Upon hearing that Serena Williams got a Deep Vein Thrombosis(DVT), it was easy for me to call on my medical knowledge and understand how this happened. I teach a lecture on DVT and Pulmonary Embolism (PE- a blood clot in the lung) for nurses new to critical care. This is my thing. Though I work in cardiology, I take often take care of patients with PE. When the lungs are impacted by a large blood clot, the heart is under stress. This can cause symptoms similar to a heart attack. So I figured I would write a blog on the topic since what is obvious to me might not be to those in other lines of work.
Disclaimer- I am a Nurse Practitioner, and work in cardiology, but the purpose of this blog is not to provide diagnosis. I am happy to provide references for any of the information provided. If you have any of the symptoms listed, please contact your medical provider or go to your local Emergency Department if they are severe.
Understanding the terminology:
DVT (Deep Vein Thrombosis)- a blood clot in a deep vein, usually in the leg or arm, which obstructs blood flow. This eventually causes impaired circulation and swelling.
PE (Pulmonary Embolism)- a DVT that dislodges and moves to the lung. This often causes difficulty breathing, and in instances of massive PE can cause cardiac arrest.
VTE (Venous Thromboembolism)- the "catch phrase" for DVT and PE
Some alarming statistics:
- 900,000 people in the US have an initial or recurrent DVT or PE each year
- An estimated 200,000-300,000 people die each year from PE
- 25% of PEs present as sudden cardiac death
- PE has a "Golden Hour". In 2/3 of fatal PE cases, cardiac arrest will occur in the first 1-2 hours
- PE causes more deaths each year than AIDS, breast cancer, and motor vehicle collisions combined
How does someone develop a PE?
Three major risk factors (Virchows Triad) predispose people to DVT and PE:
1. Venous Stasis (aka poor blood flow)- anyone who has surgery, illness, is on bedrest, is hospitalized has venous stasis. Even prolonged periods of inactivity can lead to venous stasis. It isn't just long plane flights, but also long car rides, and periods of immobility at your desk or on your couch.
2. Hypercoaguability- I always think about this as "sludgy blood". Things that dehydrate you make your blood thick, as well as some other factors. Dehydration, oral contraceptives (ever wonder why they tell you not to take birth control bills and smoke? Huge increase in DVT risk), pregnancy, tumors/cancer, blood clotting disorders are among the causes of hypercoaguability.
3. Vascular Damage- Surgery, trauma, burns. Anything that damages the blood vessel walls increases the risk of clots.
What are the symptoms of DVT/PE?
Symptoms of DVT include:
- Pain/discomfort in one or both of the legs (or arm)
- Swelling/Redness/warmth in one or both of the legs (or arm)
- Reduced ability to tolerate walking/exercise
Symptoms of a PE are often difficult to diagnose. When the PE is small in a healthy person, the symptoms are vague. When severe, the symptoms can mimic a heart attack.
- Sudden onset of shortness of breath, pain associated with breathing fatigue, decreased tolerance for activity, cough (sometimes coughing up pink foam).
- Massive PE may lead to low blood pressure, abnormal heart rhythms, and
- Again, the presentation can be vague. It is often the patient history that provides a hint to the diagnosis.
How are DVT/PE diagnosed?
Ultrasound of the affected limb is used to diagnose DVT.
CT Scan of the lung is used to diagnose DVT/PE. A different scan called a "V/Q Scan" can be used to diagnose PE in patients who have contraindication to CT Scan.
How are DVT/PE treated?
Patients are given blood thinners. These prevent further clot formation and allow the body's natural clot-busting system to do its job and break up the clot. This does not happen quickly. The body may take several weeks to dissolve a clot. In some instances of massive PE, patients may be given a clot-busting drug (similar to those given for strokes and heart attacks).
There are also surgical procedures for patients who cannot receive blood thinners or clot busters. A filter can also be placed to "catch" the clot before it gets to the lung in some patients.
How can you prevent DVT/PE?
- PE is the leading cause of preventable death in hospitalized patients. If you are hospitalized, ensure you are ambulating regularly, or ask what you are being given for DVT prophylaxis. You may receive shots in the abdomen, or "leg squeezers" (pumps that mimic the circulation changes with walking) to prevent DVT.
- If you are going on a long trip, hydrate, get up and walk around at least every two hours. Remember that this includes car trips. You can also use compression socks, and pump your legs if you aren't able to get up and walk around.
So how does a "healthy person have a DVT"?
I am not privy to Serena Williams' medical records, but from listening to interviews it is easy to figure out.
1. She gets a cut on her foot. Vessel Damage
2. She travels a lot. She is also at an age where she might possibly be on oral contraceptives. Venous Stasis
Listening to her interview on the Today Show, she thought she was just out of shape. Her symptoms were vague.
She was eventually taken to the Emergency Room and diagnosed with PE. To treat this, she was placed on a blood thinner (shots in the belly). As a result of the blood thinner, she developed a hematoma (collection of blood) in her abdomen. Who would have thought????
David Bloom, the NBC reporter, died of a PE after ignoring the symptoms of DVT. He was embedded with troops in Iraq, spending lots of time immobile in a tank. He described symptoms of a DVT to physicians, who urged him to get treatment. He was driven to continue with his work, and suffered a fatal PE.
Whew- a long post! So what is the point? While hospitalized patients are at higher risk, healthy people who suffer injury (or even just travel a lot)are at risk, too. So if you took a minute (or ten) to read this, perhaps it will come in handy if you or someone you know have these symptoms.
Thanks for reading.