This document provides an overview of pulmonary embolism (PE), including its definition, risk factors, types, natural history, symptoms, signs, investigations, diagnosis, and management. PE is defined as obstruction of the pulmonary artery or its branches by material such as thrombus. It discusses diagnostic tests like CT, VQ scan, echocardiogram and their role in determining pretest probability. Management involves anticoagulation with drugs like heparin, warfarin, rivaroxaban. Thrombolysis may be used for massive PE while inferior vena cava filters can be placed in patients who cannot receive anticoagulation.

1. Pulmonary Embolism
Salah Abusin, MD, MRCP
Cardiology Fellow
Chicago, IL
Secretary General
Sudanese American Medical Association

2. Outline
• Definition • Management
• Risk Factors – Anticoagulation
• Types – Thrombolysis
• Natural History – IVC filters
• Symptoms – Embolectomy
• Signs • Surgical
• • Catheter Based
Investigations
• Diagnosis

4. History
• A 61 year old male
– New onset shortness of breath for 4 days.
– He also noticed a cough, with blood tinged
sputum.
– He had no chest pain, no orthopnea or
paroxysmal nocturnal dyspnea, or fever.
– He used his albuterol inhaler several times with no
improvement in his shortness of breath
• .

5. • Past history:
– Hypertension
– Asthma
– Remote history (10 years prior to current
presentation) of left lower limb swelling that
subsided after treatment for 6 months.
• Social history: Smoker 40 pack year history
• Family history: no relevant family history.
• Drug history:
– fluticasone/Salmeterol combination inhaler twice
daily,
– albuterol inhaler as needed for shortness of breath
– hydrochlorothiazide 12.5mg once daily

6. Physical Examination:
• Vital Signs:
– HR 113/min,
– BP 150/93,
– respiratory rate 22/min,
– oxygen saturation via pulse oximetry 89% on
room air,
– temperature 97.2° F (36.2 °C)

7. • HEENT: (Head, Eyes, Ear, Nose, Throat
examination) was normal.
• JVP was not raised.
• Chest clear no wheezes, or crackles.
• Abdomen soft non tender, no palpable liver,
spleen.
• Lower extremities: no edema, no other
abnormalities
• PEFR (peak expiratory flow rate) was above
75% of predicted

8. What is your differential diagnosis?
What test would you like to perform
next?

9. Investigations
• Chest X ray  Clear Lung fields
• ECG  Sinus Tachycardia
• Basic metabolic panel (BMP) includes Na, K,
HCO3, Chloride, BUN, Creatinine was within
normal limits.
• Complete blood count: Hb 15.9, WBC 7200
with normal differential, platelet count 270.
• Liver function test, and liver enzymes were
within normal limits.

10. Arterial Blood Gas on Room Air
• pH 7.42 (normal)
• pCO2 33.2 (mildly reduced)
• pO2 55 (moderately reduced)
• Oxsat 87%

11. What would you like to do next?

12. CT Chest – PE Protocol

13. Definition of Pulmonary Embolism
• obstruction of the pulmonary artery or one of
its branches by material (eg, thrombus, tumor,
air, or fat) that originated elsewhere in the
body

14. Risk Factors

15. Types
• Acute
– Massive (BP <90/40 >15mins)
– Submassive – doesn’t meet above definition
• Chronic
• Saddle PE
– Embolus lodges at the Main PA bifurcation

16. Natural History
• 30% die if untreated
• Usually due to recurrent PE

18. Symptoms
• Dyspnea at rest or with exertion (73%)
• Pleuritic pain (44 %),
• calf or thigh pain (44%),
• calf or thigh swelling (41%),
• cough (34%),
• >2-pillow orthopnea (28% ),
• wheezing (21 %)
PIOPED II. Stein PD , Beemath A et al
Am J Med. 2007;120(10):871.

19. Signs
• tachypnea (54%),
• tachycardia (24%),
• crackles (18%),
• decreased breath sounds (17%),
• Loud S2 (15%),
• Raised JVP (14 %)
PIOPED II. Stein PD , Beemath A et al
Am J Med. 2007;120(10):871.

20. Laboratory Investigations
• ABGs
– Hypoxemia
– Hypocapnia
– Respiratory alkalosis
– Hypercapnia, Resp acidosis (if massive)
– Metabolic acidosis (if massive)
• Troponin
– Elevated in moderate to severe PE

21. D dimer
• Fibrin degradation product
• Is elevated in most patients with PE
• High negative predictive value
• i.e. useful to rule out PE in patients with low
to intermediate pretest probability

22. ECG
• Sinus tachycardia
• Non specific ST/T changes
• Classical findings are uncommon
– S1Q3T3 pattern,
– RV strain,
– new incomplete RBBB

23. Chest Xray
• Usually abnormal but doesn’t differentiate PE
from other diagnoses
PE No PE
Atelectasis or a pulmonary 69% 58%
parenchymal abnormality
Pleural Effusion 47% 39%
Normal 12%
Stein et al
Chest. 1991;100(3):598

24. VQ Scan
• Interpreted as probability i.e.
– Low Probability
– Intermediate Probability
– High Probability
• Diagnosis of PE using VQ scan requires
integration of the pretest probability
• Normal VQ Scan virtually excludes PE

26. CT Chest
• Advantages
– High Specificity for main, lobar and segmetal vessels
– Rapidity
– Diagnosis of other disease entities
• Disadvantages
– Availability
– Expense
– Less sensitivity with subsegmental vessels
– Contrast Load

27. Diagnosis
• Clinical findings are generally non specific,
variable, and common with other conditions
• Results of Diagnostic Investigations (VQ, CT)
have to be integrated with the pretest
probability of PE

28. Determine Pretest Probability

30. Management
• Anticoagulation (Acute)
– Unfractionated Heparin
– Low Molecular Weight Heparin
– Fondaparinux
• Anticoagulation (Chronic)
– Warfarin
• New agents
– Dabigatran
– Rivaroxaban

31. Unfractionated Heparin
• Proven to work since 1960
• Intravenous
– Bolus of 80u/kg followed by infusion at 18u/kg/hr
– Titrate to target PTT 1.5-2.5x the control aPTT
• Subcutaneous
– After IV bolus of 5000u, 250u/kg BID
– SQ bolus of 333u/kg
– aPTT Not monitored

32. LMW Heparin
• Administered subcutaneously
• Examples include
– Enoxaparin  BID or once daily dosing
– Dalteparin once daily
– Nadroparin BID dosing (not for use if wt >100kg)
– Tinzaparin
• Do not require monitoring in most cases

33. LMW Heparin vs UF Heparin
• Compared with IV UFH LMW Heparin had
– less mortality,
– less thromboembolism
– Less bleeding
• Compared to SQ UFH
– Similar outcomes

34. Fondaprinux
• Subcutaneous administration
• Similar outcomes when compared to IV UFH
• Contraindicated in patients with severe renal
failure

35. Warfarin
• Started after administration of heparin (or
heparin like agent)
• Adjusted dose to INR 2.0-3.0

36. Duration of anticoagulation
• First Episode
– Reversible  3 months
– Unprovoked  indefinite (if bleeding risk
acceptable)
• Recurrent PE
– Indefinite if risk of bleeding acceptable

37. New Anticoagulants- Rivaroxaban
• Factor Xa Inhibitor
• FDA approved for
– non valvular A fib,
– postop thromboprophylaxis hip and knee replacement
– Treatment of DVT
• Non inferior to Warfarin in Einstein PE study 2012
EINSTEIN-PE Study
NEJM 2012

38. Rivaroxaban
• Given as 15mg PO dose BID for 3 weeks then
20mg daily
• Doesn’t require monitoring
• Good safety profile (less bleeding than with
warfarin)

39. Dabigatran
• Oral thrombin inhibitor
• FDA approved for non valvular Atrial Fibrillation
• Studied in Re-cover trial for DVT (not PE)
• Non inferior to warfarin
• Good safety profile
Schulman et al
NEJM 2009

40. Thrombolysis
• Indications
– Massive PE (SBP <90 for >15mins)
• Controversial Indication
– Severe hypoxemia
– Large thrombus burden
– RV dysfunction
• ECG, Cardiac Enzyme Elevation, Echocardiography
– RV thrombus in transit
– Saddle Embolus

41. Contraindications
• Absolute Contraindications
– Intracranial neoplasm
– Recent (<3 months) intracranial surgery or trauma
– recent (<3 months) ischemic stroke
– h/o hemorrhagic stroke
– Active or recent bleeding

42. • Relative Contraindications
– BP > 180 systolic
– H/o ischemic stroke
– Recent (<4 weeks) internal bleeding
– Thrombocytopenia

43. Thrombolytic Agents
• Tissue Plasminogen Activator – tPA
– Alteplase
– IV drip 100mg over 2 hours
• Streptokinase
– IV drip 250,000 units over 30mins
– Followed by 100,000u/hr for 24hrs
• Urokinase

44. Side Effects of thrombolysis
• Bleeding (9%)
– Intracranial hemorrhage (3%)
• Allergic Reactions – Streptokinase
• Hypotension - Streptokinase

45. Real Life Case
• 52 yo male with cardiomyopathy (EF10%),
• PH of DVT/PE in 2005, Gout
• Presented with worsening shortness of breath
• Has stable ET at 2-3 blocks
• HR 69, BP 105/79
• 2/6 systolic murmur
• Trace LE edema

47. Echocardiography
• Normal echo

48. Before thrombolysis After thrombolysis

49. Surgical Embolectomy
• Experienced Surgeon
• Requires cardiopulmonary bypass
• Indicated as an alternative to thrombolysis or
when thrombolysis is contraindicated

51. Inferior Vena Cava Filter
• “Filter out” large emobli
from the pelvis, lower
extremities
• Inserted percutaneously
• Indicated for patients
who have
contraindications to
anticoagulation

52. THANK YOU