3. Introduction
Is the occlusion of one or more vessels in the
pulmonary arterial tree by matter from a
source extrinsic to the lung
Almost invariably acute
May be chronic
Common and potentially fatal due to V/Q
mismatch
4. Intro…
One of the most common cause of preventable
death and the second most common cause for
increased length of hospitalization
Diagnosis missed in about 70% of the cases
Severity depends on size and cardiopulmonary
reserve
5. Epidemiology
Prevalence: 6.2 - 50 per 100,000
population/yr
Increases with age > 70
Highest in US,
Develops in up to 20% of patients 90 days
post-surgery
High case fatality: 15 - 30%
6. Epidemiology…
In Tanzania, devoid of researches on PE
2016 – MNH, DVT incidence = 24.7%
2017 – MOI, DVT incidence post hip fracture
repair = 6.1%
7. Etiology – VTE
• Immobility or paralysis
• Heart failure
• Venous insufficiency or varicose veins
• Venous obstruction from tumor, obesity or pregnancy
• Surgery
• Trauma
• Indwelling
catheter
• Atherosclerosis
• Heart valve
disease or
replacement
• Acute phase postop
• Cancer
• Thrombophilia
• Estrogen therapy
• Pregnancy and
postpartum period
• Inflammatory bowel disease
12. Diagnosis
Clinically challenging
The Well’s score (Well’s Criteria) – to predict
probability
Use complicated by multiple versions being
available
13. Well’s Score
Clinical Characteristic Score
Previous PE or deep vein thrombosis + 1.5
HR >100 beats per minute + 1.5
Recent surgery or immobilization (within the last 30 d) + 1.5
Clinical signs of DVT + 3
Alternative diagnosis less likely than pulmonary embolism + 3
Hemoptysis + 1
Malignancy (treated within the last 6 mo) + 1
Clinical Probability of Pulmonary Embolism Score
Low 0-1
Intermediate 2-6
High ≥7
15. Investigations
1. CT angiogram
Specific
Good for large, centrally located thrombi
GFR
2. V/Q Scan
Relatively specific
Better at peripheral thrombi – chronic PE
Pneumonia may obscure
17. Westgate EJ, FitzGerald GA - Pulmonary Embolism in a Woman Taking Oral Contraceptives and Valdecoxib. PLoS
MedicineVol. 2, No. 7, e197. doi:10.1371/journal.pmed.0020197
18. Investigations..
3. US of BLE
Specific
Positive surrogate to PE
Negative test doesn’t r/o PE
4. D- dimer
Not specific
Positive rules in PE
19. Investigations...
5. Plain CXR
Not specific
Westermark’s sign - ↓ peripheral pulmonary Vasculature
Palla’s sign – Enlarged Rt descending Pulmonary Artery
6. ECHO
Not specific – Apex may/not be moving
7. EKG
Not specific
SIQIIITIII – Rt heart strain
20. The most common ECG finding in the setting of a pulmonary embolism is sinus
tachycardia. However, the “S1Q3T3” pattern of acute cor pulmonale is classic; this
is termed the McGinn-White Sign. A large S wave in lead I, a Q wave in lead III and
an inverted T wave in lead III together indicate acute right heart strain
21. Chest radiograph (posterior–anterior view) showing a lateral wedge-shaped opacity (white
arrow) in the right lower zone (Hampton’s hump), a focal area of oligemia (space between white
arrow heads) in the right lower zone (Westermark’s sign) and a prominent right descending
pulmonary artery (black arrow) (Palla’s sign).
Hameed Aboobackar Shahul et al. BMJ Case Rep
2019;12:e231693
25. Management
For convenience, may be grouped into:
a) Asymptomatic pulmonary embolism
b) Symptomatic pulmonary embolism
c) Sub-massive pulmonary embolism
d) Massive pulmonary embolism
26. Category Admission? SX Anatomy Vitals
changes
Rx
Asymptomatic
PE
NO Ø Ø Ø LMWH Coumadin
Symptomatic PE General Ward ⊕ Ø Ø LMWH Coumadin
Sub-massive PE ICU ⊕ ⊕
Trop
BNP
ECHO
Ø Heparin infusion
Massive PE ICU ⊕ ⊕
Trop
BNP
ECHO
⊕ tPA
27. Medical management
1. Fibrinolytic
Indicated for:
Hemodynamically unstable Pts
Pts with right heart strain
Pts who are expected to have multiple
recurrences of PE
28. Medical management...
Alteplase (t-PA)
Fibrin specific,
Recombinant human tissue-type plasminogen
activator (t-PA); produces local fibrinolysis.
Promotes thrombolysis by converting
plasminogen to plasmin; plasmin degrades
fibrin and fibrinogen
Metabolized by liver,Half life of 4 min
Extremely expensive
30. Medical management...
Streptokinase
Half life of 80 min
It forms a complex with plasminogen, which
then converts to the proteolytic enzyme plasmin.
This process results in a cascade that ultimately
leads to the lysis of fibrin clots. Streptokinase
causes a systemic thrombolytic state that usually
resolves within 48 hours of administration
Administered by continuous infusion for 6 hrs
OD for 2-3 days then heparin infusions
31. Medical management...
Complications of fibrinolytics
Distal embolism of partially lysed clot
Allergic reaction and rarely
anaphylaxis
Hemorrhage – Rare
32. Medical management...
2. Anticoagulants
Heparin
Augments antithrombin III which prevent
conversion of fibrinogen to fibrin
Early anticoagulation – stops clot extension and
consequent embolization of new thrombi
33. Medical management...
Heparinasation complications
Intracranial hemorrhage (4-9%)
Heparin induced Thrombocytopenia (2-5%)
Effect of Heparin can be reversed with
Protamine sulphate
34. Medical management...
Warfarin
For maintenance therapy (1-3 days post
heparinization)
Interferes with synthesis of Vit K dependent clotting
factors (II, VII, IX, X) + Protein C & S
Maintenance dose is 5mg/day
Duration is 8-12wks for normal pts and for high risk
patients 3-6 months
35. Percutaneous Treatment
Recanalizes the pulmonary trunk or arteries
When thrombolysis is contraindicated or has
failed
Access through Jugular or Femoral venotomy
Categories:
Aspiration thrombectomy
Thrombus fragmentation
Rheolytic thrombectomy
36. Percutaneous Treatment…
IVC filter placement
When anticoagulation therapy is contraindicated
Access through Jugular or Femoral vein
Complications:
More DVTs
Fracturing
Migration
Perforation
37. Surgical management
1. Acute Pulmonary Embolectomy
Indications:
Hemodynamically unstable pt deemed unlikely
to survive
Definitive dx of PE the main or lobar
pulmonary arteries
Contraindications to thrombolytic or
anticoagulation therapy
Large clot within RA or RV
38. Acute Pulmonary Embolectomy…
Trendelenburg (1908) first described it thru
transthoracic approach – no survivors
Sharp (1962) – first successful using
cardiopulmonary bypass
Median sternotomy incision
Cardiopulmonary bypass is instituted
39. Acute Pulmonary Embolectomy…
Occluding tapes are placed around SVC & IVC
Two polypropylene sutures are placed in the mid–
pulmonary artery for traction
A longitudinal incision between these sutures in
the main pulmonary artery trunk 1 to 2 cm distal
to the valve
Can be extended directly into the left
pulmonary artery
40. Acute Pulmonary Embolectomy…
• The emboli are extracted using forceps, suction,
and balloon catheters
• Pleural spaces can be entered
• Lungs manually compressed to dislodge small
distally lodged clots, which can then be suctioned
out
• Closure 6-0 polypropylene suture
41. Surgical management…
2. Extracorporeal life support (ELS)
For massive PE or imminent cardiac arrest
Can be implemented within 15 to 30 minutes &
maintained for a period up to several weeks
IV heparin bolus of 1 mg/kg
Percutaneous or surgical cut-down of the femoral
artery and femoral or internal jugular veins
42. Surgical management…
2. Extracorporeal life support (ELS)
The tip of the venous catheter is advanced into the
right atrium to obtain a flow rate of 2.5-4.0 liters/min
An electromagnetic flow- meter is placed on the
arterial line
Thrombolytic drugs may be instilled directly into the
pulmonary artery via a Swan-Ganz catheter to aid in
clot lysis
Bridge an unstable patient to surgical embolectomy
43.
44. Management...
For Chronic PE:
Long-term anticoagulation therapy
Open pulmonary thromboendarterectomy
Heart-lung transplantation
45. Management...
Open pulmonary thromboendarterectomy
Developed by Dr. Stuart Jamieson
Median sternotomy on cardiopulmonary
bypass & hypothermia
Pericardial incised longitudinally and
attached to the wound edges
Pulmonary arteries opened
Clots and scar tissues dissected
46. Management...
Alternative therapies for or CTEPH
For:
Technically non operable
Unacceptable high surgical risks
Includes:
1. Balloon angioplasty of the pulmonary
vasculature
2. Riociguat – guanylate cyclase stimulator
48. References
1. Pulmonary Embolism: Pathophysiology, Diagnosis, Treatment: Eleni
Kostadima, Epaminondas Zakynthinos
2. Brunicardi, F. Charles, et al. Schwartz's Principles of Surgery. 11th ed.,
McGraw-Hill, 2019.
3. Pearson, F. Griffith, et al. Pearson's Thoracic and Esophageal Surgery.
Churchill Livingstone/Elsevier, 2008.
4. “Pulmonary Embolism.” Sabiston & Spencer Surgery of the Chest, by
Frank W. Sellke, 9th ed., vol. 1, Elsevier, 2016.
5. Konstantinides, Stavros & Meyer, Guy & Becattini, Cecilia & Bueno,
Héctor & Geersing, Geert-Jan & Harjola, Veli-Pekka & Huisman, Menno
& Humbert, Marc & Jennings, Catriona & Jiménez, David & Kucher, Nils
& Lang, Irene & Lankeit, Mareike & Lorusso, Roberto & Mazzolai, Lucia
& Meneveau, Nicolas & Ni Ainle, Fionnuala & Prandoni, Paolo &
Pruszczyk, Piotr. (2019). 2019 ESC Guidelines for the diagnosis and
management of acute pulmonary embolism developed in collaboration
with the European Respiratory Society (ERS). European Heart Journal.
41. 10.1093/eurheartj/ehz405.
Editor's Notes
What is Pulmonary Embolism?
Extrinsic matter -- anything: Small infectious material, Fat, Air bubble, Amniotic fluid, Tumor cells. For the sake of this presentation we’ll focus entirely on thromboemboli
Reference??
Being attributed to DVT, life style could explain the observed geographical differences
Case fatality:
US – 6%
SA – 24%
Kenya – 28.1%
*A study of prophylaxis practice and incidence of DVT among patients operated for hip fracture repair at MOI
*Radiologic department at MNH on 2016
3 -- due to the release of Platelet derived mediators (serotonin and thromboxane), as well as to fibropeptide B, which is a product of fibrinogen breakdown
That’s why even with thrombectomy, you might not improve the Rt ventricular strain
4 -- that is likely to occur as a consequence of pulmonary artery dilatation
ˆP2 – Increased sound of P2 on auscultation
Alternate interpretation (Two tier)
Score > 4 - PE likely (35%-46%) Consider diagnostic imaging (CT Angio)
Score 4 or less - PE unlikely (6%-10%) Consider D-dimer to rule out PE.
Multiditector CT Angio (MDCTA) - 1mm slices can show a peripherally located thrombi in 5th order branches
V/Q Scan: Scintigraphic exam utilizing technicium-99m DTPA (Ventillation) & Tc-99m MAA (Perfusion)
D-dimer Positive: ↑ (>500ng/dl) in >90% of Pts
Chest radiograph (posterior–anterior view) showing a lateral wedge-shaped opacity (white arrow) in the right lower zone (Hampton’s hump), a focal area of oligemia (space between white arrow heads) in the right lower zone (Westermark’s sign) and a prominent right descending pulmonary artery (black arrow) (Palla’s sign).
Acute PE without systemic hypotension (systolic blood pressure >90 mm Hg) can be classified as low-risk or submassive, with submassive PE being defined by the presence of right ventricular (RV) dysfunction or myocardial necrosis
LMWH Coumadin better than Heparin infusion (requires 4hrly monitoring) in the Sx PE
tPA : Alteplase
Chronic Thromboembolic Pulmonary Hypertension (CTEPH) – Thrombectomy
Massive pulmonary embolism is defined as obstruction of the pulmonary arterial tree that exceeds 50% of the cross-sectional area, causing acute and severe cardiopulmonary failure from right ventricular overload.
Should be given when Dx of PE is suspected
Target INR 1.5-3.5
WHO recommend use of PT for monitoring effect of warfarin (1.5-2.5 times normal)
Maintenance dose is 5mg/day but can range from 1-10mg/day
Duration is 8-12wks for normal pts and for high risk patients 3-6months
Complications- H’ge. Controlled by tight regulation of INR <3.0.
Care should be taken to prevent endothelial injury during insertion of the filter
Presence of proximal thrombi should be ruled out before filter placement.