteria used, score interpretation and some info on PE prognostic.

Age [1 point per year]

Patient gender

Temperature <36°C / 96.8°F

Systolic blood pressure <100 mmHg

Heart rate >110 bpm

Respiratory rate >30 bpm

Oxygen saturation less than 90%

History of chronic pulmonary disease

History of heart failure

Altered mental status


How does this pulmonary embolism severity index PESI calculator work?

This is a health tool that works as a risk stratification assessment for mortality and severe morbidity in cases of pulmonary embolism. It is used as a prognostic tool for the 30 day outcome of a PE episode and takes account of several clinical observations.

A questionnaire is completed with the age and gender of the patient and the other clinical signs and symptoms. Each of the criteria are awarded a certain number of points which are then added to form the final PESI score. This score is retrieved in the table of results presented below and interpreted in a risk class and with a certain 30 day prognostic.

In some cases, low risk classes, I and II are even considered for out patient treatment to reduce costs and prevent over solicitation of medical units. High risk cases however, classes IV and V require higher levels of care, usually ICU.

The Pulmonary embolism severity index PESI calculator is based on the following variables:

1. Age of the patient – 1 point per each year

2. Gender – Male – score 20 – males pose a higher risk of PE in this model.

3. Temperature< 36°C / 96.8°F – score 20 – low body temperature, impaired body heat regulation.

4. Systolic blood pressure < 100mmHg – score 30 – decreased blood pressure.

5. Heart rate > 110 bpm – score 20 – pulse higher than 110 beats per minute even at rest.

6. Respiratory rate > 30 breaths per minute – score 20 – increased respiratory rate even at rest.

7. Arterial oxygen saturation below 90% – score 20 – even with supplemented oxygen.

8. History of chronic lung disease – score 10 – previous pulmonary condition.

9. History of heart failure – score 10 – previous heart condition.

10. Alteration of mental status – score 60 – e.g. loss of consciousness.

11. Malignancy – score 30 – history of malignancy, in treatment or palliative.

Score interpretation for mortality risk within 30 days.

Score Class Mortality Risk Probability
0 - 65 I Very low up to 1.6 %
66 - 85 II Low 1.7 - 3.5 %
86 - 105 III Moderate 3.2 - 7.1 %
106 - 125 IV High 4 - 11.4 %
> 126 V Very high 10 - 24.5 %

Pulmonary embolism prognosis

Mortality rates for untreated pulmonary embolism are 26% according to the Barrit and Jordan study of 1960, however advanced research shows that nowadays only up to 10% are fatal within the first hour of symptoms. The PESI model is used to estimate mortality in this potentially fatal disorder.

Prognostic rates are highly dependent on the pulmonary area affected, the size and placement of the clot, the existence of other medical conditions and associated risk factors. In terms of clot blockage, the bigger the clot and the more important the blood vessel blocked is, the more risk there is in this PE if not diagnosed and treated rapidly.

In the most serious cases, when the blood clot breaks and enters the lung, death is rapid as the lung cannot get oxygen in the blood and also blood pressure collapses. In less severe cases, where rapid treatment can be started, there is need for hospitalization and blood thinning treatment or surgery to apply a clot preventing filter. Medication will be continued for at least half a year after the episode, in some cases, even for a life time.


1) Aujesky D, Obrosky DS, Stone RA, Auble TE, Perrier A, Cornuz J, Roy PM, Fine MJ. Derivation and validation of a prognostic model for pulmonary embolism. Am J Respir Crit Care Med. 2005 Oct 15; 172(8): 1041-6. Epub 2005 Jul 14. PubMed PMID: 16020800 - PubMed Central.

2) Wicki  JPerrier  APerneger  TVBounameaux  HJunod  AF Predicting adverse outcome in patients with acute pulmonary embolism: a risk score. Thromb Haemost 2000;84 (4) 548 - 552.

01 Jul, 2015