2. Goals
Understand the historical context of pulmonary emboli
Comprehend the pathophysiology and know some
common risk factors
Be aware of the clinical features of PE and have a basic
understanding of various diagnostic test
Gain a therapeutic approach to the treatment of PE and
discuss a simplified method in the work-up of PE
Attempt to dispel a few “myths”about pulmonary emboli
2
3. Perspective
A Common disorder and potentially lethal
630,000 cases occurring annually with 2,00000
related deaths
Highest incidence in hospitalized patients
Autopsy reports suggest it is commonly “missed”
diagnosed
3
4. Perspective
Presentation is often “atypical”
Signs and symptoms are frequently vague and
nonspecific and rarely “classic”
Untreated mortality rate of 20% - 30%,
plummets to 5% with timely intervention
4
6. Historical Context
PIOPED (Prospective Investigation of Pulmonary
Embolism Diagnosis) 1990
Published their data on the sensitivities and
specificities of V/Q scans for PE.
6
7. Why care?????
PE is the most common preventable cause of death in
hospitalized patients
~600,000 deaths/year
80% of pulmonary emboli occur without prior warning signs
or symptoms
2/3 of deaths due to pulmonary emboli occur within 30
minutes of embolization
Death due to massive PE is often immediate
Diagnosis can be difficult
Early treatment is highly effective
7
12. Venous Stasis
Prior venous thrombosis
Bedrest > 24 hr
Recent cast or external fixator
Long-distance travel or prolong automobile travel
CHF,
Vessel wall Injury
Recent surgery requiring endotracheal intubation
Recent trauma (especially the lower
extremities,head and pelvis)
12
13. Natural History of VTE-
(80%–95%) of PE occur as a result of thrombus
originating in the lower extremity.
40-50% of pts with DVT develop PE, often “silent”
PE presents 3-7 days after DVT
Fatal within 1 hour after onset of respiratory symptoms
in 10%
Shock/persistent hypotension in 5-10% (up to 50% of
patients with RV dysfunction)
Most fatalities occur in untreated pts
13
14. Clinical Presentation
The Classic Triad: (Hemoptysis, Dyspnea, Pleuritic
Pain)
Not very common!
Occurs in less than 20% of patients with documented PE
Syncope=rare presentation, but indicates severely
reduced hemodynamic reserve
In pts with pre-existing CHF or COPD, worsening
dyspnea may indicate PE
14
15. Three Clinical Presentations
Pulmonary Infarction -have pleuritic chest pain
Submassive Embolism
Massive Embolism -a clot which obstructs two lobar
arteries, so-called “Saddle Embolus”. Acute cor
pulmonale
15
18. Clinical Features
Signs with Angiographically Proven PE
Sign Percent
Tachypnea > 20/min 92
Rales 58
Accentuated S2 53
Tachycardia >100/min 44
Fever > 37.8 43
Diaphoresis 36
S3 or S4 gallop 34
Thrombophebitis 32
Lower extremity edema 24
18
19. Who do we work up?
-
Transition from tech oriented approach to bayesian
analysis.
Pretest Probability
Helps in the selection and interpretation of futher
diagnostic tests to create a post test probablity
19
23. Diagnostic Testing
- CXR’s
Chest X-Ray Myth:
“You have to do a chest x-ray so you can find
Hampton’s hump or a Westermark sign.”
Reality:
Most chest x-rays in patients with PE are
nonspecific and insensitive
23
24. Diagnostic Testing
- CXR’s
Chest radiograph findings in patient with
pulmonary embolism
Cardiomegaly
Normal study
Atelectasis
Elevated Hemidiaphragm
Pulmonary Artery Enlargement
Pleural Effusion
Parenchymal Pulmonary Infiltrate
24
25. 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.
Hampton’s Hump
A triangular or rounded pleural-based infiltrate with
the apex toward the hilum, usually located adjacent to
the hilum.
25
27. Diagnostic Testing
– EKG’s
EKG
Most Common Findings:
Tachycardia or nonspecific ST/T-wave changes
Acute cor pulmonale or right strain patterns
Tall peaked T-waves in lead II (P pulmonale)
Right axis deviation
RBBB
S1-Q3-T3 (specific but occurs in only 20% of PE patients)
(Last three in V1-V3 suggests RV dysfunction)
27
30. Diagnostic Testing
- Pulse Oximetry
The Pulse Oximetry Myth:
“ You must do a pulse oximetry reading, since patients
with pulmonary embolism are hypoxemic!”
Reality:
Most patients with a PE have a normal pulse oximetry,
and most patients with an abnormal pulse oximetry will
not have a PE.
30
31. Diagnostic Testing
- ABG’s
The ABG/ A-a Gradient myth:
“You must do an arterial blood gas and calculate the alveolar-
arterial gradient. Normal A-a gradient virtually rules out PE”.
Reality:
The A-a gradient is a better measure of gas exchange than the pO2,
but it is nonspecific and insensitive in ruling out PE.
31
32. Diagnostic Testing
Echocardiography
Consider in every patient with a documented
pulmonary embolism
EKG maybe helpful in demonstrating right heart strain
Early fibrinolysis can reduce mortality 50%!
32
33. D-dimer Test
Fibrin split product
Circulating half-life of 4-6 hours
Quantitative test have 80-85% sensitivity, and 93-100% negative
predictive value
False Positives:
Pregnant Patients Post-partum < 1 week
Malignancy Surgery within 1 week
Advanced age > 80 years Sepsis
Hemmorrhage CVA
AMI Collagen Vascular Diseases
Hepatic Impairment
33
34. Diagnostic Testing
D-dimer
Qualitative
Bed side RBC agglutination test
“SimpliRED D-dimer”
Quantitative
Enzyme linked immunosorbent asssay “Dimertest”
Positive assay is > 500ng/ml
VIDAS D-dimer, 2nd
generation ELISA test
34
35. Ventilation/Perfusion Scan
- “V/Q Scan”
A common modality to image the lung and its use
still stems from the PIOPED study.
Relatively noninvasive and sadly most often
nondiagnostic
In many centers remains the initial test of choice
Preferred test in pregnant patients, renal
dysfunction
50 mrem vs 800mrem (with spiral CT)
35
39. Interpretation
Normal
Low probability/”nondiagnostic” (most common)
High Probability
Simplified approached to the interpretation of results:
High probability Treat for PE
Normal Scan If low pre-test, your done
Everything else Purse another study (CT, Angio)
39
40. Spiral (Helical) Chest CT
Advantages
Noninvasive and Rapid
Alternative Diagnosis
Disadvantages
Risk to patients with borderline renal function
Hard to detect subsegmental pulmonary emboli
40
41. At the present time, CT can be considered
confirmatory in excluding embolism in patients with a
low or intermediate likelihood of disease and
confirming embolism in patients with intermediate or
high probability of disease. When discordance
exists between the clinical assessment and CT findings,
additional studies should be considered.
41
42. Pulmonary Angiography
“Gold Standard”
Performed in an Interventional Cath Lab & invasive.
It requires expertise in study, performance &
interpretation.
Positive result is a “cutoff” of flow or intraluminal
filling defect
42
43. CT-PA
First line investigation at present.
Widespread use has resulted in the over diagnosis of
PE, i.e clinically insignificant disease
43
46. Treatment:
Goals:
Prevent death from a current embolic event
Reduce the likelihood of recurrent embolic
events
Minimize the long-term morbidity of the
event
46
Dr. Batizy explaining
the CT results
47. When a diagnosis of venous thromboembolism is
suspected, empiric treatment should be considered
until the diagnosis is either objectively excluded or
confirmed.
47
48. Treatment
Anticoagulants
Heparin
Provides immediate thrombin inhibition, which prevents
thrombus extension & embolic recurrence
Does not dissolve existing clot
Will not work in patients with antithrombin III def.
In this case use hirudins
Few absolute contraindications
48
49. Treatment
Anticoagulants
Heparin
Available as Unfractionated or LMW Heparin
FDA approved dosing:
Unfractionated: 80 units/kg bolus, 18 units/kg/hr
LMWH: 1 mg/kg every 12hr or 1.5mg/kg per Day
LMWH (Lovenox) prefered in pregnant patients
49
50. Fixed dose of s/c UFH without aPTT monitoring, as
an initial dose of 333 U/kg f/b 250 U/kg every 12
hours, has been demonstrated to be as safe and
effective as LMWH in patients presenting with DVT
and PE.
LMWH v/s UFH
Enoxaparin, Tinzaparin , Nadroparin , Dalteparin
50
51. FONDAPARINUX
Selectively binds factor Xa and inhibits thrombin
generation.
T1/2 17 hrs- renal excr.
Approved for prophylaxis before major sx and for t/t
of DVT & PE in conjuction with warfarin.
Rivaroxaban is oral factor Xa inhibitor
51
52. Direct thrombin inhibitors
Lepirudin, Argatroban- synth polysacchrides.
T1/2 40-60 mins, i/v infusion, monitering with aPTT.
Approved for t/t of VTE due to heparin IT.
52
53. Thrombolysis therapy
Indications:
Documented PE with:
Persistent hypotension
Syncope with persistent hemodynamic compromise
Significant hypoxemia
+/- patient with acute right heart strain
FDA Approved –Alteplase, STK, Urokinase,
regimen is 100mg as a continuous IV infusion.
PEITHO( PE Thrombolysis trial) – for saftey & efficacy of
Tenectiplase
53
54. Treatment
Embolectomy
Prefibrinolytic therapy this was only therapy for
massive PE
Carries a 40% operative mortality
Last resort for pts with persistant hypotension,shock
who failed thrmbolysis or C/I.
54
56. Long term managment
Recurrence common
Anticoagulants
Warfarin (Coumadin)
Vit k antagonist
Requires 3-5 days to acieve full therapeutic effecacy
Important a patient is anticoagulated with heparin before initiating
warfarin therapy
Target INR is 2.0 – 3.0
56
58. Novel agents for long term m/m
1. Dabigatran-oral direct thrombin inhibitor
2.Apixaban
3. Aspirin – reduces major vascular events
58
59. VENA CAVA INTERRUPTION
AND VENA CAVA FILTER
IVC filter placement is to prevent PE in patients who
have a contraindication to anticoagulation
59
60. CTEPH
Residual thromboembolic burden is sufficiently
extensive to cause CTEPH
0.5% to 3.8% in initial episode of PE to 13.4%
following recurrent episodes of VTE
Pulmonary thromboendarterectomy, which involves
the dissection of endothelialized thrombi under
cardiopulmonary bypass and deep hypothermia.
60
61. PROPHYLAXIS
UFH
LMWH (enoxaparin, dalteparin)
Factor Xa inhibitors (fondaparinux, rivaroxaban)
Warfarin
When administered correctly in appropriate patients,
its safe and effective with an absolute reduction in the
incidence of VTE in the range of 40% to 60%.
Major bleeding complications occur in less than 1%
of patients
61
62. Conclusion
Summary Points
Pulmonary Emboli remain a potentially deadly and common event which may
present in various ways
Don't’ be fooled if your patient lacks the “classic” signs and symptoms!
Consider PE in any patient with an unexplainable cause of dyspnea, pleuritic
chest pain, or findings of tachycardia, tachpnea, or hypoxemia
2nd
Generation Qualitative D-Dimers have NPV of 93-99%
Heparin remains the mainstay of therapy with the initiation of Warfarin to
follow
Simplified Algorithm: ( Pretest probability, D-Dimer, +/- CT angio)
62
PE It has a wide spectrum of patient presentation, which leads us to do suboptimal testing. This can stand in the way of a timely diagnosis
It’s important, because prompt diagnosis and treatment can dramatically reduce the mortality rate and morbidity of this disease.
Unfortunately, the diagnosis is missed far more than it is made. I want to offer you a historical perspective of the disorder
Cancers of primarily adenocarcinoma and CNS tumors most often cause thrombosis.
Pregnancy is the most common cause of venous thromboembolism in women younger than 40 years
old, and if untreated may account for 20% to 50% of all pregnancy-related deaths
All the above symptoms are a manifestation of cardiopulmonary stress caused by the cloth in the lung
While it’s true the most common symptom is shortness of breath, even patients with circulatory collapse may have no dyspnea, tachypnea, or pleuritic pain!
As a simple rule, if you have a patient in your department and you don’t have a good reason to explain there dyspnea, it’s a good idea to consider PE!
Cardiomegaly was the most frequent finding in those with PE of In-patients
Out-patients, it seemed to be atelectasis in the above study.
Here we see the dilated vessels and oligemia of westermark’s sign
And below Hampton’s Hump
Two types,
Qualitative RBC agglutination assay, low sensitivity and specificity and not good enough to comfortably rule out PE.
Quantitative, which measure the accurately the amount using a spectrophotometer.
Management of acute PE consists of a systematic approach that involves early intervention, patient risk stratification, selection of therapy, and determination of treatment duration
Heparin is the most frequently used drug in the treatment of PE.
Because heparin works by activating antithrombin III, this genetic mutation makes heparin ineffective.
For critically ill patients, a very rapid infusion of 100mg over 10 minutes is preferred.
Alternative is Retavase, you can give it as two IV doses of 10 units, each over two minutes.
This is a procedure where a suction tip catheter is placed in contact with the thrombus under fluoroscopy and sucked out while catheter is withdrawn
To minimize potential subtherapeutic anticoagulation, it is generally recommended that patients should receive at least 5 days of combined heparin and warfarin therapy, including at least 2 days in which the INR is in a therapeutic range before stopping heparin.