DVT&PE Final 1

8/4/2019 DVT&PE Final 1

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PULMONARYEMBOLISM

Dr. Mehreen SaiyedResident

Med 4


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-Introduction

-Clinical features

-Diagnostic modalities-Diagnostic approach

-Management

Objectives


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In pulmonary embolism, a thrombus arises elsewhere in the

body and migrates to the pulmonary vascular tree, where it

causes obstruction.

Nearly all pulmonary emboli derive from

deep venous thrombosis.

Introduction


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http://www.ceessentials.net/article12.html

Introduction


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SYMPTOMS IN PATIENTS WITH ANGIO PROVEN PTE

Symptom Percent

Dyspnea 84

Chest Pain, pleuritic 74

Anxiety 59

Cough 53Hemoptysis 30

Sweating 27

Chest Pain, nonpleuritic 14

Syncope 13

Clinical features


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SIGNS WITH ANGIOGRAPHICALLY PROVEN PE

Sign Percent

Tachypnea > 20/min 92Rales 58Accentuated S2 53Tachycardia >100/min 44

Fever > 37.8 43Diaphoresis 36S3 or S4 gallop 34Thrombophebitis 32

Lower extremity edema 24

Clinical features


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Diagnostic difficulties!

Signs / symptoms non-specific

Only 25% of suspected casesactually have pulmonary emboli1,2

1. Lee AY, Hirsh J. Diagnosis and treatment of venous thromboembolism. Annu Rev Med. 2002;53:15-33.2. The PIOPED Investigators. Value of the ventilation/perfusion scan in acute

pulmonary embolism: results of the Prospective Investigation of PulmonaryEmbolism Diagnosis (PIOPED).JAMA. 1990;263:2753-2759.

Clinical features


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- PRETEST PROBABILITY

Definition: The probability of the targetdisorder (PE) before a diagnostic test result is

known.

Used to decide how to proceed withdiagnostic testing and final disposition

Who do we work up?


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Modified Wells pretest probability scoring


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Diagnostic Modalities

ABG

Spiral/helical CT with

IV contrast

Chest X-ray

ECG

D-dimer

Venous Ultrasonography

Pulmonary angiography

Perfusion lung scanning

Echocardiography


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The ABG/ A-a Gradient myth:

You must do an arterial blood gas and calculate thealveolar-arterial gradient. Normal A-a gradient virtually

rules out PE.

Reality:

The A-a gradient is a better measure of gas exchange thanthe pO2, but it is nonspecific and insensitive in ruling outPE.

ABG


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ABG

-Characteristically reveal hypoxemia, hypocapnia, and

respiratory alkalosis.

Data from the Prospective Investigation of Pulmonary

Embolism Diagnosis (PIOPED) indicate that, contrary to classic

teaching,.

arterial blood gases lack diagnostic utility for PE..!!


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D-dimer

-D-dimers are fibrinolytic products formed when

the fibrin within a clot is proteolyzed by plasmin.

-Highly nonspecific, but are highly associated with

thrombosis and thrombolysis.

- Negative ELISA has a >99% negative predictive value

-Qualitative

-Quantitative . (ELISA) Positive assay is > 500ng/ml


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Combing Clinical Probability & D-Dimer

Christopher Study1 (n = 3,306)

Dichotomized Wells score 4 D-Dimer 500 ng/ml

Negative predictive value > 99.5%

Useful in excluding PE in outpatientsSafe to withhold treatment

1. Van Belle A, et al. Effectiveness of Managing Suspected Pulmonary Embolism

Using an Algorithm Combining Clinical Probability, D-Dimer Testing, andCom uted Tomo ra h . JAMA 2006;295 2 :172-179

D-dimer


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D-dimer


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D-dimer


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ECG

-About 70 percent of patients with acute PE have ECG abnormalities.

-The most common ECG abnormalities of pulmonary embolism are

tachycardia and nonspecific ST-T wave abnormalities.

-The classic finding of right-sided heart strain demonstrated by an S1-Q3-T3 pattern is observed in only 20% of patients with proven

pulmonary embolism.


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Chest X-ray

Chest X-Ray Myth:

You have to do a chest x-ray so you can find Hamptonshump or a Westermark sign.

Reality:

Most chest x-rays in patients with PE are nonspecific andinsensitive


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CHEST RADIOGRAPH FINDINGS IN PATIENT WITHPULMONARY EMBOLISM

Result Percent

Cardiomegaly 27%Normal study 24%Atelectasis 23%Elevated Hemidiaphragm 20%

Pulmonary Artery Enlargement 19%Pleural Effusion 18%Parenchymal Pulmonary Infiltrate 17%

Chest X-ray


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CHEST X-RAY EPONYMS OF PE

Westermark's sign

A dilation of the pulmonary vessels proximal to the

embolism along with collapse of distal vessels,sometimes with a sharp cutoff.

Hamptons Hump

A triangular or rounded pleural-based infiltrate with theapex toward the hilum, usually located adjacent to thehilum.

Chest X-ray


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Chest X-ray

Westermark'ssign

Hamptons

Hump


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Rapidly gaining importance (risk stratify)

40 % have abnormalities:

RV pressure overload

McConnel sign:

Regional RV dysfunction

Apical wall motion remains normal

Hypokinesis of free wall

Echocardiography

l / f


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V/Q Scan

Perfusion: Tc-99M

Ventilation: Xenon

Underperfusion ~ V/Q mismatch

Ventilation/Perfusion Scan

- V/Q Scan

/


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Greatest limiting factors: Structural lung disease

Availability

Often non-diagnostic (60%!)1

Still useful: peripheral small/multiple PEs

1. The PIOPED Investigators. Value of the ventilation/perfusion scan in acute

pulmonary embolism: results of the Prospective Investigation of Pulmonary

Embolism Diagnosis (PIOPED).JAMA. 1990;263:2753-2759.

V/Q Scan

l/h l l h


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Spiral/helical CT with IV contrast

-Technical advances in CT scanning, including thedevelopment of multidetector-array scanners, have led to the

emergence of CT scanning as an important diagnostic

technique in suspected PE.

-Contrast-enhanced CT scanning is increasingly used as the

initial radiologic study in the diagnosis of pulmonary

embolism, especially in patients with abnormal chest

radiographs in whom scintigraphic results are more likely tobe nondiagnostic.

i l/h li l i h


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Findings of Acute PE

Intraluminal filling defect surrounded by

contrast

Ancillary findings that are suggestive:

Expanded unopicified vessels

Eccentric filling defects

Peripheral wedge-shaped consolidation

Oligaemia

Pleural effusion


S i l/h li l C i h IV


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Spiral computed tomography of the chest with contrast showing large

clot (black arrow) obstructing right main pulmonary artery

S i l/h li l CT i h IV


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The axial CT image (left) shows large pulmonary emboli bilaterally. The

pulmonary arteries from this image are magnified on the right to show

these emboli better (yellow arrows).



S i l/h li l CT i h IV


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These two axial CT images show profound pulmonary emboli. On the left theembolus almost completely blocks the right pulmonary artery (yellow arrow).Right image show an extensive saddle embolus forming in both pulmonary

arteries and becoming extensive. Both of these types of pulmonary emboli are lifethreatening and require immediate medical attention .



P l A i h


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Pulmonary Angiography

The clot appears as a filling defect (arrow)

http://www.webmm.ahrq.gov/case.aspx?caseID=14

-Is the definitive technique or gold

standard in the diagnosis of PE.

-A filling defect or abrupt cutoff of a

vessel is indicative of PE.

-Can detect emboli as small as 1 to 2

mm.

P l A i h


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Diagnostic: filling defects

Secondary signs:

Cut-off of vessels

Segmental oligaemia

Prolonged arterial phase, slow filling Tapering of vessels

P l A i h


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http://www.nci.cu.edu.eg/lectures/pulmonary%20Embolism.pdf

filling defects


E l ti f DVT


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Duplex Doppler

Compression Ultrasound

Venogram (diagnostic dilemmas)

MRI

Helical CT Venography (CTV)

Evaluation of DVT

Di ti A h


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Diagnostic Approach

CT experienced institutions CT inexperienced institutions



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Di ti A h


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Diagnostic Approach

CT experienced institutions:-When PE is suspected, the modified Wells criteria should be applied to determine if

PE is unlikely (score 4) or likely (score >4).

-Patients classified as PE unlikely should undergo D-dimer testing with a quantitative

rapid ELISA assay or a semiquantitative latex agglutination assay. The diagnosis of PE

can be excluded if the D-dimer level is 500 ng/mL should undergo CT-PA. A positive CT-PA confirms the

diagnosis of PE. Alternatively, a negative CT-PA excludes the diagnosis of PE.

-In those rare instances in which the CT-PA is inconclusive, either pulmonaryangiography or the diagnostic approach intended for institutions without experience

in CT-PA can be used.

Diagnostic Approach


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CT-based diagnostic strategy used in patients with suspected pulmonary embolism

CT experienced institutions:

Diagnostic Approach

Diagnostic Approach


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CT inexperienced institutions:-The Wells criteria are initially applied to determine whether the clinical probability

of PE is low (score 6).

-A ventilation-perfusion (V/Q) scan is then performed, with the following

combinations of outcomes possible.

Normal V/Q scan plus any clinical probability excludes PE

Low probability V/Q scan plus low clinical probability excludes PE High probability V/Q scan plus high clinical probability confirms PE.

-Any other combination of V/Q scan result plus clinical probability should prompt

either a pulmonary angiogram or serial lower extremity venous ultrasound exams.

Only the pulmonary angiogram is able to diagnose PE.

Diagnostic Approach

Diagnostic Approach


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CT inexperienced institutions:

Diagnostic Approach

VQ-based diagnostic strategy used in patients with suspected pulmonary embolism

Management


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Supportive care

Anticoagulation

Thrombolysis

Catheter based interventions

Surgical embolectomy

Inferior vena cava filters

Management

AHA definitions


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Massive PE: Acute PEwith

sustained hypotension (SBP


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Submassive PE: AcutePE without systemic

hypotension (systolic blood pressure 90mm

Hg) but with either RV dysfunction or

myocardial necrosis.

Low-risk PE: Acute PEand the absence of the

clinical markers of adverse prognosisthat

define massive or submassive PE.

AHA definitions

Anticoagulation


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-Is the mainstay of treatment.

Anticoagulation

AHA Recommendations for Initial Anticoagulation for Acute PE

Therapeutic anticoagulation with subcutaneous LMWH, IVor SC

UFH with monitoring, unmonitored weight-based

SC UFH, orsubcutaneous fondaparinux should be givento patients withobjectively confirmed PE and no contraindicationstoanticoagulation

Therapeuticanticoagulation during the diagnostic workupshouldbe givento patients with intermediate or high clinicalprobabilityofPE and no contraindications to anticoagulation

Anticoagulants


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Anticoagulants

Unfractionated heparin therapy

Low-molecular-weight heparin therapy

Fondaparinux

Warfarin therapy

Target INR = 2 - 3

Thrombolytic Therapy


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AHA Recommendations for Fibrinolysis for Acute PE

Fibrinolysis is reasonable for patients with massive acute PEandacceptable risk of bleeding complications

Fibrinolysis may be considered for patientswith submassiveacute PEjudged to have clinical evidence ofadverse prognosis(newhemodynamic instability, worsening respiratoryinsufficiency,severe RVdysfunction, or major myocardial necrosis)and lowrisk of bleeding

complications



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orrisk PE-with lowrecommended for patientsnotFibrinolysis issubmassiveacute PE withminor RV dysfunction, minor myocardialnecrosis,and no clinical worsening .

arrestrecommended for undifferentiated cardiacnotFibrinolysis is



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Contraindications for thrombolytic therapy




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A computed tomographic angiogram shows a large saddle embolus at the bifurcation of the

main pulmonary artery, with extension into the right and left pulmonary arteries (arrow in

Panel A). Following treatment with intravenous tissue plasminogen activator, the patient's

respiratory status dramatically improved over a period of several hours. Computed

tomography obtained approximately 24 hours later demonstrates resolution of the saddle

embolus (Panel B).



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Catheter-Based Interventions


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Percutaneous techniques to recanalize complete

and partial occlusionsin the pulmonary trunk or

major pulmonary arteries are potentiallylife-saving

in selected patients with massive or submassivePE.

In general, mechanical thrombectomy should be

limited to themain and lobar pulmonary arterialbranches

Catheter-Based Interventions

Surgical Embolectomy


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Emergency surgical embolectomy with

cardiopulmonary bypass hasreemerged as an

effective strategy for managing patients

withmassive PE or submassive PE with RVdysfunction when contraindicationspreclude

thrombolysis.

Surgical Embolectomy

Recommendations for Catheter


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Either catheter embolectomy and

fragmentation or surgical embolectomyis reasonable for

patientswith massive PE and contraindications to fibrinolysis

patients with massivePE who remain unstableafter receiving

fibrinolysis

patientswith submassive acute PE judged to have clinicalevidence

ofadverse prognosis (new hemodynamic instability,worsening

respiratoryfailure, severe RV dysfunction, or majormyocardial necrosis)

Catheter embolectomy andsurgical thrombectomy are not

recommendedfor patients withlow-risk PE or submassive acute PE with

minorRV dysfunction,minor myocardial necrosis, and no clinical

worsening.

Recommendations for Catheter

Embolectomy and Fragmentation

Inferior Vena Cava Filters


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An inferior vena cava filter, also IVC filter or Greenfield Filter a

type of vascular filter, that is implanted by interventional

radiologists or vascular surgeons into the inferior vena cava to

prevent fatal pulmonary embolism (PEs).



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Recommendations on IVC Filters in the


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Setting of Acute PE

Adult patients with any confirmed acute PE (or proximal DVT)withcontraindications to anticoagulation or with active

bleedingcomplication

Anticoagulation should be resumed in patients

with an IVCfilteronce contraindications to anticoagulationor active

bleedingcomplications have resolved .

For patients with recurrent acute PE despite

therapeuticanticoagulation, it is reasonable to place an IVC filter

For DVT or PE patients who willrequire permanent IVC filtration(eg,

those with a long-termcontraindication to anticoagulation),it is

reasonable to selecta permanent IVC filter device



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For DVT or PE patients with a time-limited indicationfor

anIVC filter (eg, those with a short-term

contraindicationtoanticoagulation therapy), it is reasonable

to select a retrievableIVC filter device

Placementof an IVC filter may be considered for patients

withacute PEand very poor cardiopulmonary reserve,

including thosewithmassive PE

An IVC filtershould not be used routinelyas an adjuvant

toanticoagulationand systemic fibrinolysis in the treatment

ofacute PE


Setting of Acute PE

Resources


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Resources http://emedicine.medscape.com/article/4623

90-overview


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Thank You

Documents

DVT&PE Final 1