• Haemodynamically stable pulmonary embolism (PE) with systolic BP ≥90 mmHg and <40 mmHg drop from baseline
• PE range from small with normal BP to large with borderline BP and right ventricular dysfunction
• If patient becomes haemodynamically unstable during management, follow Pulmonary embolism: Haemodynamically unstable guideline

• Pulmonary venous thromboembolism (PE) is often missed clinically, particularly in:
• severe cardiorespiratory disease
• elderly patients
• Suspect the diagnosis in any patient who does not respond to initial therapy, or in whose condition there has been an unexplained deterioration
• Most episodes follow popliteal or iliofemoral DVT

Symptoms

• Small emboli present with dyspnoea
• Moderate-sized emboli present with signs of infarction and pleuritic pain
• Dyspnoea (present in 90% of cases) - may be of sudden onset
• Pleuritic chest pain
• Haemoptysis
• Syncope

Signs

• Tachypnoea (>20 breaths/min)
• Fever
• Pleural rub
• Tachycardia
• Maybe absent

Differential diagnosis

• Pneumonia
• Myocardial infarction (MI)
• Exacerbations of asthma and COPD

Pulmonary embolism rule-out criteria (PERC)

• If clinical suspicion of PE is low (the clinician estimates <15% probability and other diagnoses are feasible), assess PERC to help determine whether any further investigations for PE are needed
• If patient has any of the following criteria, a D-dimer and two-level PE Wells score would be required, and follow flowchart below
  
  • aged ≥50 yr
  • heart rate ≥100 bpm
  • oxygen saturation on air <95%
  • unilateral leg swelling
  • haemoptysis
  • recent surgery or trauma ≤4 weeks ago and requiring a general anaesthetic
  • hormone use - oral contraceptive pill, HRT, oestrogen therapy in man or woman
  • previous PE or DVT
• If patient has none of the above criteria, chance of PE is <2%

• FBC, INR, APTT and U&E

ECG and CXR

• ECG and CXR (with fetal screening in a pregnant woman) are often normal
• not to be used to confirm/refute the diagnosis
• useful for identifying other diseases and explaining symptoms
• ECG may show:
• sinus tachycardia, an S1 Q3 T3 pattern
• right bundle branch block, P pulmonale or right axis deviation
• Chest X-ray may show:
• non-specific shadows or a raised hemidiaphragm
• pulmonary oligaemia, linear atelectasis or small pleural effusion

D-dimer

• Raised in many clinical states
• do not request if clinical probability of PE is high, in probable massive and haemodynamically unstable PE, or where an alternative diagnosis is highly likely 
• normal D-dimer concentration virtually rules out thrombosis

Leg Doppler ultrasound

• Alternative to lung imaging in patients with clinical DVT

CTPA

• Gold standard
  
  • often shows other diagnoses
  • for patients with contrast media allergy, severe renal impairment (eGFR <30 mL/min) or at high risk from radiation, assess most appropriate imaging modality with radiologist 

General

• Oxygen - see Hypoxaemia guideline
• Adequate analgesia for pleuritic pain - paracetamol alone is unlikely to be adequate
• if well hydrated and eGFR ≥30 mL/min, ibuprofen 400 mg oral 8-hrly
• in dehydrated patient or if eGFR <30 mL/min, to prevent renal damage, prefer morphine sulphate 10 mg oral 4-hrly - ibuprofen may be substituted once adequate fluid replacement achieved if eGFR ≥30 mL/min
• if patient pregnant, prefer morphine sulphate 10 mg oral 4-hrly
• if patient taking ACE inhibitor avoid NSAIDS, including ibuprofen
• A high right atrial pressure (i.e. ↑JVP) is common and does not need to be treated
• AVOID diuretics

When to use protein pump inhibitor (PPI)

• Concurrent antiplatelet therapy doubles the risk of major bleeding with anticoagulation
  
  • confirm safety of stopping with specialist teams (i.e. cardiology, neurology) 
  • if antiplatelet therapy must continue, recommend PPI
• SSRI and SNRI medications also increase the risk of GI bleeding with anticoagulation
  
  • recommend PPI to mitigate this risk

Choice

• Assess patients by sPESI risk score and exclusion criteria 

Determine Simplified Pulmonary Embolism Severity Index (sPESI)

Table 3

Check exclusion criteria

Decision

• If sPESI is high risk or an exclusion criterion, manage as inpatient
• consider for early discharge when low risk score
• If SPESI is low risk and no exclusion criterion, manage as ambulatory care

Suitable for ambulatory care of PE

• Refer to ambulatory emergency care centre (AEC)
• Provide patient information on:
• signs and symptoms of recurrence, major bleeding and additional complications
• AMU and AEC contact details in event of complications and concerns
• Complete the PE Ambulatory proforma
• Arrange review in AEC within a week of discharge
• Refer to respiratory clinic

• Daily clinical examination for signs of further embolism, right heart failure, and secondary infection of a pulmonary infarct

Monitoring dalteparin treatment

• See Dalteparin for VTE guideline

Screen for cancer

• In all patients with a confirmed PE, perform CXR, FBC, LFT, calcium and urinalysis
• Only offer further investigations for cancer to people with unprovoked PE if they have relevant symptoms or signs 

Screen for thrombophilia

• If patient aged <45 yr with unprovoked PE, discuss screening for inherited or acquired thrombophilia with haematology consultant

Duration of anticoagulation

• After a first provoked thromboembolic event, continue anticoagulation for 3 months and arrange follow-up in haematology and respiratory clinics for reassessment
• Continue indefinitely for life-threatening PE and refer to respiratory clinic
• For recurrent or unprovoked PE and minor provoked PE discuss with haematology and/or respiratory physician for extended anticoagulation before discharge and refer to respiratory clinic
• If patient has active cancer, reassess risks and benefits of continuing anticoagulation at 6 months in haematology, respiratory or oncology clinics

Outpatient investigations

• If evidence of right ventricular dysfunction or raised troponin or BNP biomarkers, arrange echocardiogram
  
  • arrange follow-up for result in 10-12 weeks for respiratory clinic
• Refer all unprovoked PE patients to the local anticoagulation service and haematology clinic for further counselling and ongoing monitoring of anticoagulation 

Advice to patient

• Many drugs (including alcohol) interact with warfarin or DOAC 
• To remind their GP, if additional medication is added, that they are taking anticoagulant 
• To inform dentist that they are anticoagulated
• Give advice on extended travel
• Provide PE information booklet

Women of childbearing age (pregnancy, pills, periods)

• Counsel that DOACs and warfarin may be harmful in pregnancy. Seek immediate advice if pregnant or trying to conceive
• Anticoagulation may lead to menorrhagia in 70% of women. Apixaban less commonly implicated than warfarin and rivaroxaban
• Do not stop contraception at time of PE diagnosis including combined oral contraceptive pill (COCP) 
  
  • refer patient to thrombosis clinic to discuss options
  • anticoagulation negates ongoing thrombotic risk of the COCP. Stopping COCP may precipitate menorrhagia or lead to pregnancy whilst on a DOAC

Monitoring of warfarin

• Refer to anticoagulant management service for follow-up appointment date 
• Give patient a completed yellow anticoagulation therapy record 
• Ensure discharge letter includes diagnosis, dosage of warfarin and date of clinic appointment
• If anticoagulation to be monitored by GP, supply GP with written information (on separate sheet, stapled to discharge letter) about:
  
  • indication for anticoagulation
  • proposed duration of treatment
  • proposed target range for INR
  • details of anticoagulation in hospital (give dates, INR results and dosage taken) 

Document

• Document in medical record
  
  • patient has been given written and verbal information about warfarin and has been referred to anticoagulation clinic
  • duration of treatment
  • if definite risk factor identified
  • outpatient investigations
  • monitoring arrangements