DVT ultrasound

Background

Bedside ultrasound can be used to conduct compression testing on lower extremity vasculature to assess for DVT
Intended to be rapid, limited, but revealing most clinically significant DVTs
Amongst ED providers, there is a sensitivity of 95% and specificity of 96%^[1]

Indications

Clinical suspicion of DVT: edema, tenderness over the calf, Homan's sign
Clinical suspicion of PE: chest pain, SOB, tachycardia, tachypnea

Technique

Sites of Compression for 3-Point Evaluation

Common Femoral Vein
Saphenofemoral Junction
Popliteal Vein

Steps

Select transducer
- Linear array vascular probe 6–10 MHz
- For morbidly obese patients, consider abdominal probe
Common Femoral Vein and Saphenofemoral Junction
- Patient positioning
  - Reverse Trendelenburg or semi-sitting with 30 degrees of hip flexion
  - Mild external rotation (30 degrees) hip
- Probe at medial inguinal crease
- Apply generous compression every centimeter
- Continue distal to 1-2cm beyond bifurcation of the common femoral vein
Popliteal vein
- Patient positioning
  - Prone, decubitus position, or seated on edge of gurney
  - Knee flexed 10–30 degree
  - Reverse Trendelenburg
- Apply generous compression over the popliteal vessals
- Vein usually anterior to the artery

Findings

Each segment of vein identified must be assess as compressible and noncompressible
- Touching of the anterior and posterior walls indicates a normal exam
- No touching with pressures sufficient to deform the artery indicates DVT

Images

Normal

Abnormal

Pearls and Pitfalls

Arteries are the thick walled and more circular vessels identified
Doppler flow can be used to identify different directions of flow in vessels and to identify no vascular structures
Noncompressible vein may be mistaken for an artery, leading to a false negative result
An artery may be mistaken for a non-compressible vein, leading to a false positive result
Lymph nodes may be confused with noncompressible vein and if found, can be identified by moving up or down 1 cm

Documentation

Normal Exam

A bedside ultrasound was conducted to assess for DVT with clinical indications of edema and pain. The extremity was assessed at 3 locations – common femoral vein, saphenofemoral junction, and the popliteal vein. Sequential compressions at these sites showed fully compressible veins. No sonographic evidence of DVT at these sites.

Abnormal Exam

A bedside ultrasound was conducted to assess for DVT with clinical indications of edema and pain. The extremity was assessed at 3 locations – common femoral vein, saphenofemoral junction, and the popliteal vein. Sequential compressions at these sites showed a noncompressible popliteal vein. DVT is present at the level of the popliteal vein.

Video

External Links

References

↑ Burnside P, Brown M, and Kline J. Systematic review of emergency physician-performed ultrasonography for lower-extremity deep vein thrombosis. Acad Emerg Med. 2008; 15:493–498.

Authors:

[1] Burnside P, Brown M, and Kline J. Systematic review of emergency physician-performed ultrasonography for lower-extremity deep vein thrombosis. Acad Emerg Med. 2008; 15:493–498.

[1]