Dr Viviana Elliott

Consultant Physician

Acute Medicine

Pulmonary Embolism

Aim

• Provide a practical approach for the diagnosis and management of pulmonary embolism

Objectives

• To be able to understand pathophysiology

• To be able to understand importance of early diagnosis

• To be able to recognise signs and symptoms

• To be able to request investigations appropriately

• To be able to treat pulmonary embolism

• To be able to investigate and treat PE in special situations ( Massive PE, pregnancy and cancer)

Pathophysiology

Venous thrombi originatepredominantly in venous valve pockets and at other sites of

presumed venous stasis

Virchow’s Triad

Why is it so important to think PE?

Case 1

• Female 40 years old

• Chest tightness and shortness of breath for two days

• Past Medical History: Crohn’s disease

• Presents to ED RR 35x’, BP 80/40 mmHg, Sat: 80%

• Transferred to resus with suspected PE

• Thrombolised

• Arrested and died within 20’ of arrival

• Post mortem: massive PE

PE is an acute medical emergency!

Incidence of Pulmonary embolism• 60-70 cases/100.000

• 50% develop PE while in hospital or in long term care

• 25% idiopathic cases

• 25% have recognised risk factors

Most VTE affect acutely ill patients

Risk factors for VTE

• Acquired

• Hereditary

Reduced mobility

• Hospitals stay !!!!!!• Fractures (Hip-Knee- Ankle)• Major surgery • Trauma • Spinal cord injury• Immobilizer or cast

Acute medical conditions

Hospital admission for acute illnessPregnancy Postpartum periodPolycythemia veraOral contraceptives Hormone-replacement Cancer Chemotherapy Advanced age Obesity Central venous catheterization

Hereditary Clue in the history!!!

Factor V LeidenAntithrombin deficiencyProtein C deficiencyProtein S deficiencyActivated protein C resistance without factor V LeidenProthrombin gene mutationDysfibrinogenemiaPlasminogen deficiency

Which are the most common symptoms?

PIOPED- symptoms and signs

Symptoms Dyspnoea (SOB) 73%

Pleuritic pain 66%

Cough 37%

Haemoptisis 13%

Signs Tachypnoea70%

Crackles 51%

Tachycardia 30%

Syndromes Pain & haemoptisis 65%

CVS collapse 8%

Which are the most common radiological signs?

CXR findings in PE• Normal

• Laminar atelectasia

• Wedge infarct

• Pleural effusion

• Infiltrates

• Prominent pulmonary arteries (Fleishner sign)

• Oligemia ( Westermark’s sign)

• Pleural based opacity (Hampton’s hump sign)

Case• Female 82

• Admitted to ED

• Carers rung the ambulance as patient was short of breath and collapsed at home

• Ambulance crew

HR: 115 x’ RR: 32 x’ Sat: 82% on air

• PMH:

Discharged from hospital the week before admission with haemorrhagic cystitis

Recurrent UTIs :E. Coli ESBL (Extended Spectrum Beta Lactamase )

USS BOTH LEGS AND ABDOMEN• Right  leg:

occlusive  DVT  is  seen  in  right  femoral  vein  extending  to adductor  canal  region.  The  right  popliteal  vein  was  patent.   Left  leg: Short  segment  of  non-occlusive  DVT  in  the  common  femoral vein.  The  rest  of  the  SFV  and  popliteal  vein  remain  patent.   US  Pelvis  (Transabdominal)  :    Urinary  bladder  empty  with  catheter  in  situ. No  pelvic  free  fluid.  uterus  and  ovaries  not  seen. No  pelvic  masses.

How many patients with PE have a DVT?

How many patients with DVT will have a PE?

More informatio:

• 79% of patients presenting with PE have DVT in their legs!!!

• 50% of patients with DVT will have a PE

Symptoms and signs are nonspecific the clue is in the history!!!!!

What test would you request initially?

Preliminary Testing• Blood tests:

Mildly raised WBC and CRP

• ECG:

tachycardia

atrial fibrilation

manifestations of acute cor pulmonale

S1, Q3, T3 pattern,

right bundle-branch block

P-wave pulmonale

right axis deviation

Patient to ED with suspected PE

History + Risk factors + CxR and ECG

Potential PE identified &Well’s Score

Low probability(Well’s Score <4) High probability

abnormal X ray pre-existing cardio respiratory disease

High probabilityNormal chest X ray

D Dimer

If –ve, discharge

CTPA undertakenwithin 24 hours

UHCW:Q/VQ scan (weekdays)

CTPA (weekends)

Management plan

How would you treat a suspected PE?

Anticoagulation cascade

Enoxaparine

Treatment• LMWH 1.5 mg/kg

• Warfarin until INR between 2-3

• When INR 2-3 continue LMWH 5 more days– INR is often deceptive in the first days

factor VII has a half-life of 6 to 8 hours, the initial increase in

INR following the start of warfarin therapy reflects factor

VII depletion rather than attainment of true systemic anticoagulation.

- Factor II and X depletion takes 4 to 5 days

• Duration 6 months at UHCW

( 3 months same mortality less bleeding risk)

Special situations

• Massive PE

• Pregnancy and PE

• Cancer and PE

Massive PE• High suspicious

50% EMD (electromechanical dissociation)

Asystolic

very few survive whatever you do

• Diagnosis

ECHODiagnostic abnormal in 80%dilated RV & PAregional RV wall abnormalityintracardiac clot

CTPA (if stable)

Treatment for massive PE Thrombolysis

• What to give?

• 50 mg bolus of Alteplase

• If cardiac arrest CPR 60’

• Alternative to thrombolisis:

Embolectomy / right heart catheter clot fragmentation

can be considered if experience and facilities available

PE and pregnancy: How would you investigate?

Suspected PE in pregnancy

• History with risk factors

• D Dimer? : NO THANK YOU!!!

• ECG

• Further investigation: gold standard USS both legs

Further investigation

Procedure Effective radiation dose Natural background radiation

CT-Chest 7 mSv 2 years

Chest X ray 0.1 mSv 0.1 to 0.9 mGy

10 days

Pregnancy and PEFetal Radiation

V/Q 0.11-0.22 mGy (milligray)

CTPA 0.01-0.06 mGy

Incidence of malignancy 1:16,000 per mGy

IV iodinated contrast : neonatal hypotyroidism

Mother

CTPA 35 mGy per breast

½ perfusion V/Q 0.25 mGy per breast

Life time risk of breast cancer reported with one dose of 10 mGy

PE in pregnancy- imaging at UHCW

• CxR to exclude other causes

• Half dose perfusion V/Q

• CTPA only in cardio respiratory disease or abnormal CxR

PE and pregnancy: How would you treat?

Treatment of PE in pregnancy

• Treatment:

Enoxaparine 1 mg BD

Warfarine is teratogenic

UFH should be given as delivery approaches

? Stop 4-6 hs pre – delivery

Continue anticoagulation 6 weeks post delivery or 3 months post event

Cancer Screening in PE

• 7 -12 % of idiopatic VTE presents with cancer in next 6 – 12 months

• Should we hunt for it?

• Most will be picked up by:

clinical history examination CxR

• Further tests are not warranted

1 year survival of occult cancer is 12 %

Most have metastasis at the diagnosis

VTE in cancer patients is poor prognostic factor

• Treatment LMWH

Messages to take home• PE is a medical emergency

• High level of suspicion

• Think PE in all patients recently discharged from hospital

• Request D Dimer only in low probability PEs

• Remember to continue Enoxaparine 5 more days after the INR is in range (2-3)

• Thrombophylia screen after the treatment has been completed

• Best treatment: PREVENTION!!!

Has the patient been assessed?

Has prophylaxis been prescribed?

References• British Thoracic Society guidelines for the

management of suspected acute pulmonary embolism. Thorax 2003;58:470–484

• Victor F. Tapson, M.D Acute Pulmonary Embolism NEJM 358;10, 2008

• Why shouldn’t we use Warfarin alone to treat acute venous thrombosis? Cleveland Clinic Journal of medicine, volume 69, number 7 July 2002

• Investigating suspected pulmonary embolism in pregnancy. BMJ 2007:334:418-9