What is Deep vein thrombosis - Meaning and definition

Published by Roberto Wenk. Reviewed by Alison Ramsey. Last updated date: November 9, 2018.

Deep vein thrombosis is defined as an acute formation of a blood clot or thrombus within a vein resulting in obstruction of venous return.

Causes are unknown, but the triad of venous stasis, injury to vessel intima, and altered blood coagulability are central to the process.

Risk factors
- Prolonged bed rest for any reason
- Paralysis
- Malignant disease
- Childbirth
- Pregnancy
- Use of oral contraceptives
- Leg trauma
- Major surgery
- Infection after orthopedic surgery
- Acute myocardial infarction
- Stroke
- Old age (related to decreased activity)

Characteristics
- Symptoms may be subtle, variable, or vague
- Usually occurs in leg or deep pelvic veins (popliteal, femoral, iliac)
- Presence of one or more risk factors (see above)
- Recent leg injury
- Leg pain may be mild or absent
- Pain described as a dull ache or tightness, rarely severe
- Leg discomfort worse when walking
- Swelling of lower leg
- Fever

Symptoms may be absent or minimal until shortness of breath and other pulmonary complaints appear because of embolism to the lungs. The risk of pulmonary emboli is low when only the calf veins are involved, but increases to 40% when the thigh veins are involved.

Physical findings are variable; they depend on size and location of the clot and severity of the venous obstruction.
- Heart rate may be elevated
- Minimal to moderate distress
- Difficulty walking
- Minimal to marked swelling of lower leg
- Redness of affected calf or leg may be present
- Superficial leg veins may be distended
- Mild to moderate calf tenderness; flexion of the ankle may increase pain
- Localized warmth may be present
- Peripheral pulses (compare sides for symmetry)

Adapted from Clinical Practice Guidelines for Nurses in Primary Care. Cardiovascular System. Internet. Accessed on June 20, 2016.

Published by Roberto Wenk. Last updated date: June 20, 2016.

Thrombosis is the most frequent complication and the second cause of death in patients with overt malignant disease.
Cancers of the brain, bone, ovary, and pancreas are associated with the highest incidence of thrombosis.
Presenting features of lower extremity deep vein thrombosis include pain and swelling of the lower limbs.
Pain is often mild, a dull cramp or diffuse heaviness in the calf but may involve the feet, thigh, groin and pelvis which usually increases on standing and walking. There is swelling warmth, dilatation of superficial veins, tenderness along the venous tract and pain on stretching.
Upper extremity deep venous thrombosis, superior venacave obstruction, acute mesenteric vein thrombosis and superficial thrombophlebitis may also occur in patients with cancer.

Diagnosis:
By venography, plethysmography or Doppler studies.

Treatment:
Low molecular weight heparin 100 U/kg offers substantial advantages over unfractionated heparin in the prevention of DVT and pulmonary embolism in terminally ill patients.

Hanks G, Cherny NI, Christakis NA, Fallon M, Kaasa S, Portenoy RK (Eds). Oxford Textbook of Palliative Medicine. Oxford University Press, Fourth Edition, 2010, pp.610, 932, 1250.

Deep vein thrombosis

To cite