management of pulmonary embolism in emergency department
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Management of Pulmonary Embolism in Emergency Department
Dr A. BaraiMBBS, MRCS Ed, MSc
Registrar in Emergency Medicine
Topics• Introduction
• Diagnostic approach
• Treatment options
• Special circumstances: Pregnant patient
• Prevention
Introduction• Pulmonary embolism (PE) is a medical emergency
where pulmonary artery or its branches are blocked with embolic substances most commonly blood clots
• Most cases are not life threatening.
• Incidence: 600,000/year in USA
• Mortality rate: 50,000 to 200,000/yr in US
Types of PE• Massive PE: Acute PE with obstructive shock or SBP
<90 mmHg
• Sub-massive PE: Acute PE without systemic hypotension (SBP ≥90 mm Hg) but with either RV dysfunction or myocardial necrosis
• Non-massive or low risk PE: None of the above severe features.
Pathophysiology
Deep vein thrombosis from large vein commonly above the knee → Inferior vena cava → Right atrium → Right ventricle → Pulmonary artery → PE
Ventilation perfusion mismatch → Hypoxemia
↓Venous return → Right heart failure → Shock
Diagnosis• Risk stratification
• Clinical examination
• Bed side tests
• Laboratory tests
• Imaging techniques
Risk factors• Alteration of blood flow:
– Prolonged immobilisation, – Obesity, – Pregnancy, – Cancer
• Factors in blood vessel wall: – Surgery, – Catheterisation.– Trauma
• Hypercoagulable states: – Estrogen containing OCP, – Genetic thrombophilia (Factor V Leiden deficiency, Protein C and
Protein S deficiency, antithrombin deficiency etc.), – Acquired thrombophilia (antiphospholipid syndrome, nephrotic
syndrome, paroxysmal nocturnal hemoglobinuria)
Risk stratification• Clinical judgement
• Wells score for PE
• Modified Geneva score for PE
Wells score for PE
Modified Geneva score for PE
Clinical Presentation: Symptoms• Chest pain: Sharp, pleuritic in nature, no radiation,
aggravated by coughing and deep breath
• Haemoptysis
• Shortness of breath
• Collapse
• Palpitations
• Sudden death: 15% of sudden death due to PE
Clinical Presentation: Signs• Dyspnoea, cyanosis, pale
• Tachypnea
• Tachycardia
• Hypoxia
• Hypotension
• Pulmonary hypertension
Chest examination• May be normal
• Friction rub
• Features of pleural effusion
• Raised JVP
Investigations• Bed side tests: ECG, ABG
• Blood tests: D-dimer, FBC, Troponin, UEC
• Imaging techniques: Ultrasound/ Doppler scan, Chest xray, CTPA, V/Q scan, Echocardiogram
ABG findings in PE
• pH= ↑ • PaO2= ↓• PaCO2= ↓• HCO3= Normal• Aa gradient= Large
Aa gradient= PAO2- PaO2
Chest xray• Mostly normal findings
• Done to exclude other pathology
• Plural effusion
• Specific signs:- Hampton’s hump- Westermark sign
Hampton’s hump
Westermark sign
ECG findings in PE• Normal sinus rhythm
• Sinus tachycardia
• Tall peaked T waves in V1- V4
• S1Q3T3 pattern: Not specific. Can be seen in any Cor pulmonale syndrome
• RBBB
S1Q3T3 pattern ECG
D-dimer in PE• D-dimer is a type of Fibrin degradation product
• Can be raised due to a number of reasons
• Negative D-dimer rules out PE/DVT in 98% cases
• False positive D-dimer: infection, pregnancy, renal failure, post-operative
Echocardiogram in PE
CTPAIndications:
- Suspected PE
Contra-indications:- Renal failure- Pregnancy- Allergy to radio-contrast
Procedure:- Radioactive iodine administered IV- CT scan performed
Ventilation-perfusion scanIndications:
- Renal failure- Pregnancy
Procedure:- Ventilation scan with Xenon inhalation- Perfusion scan with Tc99m labelled radioactive dye infusion- Scan V/Q- Result: unmatched V/Q
Pulmonary angiogram• Gold standard test for PE
• Not practised due to the side effects and high mortality
• Procedure:– Catheter inserted to right ventricle– Radio opaque dye injected– Imaging technique used to identify the clot
Treatment options• Symptomatic treatment:
– ABCD approach– Oxygen– Analgesia
• Anticoagulation:– IV Heparin– S/C LMWH eg Enoxaparine, Dalteparine– Oral Warfarin
• IVC filter: If there is contra-indications for anti-coagulation
• Thrombolysis: tPA eg Alteplase, Tenectaplase
• Surgical procedures: Pulmonary embolectomy
Treatment options
• Massive PE: Thrombolysis/embolectomy
• Sub-massive PE: Strongly consider thrombolysis/embolectomy but need to balance risk of bleeding
• Non-massive PE: Anticoagulation
Thrombolysis• Indications:
– Massive PE– Sub-massive PE where risk of bleeding low
• Contraindications:– Bleeding, recent stroke, HI, current GI bleeding, bleeding
PUD, surgery within 7 day, prolonged CPR
• Drugs:– Alteplase 100mg IV: 15mg IV stat followed by 85mg over
2 hours– Followed by Heparin infusion
Anticoagulation• IV Heparin:
– 80 units/kg bolus followed by – 18 units/kg infusion
• Monitor APTT 60-90 sec
• Side effects: – HITS (Heparin induced thrombocytopenia syndrome):
paradoxical hypercoagulable state leads to clots– Bleeding
AnticoagulationLow molecular weight Heparin (LMWH)
Enoxaprin (Clexane): S/C- 1.5mg/kg/24 hours Or 1mg/kg/12 hours- 1 mg/kg/24 hours in renal impairment
Duration: 6 to 9 months
Side effect: Low HITS
Anticoagulation• Vitamin K antagonist
• Warfarin: – 5mg PO initial dose– Check regular INR 2-3
• Side effects:– Bleeding– Unusual bruises– Headache
IVC filter
Indications:- DVT with massive pulmonary embolus- Recurrent PE not treatable with anticoagulation- Absolute contra-indications for anti-coagulation- Trauma patients
PE in Pregnancy• All three components of Virchow’s triad are affected during
pregnancy
• D-dimer has high negative predictive value. False positive result is common
• V/Q scan is preferred technique
• CTPA can be done if VQ is inconclusive
• Preferred treatment option: LMWH
• Warfarin is contraindicated
Prevention of PE• Control of obesity
• Stop smoking
• Stockings
• Heparin: 5000 units/day IV
• Enoxaprin: 40 mg/day S/C
And finally…
PE is often over-diagnosed;
PE is often under-diagnosed;
The over- or under-diagnosis of PE results in increased cost, morbidity, mortality and medico-legal risks.
References• Agnelli G, Becattini C. Acute pulmonary embolism. N Engl J Med. 2010 Jul 15;363(3):266-74. doi:
10.1056/NEJMra0907731. Epub 2010 Jun 30
• Bourjeily G, Paidas M, Khalil H, et al. Pulmonary embolism in pregnancy.Lancet. 2010;375:500-512
• Hofman, M. S.; Beauregard, J. -M.; Barber, T. W. et al.(2011). 68Ga PET/CT Ventilation-Perfusion Imaging for Pulmonary Embolism: A Pilot Study with Comparison to Conventional Scintigraphy. Journal of Nuclear Medicine 52 (10): 1513–1519.
• Jaff MR, et al. Management of massive and submassive pulmonary embolism, iliofemoral deep vein thrombosis, and chronic thromboembolic pulmonary hypertension: a scientific statement from the American Heart Association. Circulation. 2011 Apr 26;123(16):1788-830. doi: 10.1161/CIR.0b013e318214914f. Epub 2011 Mar 21. Erratum in: Circulation. 2012 Mar 20;125(11):e495. Circulation. 2012 Aug 14;126(7):e104.
• Mattu, A. PE in pregnancy: A complicated diagnosis. Medscape. August 9, 2010 (Online) URL: http://www.medscape.com/viewarticle/726318
• Pulmonary embolism. Life in the fast lane. (Online). http://lifeinthefastlane.com/education/ccc/pulmonary-embolism/
Thank you!
drbarai@gmail.com
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