What is the cut-off on the two-level PE Wells score?

More than 4 points means pulmonary embolism is likely, and 4 points or less means it is unlikely. NICE NG158 prints that split in the same table as the seven scoring items, and the two halves lead to completely different pathways: immediate imaging on one side, a D-dimer on the other.

How quickly does a D-dimer result need to be available?

Within 4 hours if possible. NICE NG158 says that if the result cannot be obtained within 4 hours, in any setting, you should offer interim therapeutic anticoagulation while waiting for it. The same 4-hour standard applies to the D-dimer used in the suspected deep vein thrombosis pathway.

Which anticoagulant is first line for confirmed pulmonary embolism?

Apixaban or rivaroxaban, offered for at least 3 months. If neither is suitable, NICE NG158 offers low molecular weight heparin for at least 5 days followed by dabigatran or edoxaban, or low molecular weight heparin with a vitamin K antagonist for at least 5 days or until the INR is at least 2.0 on two consecutive readings.

Who gets thrombolysis for pulmonary embolism?

Only people with haemodynamic instability. NICE NG158 says to consider pharmacological systemic thrombolytic therapy in that group, alongside a continuous unfractionated heparin infusion, and says explicitly not to offer it to people who are haemodynamically stable, with or without right ventricular dysfunction.

How long does anticoagulation continue after a pulmonary embolism?

At least 3 months for everyone with a confirmed proximal deep vein thrombosis or pulmonary embolism. After that, NICE NG158 says to consider stopping if the event was provoked and the provoking factor has gone, and to consider continuing beyond 3 months if it was unprovoked, balancing recurrence risk against bleeding risk.

Pulmonary Embolism — IMT Interview Clinical Station Answer

Q: When is a V/Q scan used instead of CTPA?

NICE NG158 names three situations: allergy to contrast media, severe renal impairment with an estimated creatinine clearance less than 30 ml per minute, and a high risk from irradiation. In those cases assess the suitability of a V/Q SPECT scan, or a V/Q planar scan if SPECT is not available.

Pulmonary embolism at the IMT (Internal Medicine Training) clinical station is answered by naming the score and then the pathway it opens. NICE NG158 recommends the two-level PE Wells score, where more than 4 points means PE is likely and leads to an immediate CTPA, and 4 points or less means PE is unlikely and leads to a D-dimer.

Key takeaways

NICE NG158 recommends a history, examination and a chest X-ray in anyone presenting with signs or symptoms of pulmonary embolism, to exclude other causes.
The two-level PE Wells score has a single cut-off: more than 4 points is PE likely, and 4 points or less is PE unlikely.
PE likely means a CTPA immediately if possible, with interim therapeutic anticoagulation if the scan cannot be done immediately.
PE unlikely means a D-dimer with the result available within 4 hours if possible, and interim therapeutic anticoagulation if it cannot be.
NICE NG158 says to consider an age-adjusted D-dimer threshold for people aged over 50, and to use a fully quantitative test if testing at the point of care.
Confirmed pulmonary embolism is treated with apixaban or rivaroxaban for at least 3 months; haemodynamic instability means a continuous unfractionated heparin infusion with thrombolysis considered.

How do you recognise pulmonary embolism in the scenario?

Pulmonary embolism presents as pleuritic chest pain, breathlessness or haemoptysis, and NICE NG158 names exactly those three when it asks for a history, examination and chest X-ray to exclude other causes.

The station usually gives you a patient with unexplained tachycardia and hypoxia after surgery, immobility or a long flight, and a chest X-ray that is normal.

Say that a normal chest X-ray supports the diagnosis rather than excluding it, and that a sinus tachycardia is a far more common ECG finding in pulmonary embolism than the classic right heart strain pattern.

What does the A to E assessment and the first hour look like?

The first hour of suspected pulmonary embolism is an A to E assessment, oxygen if hypoxic, intravenous access with baseline bloods, and a decision about interim anticoagulation taken before any scan happens.

Airway and breathing: respiratory rate, saturations, oxygen titrated to target, and a chest X-ray to exclude pneumothorax, consolidation and other causes
Circulation: heart rate, blood pressure and perfusion, because sustained hypotension is what separates a massive pulmonary embolism from every other presentation
Disability and exposure: conscious level, calf examination for deep vein thrombosis, and a risk-factor history covering surgery, immobility, malignancy, pregnancy and oestrogen
Baseline bloods: NICE NG158 asks for full blood count, renal and hepatic function, prothrombin time and activated partial thromboplastin time, says not to wait for the results before starting anticoagulation, and asks that they be reviewed within 24 hours

That said, the sentence that separates candidates in pulmonary embolism is about delay. NICE NG158 offers interim therapeutic anticoagulation whenever the diagnostic test cannot be delivered in the stated time, so the answer is never simply to wait.

Which investigations confirm pulmonary embolism?

The investigation that confirms pulmonary embolism is a computed tomography pulmonary angiogram, with a ventilation and perfusion scan reserved for people who cannot have one.

NICE NG158 names three reasons to use V/Q SPECT, or a V/Q planar scan if SPECT is unavailable, instead of CTPA: allergy to contrast media, severe renal impairment with an estimated creatinine clearance less than 30 ml per minute, and a high risk from irradiation.

If the scan identifies pulmonary embolism, offer or continue anticoagulation, or consider a mechanical intervention if anticoagulation is contraindicated
If the scan does not identify pulmonary embolism, consider a proximal leg vein ultrasound if deep vein thrombosis is suspected, and otherwise stop interim anticoagulation and think about alternative diagnoses
NICE NG158 also allows the pulmonary embolism rule-out criteria, the PERC rule, where clinical suspicion is low on the overall clinical impression and other diagnoses are feasible
For people with unprovoked pulmonary embolism, review the history, the baseline bloods and a physical examination, but NICE NG158 says not to offer further investigations for cancer unless there are relevant symptoms or signs

What is the Wells score, and where is the cut-off?

The threshold that decides the pulmonary embolism pathway is 4 points on the two-level PE Wells score. NICE NG158 prints the items and the cut-off in the same table, so quote both.

Clinical signs and symptoms of deep vein thrombosis, meaning at least leg swelling and pain on palpation of the deep veins: 3 points
An alternative diagnosis is less likely than pulmonary embolism: 3 points
Heart rate more than 100 beats per minute: 1.5 points
Immobilisation for more than 3 days, or surgery in the previous 4 weeks: 1.5 points
Previous deep vein thrombosis or pulmonary embolism: 1.5 points
Haemoptysis: 1 point
Malignancy, on treatment, treated in the last 6 months, or palliative: 1 point

More than 4 points is PE likely and goes straight to imaging. Four points or less is PE unlikely and goes to a D-dimer, with a positive result then following the same imaging pathway.

In practice the trap is using a D-dimer to rule out pulmonary embolism in a patient whose Wells score is more than 4. That patient needs a scan whatever the D-dimer says.

What is the definitive management of pulmonary embolism?

Definitive management of confirmed pulmonary embolism is apixaban or rivaroxaban, offered for at least 3 months, which NICE NG158 recommends as the first-line anticoagulants for confirmed proximal deep vein thrombosis or pulmonary embolism.

If neither apixaban nor rivaroxaban is suitable, offer low molecular weight heparin for at least 5 days followed by dabigatran or edoxaban, or low molecular weight heparin with a vitamin K antagonist for at least 5 days or until the INR is at least 2.0 on two consecutive readings
For confirmed pulmonary embolism with haemodynamic instability, offer a continuous unfractionated heparin infusion and consider thrombolytic therapy
NICE NG158 says not to offer systemic thrombolysis to people with pulmonary embolism who are haemodynamically stable, with or without right ventricular dysfunction
Consider outpatient treatment for suspected or confirmed low-risk pulmonary embolism, using a validated risk stratification tool to decide suitability, with written information and direct contact details
Consider regular monitoring of therapeutic levels for people who weigh less than 50 kg or more than 120 kg

For duration, NICE NG158 says to consider stopping anticoagulation at 3 months after a provoked pulmonary embolism if the provoking factor has gone, and to consider continuing beyond 3 months after an unprovoked one.

That long-term decision is where HAS-BLED appears. NICE NG158 says to consider using it for people on anticoagulation after an unprovoked event, and to discuss stopping if the score is 4 or more and cannot be modified.

When and to whom do you escalate pulmonary embolism?

Escalate pulmonary embolism immediately when the patient is haemodynamically unstable, because that is the group for whom thrombolysis is considered and the decision is not a foundation doctor's to make alone.

Call the medical registrar for every suspected pulmonary embolism you cannot image promptly, and critical care for sustained hypotension, refractory hypoxia or cardiac arrest with suspected pulmonary embolism.

Involve radiology early about the scan, obstetrics for a pregnant patient, and haematology where anticoagulation is complicated by bleeding, renal failure, extremes of weight or antiphospholipid syndrome.

How do you hand over pulmonary embolism in one minute?

The pulmonary embolism handover uses SBAR and leads with the Wells score and the observations, because the receiving team is deciding between a scan tonight and a scan tomorrow.

Situation: a 58 year old, three weeks after a knee replacement, with pleuritic chest pain, a heart rate of 112 and saturations of 91% on air. Background: no anticoagulant since discharge, no bleeding history.

Assessment: two-level PE Wells score of 6, so PE likely, chest X-ray clear, blood pressure 118 over 70. Recommendation: interim therapeutic anticoagulation given, CTPA requested, please review after the scan and confirm the anticoagulation plan.

What does the panel listen for in a pulmonary embolism answer?

The panel listens for the two-level Wells score named as such, the cut-off of more than 4 points, the 4-hour D-dimer, and interim anticoagulation offered whenever the test is delayed.

In practice they also mark whether you say apixaban or rivaroxaban by name and for at least 3 months, because vague answers about 'starting a DOAC' read as textbook recall. The internalmedicineinterview bank of 361 questions across 56 scenarios, with AI-marked spoken practice, rehearses that full arc.

What are the common mistakes in a pulmonary embolism station?

Sending a D-dimer in a patient whose Wells score is more than 4, and then being reassured by it
Waiting for the scan before giving interim therapeutic anticoagulation when the scan cannot be done immediately
Waiting for baseline bloods before starting anticoagulation, when the guideline says not to
Thrombolysing a haemodynamically stable patient because the CTPA report mentions right ventricular strain
Naming PESI as the outpatient tool; the guideline says a validated risk stratification tool without naming one
Ordering extensive cancer screening after an unprovoked pulmonary embolism with no relevant symptoms or signs

How this comes up at the IMT interview

Pulmonary embolism maps onto all three parts of the IMT clinical station. Investigations and diagnosis is the Wells score, the D-dimer and the CTPA; management is interim anticoagulation, then apixaban or rivaroxaban, then a duration decision; and communication is explaining to a patient why a normal chest X-ray has not settled anything.

The handover minute is where the score, the observations and the imaging request have to be said in one breath, with a clear ask and a time for review.

Pulmonary Embolism and Wells Scoring: More Than 4 Points, and What Follows