Pulmonary Embolism- Diagnosis by Dr.Tinku Joseph

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 , 2 nd 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

6. Prognostic Value of Troponins in Acute Pulmonary Embolism

7. 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.

8. 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.

9. 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

10. 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)

11. 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

12. 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.

13. 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

14. Echocardiography Am J Med 122:257,2009

15. Echocardiogram in PE

16. 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.

17. Chest x ray A normal or nearly normal chest x-ray

18. 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

19. 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.

20. 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

21. Westermark’s sign

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

23. Hampton’s hump

24. 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.

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

26. 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)

27. V/Q Scan VQ scan Technique

28. Normal Ventilation Left UL PE Perfusion scan Ventillation scan

29. Ventilation/Perfusion S can 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

30. 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

31. VQ Scan

32. 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.

33. 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.

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

35. Multidetector Helical CT Pulmonary Angiography

36. Multidetector Helical CT Pulmonary Angiography Advantages

37. Multidetector Helical CT Pulmonary Angiography Limitations

38. 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 .

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

40. Intraluminal filling defect (polo mint sign)

41. Intraluminal filling defect (railway track sign)

42. Enlargment of the occluded vessel

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

44. MRA

45. MRA

46. 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”

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

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

49. 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.

50. 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

51. 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 .

52. 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.

53. 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.

54. 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.

55. 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

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

57. 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.

58. 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

59. 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

60. 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

61. Original Geneva score

62. Revised Geneva score

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

64. 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)

65. 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

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

67. 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

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

69. 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

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

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

72. 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 .

73. Padua Score

74. 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)

75. 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

76. 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

77. 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

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