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Thromboembolism Workup

  • Author: Vera A De Palo, MD; Chief Editor: Harris Gellman, MD  more...
 
Updated: Nov 25, 2015
 

Laboratory Studies

The arterial blood gas on room air demonstrates hypoxemia (PaO2 < 80 mm Hg) and an elevated alveolar-arterial oxygen gradient. Acid-base status may demonstrate a respiratory alkalosis.

Enzyme-linked immunoassay (ELISA) can be used to quantify the presence of D-dimer, which is a specific degradation product of cross-linked fibrin.[20] This is an important marker of the activation of fibrinolysis. It can be elevated in pneumonia, cancer, sepsis, and surgery.

A plasma D-dimer level of higher than 500 ng/mL has been shown to have a sensitivity of 97% and a specificity of 45%. The value of D-dimer is in its negative predictive value. A plasma D-dimer level of less than 500 ng/mL essentially excludes PE.

Elevated troponins are associated with adverse prognosis in acute PE.[21] Elevated natriuretic peptides, brain natriuretic peptide (BNP), and N-terminal pro-BNP have been shown to be predictive of adverse short-term outcomes in acute PE and can be predictive of mortality.[22, 23] Measurement of both troponin and BNP are important for risk stratification in patients with PE.

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Chest Radiography

Chest radiographic findings most often are normal. Radiographs may, however, reveal an enlarged right descending pulmonary artery, decreased pulmonary vascularity (Westermark sign), a wedge-shaped infiltrate, or an elevation of the hemidiaphragm (Hampton hump). If infarction occurs, a pleural effusion may be present.

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Helical (Spiral) Computed Tomography

Helical (spiral) computed tomography (CT) allows for the imaging of pulmonary vessels by way of intravenous contrast material as the patient moves through a gantry at a constant rate and the radiography source rotates. PE is diagnosed by filling defects, which are either central or adherent to the wall. The CT scan below shows a filling defect.

Helical CT scan of the pulmonary arteries. A filli Helical CT scan of the pulmonary arteries. A filling defect in the right pulmonary artery is present, consistent with a pulmonary embolism.

The advantage of helical CT scanning is that it is minimally invasive and allows concurrent visualization of the parenchyma, pleura, and mediastinum. When looking at the main, lobar, and segmental veins, the sensitivity of helical scanning is about 93%. Its positive predictive value is approximately 95%.

The limitations of helical CT scanning include the need for contrast and for a higher dose of radiation than that required by some other diagnostic modalities. Obliquely or horizontally oriented vessels like those of the segmental branches of the right middle lobe and lingula are poorly visualized. The scan is technically inadequate or inconclusive in approximately 1-10% of the cases.

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Doppler Ultrasonography

Results from Doppler ultrasonography can indicate the presence of thrombus within a vein. A normal vein is free of internal echoes and can be compressed. In acute DVT, however, internal echoes are present and the vessel is not compressible.

Duplex scanning of the venous system uses Doppler flow assessment combined with B-mode ultrasonography. The advantage of color flow Doppler ultrasonography is the ability to determine motion and the direction of flow.

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Echocardiography

Echocardiography can demonstrate signs of right-sided heart strain. Right ventricular dilatation, right ventricular hypokinesis, or tricuspid regurgitation may be present. Interventricular septum bulging into the left ventricle may be present, and the size of the left ventricle may be reduced. Echocardiography can also be used to identify signs of impending heart failure.

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Pulmonary Angiography

Pulmonary angiography has long been the diagnostic criterion standard. Angiography allows for the visualization of the pulmonary vasculature using contrast material, and in the event of PE, it evidences the cutoff of a vein and a lack of flow to the affected area.

It is an invasive procedure that requires the administration of intravenous contrast material, and it is more expensive than other procedures.

Pulmonary angiography leads to increased morbidity in approximately 2-5% of patients; this is related to bleeding and to complications from the use of intravenous contrast material. Mortality occurs in less than 1% of patients in whom this procedure is performed.

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Venography

Contrast venography is an invasive technique that can provide direct proof of thrombus by demonstrating a filling defect with the aid of contrast medium through the deep venous system. However, it can cause iatrogenic venous thrombosis, tissue sloughing from contrast extravasation, and an allergic contrast reaction.

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Ventilation-Perfusion Scanning

Ventilation-perfusion scanning is a common screening technique. This modality provides a probability estimate for PE by evaluation of the size and the number of defects in the perfusion of the lung compared with the areas of ventilation.

The diagnosis of PE is easily made with this modality when the probability estimate is high for PE. With a normal scan finding, the possibility of PE is excluded. However, the test results are nondiagnostic in about 66% of cases. The image below compares normal ventilation findings with a perfusion defect.

Ventilation-perfusion scan. Left image: Posterior Ventilation-perfusion scan. Left image: Posterior view of normal findings on ventilation scan. Right image: Posterior view of a perfusion scan that reveals a perfusion defect in the left upper quadrant. The defect in the middle of the image is due to the position of the heart.
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Plethysmography

Impedance plethysmography may detect impaired venous emptying of the leg by assessing the volume response to temporary occlusion of the venous system. Emptying is assessed by the rapidity of volume decrease. Slow emptying indicates obstruction.

Impedance plethysmography is a noninvasive method of assessment. Sensitivity and specificity have been reported to be between 92% and 95%. However, it is of limited value when DVT is asymptomatic or distal or when findings are nonocclusive.

Conditions leading to poor forward blood flow, hypotension, or vein compression can be responsible for false-positive results.

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Electrocardiography

Electrocardiography is of greatest value in ruling out myocardial infarction. Sinus tachycardia often is present, and right axis deviation, right bundle branch block, and deeply inverted T waves in V1 -V3 may be found. An S1 Q3 T3 pattern may be seen.

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Contributor Information and Disclosures
Author

Vera A De Palo, MD Associate Professor, Department of Medicine, The Warren Alpert Medical School of Brown University; Associate Chief of Medicine, Memorial Hospital of Rhode Island

Vera A De Palo, MD is a member of the following medical societies: American College of Chest Physicians, American College of Physicians, American Medical Association, American Thoracic Society, Rhode Island Medical Society, Society of Critical Care Medicine

Disclosure: Nothing to disclose.

Coauthor(s)

Abdallah E Kharnaf, MD Resident Physician, Department of Medicine, Memorial Hospital of Rhode Island, The Warren Alpert Medical School of Brown University

Abdallah E Kharnaf, MD is a member of the following medical societies: American College of Physicians

Disclosure: Nothing to disclose.

Chief Editor

Harris Gellman, MD Consulting Surgeon, Broward Hand Center; Voluntary Clinical Professor of Orthopedic Surgery and Plastic Surgery, Departments of Orthopedic Surgery and Surgery, University of Miami, Leonard M Miller School of Medicine, Clinical Professor, Surgery, Nova Southeastern School of Medicine

Harris Gellman, MD is a member of the following medical societies: American Academy of Medical Acupuncture, American Academy of Orthopaedic Surgeons, American Orthopaedic Association, American Society for Surgery of the Hand, Arkansas Medical Society

Disclosure: Nothing to disclose.

Acknowledgements

Michael J Belanger, MD Clinical Instructor, Department of Orthopedics, Harvard Medical School

Disclosure: Nothing to disclose.

Jegan Krishnan, MBBS, FRACS, PhD Professor, Chair, Department of Orthopedic Surgery, Flinders University of South Australia; Senior Clinical Director of Orthopedic Surgery, Repatriation General Hospital; Private Practice, Orthopaedics SA, Flinders Private Hospital

Jegan Krishnan, MBBS, FRACS, PhD, is a member of the following medical societies: Australian Medical Association, Australian Orthopaedic Association, and Royal Australasian College of Surgeons

Disclosure: Nothing to disclose.

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Medscape Salary Employment

Jerome D Wiedel, MD Chair, Professor, Department of Orthopedics, University of Colorado Health Sciences Center

Disclosure: Nothing to disclose.

References
  1. Merli GJ. Prevention of thrombosis with warfarin, aspirin, and mechanical methods. Clin Cornerstone. 2005. 7(4):49-56. [Medline].

  2. Agnelli G, Sonaglia F, Becattini C. Direct thrombin inhibitors for the prevention of venous thromboembolism after major orthopaedic surgery. Curr Pharm Des. 2005. 11(30):3885-91. [Medline].

  3. Agudelo JF, Morgan SJ, Smith WR. Venous thromboembolism in orthopedic trauma patients. Orthopedics. 2005 Oct. 28(10):1164-71; quiz 1172-3. [Medline].

  4. Mismetti P, Zufferey P, Pernod G, Baylot, Estebe JP, Barrelier MT, et al. [Thromboprohylaxis in orthopedic surgery and traumatology]. Ann Fr Anesth Reanim. 2005 Aug. 24(8):871-89. [Medline].

  5. Jaffer AK, Barsoum WK, Krebs V, Hurbanek JG, Morra N, Brotman DJ. Duration of anesthesia and venous thromboembolism after hip and knee arthroplasty. Mayo Clin Proc. 2005 Jun. 80(6):732-8. [Medline].

  6. Eikelboom JW, Karthikeyan G, Fagel N, Hirsh J. American Association of Orthopedic Surgeons and American College of Chest Physicians guidelines for venous thromboembolism prevention in hip and knee arthroplasty differ: what are the implications for clinicians and patients?. Chest. 2009 Feb. 135(2):513-20. [Medline].

  7. Prevention of Symptomatic Pulmonary Embolism in Patients Undergoing Total Hip or Knee Arthroplasty. AAOS Clinical Practice Guideline Summary:. American Academy of Orthopaedic Surgeons. Available at http://www5.aaos.org/dvt/physician/ADU013/suppPDFs/OKO_ADU013_S10.pdf. Accessed: December 9, 2009.

  8. Lachiewicz PF. Prevention of symptomatic pulmonary embolism in patients undergoing total hip and knee arthroplasty: clinical guideline of the American Academy of Orthopaedic Surgeons. Instr Course Lect. 2009. 58:795-804. [Medline].

  9. Johanson NA, Lachiewicz PF, Lieberman JR, Lotke PA, Parvizi J, Pellegrini V, et al. Prevention of symptomatic pulmonary embolism in patients undergoing total hip or knee arthroplasty. J Am Acad Orthop Surg. 2009 Mar. 17(3):183-96. [Medline].

  10. Mont MA, Jacobs JJ, Boggio LN, et al. Preventing venous thromboembolic disease in patients undergoing elective hip and knee arthroplasty. J Am Acad Orthop Surg. 2011 Dec. 19(12):768-76. [Medline].

  11. Khokhar A, Chari A, Murray D, McNally M, Pandit H. Venous thromboembolism and its prophylaxis in elective knee arthroplasty: An international perspective. Knee. 2012 Jul 31. [Medline].

  12. Attaya H, Wysokinski WE, Bower T, Litin S, Daniels PR, Slusser J, et al. Three-month cumulative incidence of thromboembolism and bleeding after periprocedural anticoagulation management of arterial vascular bypass patients. J Thromb Thrombolysis. 2012 Jul 29. [Medline].

  13. Woller SC, Stevens SM, Jones JP, et al. Derivation and validation of a simple model to identify venous thromboembolism risk in medical patients. Am J Med. 2011 Oct. 124(10):947-954.e2. [Medline].

  14. Liem TK, Deloughery TG. First episode and recurrent venous thromboembolism: who is identifiably at risk?. Semin Vasc Surg. 2008 Sep. 21(3):132-8. [Medline].

  15. Hippisley-Cox J, Coupland C. Development and validation of risk prediction algorithm (QThrombosis) to estimate future risk of venous thromboembolism: prospective cohort study. BMJ. 2011 Aug 16. 343:d4656. [Medline]. [Full Text].

  16. Mahan CE, Borrego ME, Woersching AL, Federici R, Downey R, Tiongson J, et al. Venous thromboembolism: Annualised United States models for total, hospital-acquired and preventable costs utilising long-term attack rates. Thromb Haemost. 2012 Jul 25. 108(2):291-302. [Medline].

  17. Venous thromboembolism in adult hospitalizations - United States, 2007-2009. MMWR Morb Mortal Wkly Rep. 2012 Jun 8. 61(22):401-4. [Medline]. [Full Text].

  18. Cohen AT, Agnelli G, Anderson FA, et al. Venous thromboembolism (VTE) in Europe. The number of VTE events and associated morbidity and mortality. Thromb Haemost. 2007 Oct. 98(4):756-64. [Medline].

  19. Pasha SM, Klok FA, Snoep JD, et al. Safety of excluding acute pulmonary embolism based on an unlikely clinical probability by the Wells rule and normal D-dimer concentration: a meta-analysis. Thromb Res. 2010 Apr. 125(4):e123-7. [Medline].

  20. Pabinger I, Ay C. Biomarkers and venous thromboembolism. Arterioscler Thromb Vasc Biol. 2009 Mar. 29(3):332-6. [Medline].

  21. La Vecchia L, Ottani F, Favero L, et al. Increased cardiac troponin I on admission predicts in-hospital mortality in acute pulmonary embolism. Heart. 2004 Jun. 90(6):633-7. [Medline]. [Full Text].

  22. Klok FA, Mos IC, Huisman MV. Brain-type natriuretic peptide levels in the prediction of adverse outcome in patients with pulmonary embolism: a systematic review and meta-analysis. Am J Respir Crit Care Med. 2008 Aug 15. 178(4):425-30. [Medline].

  23. Ray P, Maziere F, Medimagh S, et al. Evaluation of B-type natriuretic peptide to predict complicated pulmonary embolism in patients aged 65 years and older: brief report. Am J Emerg Med. 2006 Sep. 24(5):603-7. [Medline].

  24. Bauer KA. New anticoagulants. Curr Opin Hematol. 2008 Sep. 15(5):509-15. [Medline].

  25. Farge D, Debourdeau P, Beckers M, Baglin C, Bauersachs RM, Brenner B, et al. International clinical practice guidelines for the treatment and prophylaxis of venous thromboembolism in patients with cancer. J Thromb Haemost. 2013 Jan. 11(1):56-70. [Medline].

  26. Chustecka Z. ASCO issues update on VTE in cancer: tell patients of risk. Medscape Medical News. May 15, 2013. [Full Text].

  27. [Guideline] Lyman GH, Khorana AA, Kuderer NM, Lee AY, Arcelus JI, Balaban EP, et al. Venous Thromboembolism Prophylaxis and Treatment in Patients With Cancer: American Society of Clinical Oncology Clinical Practice Guideline Update. J Clin Oncol. 2013 May 13. [Medline].

  28. Guyatt GH, Akl EA, Crowther M, Gutterman DD, Schuünemann HJ. Executive summary: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest. 2012 Feb. 141(2 Suppl):7S-47S. [Medline]. [Full Text].

  29. Akl EA, Gunukula S, Barba M, et al. Parenteral anticoagulation in patients with cancer who have no therapeutic or prophylactic indication for anticoagulation. Cochrane Database Syst Rev. 2011 Apr 13. 4:CD006652. [Medline].

  30. Akl EA, Vasireddi SR, Gunukula S, et al. Oral anticoagulation in patients with cancer who have no therapeutic or prophylactic indication for anticoagulation. Cochrane Database Syst Rev. 2011 Jun 15. 6:CD006466. [Medline].

  31. Boutitie F, Pinede L, Schulman S, et al. Influence of preceding length of anticoagulant treatment and initial presentation of venous thromboembolism on risk of recurrence after stopping treatment: analysis of individual participants' data from seven trials. BMJ. 2011 May 24. 342:d3036. [Medline]. [Full Text].

  32. Merli G, Spyropoulos AC, Caprini JA. Use of emerging oral anticoagulants in clinical practice: translating results from clinical trials to orthopedic and general surgical patient populations. Ann Surg. 2009 Aug. 250(2):219-28. [Medline].

  33. Akl EA, Labedi N, Barba M, et al. Anticoagulation for the long-term treatment of venous thromboembolism in patients with cancer. Cochrane Database Syst Rev. 2011 Jun 15. 6:CD006650. [Medline].

  34. Bauersachs R, Berkowitz SD, Brenner B, Buller HR, Decousus H, Gallus AS, et al. Oral rivaroxaban for symptomatic venous thromboembolism. N Engl J Med. 2010 Dec 23. 363(26):2499-510. [Medline]. [Full Text].

  35. Büller HR, Prins MH, Lensin AW, Decousus H, Jacobson BF, Minar E, et al. Oral rivaroxaban for the treatment of symptomatic pulmonary embolism. N Engl J Med. 2012 Apr 5. 366(14):1287-97. [Medline]. [Full Text].

  36. Cohen AT, Dobromirski M. The use of rivaroxaban for short- and long-term treatment of venous thromboembolism. Thromb Haemost. 2012 Jun. 107(6):1035-43. [Medline].

  37. Romualdi E, Donadini MP, Ageno W. Oral rivaroxaban after symptomatic venous thromboembolism: the continued treatment study (EINSTEIN-extension study). Expert Rev Cardiovasc Ther. 2011 Jul. 9(7):841-4. [Medline].

  38. Agnelli G, Buller HR, Cohen A, Curto M, Gallus AS, Johnson M, et al. Oral Apixaban for the Treatment of Acute Venous Thromboembolism. N Engl J Med. 2013 Jul 1. [Medline].

  39. Schulman S, Kearon C, Kakkar AK, Mismetti P, Schellong S, Eriksson H, et al. Dabigatran versus warfarin in the treatment of acute venous thromboembolism. N Engl J Med. 2009 Dec 10. 361(24):2342-52. [Medline].

  40. Schulman S, Kakkar AK, Goldhaber SZ, Schellong S, Eriksson H, Mismetti P, et al. Treatment of acute venous thromboembolism with dabigatran or warfarin and pooled analysis. Circulation. 2014 Feb 18. 129(7):764-72. [Medline].

  41. Schulman S, Kearon C, Kakkar AK, Schellong S, Eriksson H, Baanstra D, et al. Extended use of dabigatran, warfarin, or placebo in venous thromboembolism. N Engl J Med. 2013 Feb 21. 368(8):709-18. [Medline].

  42. Büller HR, Décousus H, Grosso MA, Mercuri M, Middeldorp S, Prins MH, et al. Edoxaban versus warfarin for the treatment of symptomatic venous thromboembolism. N Engl J Med. 2013 Oct 10. 369(15):1406-15. [Medline]. [Full Text].

  43. Goldhaber SZ, Haire WD, Feldstein ML, et al. Alteplase versus heparin in acute pulmonary embolism: randomised trial assessing right-ventricular function and pulmonary perfusion. Lancet. 1993 Feb 27. 341(8844):507-11. [Medline].

  44. The EINSTEIN Investigators. Oral Rivaroxaban for Symptomatic Venous Thromboembolism. N Engl J Med. 2010 Dec 3. [Medline]. [Full Text].

  45. American College of Chest Physicians. Antithrombotic Therapy and Prevention of Thrombosis, 9th ed. Chest. 2012. 141(2):7S-70S.

  46. Aujesky D, Roy PM, Verschuren F, et al. Outpatient versus inpatient treatment for patients with acute pulmonary embolism: an international, open-label, randomised, non-inferiority trial. Lancet. 2011 Jul 2. 378(9785):41-8. [Medline].

  47. Enden T, Haig Y, Kløw NE, et al. Long-term outcome after additional catheter-directed thrombolysis versus standard treatment for acute iliofemoral deep vein thrombosis (the CaVenT study): a randomised controlled trial. Lancet. 2012 Jan 7. 379(9810):31-8. [Medline].

  48. Makris M, Van Veen JJ, Tait CR, Mumford AD, Laffan M. Guideline on the management of bleeding in patients on antithrombotic agents. Br J Haematol. 2013 Jan. 160(1):35-46. [Medline].

  49. Lanzarotti S, Weigelt JA. Heparin-induced thrombocytopenia. Surg Clin North Am. 2012 Dec. 92(6):1559-72. [Medline].

  50. Bilen O, Teruya J. Complications of anticoagulation. Dis Mon. 2012 Aug. 58(8):440-7. [Medline].

  51. Iorio A, Kearon C, Filippucci E, et al. Risk of recurrence after a first episode of symptomatic venous thromboembolism provoked by a transient risk factor: a systematic review. Arch Intern Med. 2010 Oct 25. 170(19):1710-6. [Medline].

  52. Nainggolan L. ASPIRE: Aspirin good option for extended treatment of VTE. Medscape Medical News. November 4, 2012. Available at http://www.medscape.com/viewarticle/772769. Accessed: November 19, 2012.

  53. Brighton TA, Eikelboom JW, Mann K, Mister R, Gallus A, Ockelford P, et al. Low-dose aspirin for preventing recurrent venous thromboembolism. N Engl J Med. 2012 Nov 4 [Epub ahead of print]. 367(21):1979-87. [Medline]. [Full Text].

  54. Warkentin TE. Aspirin for dual prevention of venous and arterial thrombosis. N Engl J Med. 2012 Nov 22. 367(21):2039-41. [Medline]. [Full Text].

  55. Schulman S. Current strategies in prophylaxis and treatment of venous thromboembolism. Ann Med. 2008. 40(5):352-9. [Medline].

  56. Prevention of venous thromboembolism in orthopedic surgery. Med Lett Drugs Ther. 2008 Nov 3. 50(1298):86-8. [Medline].

  57. Jaffer AK, Brotman DJ. Prevention of venous thromboembolism after surgery. Clin Geriatr Med. 2008 Nov. 24(4):625-39, viii. [Medline].

  58. Piazza G, Goldhaber SZ. Physician alerts to prevent venous thromboembolism. J Thromb Thrombolysis. 2009 Nov 4. [Medline].

  59. Wittkowsky AK. New oral anticoagulants: a practical guide for clinicians. J Thromb Thrombolysis. 2009 Nov 4. [Medline].

  60. Lu JP, Knudson MM, Bir N, Kallet R, Atkinson K. Fondaparinux for prevention of venous thromboembolism in high-risk trauma patients: a pilot study. J Am Coll Surg. 2009 Nov. 209(5):589-94. [Medline].

  61. Muntz J. Thromboprophylaxis in orthopedic surgery: how long is long enough?. Am J Orthop. 2009 Aug. 38(8):394-401. [Medline].

  62. Huo MH, Muntz J. Extended thromboprophylaxis with low-molecular-weight heparins after hospital discharge in high-risk surgical and medical patients: a review. Clin Ther. 2009 Jun. 31(6):1129-41. [Medline].

  63. Sharma A, Chatterjee S, Lichstein E, Mukherjee D. Extended thromboprophylaxis for medically ill patients with decreased mobility-does it improve outcomes?. J Thromb Haemost. 2012 Aug 2. [Medline].

  64. Goldhaber SZ, Leizorovicz A, Kakkar AK, Haas SK, Merli G, Knabb RM, et al. Apixaban versus enoxaparin for thromboprophylaxis in medically ill patients. N Engl J Med. 2011 Dec 8. 365(23):2167-77. [Medline].

  65. Brown T. Aspirin effective for VTE prevention after hip replacement. Medscape Medical News. June 3, 2013. [Full Text].

  66. Anderson DR, Dunbar MJ, Bohm ER, Belzile E, Kahn SR, Zukor D, et al. Aspirin versus low-molecular-weight heparin for extended venous thromboembolism prophylaxis after total hip arthroplasty: a randomized trial. Ann Intern Med. 2013 Jun 4. 158(11):800-6. [Medline].

  67. Brown T. FDA OKs Pradaxa for thromboprophylaxis after hip surgery. Medscape Medical News. November 24, 2015. [Full Text].

  68. Kabrhel C, Varraso R, Goldhaber SZ, Rimm E, Camargo CA Jr. Physical inactivity and idiopathic pulmonary embolism in women: prospective study. BMJ. 2011 Jul 4. 343:d3867. [Medline].

  69. Izumi M, Ikeuchi M, Aso K, Sugimura N, Kamimoto Y, Mitani T, et al. Less deep vein thrombosis due to transcutaneous fibular nerve stimulation in total knee arthroplasty: a randomized controlled trial. Knee Surg Sports Traumatol Arthrosc. 2014 Jun 24. [Medline].

  70. Merkow RP, Bilimoria KY, McCarter MD, et al. Post-Discharge Venous Thromboembolism After Cancer Surgery: Extending the Case for Extended Prophylaxis. Ann Surg. 2011 Jul. 254(1):131-137. [Medline].

  71. Falck-Ytter Y, Francis CW, Johanson NA, et al. Prevention of VTE in orthopedic surgery patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest. 2012 Feb. 141(2 Suppl):e278S-325S. [Medline]. [Full Text].

  72. Markel DC, York S, Liston MJ Jr, Flynn JC, Barnes CL, Davis CM 3rd. Venous Thromboembolism Management by American Association of Hip and Knee Surgeons. J Arthroplasty. 2009 Oct 16. [Medline].

  73. Qaseem A, Chou R, Humphrey LL, Starkey M, Shekelle P. Venous Thromboembolism Prophylaxis in Hospitalized Patients: A Clinical Practice Guideline From the American College of Physicians. Ann Intern Med. 2011 Nov 1. 155(9):625-632. [Medline].

  74. Harrison L. Statins may lower clot risk after joint replacement. Medscape Medical News. March 12, 2014. [Full Text].

 
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Pulmonary embolism within the pulmonary artery.
Ventilation-perfusion scan. Left image: Posterior view of normal findings on ventilation scan. Right image: Posterior view of a perfusion scan that reveals a perfusion defect in the left upper quadrant. The defect in the middle of the image is due to the position of the heart.
Helical CT scan of the pulmonary arteries. A filling defect in the right pulmonary artery is present, consistent with a pulmonary embolism.
 
 
 
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