Deep vein thrombosis resident survival guide
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Definition
Deep vein thrombosis (also known as deep venous thrombosis or DVT and colloquially referred to as economy class syndrome) is the formation of a blood clot ("thrombus") in a deep vein. The risk is significantly increased if the thrombus embolizes to the lungs, causing pulmonary embolism.
Causes
Life Threatening Causes
Common Causes
- Long term immobility
- Clotting disorders
- Cardiac failure
- Hip replacement
- Estrogen in OCP and HRT
- Nephrotic syndrome
- Obesity
- Pregnancy
Diagnostic approach
| Pretest Probability of DVT Major points 1-Active cancer 2-Paralysis,paresis or plastic immobilization of leg or foot 3-Recent bed rest >3 days or major surgery in the last 4 weeks or both 4-Calf or thigh swelling 5->3 cm calf swelling below the tibial tuberosity 5-Strong F/H of DVT Minor points 1-H/O recent trauma to the suspected leg 2-Pitting edema in the suspected leg 3-Dilated superficial veins in the suspected leg 4-Hospitalization in the last 6 months 5-Erythema | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Low probability* | Moderate probability* | High probability* | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| D-Dimer | D-Dimer | U/S | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Negative | Positive | Negative | Positive | Negative | Positive | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| No DVT | U/S | No DVT | U/S | Repeat in 7 days | D-Dimer | Treat | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Negative | Positive | Negative | Positive | Negative | Positive | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| No DVT | Treat | Repeat in 7 days | Treat | No DVT | Repeat in 7 days | U/S | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
High probability:
>3 major points+ no alternative diagnosis
or 2 major points + 2 minor points + no alternative diagnosis.
Low probability:
1 major point +≥2 minor + alternative diagnosis
or 1 major + ≥1 minor + no alternative diagnosis
or no major points+ irrespective of minor points +irrespective of diagnosis.
Moderate probability: neither high or low probability .