1. Pulmonary Embolism Yuan Zhiming Department of Emergency Medicine The General Hospital Tianjin Medical University

2. Contents ● General Considerations ● Etiology ● Pathophysiology ● Symptoms ● Diagnosis ● Treatment ● Prevention

4. ● Emboli ● Thrombosis ● Deep vein thrombosis ● Pulmonary embolism Key Terms

9. How dose pulmonary embolism occur ?

11. Prevalence & Incidence ● The term ' prevalence ' of pulmonary embolism usually refers to the estimated population of people who are managing pulmonary embolism at any given time. ● The term ' incidence ’ of pulmonary embolism refers to the annual diagnosis rate, or the number of new cases of pulmonary embolism diagnosed each year.

12. Incidence (annual): approximately 650,000 cases in the USA Incidence Rate : approx 1 in 418 or 0.24% in USA

14. Common risk factors for pulmonary embolism : oral contraceptives; the early postpartum period; surgery; DVT ; hypercoagulable states; right heart failure; fractures of the pelvic and lower extremities etc. congestive heart failure; leukemia; polycythemia; sickle cell anemia; dysproteinemias; massive obesity; immobility; cancer; pregnancy;

18. Pulmonary embolism Anatomical obstruction Neurohumoral effects PA pressure RV afterload RV wall tension RV O 2 demand RV dilation/dysfunction RV ischemia RV output LV preload LV output Interventricular septal shift to LV Systemic perfusion hypotension Coronary perfusion RV O 2 supply

23. Plasma D-dimer levels ● Low specificity (40-43%) High sensitivity (92-100%) ● Plasma D-dimer levels <500ug/L by ELISA may exclude PE

25. S 1 -Q 3 -T 3

28. Posteroanterior chest film of patient with pulmonary embolism showing &quot;Hampton's hump&quot; in right lower lung field, a homogeneous, wedge-shaped density in the peripheral field, convex to the hilum.

30. Normal ventilation, perfusion Lung Scanning show poor flow of blood.

32. Right pulmonary arteriogram showed multiple filling defects clustered mainly around the hilum (arrow)

33. Pulmonary angiogram with digital subtraction demonstrates a large, acute embolus in the right lower lobar pulmonary artery (arrowhead).

36. Haemodynamic and respiratory support ● Fluid loading ● Dobutamine and dopamine ● Vasopressive drugs ● Oxygen therapy

37. Anticoagulation Therapy ● Patients with PE should be treated with intravenous heparin, with an adjusted activated partial thromboplastin time (aPTT) between 1.5 to 2.5 control ● Low-molecular-weight heparin may be used in patients with symptomatic non-massive PE .

38. ● Oral anticoagulant treatment should he initiated during the first 3 days with an overlap with heparin treatments for at least 4 to 5 days. Heparins could be discontinued when the international normalized ratio ( INR ) has been therapeutic (range 2.0 to 3.0) for 2 consecutive days.

39. ● Patients with a first episode of PE should be treated for at least 3 months if they have a reversible risk factor and for at least 6 months if they have idiopathic venous thromboembolism.

40. ● Oral anticoagulants should be continued for a longer period, possibly indefinitely, in patients with recurrent venous thromboembolism, or continuing risk factors such as cancer.

41. Thrombolytic Therapy ● Thrombolytic regimens for PE: Recombinant tissue plasminogen activator (rtPA), Streptokinase, Urokinase ● Thrombolytic therapy is indicated in patients with massive pulmonary embolism, as shown by shock and/or hypotension

42. ● Thrombolytic therapy in patients with sub-massive pulmonary embolism(right ventricular hypokinesia) is controversial ● Contraindications: (1) active internal bleeding; (2) recent acute cerebrovascular event(2-3mo); (3) recent cerebrovascular procedure (2-3 mo)

43. Left, A large embolus in the right pulmonary artery (arrow). Right, After a 2-hour infusion of rt-PA through a peripheral vein, there is pronounced resolution, with only a small amount of residual thrombus in segmental branches.

44. Venous filters ● Inferior vena cava (IVC) filters are indicated to prevent pulmonary embolism in patients with either absolute anticoagulation contraindications or patients who suffer from recurrent venous thromboembolism despite adequate anticoagulant treatment. ● Inferior vena cava filters are probably indicated after surgical embolectomy

46. Inferior vena caval filters. Most filters are placed percutaneouslv via the right femoral vein. Bird's Nest Filter

47. Surgical embolectomy It might be considered in circumstances including (1) severe hemodynamic instability (2) almost certain clinical diagnosis of massive pulmonary embolus (3) contraindication to thrombolytic therapy (4) close proximity to the operating room with bypass capability

49. Prognosis About 10% of patients with pulmonary embolism die suddenly within the first hour of onset of the condition. The outcome for all other patients is generally good; only 3% of patients who are properly diagnosed and treated die. In cases of undiagnosed pulmonary embolism, about 30% of patients die.

50. Prevention Pulmonary embolism risk can be reduced in certain patients through judicious use of antithrombotic drugs such as heparin, venous interruption, gradient elastic stockings and/or intermittent pneumatic compression of the legs.

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