The PE GUIDELINES SUMMARY
The new guidelines are a hefty document. The AHA change the way we classify PE, such that it gives a more detailed approach to risk and outcomes, based on 5 Categories of clinical presentation. They give guidance on all other aspects of acute management and outpatient treatment, as well as the approach to the sickest patients with PE. Below is a quick summary. Read the full review on Literature Rounds
NEW CLASSIFICATION OF PE
There is a new classification of PE. The previous categories of low risk, submassive and massive PE, have been replaced by five new categories. This new classification describes severity and prognosis. It appears complex at first, however simply put it looks like this:
Categories A and B are made up of asymptomatic, or symptomatic patients who are patients at lower risk of adverse outcomes based on the severity indices.
Category C are symptomatic patients with increased risk of adverse outcomes depending on cardiac biomarkers and echocardiography
Cateries D and E are the sickest patients at risk of cardiopulmonary failure and arrest.
A Respiratory Modifier is also included in Categories C to E.
All are explained in detail on the Literature Rounds.
EVALUATION OF THE PATIENT FOR PE
The guidelines recommend the use of clinical probability, followed by either the PERC rule, or the D-dimer with the YEARS criteria, to rule out PE or alternatively to perform imaging.
Suspicion of a PE based on the history and examination, requires determination of a pre-rest probability. Validated rules such as the Wells Score and the Revised Geneva Score, as well as our own clinical gestalt, can be used to risk stratify patients.
Gestalt is something we use every day in our clinical practice, however it does depend on our experience. (Paper coming soon on gestalt from Dr Joe Nemeth and myself in the CJEM) The Wells Score also includes gestalt, in that we need to decide if âPE is the most likely diagnosisâ.
The Revised Geneva Score, is what I personally recommend, as it contains no gestalt, is based on history and clinical examination findings.
Having said this, if the Clinical suspicion is high for a PE, regardless of what the Clinical Scores show, that patient should be investigated for a PE. Any patient with a high clinical probability needs imaging.
OTHER CRITERIA USED IN DECISION MAKING DURING EVALUATION
PERC RULE
In low clinical probability patients(<15%), the PERC RULE can be used to rule out PE.
To be able to rule out PE with the PERC rule, all the following must be negative.
- Age > 50
- HR > 100 (At any time)
- O2 sat on room air < 95%
- Unilateral Leg Swelling
- Haemoptysis
- Recent Surgery or Trauma
- Surgery or Trauma < 4 weeks ago, requiring general anaesthesia
- Prior PE or DVT
- Hormone use
- Oral contraceptives, hormone replacement or oestrogenic hormones use in male or female patients.
If the patient can be ruled out with the PERC rule, nothing further is needed. If they cannot, then they move to the intermediate clinical probability group, where a D-dimer and YEARS criteria are use.
YEARS CRITERIA
YEARS Criteria are used with a D-dimer
There are 3 YEARS Criteria are:
- Clinical Signs of a DVT
- Haemoptysis
- PE is the most likely diagnosis (gestalt again enters the equation)
No YEARS criteria present:
If the D-dimer is:
- < 1000 ng/mL: PE is excluded
- >1000 ng/mL the patient requires imaging
>1 YEARS Criteria present
If the D-dimer is:
- <500ng/mL or age adjusted is normal then PE is excluded.
- >500ng/mL or age adjusted is high then imaging is required.
INVESTIGATIONS
- Cardiac Biomarkers such as Troponin and BNP identify patients at risk of short term complications and mortality.
- Lactate can give clues into subclinical end-organ hypoperfusion. It is important to perform in normotensive patients.
- Echocardiography and chest CT are recommended for patients with acute symptomatic PE and an elevated severity score.
RISK SCORES
Risk Scores identify patients with a low risk of short term adverse outcomes.
Hestia, PESI and sPESI can all identify low risk patients who can be treated as outpatients.
ACUTE PE TREATMENT OPTIONS
Anticoagulation
Anticoagulation of patients is the mainstay of treatment. More invasive techniques can also be added depending on the classification severity.
Categories A and B: Patients who are asymptomatic, or symptomatic with a low clinical severity score, can be treated with DOAC and are suitable for outpatient management.
DOACs and VKAs are contraindicated in pregnancy as they pose risks to the fetus as they cross the placenta.
DOACs are contraindicated in patients who are breastfeeding, as they may be excreted into breast milk.
Categories C to E: All other categories of patients can have LMWH, have cardiac biomarkers and a lactate measured. They will also need to have RV size and function assessed.
Categories D and E: Patients will require systemic thrombolysis and those in E1 may require surgical embolectomy
Haemodynamic Support
Noradrenaline(NA) is considered the vasopressor of choice. At doses < 15mcg/min it has no effect on PVR. So it increases SVR/PVR ratio. At levels above 15mcg/min, NA begins to increase PVR. A second vasopressor like Vasopressin can be added at this point.In patients with low cardiac output and hypotension dobutamine may be added to NA.
POST ACUTE PE MANAGEMENT
Outpatient follow-up is needed to assess symptom improvement, anticoagulation adherence and appropriateness and to look at the potential future course of the condition.
Most patients with uncomplicated PE can be seen by their local doctor.
Patients should be referred to speciality clinics if:
- The have complex anticoagulation management requirements\
- VTE history or recurrent PE
- Unresolved symptoms
- Pregnancy-related PE
- Complicated clinical presentation
- Expert second opinion is needed
PATIENT ACTIVITY AND TRAVEL
Patients will usually be on a 3-6 month course of anticoagulants. Those who have ceased their anticoagulation and are travelling, may benefit from a one time dose of anticoagulant (LMWH or a DOAC) if travelling for long distances ie >4hr flight.
Read it all and see the flow diagrams on Lit Rounds.
Peter Kas
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