Embedded Files
Learning Objectives
Introduction to Lower Extremity Vascular Anatomy
Describe the technique and steps for performing vascular assessment for deep vein thrombosis (DVT)
Recognize DVT Ultrasound False Positives.
Key Points
DVT Evaluation - determine compressibility of vein (may not always clearly visualize clot), with consideration to use color doppler
DVT False Positive - Baker Cyst, Lymph Nodes, Hematoma, etc...
Introduction to Vascular Anatomy
Position the patient supine with legs in frog leg position (45 degree external rotation at the hip, with knees partially bent).
DVT Technique (proper compression) with Steps
Above: Fully compressible vein
Below: Incompletely compressible vein (positive for DVT)
DVT Technique (compressible vein on left).:
Direct visualization of the clot: a hyperechoic figure is seen within the vessel that can be either partially or totally occluding its lumen.
Lack of compressibility: a normal vein should be able to be completely compressed when applying pressure with the probe, and so a lack of compressibility indicates presence of a clot even if it cannot be directly visualized. If the adjacent vein compresses completely, there is no DVT.
Color Doppler: lack of blood flow visualized by color doppler indicates presence ofan obstruction within the vessel. This test is not routinely done and not performing it doesn't decrease the diagnostic yield of the previous methods (Blaivas, 2007; Kory 2011).
Steps for Performing DVT POCUS Evaluation:
Utilize a high-frequency transducer (linear array or vascular probe), with marker pointing to the right of the patient (9 o'clock position).
Identify the common femoral vein (CFV) and then perform serial compressions. Compress every 1-2 cm while moving distally along the CFV, until the common femoral vein is seen branching into the superficial and deep branches and the veins become deeper. Make sure you increase the depth of your probe as you advance your probe caudad (vein of interest should always be in the center of the screen).
Scan the popliteal vein by flexing the knee 45° while externally rotated. The popliteal vein (PV) overlies the popliteal artery (PA), and is typically very compressible. Perform compression at this site.
False Positives: AKA Clot Mimickers
Superficial thrombophlebitis: clot seen in a superficial vein
Lymph node: a round/ovoid hypoechoic image that is non compressible and changes size/shape while scanning longitudinally.
Cysts: anechoic and non-compressible. Think Baker's cyst if near popliteal vein (pictured above).
Hematoma: often seen as a collection of blood adjacent to or surrounding a vessel. Scan longitutinally to track.
Images / information from: https://www.pocus101.com/lung-ultrasound-made-easy-step-by-step-guide/
This site was created for educational purposes only. No copyright is claimed in the images and videos presented here and to the extent that material may appear to be infringed, we assert that such alleged infringement is permissible under fair use principles in U.S. copyright laws.
If you believe material has been used in an unauthorized manner, please contact the poster at slwpocus@gmail.com
Page updated
Google Sites
Report abuse