This document discusses diagnostic standards and guidelines for pulmonary embolism (PE). It defines what is meant by "confirmed PE" and "excluded PE" from a clinical management perspective. It also discusses how the severity of PE should be based on estimated mortality risk rather than the anatomical features. Several clinical prediction rules and markers for risk stratification are mentioned. Validated diagnostic criteria are presented for diagnosing non-high risk PE based on clinical probability.

1. diagnostic standards for
pulmonary embolism
Tomasz Rakowski
Jagiellonian University Medical College
Krakow, Poland

3. Diagnosis
Throughout these guidelines and for the purpose of clinical
management, ‘confirmed PE’ is understood as a probability of
PE high enough to indicate the need for PE-specific treatment
and ‘excluded PE’ as a probability of PE low enough to justify
withholding specific PE-treatment with an acceptably low risk
despite a clinical suspicion of PE. These terms are not meant
to indicate absolute certainty regarding the presence or
absence of embolii in the pulmonary arterial bed.
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5. Severity of pulmonary embolism
The severity of PE should be understood as an individual
estimate of PE-related early mortality risk rather than the
anatomical burden and the shape and distribution of
intrapulmonary emboli. Therefore, current guidelines suggest
replacing potentially misleading terms such as ‘massive’,
‘submassive’ and ‘non-massive’ with the estimated level of
the risk of PE-related early death.

6. Principal markers useful for risk stratification

7. Risk stratification according to expected pulmonary
embolism-related early mortality rate
a In the presence of shock or hypotension it is not necessary to confirm RV dysfunction/injury to
classify as high risk of PE-related early mortality.

10. Clinical prediction rules for PE
Revised Geneva score Wells score

11. Simplified clinical prediction rules for PE
Revised Geneva score Wells score
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Low: 0 to 1; intermediate: 2 to 4; high: 5+ PE unlikely: 0 to 1; PE likely: 2 or more
PE unlikely: 0 to 2; PE likely: 3 or more
Thromb Haemost 2009;101:197-200
Arch Intern Med. 2008;168:2131-6

14. Validated diagnostic criteria for diagnosing PE in patients
without shock and hypotension (non-high-risk PE)
according to clinical probability

15. Validated diagnostic criteria for diagnosing PE in patients
without shock and hypotension (non-high-risk PE)
according to clinical probability