AM I IN DANGER OF A BLOOD CLOT??

AM I IN DANGER OF A BLOOD CLOT? 

By Joan Rubinger & Andy Masís

 

Lately in the media, we have seen elite athletes being hospitalized more and more often due to blood clots, especially in the lungs.  Most recently, during this NBA season, two superstars, Victor Wembanyama and Damian Lillard have been sidelined with blood clots. We have asked our colleague Joan Rubinger, the director of clinical sports medicine for Attack Athletics and founder of All Pro Sports Medicine, to help explain blood clots in detail for us, why it's dangerous, what causes them, how it's treated, and how to recognize and prevent them.

ANDY MASIS:  Hello Joan, can you explain for us what exactly is a blood clot?

JOAN RUBINGER:  Hi Andy, thank you so much for inviting me to participate in this blog.  A blood clot can be classified medically in two forms:  a thrombus, and an embolus.  A thrombus is a solid or semi-solid mass comprised of platelets, fibrin and other blood products, which causes an obstruction within a blood vessel.  An embolus is a thrombus (clotted mass) which has broken free from the walls of the vessel, and has now entered circulation within the vascular system.  When the traveling embolus floats within our circulatory system and causes an obstruction away from its home vessel, this event is called an embolism.  They can further be classified by their location.  For example, a clot that lands in the lung is called a “pulmonary embolism,” which can be fatal if not treated immediately. Clots that form in the arteries can be related to atherosclerosis, which is a hardening of the vessel wall, usually caused by high blood pressure and plaque.  

AM:  Why are clots so dangerous?

JR:  Any time your circulation is obstructed, it causes tissue and organ damage, due to lack of perfusion.  Perfusion is the act of supplying tissue and organs with an uninterrupted source of oxygenated blood.  So when tissue is deprived of oxygen for a certain amount of time, it begins to die.  It's important to know that some of the most essential vessels in the body, (the coronary arteries, carotid arteries, and the pulmonary vein system), are the most dangerous destinations for these emboli to travel, because they connect to major organs.  A coronary embolism is a blood clot obstructing the vessels that supply your heart with oxygen.  The result is usually a myocardial infarction (heart attack).  An embolism that occurs in your carotids or travels up to the brain usually results in a stroke.  And a clot that interrupts the flow of oxygenated blood in the lungs is called a pulmonary embolism.  The reason a pulmonary embolism is so dangerous is because the pulmonary veins exit the lungs at high pressure and flow directly into the heart and up to the brain.  If a loose clot dislodges and travels to the heart or brain, it is a recipe for disaster!  If clots continue to stay within the vascular system of the lungs, there is a risk of obstructing the smaller vessels, and could cause major lung damage.

AM:  What causes these clots to form?

JR:  Typically, thrombi form in peripheral veins of the lower extremities due to decreased movement or blood supply.  This is called deep vein thrombosis, or DVT.  Patients who have peripheral vascular or arterial disease have increased resistance against the blood to flow back up toward the heart.  This can lead to pooling of blood in the vascular space.  Platelets in that stagnant blood can make the blood quite sticky, forming clots (thrombi).   It's not just those with vascular disease who are at risk for clots. Anyone who is immobile (restricted to wheelchair or bed-rest), sedentary, or post-surgical are at extremely high risk.  Additionally at risk are individuals who sit in chairs or stand upright for extensive periods, and especially those who fly frequently on airplanes.  Airplanes not only restrict mobility, but the fluctuation in air pressure can be reflected within our vascular system.  (This is also a major reason for constipation, which we can discuss in another blog.)  There are additional risk factors for blood clots, such as smoking/vaping (nicotine, marijuana, tobacco), obesity, pregnancy, high blood pressure and/or cholesterol, sedentary lifestyle, and the use of hormones or birth control.

 

AM:  Why are athletes so susceptible to blood clots?

JR:  Yes Andy, it seems that each year there are more and more news stories featuring athletes being sidelined for a whole season (or even lose their careers) due to blood clots.  Chris Bosh's career was cut short in this way.  The risk for athletes to have blood clots is multifactorial, and a lot of times, becomes a cascade of events stemming from one action. To explain, let’s start with the idea of an athlete going to the gym for a workout. The intense exercise of the athlete leads to a buildup of lactic acid in the blood. This lactate is formed from excess hydrogen ions circulating in the blood volume, due to the muscles’ rapid consumption of oxygen. A decrease in oxygenated blood leads to dehydration of the blood cells, making the blood more viscous (thick & sticky). When an athlete doesn’t cool down properly to vacate the lactic acid and rehydrate enough to flush his system, that sticky, viscous blood will struggle to circulate properly.  When an athlete sits for prolonged periods of time, that viscous blood will begin to pool in the lower extremities, with high risk of forming deep vein thrombosis.

Many athletes also travel on airplanes, and the fluctuations in oxygen and cabin pressure, along with prolonged sitting, can potentiate and accelerate the risk of thrombi (clots) forming.  If a thrombus dislodges from a vein, it becomes an embolus. A critical event called an embolism will occur if that embolus reaches the lungs (pulmonary embolism), the brain (stroke), or the heart (myocardial infarction, or “heart attack”).

Additionally, if an athlete sustains an injury which needs surgical intervention, there's risk of clotting each time a layer of tissue is cut causes bleeding.  This, combined with the post-surgical decrease in mobility can lead to improper blood circulation, leading to blood pooling, leading to thrombi, leading to embolism. So, to summarize, athletes (though, usually considered “very healthy” individuals), are often at the highest risk of blood clots.  This is from having risk factors such as the formation of lactic acid, dehydration, improper cool-down, prolonged sitting, flying in airplanes, inadequate hydration, and lack of mobility/obstructed circulation after surgery.

 

AM:  How would somebody know if they have a clot?  

JR:  Remember what I said earlier about lack of perfusion?  Well, sometimes when a thrombus is obstructing blood flow, that tissue (for example, the calf muscle) is not getting an adequate supply of oxygen.  This can cause pain, swelling, warmth, redness, throbbing, and an overall dull, achy feeling.  A common site for thrombi to form are the lower legs, as prolonged sitting or standing causes blood to pool and stagnate.  Sometimes, these symptoms are not always present, and a patient won't know they have a clot until it's very well developed- and by that time, medical staff need to intervene.  There are hospital tests which can help confirm the presence of a clot, such as D-Dimer in the blood analysis, a Doppler ultrasound, a CT angiogram, or a VQ lung scan.  

Pulmonary emboli, the most common high-risk events, have some hallmark symptoms to watch for:

Shortness of breath; sudden sharp chest pain that can be localized to a specific area ("pinpoint chest pain");  chest pain that occurs with a deep breath or cough; increased heart rate; rapid shallow breathing; fatigue and weakness; sweating; fainting; coughing up blood or pink foam; and heart palpitations (increased awareness and sensation of your heartbeat).

AM:  How are clots treated?

JR:  Well, Andy, there are different levels of urgency and severity when treating blood clots.  For example, if a patient arrives in the emergency room with a life-threatening embolism (lung, heart or brain), there is a high probability that we will use "thrombolytics."   This is a type of emergency medication which has the potential to break up a clot, often called "clot busters."  Not every patient is a candidate for this medication, as there are extremely high risks involved.  This is a critical decision made by the ER staff, along with the patient and/or family members.  

For less severe clots, a patient is usually placed on "anticoagulants" (blood thinners) for an extended period of time, usually 6 months.  The patient can be transitioned from a hospital IV, to self-injection medications, then to pills, depending on their response to these interventions.  This is typically measured with 3 readings of the blood analysis:  PT, PTT, and INR. When those values are in the desirable range, the healthcare provider will then discuss options to taper off the anticoagulants and consider platelet therapy.

Some patients who have heart conditions, such as atrial fibrillation, may be placed on permanent anticoagulants.  

AM:  How can we prevent clots?

JR:  Mobility is most important!  Americans have become quite a sedentary culture, and so we must make a conscious effort to get at least 30 minutes of physical activity every day.  When seated at your desk at work, or on an airplane, it's important to rotate your feet and squeeze your calves every few minutes to promote blood flow. The increased mobility will help prevent blood from pooling. Lifestyle changes in addition to exercise include smoking cessation and a healthy diet.  These can help decrease blood pressure and cholesterol, which are risk factors for atherosclerosis.  (Your healthcare provider may decide medications for these conditions are also indicated.)

Another way we can prevent clots is by using low-dose aspirin therapy.  Aspirin is a platelet aggregation inhibitor, meaning it may help prevent sticky platelets from clumping together.  This can be especially helpful with frequent flyers.  

*Note:  If you are considering making any of these adjustments, it is important to always consult your healthcare provider first.

 

 

AM:  Wow, thank you Dr. Rubinger for your wonderful insights. This is great information for us to share with our patients and readers. 

JR:  Aww, thanks Andy! Thank you so much for having me. It’s been an honor. 

Joan Rubinger, FNPC, PhD, ATC, CSCS

Founder, All Pro Sports Medicine; Sports Rehab Specialist; Director of Sports Medicine & Nutrition, Attack Athletics; Former 2-sport NCAA Division I athlete; 20+ years experience working with elite, pro, & high performance athletes.

 

Andy Masis

DPT at Ortho Rehab Specialists

Functional Movement Specialist (FMS, SFMA, TPI-MP2). Performance Physical Therapist. Manual, Spinal, Extremity, Pre and Post Operative Care.
PT of Costa Rican National Soccer Team for 2007 World Cup in Victoria, CAN. Clinical Instructor for University of Minnesota Doctor of Physical Therapy Affiliations