PowerPoint presentation on various modalities to diagnose Pulmonary Embolism.

1. PULMONARY EMBOLISM
DIAGNOSIS
Dr.Tinku Joseph
DM Resident
Dept. Of Pulmonary Medicine
AIMS, Kochi.

2. Diagnostic Tests
 Imaging Studies
– CXR
– V/Q Scans
– Spiral Chest CT
– Pulmonary Angiography
– Echocardiograpy
 Laboratory Analysis
– CBC, ESR,
– D-Dimer
– ABG’s
 Ancillary Testing
– ECG
– Pulse Oximetry

3. 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
Collagen Vascular Diseases
Hepatic Impairment
Arch Intern Med 2004;140:589

4. 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

5. D-DIMER
• False Positive D-Dimer
– Pregnancy
– Trauma
– Postoperative Recovery
– Inflammation
– Cancer
– Rheumatoid Factor
– Older Age
• False Negative D-Dimer
– Heparin

7. Prognostic Value of Troponins in Acute
Pulmonary Embolism

8.  Conclusion: Elevated troponin levels were associated
with a high risk of (early) death resulting from
pulmonary embolism (OR, 9.44; 95% CI, 4.14 to
21.49)
 These findings identify troponin as a promising tool
for rapid risk stratification of patients with
pulmonary embolism.

9. BNP & pro-BNP
 Typically greater in patients with PE.
 Sensitivity of 60% and specificity of 62%.
 At a threshold of 500 pg/mL, the sensitivity of pro-
BNP for predicting adverse events was 95%, and the
specificity was 57%.
Kucher N et al. Low pro-brain natriuretic peptide levels predict benign clinical
outcome in acute pulmonary embolism. Circulation 2003 Apr 1; 107:1576-8.

10. WBC
 Poor sensitivity and nonspecific
Can be as high as 20,000 in some patients
Hb
 PTE does not alter count but if extreme, consider
polycythemia, a known risk factor
ESR
 Don’t get one, terrible test in regard to any predictive
value

11. Doppler ultrasound of leg veins
Principle - Veins are normally compressible;
Presence of DVT renders veins non-compressible
50% of patients with PE have positive ultrasound
(95% of PE are due to leg DVT)

12. ECG
– 2 Most Common finding on ECG:
 Nonspecific ST-segment and T-wave changes
 Sinus Tachycardia
– Historical abnormality suggestive of PE
 S1Q3T3
 Right ventricular strain
 New incomplete RBBB

13. Echocardiography
 This modality generally has
limited accuracy in the
diagnosis.
 The overall sensitivity and
specificity for diagnosis of
central and peripheral
pulmonary embolism by ECHO is
59% and 77%.
 It may allow diagnosis of other
conditions that may be confused
with pulmonary embolism.

14. ECHO signs of PE
 RV enlargement or hypokinesis especially free wall
hypokinesis, with sparing of the apex (the McConnell
sign)
 60/60 Sign- Acceleration time of RV ejection <60ms
in the presence of TR pressure gradient </=
60mmHg.
 Interventricular septal flattening and paradoxical
motion toward the LV resulting in a “D-shaped” LV in
cross section.
 Tricuspid regurgitation

15. Echocardiography
Am J Med 122:257,2009

16. Echocardiogram in PE

17. ABG analysis
 ABG has a limited role.
 It usually reveal hypoxemia,
hypocapnia and respiratory
alkalosis.
 Alveolar arterial oxygen gradient
, done at room air, a-a gradient >
15-20 is considered abnormal.

18. Chest x ray
 A normal or nearly
normal chest x-ray

19. Chest Xray
 Chest radiograph findings in patient with pulmonary
embolism
Result Percent
Cardiomegaly 27%
Normal study 24%
Atelectasis 23%
Elevated Hemidiaphragm 20%
Pulmonary Artery Enlargement 19%
Pleural Effusion 18%
Parenchymal Pulmonary Infiltrate 17%
Am Heart J 1997;134:479-87

20. Radiographic signs of acute pulmonary
embolism
 Signs with relative high specificity but low
sensitivity for acute pulmonary embolism:
 Decreased vascularity in the peripheral lung (Westermark sign).
 Enlargement of the central pulmonary artery (Fleischner sign).
 Enlarged right descending pulmonary artery (Palla's sign)
 Pleural based areas of increased opacity (Hampton hump).
 Hemidiaphragm elevation.

21.  Non specific signs associated with acute pulmonary
embolism that may be associated with other diseases:
 Focal area of increased opacity.
 Linear atelectasis.
 Pleural effusion.
Radiographic signs of acute pulmonary
embolism

22. Westermark’s sign

23. Westermark sign, with hilar enlargement
Dilatation of
pulmonary vessels
proximal to
embolism along
with collapse of
distal vessels, often
with a sharp cut off.

25. Hampton’s hump

26. Hampton’s hump
 Dome shaped pleural based opacity due to lung
infarction.
 Pulmonary infarct is dome shaped instead of being
wedge shaped because of double blood supply with
preserved bronchial arteries resulting in sparing of the
expected apex of the wedge.

27. Radiographic Eponyms
- Hampton’s Hump, Westermark’s Sign
Westermark’s
Sign
Hampton’s Hump

28. Ventilation/Perfusion Scan
- “V/Q Scan”
 A common modality to image the
lung.
 Relatively noninvasive.
 In many centers remains the initial
test of choice
 Preferred test in pregnant patients
 50 mrem vs 800mrem (with spiral CT)

29. V/Q Scan
VQ scan
Technique

30. Normal
Ventilation
Left UL PE
Perfusion scanVentillation scan

31. Ventilation/Perfusion Scan
 HIGH PROBABILITY (>80%): 2 or more large mismatched
segments or the equivalent.
 any perfusion defect substantially larger than
radiographic abnormality
 INTERMEDIATE PROBABILITY (20-79%): 1 moderate to 2
large mismatched segments
 LOW PROBABILITY (<20%): Non-segmental perfusion
defects, matched defects
 NORMAL: no perfusion defects

32. PIOPED: PREDICTIVE VALUE V/Q SCAN
SCAN CATEGORY CLINICAL SUSPICION
80-100% 20-79% 0-19%
HIGH
INTERMEDIATE
LOW
PIOPED INVESTIGATORS.
JAMA.1990; 263: 2753-2759

33. VQ Scan

34. Spiral CT
 Major advantage of Spiral CT is speed:
 Often the patient can hold their breath for
the entire study, reducing motion artifacts.
 Allows for more optimal use of intravenous
contrast enhancement.
 Spiral CT is quicker than the equivalent
conventional CT permitting the use of higher
resolution acquisitions in the same study
time.
 Contraindicated in cases of renal disease.
 Sensitive for PE in the proximal pulmonary
arteries, but less so in the distal segments.

35. CT Angiogram
 Quickly becoming the test of choice for initial
evaluation of a suspected PE.
 CT unlikely to miss any lesion.
 Better sensitivity, specificity and can be used directly
to screen for PE.
 Used to follow up “non diagnostic V/Q scans.

36. CT Angiogram
Chest computed tomography scanning
demonstrating extensive embolization of
the pulmonary arteries.

37. Multidetector Helical CT Pulmonary Angiography

38. Multidetector Helical CT Pulmonary Angiography
Advantages

39. Multidetector Helical CT Pulmonary Angiography
Limitations

40. CT findings of acute pulmonary embolism
Vascular abnormalities:
 Intraluminal filling defects that forms an acute
angle with the vessel wall & may be surrounded by
contrast material (polo mint sign or railway sign).
 Total cutoff of vascular enhancement.
 Enlargement of the occluded vessel.
Ancillary findings:
 Pleural based wedge shaped areas of increased
attenuation with no contrast enhancement.
 Linear atelectasis.

41. Partial eccentric filling defect with acute
angle with the vessel wall

42. Intraluminal filling defect
(polo mint sign)

43. Intraluminal filling defect
(railway track sign)

44. Enlargment of the occluded vessel

45. Ancillary findings of acute pulmonary
embolism
(atelectatic band)

46. MRA

47. MRA

48. Pulmonary angiogram
 Gold Standard.
 Positive angiogram provides 100% certainty that an
obstruction exists in the pulmonary artery.
 Negative angiogram provides > 90% certainty in the
exclusion of PE.
 “Court of Last Resort”

49. Pulmonary angiogram
Left-sided pulmonary
angiogram showing extensive
filling defects within the left
pulmonary artery and its
branches.

50. Angiographic severity scoring
Miller, et al. Amer Journ Roent,Rad Therapy & Nuc Med. 125(4):895-9, 1975 Dec.

51. Further Alternative Imaging Tests (Newer modalities)
Dual-energy CTPA
Electrocardiographically gated CTPA
Three-dimensional images acquired by single-
photon emission computed tomography (SPECT)
using a gamma-emitting radioisotope may improve
V/Q scintigraphy and has a lower radiation dose.

52. Dual-energy CTPA
Provides functional and anatomic lung imaging
Demonstrates perfusion defects beyond obstructive and non-
obstructive clots
Diagnostic accuracy requires further research
Advantages
Indirect evaluation of peripheral pulmonary arterial bed
Disadvantages
Longer data acquisition time
Increased radiation exposure

53. Dual-energy CTPA
[A] Axial reconstruction with color-coded
dual energy perfusion information. Note
the large perfusion defects in both lungs.
[B] Coronal reconstruction. Only
the apical parts show a normal
perfusion.

54. Electrocardiographically gated
CTPA
Can differentiate between cardiac events and PE
 May be of use in patients presenting with thoracic pain and
suspected PE, cardiac events, or aorta dissection.
 More contrast material is needed, and the radiation dose is
higher compared with CTPA.

55. Imaging in Pregnancy
 No validated clinical decision rules
 No consensus in evidence for diagnostic imaging algorithm
 Balance risk of radiation vs. risk of missed fatal diagnosis or
unnecessary anticoagulation
 MDCT delivers higher radiation dose to mother but lower
dose to fetus than V/Q scanning
 Consider low-dose CT-PA or reduced-dose lung scintigraphy
Stein P et al. Radiology. 2007 Jan;242:15-21.
Marik PE; Plante LA. N. Engl. J. Med. 2008;359:2025-33.

56. Imaging-nut shell
 Plain chest radiograph – Usually normal and non-
specific signs.
 Radionuclide ventilation-perfusion lung scan –
Excellent negative predictive value.
 CT Angiography of the pulmonary arteries – Quickly
becoming method of choice.
 Pulmonary angiography – Gold standard but invasive.

57. Diagnostic Tests for Suspected Pulmonary
Embolism
Oxygen saturation Nonspecific, but suspect PE if there is a sudden, otherwise
unexplained decrement
D-dimer An excellent “rule-out” test if normal, especially if accompanied
by non–high clinical probability
Electrocardiography
May suggest an alternative diagnosis, such as myocardial
infarction or pericarditis
Lung scanning Usually provides ambiguous result; used in lieu of chest CT for
patients with anaphylaxis to contrast agent, renal insufficiency, or
pregnancy
Chest CT The most accurate diagnostic imaging test for PE ; beware if CT
result and clinical likelihood probability are discordant
Pulmonary angiography Invasive, costly, uncomfortable; used primarily when local
catheter intervention is planned
Echocardiography Best used as a prognostic test in patients with established PE
rather than as a diagnostic test ; many patients with large PE will
have normal echocardiograms
Venous ultrasonography Excellent for diagnosis of acute symptomatic proximal DVT; a
normal study does not rule out PE because a recent leg DVT may
have embolized completely; calf vein imaging is operator
dependent
Magnetic resonance Reliable only for imaging of proximal segmental pulmonary
arteries; requires gadolinium but does not require iodinated
contrast agent

60. Pulmonary Embolism
(Treatment) Part 2
Dr.Tinku Joseph
DM Resident
Dept. Of Pulmonary Medicine
AIMS, Kochi.

61. Approach to the patient of PE
 Stratify patients into high clinical likelihood or non–
high clinical likelihood of PE .
 In low-risk group, only about 5% of patients were
subsequently diagnosed with PE.

62. How do we work up?
- Pretest Probability
 Definition: “The probability of the target disorder
(PE) before a diagnostic test result is known”.
 Used to decide how to proceed with diagnostic
testing and final disposition

63. Classic Wells Criteria to Assess Clinical
Likelihood of Pulmonary Embolism
SCORE POINTS
DVT symptoms or signs 3
An alternative diagnosis is less
likely than PE
3
Heart rate >100/min 1.5
Immobilization or surgery
within 4 weeks
1.5
Prior DVT or PE 1.5
Hemoptysis 1
Cancer treated within 6 months
or metastatic
1
>4 score points = high probability
≤4 score points = non–high probability JAMA 295:172,2006

64. Simplified Wells Criteria to Assess Clinical Likelihood
of Pulmonary Embolism
DVT symptoms or signs 1
An alternative diagnosis is less
likely than PE
1
Heart rate >100/min 1
Immobilization or surgery
within 4 weeks
1
Prior DVT or PE 1
Hemoptysis 1
Cancer treated within 6 months
or metastatic
1
>1 score point = high probability
≤1 score point = non–high probability
Thromb Haemost 101:197,2009

65. Original Geneva score

66. Revised Geneva score

67. ACC/AHA Classification
• Massive
• Submassive
• Low-Risk PE
• Pulmonary infarction syndrome

68. Massive PE
• Acute PE with sustained hypotension (systolic blood
pressure 90 mm Hg for at least 15 minutes or
requiring inotropic support, not due to a cause other
than PE, such as
 Arrhythmia
 Hypovolemia
 Sepsis
 Left ventricular (LV) dysfunction
 Pulselessness
 Persistent profound bradycardia (heart rate 40 bpm
with signs or symptoms of shock)

69. Submassive PE
• Acute PE without systemic hypotension (systolic blood pressure 90mm Hg)
but with either RV dysfunction or myocardial necrosis
• RV dysfunction means the presence of at least 1 of the following
 RV dilation (apical 4-chamber RV diameter divided by LV diameter 0.9) or
RV systolic dysfunction on echocardiography
 RV dilation (4-chamber RV diameter divided by LV diameter 0.9) on CT
 Elevation of BNP (90 pg/mL)
 Elevation of N-terminal pro-BNP (500 pg/mL)
 Electrocardiographic changes (new complete or incomplete right bundle-
branch block, anteroseptal ST elevation or depression, or anteroseptal T-
wave inversion)
Torbicki A et al. Eur Heart J 29(18):2276–2315,
2008

70. Low-Risk PE
• Acute PE and the absence of the clinical
markers of adverse prognosis that define
massive or submassive PE

71. Pulmonary Infarction Syndrome
• Caused by a tiny peripheral pulmonary embolism
 Pleuritic chest pain, often not responsive to
narcotics
 Low-grade fever
 Leukocytosis
 Pleural rub
 Occasional scant hemoptysis

72. Treatment:
Goals:
 Prevent death from a current embolic event
 Reduce the likelihood of recurrent embolic events
 Minimize the long-term morbidity of the event

73. 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

74. Treatment options
 Massive PE: Thrombolysis/embolectomy
 Sub-massive PE: Strongly consider
thrombolysis/embolectomy but need to balance risk
of bleeding
 Non-massive PE: Anticoagulation

75. KEY STUDIES & guidelines IN PE
TREATMENT
• 1937 Murry: first use of heparin
• 1960 Barritt:“RCT” warfarin vs.
placebo
• 1968 Sasahara: UPET
• 2003 Konstantinides: Alteplase

77. Prevention
 ACCP guide lines
• For acutely ill hospitalised medical pts at low risk of
thrombosis ACCP recommends against the use of
prophylaxsis.
• Pts at moderate to high risk but who are not
bleeding or at high risk of bleeding should be given
either LMWH or UFH or fondaparinux.

78. Padua Score

79. Prevention of PE
1 Hospitalization with
medical illness
Enoxaparin 40 mg SC qd or
Dalteparin 5000 units SC qd or
Fondaparinux 2.5 mg SC qd (in patients with a
heparin allergy such as heparin-induced
thrombocytopenia) or
Graduated compression stockings or intermittent
pneumatic compression
2 General surgery Unfractionated heparin 5000 units SC bid or tid or
Enoxaparin 40 mg SC qd or
Dalteparin 2500 or 5000 units SC qd
3 Major orthopedic
surgery
Warfarin (target INR 2 to 3) or
Enoxaparin 30 mg SC bid or
Enoxaparin 40 mg SC qd or
Dalteparin 2500 or 5000 units SC qd or
Fondaparinux 2.5 mg SC qd
Rivaroxaban 10 mg qd (in Canada and Europe)
Dabigatran 220 mg bid (in Canada and Europe)

80. 4 Oncologic surgery Enoxaparin 40 mg SC qd
5 Neurosurgery Unfractionated heparin 5000 units SC bid or
Enoxaparin 40 mg SC qd and
Graduated compression stockings or intermittent
pneumatic compression
Consider surveillance lower extremity ultrasonography
6 Thoracic surgery Unfractionated heparin 5000 units SC tid and
Graduated compression stockings or intermittent
pneumatic compression
Prevention of PE

81. • For pts who are bleeding or at risk of bleeding use
leg compression devices only.
• Pts are considered to be at high risk of bleeding if
they meet any of the following criteria
• Active gastrodeodenal ulcer
• Bleeding in 3 months prior to admission
• Platelet count <50,000
Prevention of PE

82.  Or if they had multiple risk
factors for bleeding of lesser
predictive strengthlike age >84
yrs,severe renal failure , hepatic
failure with INR > 1.5 , male
,current cancer, ICU admission.
Prevention of PE

83. References
 Harrison -18 th edition
 ACCP guidelines
 Fishman's Pulmonary Diseases and Disorders
 Crofton and Douglas's Respiratory Diseases
(Wiley, 2000)