(Blood) Clot Culprit: Cause for Deep Vein Thrombosis

By Dr. Tim Moser, Denver House Calls in Denver
Posted

Rochelle was having severe leg pain.  Her symptoms had started about a week ago, with gradual and persistent swelling of her left calf. At first there was no pain, but now the steady throbbing was getting worse with sitting or standing. The pain was less severe if she was lying on her back with her leg elevated.

Her symptoms started after a long road trip down the coast to visit family. Spending six hours a day riding is a car was bad enough, but now the leg pain was really starting to worry her. Later she mentioned the leg pain and swelling to her sister, who talked Rochelle into being evaluated by a doctor.  Blood tests and an ultrasound of the leg confirmed a blood clot was present. The nurse congratulated Rochelle for seeking treatment when she did, since complications of a blood clot could be fatal.

 

About Deep Venous Thrombosis

Deep venous thrombosis (abbreviated ‘DVT’), is a serious medical condition where blood stops flowing in a vein and forms a clot.  If left untreated, the clot can increase in length, and become unstable. Pieces of the clot typically flow to the lung, where the clot becomes lodged and blocks blood flow.

 

Keeping Things in Circulation

As blood is pumped by the heart, it flows through arteries out to the various body parts.  Arteries always carry blood away from the heart, and in most cases, this blood is rich in oxygen. Once the blood cells deposit oxygen and nutrients to the cells, waste products, such as carbon dioxide, are carried back to the heart.  Veins always return blood to the heart, and in most cases this blood is oxygen-poor.

Blood is an amazing thing. It remains a liquid most of the time, but turns to a rubbery, solid clot under the right conditions -- namely when bleeding is taking place.  This helps prevent the loss of our vital fluids when our body is damaged in some way. The system for keeping blood in a liquid state and flowing is very elaborate and elegant, but sometimes things run awry. 

 

All About Clots

Blood clots form for a variety of reasons.  Most people's bodies that form a blood clot do so for one of the following three reasons:

1. Altered blood flow.  Blood was meant to move.  If kept still for a prolonged time, the blood may clot.  Since blood in the legs is returned to the heart by moving the muscles of the legs, sitting still for long periods of time can result in blood clots.

This is common with extended trips in a car or airplane, where getting up and walking is difficult.  It is also seen in hospitalized patients that cannot get out of bed after a recent surgery or an illness. Patients with atrial fibrillation are also at an increase risk for forming blood clots in the heart itself.

2. Hypercoagulability This is a very technical way of saying the blood clots too easily for some reason. This may be due to medications (such as Estrogen), a genetic disorder, or the presence of some disease in the body that is affecting the blood.

3. Blood vessel injury  If a blood vessel is somehow damaged on the inside, then the body may react by forming a blood clot. The damage could occur from use of a catheter in the vein, a crush-type injury of the leg from the outside, or a medical condition that damages blood vessels.

Clots on the Move

The medical term for a blood clot that forms in a blood vessel is called a thrombosis.  If this occurs in a vein, it is referred to as a venous thrombosis.  Since not all clots in a vein are of equal importance, the clot can be further described as deep, or superficial. 

In the world of blood clots, the superficial variety is almost completely harmless. The deep clots, however, have the potential of breaking loose and causing great mischief in the body.  It is not surprising these bad players are called a deep venous thrombosis, or DVT for short.

A deep clot has a tendency to increase in length over time, with growth directed towards the heart. As the clot becomes longer, it also becomes more unstable, and has the potential to break loose. If a portion of the clot breaks off, there is nothing to stop the clot from reaching the heart.

In turn, the heart efficiently pumps the blood clot to the lung, along with the other poorly oxygenated venous blood. If this happens, the clot becomes lodged in the lung, and is now called a pulmonary embolus (abbreviated PE).  If the clot is large enough, the heart can stop beating in protest, and a very rapid death results. 

 

Treatment and Prevention

When a blood clot is detected (usually with the use of an ultrasound), blood thinners are used to keep the clot from growing longer. 

For the first several days, an injectable medication is used, followed by blood thinners taken by mouth (Coumadin, otherwise known as Warfarin).

After the course of several days, the body stabilizes the blood clot and, overtime, the clot is often completely dissolved by the body.  Treatment with the blood thinners usually continues for about six months if the patient has never had a blood clot in the past; sometimes blood thinners are continued for life if the patient is at a high risk for recurrence.

 

Want more information about deep venous thrombosis?

http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001209/

http://www.mayoclinic.com/health/deep-vein-thrombosis/DS01005

No comments on this story | Add your comment
Please log in or register to add your comment