PE is somehow both the most over and under diagnosed condition. with severity ranging from the questionable sub-segmental PE to the Massive PE (an indication for thrombolysis). So think:

• Does this presentation sound like a PE? – If not STOP here
• Pregnant?  – Click Here
• Do you think this is likely a PE? (if so you can’t use PERC)
• Does D-Dimer answer  your question? (whats the Wells)
• Massive PE  – think Thrombolysis
• Sub-Massive PE – there is lots of debate (involve seniors), locally needs 2 consultant sign off and not considered time critical.

Step 1 – Wells Score

PE Wells - Clinical Feature	Score
Clinical signs and symptoms of DVT (minimum of leg swelling and pain with palpation of the deep veins)	3
An alternative diagnosis is less likely than PE	3
Heart rate > 100 beats per minute	1.5
Immobilisation for more than 3 days or surgery in the previous 4 weeks	1.5
Previous DVT/PE	1.5
Haemoptysis	1
Malignancy (on treatment, treated in the last 6 months, or palliative)	1
Risk Based Action	Score
High Risk Pathway	Over 4
Low Risk Pathway	4 and under
Consider PERC - to avoid further investigation	Under 3

PERC (Wells ≤2)

PERC - Clinical Feature	Score
Age <50yrs	1
Pulse <100bpm	1
SaO2 >94%	1
No Unilateral Leg Swelling	1
No Haemoptysis	1
No Recent Trauma/Surgery	1
No Previous PE/DVT	1
No Hormone Use/Pregnant	1
Risk Based Action	Score
Risk of PE <2%, may stop investigating	8
Low Risk Pathway	Under 8

Low Risk Pathway – D-Dimer

• D-Dimer <500ng/ml – No further investigation is required (be aware in the original studies this did miss patients but none of those had adverse out comes)
• D-Dimer 500-1000ng/ml – Consultants/MG’s can consider using age adjusted D-Dimer in the over 50’s (10ng/ml per year of age), as D-Dimer elevates with age, however do make sure its truly is a low risk patient. If above cut-off or unable to apply follow High-Risk Pathway.
• D-Dimer >1000ng/ml – Follow High Risk Pathway

High Risk Pathway – CTPA

• D-Dimer is irrelevent if Wells >4
• Commence Tinzaparin – if not contraindicated; [BNF]
• Order CTPA (consider VQ if Pregnancy)– Remember to input Wells, eGFR, and D-dimer (if low risk) in to clinical details
• Consider AAU or AMU – dependant on sPESI

sPESI - Clinical Feature	Score
Over 80yrs old	1
History of Cancer	1
Chronic cardiopulmonary disease	1
HR >109bpm	1
sBP <100mmHg	1
SaO2 <90%	1
Destination	Score
AAU	0
AMU / MAU	1 or more

Sub-Massive PE

Treatment of submissive PE is controversial, there is a theoretical reduction in morbidity if these patients get thrombolysis, however, there are significant risks.

Massive PE – Thrombolysis

Either (confirm with scan if at all possible):

• CTPA/Echo evidence of PE and features of shock (Systolic BP < 90mmg Hg or a pressure drop of > 40mmHg in < 15 minutes)
• Periarrest (unsuitable for imaging) and high clinical suspicion of pulmonary embolism)

Treatment

• Heparin 80unit/kg OR treatment dose Tinzaparin – (Give Prior to Urgent CTPA)
• Alteplase (tPA) (national shortage small stock for cardiac arrest only)
  • Non-Arrest – 10mg by IV injection over 1‐2 minutes followed by IV infusion of 90mg over 2 hours; max 1.5mg/kg in patients less than 65kg 
  • Cardiac Arrest – 50mg IV injection over 1-2min, (consider second dose if no ROSC at 15min)
• Streptokinase (preferred agent if alive) – BNF
  • 250’000 units, dose to be given over 30 minutes, then 100’000 units every 1 hour for 24 hours
  • alternatively 1’500’000 units, dose to be given over 1–2 hours
• Tenecteplase (national shortage)
  • is a suitable alternative if alteplase not immediately available
  • BUT… increased chances major  bleeds inc. fatal intracranial bleeds

Contraindications for Thrombolysis (PE)

“Contraindications to thrombolysis that are considered absolute, e.g. in acute myocardial infarction, might become relative in a patient with immediately life-threatening high-risk PE.”

Absolute

• Haemorrhagic stroke or stroke of unknown origin at any time
• Ischaemic stroke in preceding 6 months
• Central nervous system damage or neoplasm
• Recent major trauma/surgery/head injury (within preceding 3 weeks)
• Gastrointestinal bleeding within the last month
• Known bleeding

Relative

• Transient ischaemic attack in preceding 6 months
• Oral anticoagulant therapy
• Pregnancy or within 1 week post-partum
• Non-compressible punctures
• Traumatic resuscitation
• Refractory hypertension (systolic blood pressure >180 mmHg)
• Advanced liver disease
• Infective endocarditis
• Active peptic ulcer