Thromboembolism Workup

  • Author: Vera A De Palo, MD; Chief Editor: Harris Gellman, MD   more...
 
Updated: Jan 24, 2012
 

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.
  • Plasma D-dimer by the enzyme-linked immunoassay (ELISA) method quantifies the presence of D-dimer, which is a specific degradation product of cross-linked fibrin.[15]
  • 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 higher than 500 ng/mL has been shown to have a sensitivity of 97% and a specificity of 45%. The plasma D-dimer level less than 500 ng/mL has a high negative predictive value. A value of less than 500 ng/mL excludes PE.
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Imaging Studies

  • Chest radiograph findings most often are normal.
    • Radiographs may 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.
  • Doppler ultrasonography can evidence the presence of thrombus within a vein.
    • A normal vein is free of internal echoes and can be compressed. In acute DVT, internal echoes are present and the vessel is not compressible.
    • Duplex scanning of the venous system uses Doppler flow assessment combined with B-mode ultrasound. The advantage of color flow Doppler is the ability to determine motion and the direction of flow.
  • Pulmonary angiography long has 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 a cutoff of a vein and 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.
    • Morbidity is increased in approximately 2-5% of patients. It is related to bleeding and to complications of intravenous contrast material. Mortality occurs in less than 1% of patients in whom this procedure is performed.
  • Ventilation-perfusion scanning, as shown in the image below, is the most common screening technique.
    • Ventilation-perfusion scanning is a probability estimate for PE that evaluates the size and the number of defects in the perfusion of the lung compared to the areas of ventilation.
    • The diagnosis of PE is made easily with this modality when the probability estimate is high for PE. Likewise, with normal scan findings, the possibility of PE is excluded. However, the test results are nondiagnostic in about 66% of cases. The image below compares normal findings and 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.
  • Helical (spiral) CT scanning, as shown in the image below, allows for the imaging of the pulmonary vessels by way of intravenous contrast material as the patient moves through a gantry at a constant rate with rotation of the radiography source.
    • 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 filliHelical 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%.
    • Its limitations include the need for contrast and a comparatively higher dose of radiation than that of some of the other diagnostic modalities. Obliquely or horizontally oriented vessels like those of the segmental branches of the right middle lobe and lingula are poorly visualized. Lymph nodes may result in false-positive results. The scan is technically inadequate or inconclusive in approximately 1-10% of the cases.
  • Contrast venography is an invasive technique that can provide direct proof of thrombus by demonstrating a filling defect with the aide of contrast medium through the deep venous system. It is the standard test for validating new diagnostic procedures. It can cause iatrogenic venous thrombosis, tissue sloughing from contrast extravasation, and allergic contrast reaction.
  • 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.
    • It is a noninvasive method of assessment. Sensitivity and specificity have been reported to be between 92% and 95%.
    • It is of limited value when DVT is asymptomatic, distal, or findings are nonocclusive.
    • Conditions leading to poor forward blood flow, hypotension, or vein compression can be responsible for false-positive results.
  • Echocardiography can demonstrate signs of right heart strain.
    • Right ventricular dilatation, right ventricular hypokinesis, or tricuspid regurgitation may be present.
    • Interventricular septum bulging into the left ventricle may be present. The size of the left ventricle may be reduced.
    • Echocardiography can be used to identify signs of impending heart failure.
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Other Tests

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

The thrombus is a solid mass composed of platelets and fibrin with a few trapped red and white blood cells that forms within the blood vessel.

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Contributor Information and Disclosures
Author

Vera A De Palo, MD  Assistant Professor, Department of Medicine, Brown University School of Medicine; Director, Intensive Care Unit, 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, and Society of Critical Care Medicine

Disclosure: Nothing to disclose.

Specialty Editor Board

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.

Dinesh Patel, MD, FACS  Associate Clinical Professor of Orthopedic Surgery, Harvard Medical School; Chief of Arthroscopic Surgery, Department of Orthopedic Surgery, Massachusetts General Hospital

Dinesh Patel, MD, FACS is a member of the following medical societies: American Academy of Orthopaedic Surgeons

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

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, and Arkansas Medical Society

Disclosure: Nothing to disclose.

Additional Contributors

The authors and editors of Medscape Reference gratefully acknowledge the contributions of previous coauthor Dr Michael Belanger to the development and writing of this article.

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. Oct 2005;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. Aug 2005;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. Jun 2005;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. Feb 2009;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. Mar 2009;17(3):183-96. [Medline].

  10. 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. Oct 16 2009;[Medline].

  11. 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. Aug 2009;250(2):219-28. [Medline].

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

  13. 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. Nov 1 2011;155(9):625-632. [Medline].

  14. 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. Oct 2011;124(10):947-954.e2. [Medline].

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

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

  17. 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. Apr 13 2011;4:CD006652. [Medline].

  18. 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. Jun 15 2011;6:CD006466. [Medline].

  19. 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. May 24 2011;342:d3036. [Medline]. [Full Text].

  20. 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. Jun 15 2011;6:CD006650. [Medline].

  21. 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. Feb 27 1993;341(8844):507-11. [Medline].

  22. Hirsh J, Dalen J, Guyatt G. The sixth (2000) ACCP guidelines for antithrombotic therapy for prevention and treatment of thrombosis. American College of Chest Physicians. Chest. Jan 2001;119(1 Suppl):[Medline].

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

  24. 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. Jul 2 2011;378(9785):41-8. [Medline].

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

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

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

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

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

  30. 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. Nov 2009;209(5):589-94. [Medline].

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

  32. 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. Jun 2009;31(6):1129-41. [Medline].

  33. 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. Dec 8 2011;365(23):2167-77. [Medline].

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

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

  36. 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. Jan 7 2012;379(9810):31-8. [Medline].

 
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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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