House Officer Lecture on Pulmonary Embolism

1. Pulmonary Embolism
For Housestaff
Heuristics, Hoopla, and Heroics
Frank W Meissner, MD, RDMS
FACP, FACC, 1 FCCP, FASNC, CPHIMS, CCDS

2. Basic Definition
MPA > Ao =>
PAH
Occlusion of pulmonary blood vessels by embolus.
2

3. Startling Facts
3rd most common cause of death
2nd most common of unexpected
death
60% of pxts dying in hospital have
P.E.
Diagnosis is missed 70% time
3

4. Incidence/
Mortality
In U.S. 355,000 cases per year
240,000 deaths per year
=> crude mortality rate 240/355
= 68%
4

5. US AMI Deaths
959.2
1,000
750
Deaths (thousands)
544.7
500
250
93.8
32.7
0
CHD Cancer Accidents HIV/AIDS
American Heart Association. Heart and Stroke Statistical Update 2007.
5

6. AMI per Day
5%
CRUDE
MORTALITY
RATE
68%
Vs CRUDE MORTALITY RATE
PE per Day
6

7. Primary Internship Heuristic
Why is my cross cover patient
not having an AMI, Pulmonary
Embolism, or Sepsis Syndrome?
If you can always explain why
NOT - you will never have
innocent blood on your hands.
7

8. Thrombus Formation
8

9. Other Embolic Phenomena
Fat Embolism
Air Embolism
9

10. Principle Pathophysiology
10

11. Virchow’s Triad
Stasis
Immobility - Advanced Age - Recent Surgery
Pregnancy - Obesity - Chronic Lung Disease - HF - Afib
Hypercoagulability
Pregnancy - Malignancy - Hormonal Therapy (estrogen/OCPs)
Polycythemia Vera, Thrombocytosis, AIHA, Sickle Cell Dz
Factor V Leiden, Protein C&S deficiency, Factor VIII mutations
Prothrombin mutations, anti-thrombin III deficiency
" The physicians are the natural
Chronic Lung Disease - HF - Afib attorney's of the poor, and the social
problems should largely be solved by
them." Rudolph Virchow, MD
Vascular Injury
Recent Surgery - Varicose Veins - Thrombophlebitis
Lower- Extremity Fractures - Burns
11

12. Clinical
Chest pain (esp pleuritic) shock, collapse
Tachycardia, atrial fibrillation, arrhythmia,
anxiety
Dizziness, pre-syncope, syncope
Dyspnea, tachypnea, hemoptysis, non-
productive cough
Findings suggesting DVT : Swelling; Pain or
tenderness; Increased warmth; Red, blue, or
discolored skin
12

13. Clinical Findings
Angio Proven PE
Tachypnea (>20) 92%
Dyspnea 84%
Rales 58%
Pleurisy 74%
Accentuated S2 53%
Anxiety 59%
Tachycardia 44%
Cough 53%
Fever >37.8 43%
Hemoptysis 30%
Diaphoresis 36%
Sweating 27%
S3/S4 34%
Nonpleuritic Chest
Pain 14%
Thrombophlebitis 32%
Syncope 13%
LE Edema 24%
13

14. Dos Heuristic
New Onset Atrial Fibrillation =
Pulmonary Embolism until proven
not to be the case
Pulmonary embolism MOST easily
corrected (obstructive) shock state
∴ never < #2 Differential Dx
Unexplained sudden shock
Collapsed patient
14

15. Clinical Syndromes
Classic Triad (Pleuritic Chest Pain,
Dyspnea, Hemoptysis) < 20% of cases
3 discrete presentations
Pulmonary Infarction
Submassive PE
Massive PE
15

16. Graphics, Labs, Images
Two Classical EKG Patterns
N0-4 Boards
S1-
Q3 RAE >2.5 mm RV
T3
= p pulmonale Strain
16

17. Graphics, Labs, Images
Chest X-ray Findings
Cardiomegaly 27%
Normal Study 24%
Atelectasis 23%
Elevated Hemidiaphragm 20%
Pleural Effusion 18%
Parenchymal Pulmonary Infiltrates 17%
17

18. Classical Chest X-ray Findings
N0-4 Boards
Westermark’s
Sign
Dilitation of Pulmonary
Artery Proximal to
embolus with collapse of
distal vessels with sharp
cutoff of vessel contour
Hampton’s Hump
Triagnular or rounded
pleural-based infiltrate
with the apex toward the
hilum, usually located
adjacent to the hilum.
18

19. Pulse Ox & ABG Myths
Hypoxia
Most Pxts with PE will have nml
oximetry and nml A-a gradient
with PE
A-a gradient measure of gas
exchange
Classical finding of PE is
increased dead space ventilation
19

20. Dead Space
Ventilation
Tv 500 ml, paCO2 42 mmHg, ETCO2 40 mmHg
ETCO2 surrogate for expired CO2 ETCO2
According to Bohr Equation
Normal Alveolar Dead Space is
negligible in PE can become large
20

21. D-Dimer
A Fibrin split product
Multitude of False (+) causes
Marker of clot lysis
Circulating T1/2 approx 4-6 hr
Quantitative Assay
sensitivity 80-85%
negative predictive value 93-100%
21

22. D-Dimer Assays
Qualitative
Bedside RBC agglutination test
Quantitative
Enzyme lined immunosorbent
assay (ELISA)
Positive > 500 ng/ml
22

23. V-Q Scan
PIOPED
Prospective Investigation of Pulmonary Embolism Diagnosis
V-Q imaging approach in PIOPED
Preferred test for Pregnant Patient
50 mrem vs 800 mrem (Spiral CT)
23

24. V/Q
Decision Schema
High Prob Rx 4 PE
Normal 20% PE rate
Pre-test Prob
Low (-) Rx
High => angio
Low Prob => angio
24

25. V-Q Scan
Matched Defect -=>
Low Prob
Mismatched
Defect -=>
High Prob
25

26. Spiral CT Scaning
Advantages
Quick & Commonly available
Alternative Dx (“triple R/O”)
DisAdvantages
Cost ($600-$900/scan)
Renal Fxn limits Use (Crea ≤ 1.2-1.6)
Rad Dose
Limited Specificity for subsegmental emboli
26

27. THROMBUS L-PULMONARY ARTERY
27

28. THROMBUS 2ND ORDER ARTERY
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29. THROMBUS 3RD ORDER ARTERY
29

30. THROMBUS 3RD ORDER ARTERY
30

31. THROMBUS 3RD ORDER ARTERY
31

32. Pulmonary
Angio
“gold standard” Test
Interluminal defect or cutoff sign
‘Court of Last Resort’
Less radiation and less dye than CT
32

33. Echo Dx of Pulm Embolism
More than 80% have R-heart Abnmlty
Direct Viz of thrombus
RV Dilatation
RV hypokinesis with apical sparing
Abnml intraventricular septal motion
TR - acute
PA Dilatation
Lack of inspiratory collapse of IVC
33

34. 2/3 Echo Criteria =
56% Sensitivity &
90% Specificity
RV Hypokinesis
RVEDD > 27 mm (without
RV Hypertropy)
TR Velocity > 2.7 m/sec
34

35. Echo - D-Shaped Septum
Paradoxical Septal Motion
35

36. Echo - McConnell’s Sign
1. McConnell M.V., Solomon S.D., Rayan M.E., Come P.C., Goldhaber S.Z., Lee R.T.
2. Regional right ventricular dysfunction detected by echocardiography in acute pulmonary embolism.
3. Am J Cardiol 36
1996;78(4):469-473

37. Echo - Severe TR -
Severe RV Systolic
37

38. Echo - Elevated IVC Pressure
38

39. LE Ultrasound
Useful only if (+)
unless pxt has symptomatic LE findings
(swelling or pain) DVT Test Criteria
30-40% ‘negative’ studies Criteria Sensitivity Specificity PPV NPV
In Asymptomatic LE Thrombus 50% 92% 95% 37%
Have MD-CT Dx’ed PE Incompressible 79% 67% 88% 50%
No Spontaneous
76% 100% 100% 57%
Flow
Critical Care Ultrasonography: Levitov, Absent Phasic
92% 92% 97% 79%
Mayo, Slonim - 2009 - pg 300/Table Flow
26.1 - McGraw Hill Medical
39

40. Tables
TABLE 2
Massive PE
TABLE 1
-Systolic arterial pressure <90 mm Hg or drop in 40
Modified Wells Criteria
mm
Hg from baseline
Clinical Assessment for pulmonary embolism
-Shock manifested by signs of tissue hypoperfusion
Clinical Symptoms of DVT (leg swelling, pain with palpation)
Submassive PE
3.0
-Right ventricular dysfunction or pulmonary
Other Diagnosis less likely then pulmonary embolism 3.0
hypertension
Heart rate > 100 1.5
-Hemodynamically stable
Immobilization (≥ 3 days) or surgery in the previous 4
-No evidence of shock
weeks 1.5
Previous DVT/PE 1.5
TABLE 3
Hemoptysis 1.0
Thrombolytic Therapy Contraindications
Malignancy 1.0
Absolute
Simplified clinical probability assessment Score
History of hemorrhagic stroke
PE likely >4.0
Active intracranial neoplasm
PE unlikely ≤4.0
Recent (<2 months) intracranial surgery or trauma
Active or recent internal bleeding in prior 6 months
PERC Score Applies only to
low risk pxt Relative
(<15%) Bleeding diathesis
Age < 50 Uncontrolled severe hypertension
HR < 100 -(systolic BP >200mmHG or diastolic BP > 110mmHG)
If all 8 criteria
O2 Sat RA >94% Surgery within the previous 10 Days
are meet than
No past Hx/o DVT/PE Thrombocytopenia
clinical
No recent trauma or surgery
probability <2%
No hemoptysis
and CT imaging
No exogenous estrogen
is not necessary
No clinical signs of DVT
40

41. Immediately Administer
1) Unfractionated heparin (UH) 80 units/
kg/bolus
Diagnostic Treatment Algorithm for Suspected or followed by 18 units/kg/hr
or
2) Lovenox 1 mg/kg SQ
Diagnosed Submassive/Massive Pulmonary Embolism -Consider renal function
-Consider need for procedures or
surgery
+
TABLE 1 1) LE Dopplers 3) Stabilize patient and transfer to MICU/
Modified Wells Criteria 2)Consider SICU
TABLE 2
Pulmonary ( - ) Spiral Chest CT +
angiogram or 4) Obtain EKG
Massive PE repeat (PE Protocol CT)
Submassive PE test in 24
*Note normal troponin I and
TABLE 3
hours if
clinical
( + ) pro-BNP values have been
associated with low mortality
Thrombolytic Therapy suspicion
and anticoagulation alone may
remains high
Contraindications Echo
Echo Order
Troponin I
Echo & pro-BNP* Hemodynamically
1) IVC Filter
Unstable
2) Consider Surgical Embolectomy
Submassive PE Massive or Submassive
Hemodynamically
1) Continue UH
or Stable 1) TPA 100 mg over 2 hr
-Consider contraindications
2) Continue Lovenox
(Table 4)
-Consider renal function
or
or 2) Catheter Embolectomy/TPA
Absolute contraindication 3) TPA 100 mg over 2 hr or
anticoagulation -Consider contraindications 3) Surgical Embolectomy
(Table 3) and
or 4) UH/LMWH after 1,2,3
4) Catheter directed and
If clinical 5) Consider IVC filter
embolectomy/TPA
placement
deterioration
41

42. 42

43. Interventional Techniques
Pigtail Catheter - macerate fresh clot
Balloon Angioplasty - rapid frag of clot - successful even
with chronic clot
Rheolytic Catheter (Angiojet) - large volumes of saline and
aspiration - arrhythmia 2ndary Adenosine release from
hemolyzed RBC’s
Arrow-Treretola Percutaneous Thrombolytic Device
Ultrasound Fragmentation Catheter
43