pulmonary embolism

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Pulmonary Embolism

Pulmonary EmbolismAmina Adel Al-QaysiRAK Medical & Health Sciences University19/05/20121

ObjectivesOverview of pulmonary circulationPulmonary embolismDefinition & SourcesRisk factors & aetiologyPathogenesisClinical presentationDifferential DiagnosisInvestigationsManagementComplicationsPrevention19/05/20122

Pulmonary circulation19/05/20123

Pulmonary EmbolismOcclusion of a pulmonary artery(ies) by a blood clot.Results from DVTs that have broken off and travelled to the pulmonary arterial circulation.PE is one of the leading causes of preventable deaths in hospitalized patients.19/05/20124

19/05/20125

SourceDVTIEC of the right side of heart Air embolismFat embolismAmniotic fluid embolismSeptic embolismTumor embolism19/05/20126

Risk FactorsVirchows Triad19/05/20127

Risk FactorsVTE is most prevalent in three clinical conditions:

Major surgery (particularly if it is cancer related or involves the hip or knee)Acute strokeMajor trauma (especially spinal cord injury)19/05/20128

Risk FactorsPrior DVT or PECongestive Heart FailureMalignancyObesitysmokingEstrogen, OCP, HRTPregnancyLower limbs injuryOrthopedic SurgeryProlonged immobilization, travelSurgery requiring > 30 minutes general anesthesia19/05/20129

Risk Factors ContdAge > 40Venous StasisFactor V Leiden mutationProtein C deficiencyProtein S deficiencyAntithrombin deficiencyProthrombin G20210A mutationAnticardiolipin antibodiesSLE, APSHyperhomocystinemia19/05/201210

Risk Factors ContdICU-related factors:

ImmobilityNeuromuscular paralysis (drug-induced)Central venous cathetersSevere sepsis19/05/201211

Pathogenesis19/05/201212

Clinical PresentationSmall PE: Asymptomatic, SOB, chest discomfort.

Medium PE: SOB, Haemoptysis, Pleuritic chest pain, Tachycardia, Tachypnea, Pleural rub.

Massive PE: Death, Shock, Severe central chest pain, Syncope, Pallor, Sweating, Central cyanosis, Elevated JVP, Loud P2, S2 split, gallop rhythm.

DVT19/05/201213

Massive PE: obstructing more than 50% of pulmonary vasculature13

Differential DiagnosisMyocardial InfractionPleurisy PneumoniaBronchitisPneumothoraxCostochondritisRib #19/05/201214

InvestigationsLaboratory:CBC, Coagulation profile, ESR, LDH, ABG

D-dimer:Sensitive but not specificUp to 80% of ICU patients have elevated D-dimer in the absence of VTEMore than 500 Mg/mL19/05/201215

FibrinolysisIncreased in pneumonia, inflammatory disease, malignancy, sepsis, pregnancyD-dimer becomes less useful the longer the period spent in hospital due to clot formation at venepuncture sites, venous stasis due to bed rest.15

Alveolar-Arterial O2 GradientA-a O2 gradient = PaO2 (alveolar) - PaO2 (arterial)Gradient > 15-20 is considered abnormal.16

ECG19/05/201217

Sinus tachycardiaAFRBBBInverted T wave in V1-V4 = Rt ventricular strain17

Imaging Investigations19/05/201218

19/05/201219

Westermarks sign19/05/201220

Lower limb venous system Ultrasonography & Doppler19/05/201221

Ventilation/Perfusion Ratio

22Radionuclide Lung ScanPt inspires Xenon (gas with radioactive material): detect gas distribution in lungs using gamma cameraGive IV injection of TC (radioactive material): detect lung intake through pulmonary arteries using gamma camera

Normal ventilation+ abnormal perfusion: highly suggestive of PE

CT Pulmonary Angiography19/05/201223

Gold standard investigation, now recommended as the initial imaging technique in suspected PE.Sensitivity of >95%should be performed within 1 hour in suspected massive PE, and within 24 hours of suspected non-massive PE.23

Pulmonary Angiography19/05/201224

Diagnostic but invasive24

Other Tests

Echocardiography

Cardiac troponin19/05/201225

Diagnostic only in massive PE. The transoesophageal route is more sensitive, enabling visualization of intrapulmonary and intracardiac clot.

Cardiac troponin: A rise indicates acute right heart strain. For prognostic information only25

ManagementEmergency management

Further management: Anticoagulation, Thrombolysis, ......19/05/201226

ResuscitationABCOxygen 100%IV access. Send baseline bloods, including clotting profile. Perform ECGAnalgesia: Pethidine, Morphine 5-10 mg IVManagement of cardiogenic shock (fluids and inotropes- Dobutamine)19/05/201227

Mostly for massive PE27

Thrombolytic TherapyStreptokinase, Urokinase, Alteplase ,Recombinant tissue plasminogen activator

Streptokinase 250,000 U over 30 mins

Aim to: Relieve pulmonary vasculature obstruction, Improve right ventricular efficacy, Correct the hemodynamic instability.19/05/201228

In cardiac arrest due to suspected massive PE, 50 mg IV alteplase immediately may be life-saving.28

Anticoagulant TherapyHeparin5000-10000 Units IV Loading DoseThen 1000 Units/hr IV infusion drip

Duration: 7-10 days OR till clinical improvement

Follow up by PTT (1.5-2.5)19/05/201229

Heparin preferred because of low incidence of HrgCheck PTT every 6 hours after initial bolus and every 10 hours after any dose change. When APTT is in the therapeutic range, check it daily.29

Anticoagulant Therapy ContdWarfarin2.5-7.5 mg/day OrallyStarted with Heparin (5-7 days to start acting)

Duration: 3-6 months

Monitor INR (2-3)19/05/201230

Pregnancy ??? TeratogenicSafe in breast feeding

Temporary risk factor: 4-6 weeksFirst episode of idiopathic PE: 3 monthsRecurrent idiopathic PE: no guidelines exist; length of treatment depends on individual circumstancesPersisting risk factors: lifelong anticoagulation

Ximelagatran is oral direct thrombin inhibitor with a wide therapeutic range that does not need anticoagulation monitoring. It can cause liver function derangement therefore needs LFT monitoring. It is now licensed in some European countries but there are concerns over toxicity.

30

Recurrent DVT & PE: Vena cava filter19/05/201231

If anticoagulant or thrombolytic therapy is CI or fails to prevent thrombo-embolism, Patients with massive PE who survive (in whom a second PE may be fatal)

Greenfield filter inserted above the level of renal veins31

EmbolectomySurgical EmbolectomyCatheter Embolectomy

Massive life-threatening PE19/05/201232

Complications

Instant DeathChronic pulmonary hypertensionRespiratory failureCongestive heart failureRecurrence

19/05/201233

PreventionProphylaxis is the single most important measure for ensuring patient safety in hospitalized patients

Compressive stockings, Aspirin, AnticoagulationManagement of risk factorsFollow up19/05/201234

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