Ultrasound evaluation for deep venous thrombosis (DVT) is one of the 11 core ultrasound applications for emergency physicians as listed in the 2008 American College of Emergency Physicians guidelines (1). Because ultrasound applications started to be implemented into medical school curriculum in many countries, learning basic ultrasound applications as early as possible will benefit medical students and junior residents. In this post, I will share lower extremity venous ultrasound illustrations with you.
Indications
The clinical indications for performing a lower venous ultrasound examination is the suspicion of a lower extremity DVT in a swollen or discoloured leg.
Transducer
Select a high-frequency linear transducer, (5-10) MHz transducer since it provides optimal venous copmression and image resolution.
Remember Risk Factors of DVT
Age > 60
Cancer
Central venous catheter/insertion
Genetic causes of hypercoagulopaty
History of DVT
Immobilization
Obesity
Pregnancy
Smoking
Trauma or recent surgery
Use of birth control pills or hormone replacement therapy
Wells Score for Deep Vein Thrombosis
Criteria
Score
Active cancer(treatment ongoing or within previous 6 months or palliative treatment)
1
Paralysis, paresis, or recent plaster immobilization or of the lower extremities
1
Recently bedridden for 3 days or more or major surgery within the previous 12 weeks requiring general or regional anesthesia
1
Localized tenderness along the distribution of the deep venous system
1
Entire leg swollen
1
Calf swelling > 3cm compared to asymptomatic leg (measuring 10 cm below tibial tuberosity)