WELCOME BACK TO ANOTHER CLINICAL IMAGE OF THE WEEK FROM THE CASE FILES OF THE BROWN EM RESIDENCY!

HPI/ROS: A 24 year-old male presents to the ED with three days of right calf pain. He reports that the pain came on gradually and has been steadily worsening. Ambulating intensifies the sensation, which is further described as a cramping pain that does not radiate.  It is associated with right calf swelling and redness. This has never happened before. He denies fevers, chills, shortness of breath, chest pain, abdominal pain, numbness, tingling, or weakness. No history of trauma, although he is post-op day six from an appendectomy. There were no complications during the surgery, and he was discharged on day two following an uneventful post-operative course.

PMH: None

PSH: Appendectomy

Vital Signs: T 100.2, HR 82, RR 20, BP 117/72, SpO2 98% on RA

Pertinent physical exam: Patient is an uncomfortable appearing young male. Heart sounds are normal. Lung sounds are clear bilaterally. Abdomen is soft and non-tender. The right calf is noted to be moderately swollen as compared to the left. There is mild erythema overlying the right calf. There is tenderness to palpation of the right calf and a positive Homan’s sign. DP and PT pulses in the right lower extremity are intact. He has 5/5 strength throughout the right lower extremity with intact sensation as well. No other pertinent exam findings.

A bedside ultrasound of the right lower extremity was performed:

What's the diagnosis?

Hopefully this was not too tricky of a case! Note the non-compressible thrombus in the popliteal vein of this patient:

Let’s discuss the diagnosis and management of DVTs in the Emergency Department:

The Clinical Diagnosis:

• A diagnosis of DVT should be suspected in patients with palpable cords (reflecting thrombosed veins) and/or ipsilateral calf swelling (>2 cm than the opposite calf, 10 cm below the tibial tubercle).  
• One quarter of patients will have tenderness and redness in the swollen extremity, similar to findings seen in cellulitis.
• Homan’s sign (calf pain elicited by passive foot dorsiflexion) has no predictive value for DVT secondary to low sensitivity and specificity.
• It is recommended to implement a clinical decision rule such as the Well’s Criteria for DVT, which takes into account both physical examination findings, as well as other high risk criteria including history of malignancy, sedentary lifestyle, recent immobilization or surgery, and history of prior DVTs. 
• The Well’s Criteria were derived in 2003, and then validated in 2006. They are supported by the American College of Chest Physician’s guidelines for the evaluation of DVT.
• Interestingly, the incidence of DVT in patients with clinical concern for DVT was only about 15% in the original study, demonstrating that only a minority of these patients will have a DVT.

• A score of 0 or less (pre-test probability <5%) should undergo D-dimer testing (either moderate or high sensitivity testing), and if positive, compressive ultrasonography should be utilized.
• A score of 1-2 (pre-test probability 17%), should undergo high sensitivity d-dimer testing, and is positive, compressive ultrasonography should be utilized.
• A score of 3 or higher (pre-test probability 17-53%) should go straight to compressive ultrasonography. If ultrasonography is negative in these patients, they should have a repeat ultrasound in one week.

Bedside Ultrasound: 

• Poley, et al. compared limited compression ultrasound (bedside) versus the gold standard of comprehensive ultrasound.
• They attempted to incorporate limited compression ultrasound into the diagnostic workup of lower extremity DVT in an attempt to determine if they could reduce the rates of imaging (comprehensive ultrasound), d-dimer testing, and unnecessary anti-coagulation.
• Patients with Well’s scores less than 2 and a negative limited compression ultrasound were considered negative for DVT.
• Patients with Well’s scores greater than or equal to 2 and a negative limited compression ultrasound, had d-dimer testing, and if positive then had confirmatory comprehensive ultrasounds.
• Any positive limited compression ultrasounds underwent confirmatory comprehensive ultrasounds.
• The sensitivity and specificity of limited compression ultrasound was 91% and 97% respectively.
• They determined that they could have reduced the rate of comprehensive ultrasound imaging from 70% to 43% and d-dimer testing from 100% to 33%.
• Performing a limited compression ultrasound is quick and easy, involving compression ultrasound at the femoral vein where the saphenous vein inserts (see figure 1), and compression ultrasound in the popliteal fossa (see figure 2).
• For a nice review of this study, check out episode 10: 
  http://www.ultrasoundpodcast.com/tag/dvt/
• Newer studies have also investigated the diagnostic accuracy of 5 point compression ultrasound versus the current standard of 2-point compression ultrasound. We’ve discussed this previously on our previous blog. Check it out here: http://blogs.brown.edu/emergency-medicine-residency/eus-comprehensive-le-dvt-studies-lp-guidance/ 

ED Management and Disposition:

• The decision to anticoagulate and what agent to use (including for how long) is a highly individualized decision taking into account the nature and cause of the DVT (clot burden, provoked or not, etc), patient co-morbidities, age, risk of bleeding, social concerns, costs of treatment, patient follow up, as well as patient and physician preferences.
• Initial anticoagulation (0-10 days since diagnosis) should be started immediately in a patient with a confirmed DVT, assuming the risk of bleeding is not high.
• There are no well validated tools for estimating bleeding risks in patients being anticoagulated for VTE.
• Options include low-molecular weight heparin (LMWH), oral Xa inhibitors (rivaroxaban or apixaban), or unfractionated heparin (UFH), with the novel oral anticoagulants now being the preferred treatment as per the American College of Chest Physicians.
• IVC filters should be considered for patients in which the bleeding risk outweighs the benefits of anticoagulation or continued clot formation while on anticoagulants.
• Patient’s with massive clot burden (iliofemoral DVT or phlegmasia cerulean dolens) should be considered for catheter directed thrombolysis and/or mechanical extraction. 
• Outpatient management should be considered in low risk patients who are ambulatory, hemodynamically stable, have appropriate follow up and living situations, and are understanding of the management plan (including return precautions).
• Long term anti-coagulation (minimum of three months, up to 6-12 months) includes agents such as Coumadin and direct thrombin inhibitors (dabigitran).

Case Resolution:

A hypercoagulable workup was initiated and low molecular weight heparin was started. The patient was admitted to the medicine service for further evaluation and management.

References:

• Bauer, Kenneth. Approach to the Diagnosis and Therapy of Lower Extremity Deep Venous Thrombosis. UptoDate. 2016.
• Lip G, Hull R. Overview of the Treatment of Lower Extremity Deep Vein Thrombosis. UptoDate. 2016. 
• Poley, Rachel et al. Estimated Effect of an Integrated Approach to Suspected Deep Venous Thrombosis Using Limited Compression Ultrasound. Academic Emergency Medicine. 2004 Sep;21(9):971-80.
• Scarvelis D, Wells PS. Diagnosis and treatment of deep-vein thrombosis. CMAJ. 2006 Oct 24;175(9):1087-92. Review. Erratum in: CMAJ. 2007 Nov 20;177(11):1392.
• Slovis, Benjamin. Wells Criteria for DVT. 2016. <http://www.mdcalc.com/wells-criteria-for-dvt/>.
• Tintinalli, et. al. Emergency Medicine. 8th Edition. 2016. 391.
• Wells PS, Anderson DR, Rodger M, Forgie M, Kearon C, Dreyer J, Kovacs G, Mitchell M, Lewandowski B, Kovacs MJ. Evaluation of D-dimer in the diagnosis of suspected deep-vein thrombosis. N Engl J Med. 2003 Sep 25;349(13):1227-35.

The contents of this case were deliberately altered to protect the identity of the patient. All content in this report are for educational purposes only. The patient consented to the use of these images.

Faculty Reviewer: Drs. Alyson McGregor, Otto Liebmann, and Frantz Gibbs

See you again soon!