URJHS Volume 12

Athletes and Pulmonary Embolism

Aimee N. Thompson
California University of Pennsylvania

Keywords: Pulmonary embolism, athletes

Abstract

A pulmonary embolism is an obstruction of one or more arteries in the lungs. In most cases, a pulmonary embolism is caused by a blood clot that travels to the lungs from another part of the body. Due to the severity of a pulmonary embolism, various complications such as difficulty breathing, heart failure, or death may occur. Blood clots typically are uncommon in young, healthy individuals. Athletes are generally healthy and well-conditioned individuals but can be at a greater risk of developing a pulmonary embolism because symptoms may be misinterpreted by something less serious and become undiagnosed. This study discussed the leading causes of pulmonary emboli and determined whether or not they related to one another in the athletic population. Current clinical research suggests that post-surgical complications, genetic mutations, protein deficiencies, and oral contraceptives are leading causes of pulmonary emboli. This study compared the leading causes of pulmonary emboli in the athletic population and determined what predisposed them to this pathology.

Introduction

A pulmonary embolism is a leading cause of unexpected death in the United States with an estimated number of 50,000 to 200,000 deaths every year (Kahanov & Daly, 2009). A pulmonary embolism is an obstruction of one or more arteries in the lungs. In most cases, a pulmonary embolism is caused by a blood clot that travels through the bloodstream to the lungs from another part of the body (Goldhaber, 2004). A pulmonary embolism is one of the many complications of deep vein thrombosis. There are a number of other reasons an individual could develop a pulmonary embolism, but the leading causes of pulmonary emboli are post surgery complications, genetic clotting disorders, protein deficiencies, or use of oral contraceptives. Pulmonary emboli can occur in all different populations. Many individuals may think that blood clots are only problematic in the elderly and do not occur in young or healthy individuals. This statement is not true. Pulmonary emboli in athletes may be misdiagnosed because signs such as shortness in breath, rapid heart rate, and chest pain are common occurrences in competing athletes. Due to this assumption, health care providers may not consider such medical problems.

Studies have defined the risk factors for the development of pulmonary emboli and have determined the likelihood of death resulting from pulmonary emboli following surgical procedures, genetic disorders, protein deficiencies, and the use oral contraceptives. Blood clots usually form and start in the lower extremities. The presence of sudden swelling and leg pain is one indicator of the development of blood clots. There is a possibility that the blood clot could break loose, travel to the lungs, and block off blood flow to the lungs (Goldhaber, 2004). Individuals are more at risk for developing blood clots after surgery. Causes of the development of blood clots after surgery are prolonged sitting and immobilization. Individuals who have diabetes, history of stroke, history of cancer, and smokers are more at risk to develop blood clots (Goldhaber, 2004).

Another potential cause of blood clots is protein deficiencies such as Protein S and Protein C. These listed deficiencies are blood-clotting disorders. The combination between protein deficiencies and other inherited clotting disorders such as Factor V can also influence the risk and development of blood clots. Protein deficiencies and genetic clotting disorders are uncommon and often go undiagnosed. Approximately one in 500 individuals is affected with a Protein S deficiency, which is caused by mutations of the PROS1 gene. This gene is responsible for making protein S, which is found in the bloodstream and is important for maintaining blood clotting. Protein S helps block the activity of inactive proteins that promote the formation of blood clots (Alhadad, Acosta, Sarabi, & Kolbel, 2010). These proteins and genetic mutations will be further discussed throughout this paper.

Oral contraceptives contain estrogen and progestin hormones and are taken to treat many conditions such as abnormal menstrual cycles, severe cramping, and to prevent pregnancy. These hormones work to slow down the body's natural cyclical hormones to prevent pregnancy. Like many other medications, oral contraceptive pills have several side effects. One side effect from taking oral contraceptives is blood clots. Women are three to six times more likely to develop blood clots when using estrogen-containing birth control pills (Westgate & FitzGerald, 2005).

The researcher's interest focuses on the leading causes of pulmonary emboli in the athletic population. Due to the severity of obstructed blood vessels in the lungs, many complications such as difficulty breathing, heart failure, or possible death may occur (Cloutier, 2007). This study discusses the leading causes, risk factors, treatment, diagnosis, and prevention methods of pulmonary emboli in the athletic population.

There will be delimitations that are involved in this research. This research will concentrate on the athletic population, both men and women, who have all been diagnosed with pulmonary emboli. In all of these cases, there are different leading causes and reasons they were affected.

Discussion

A pulmonary embolism is a common, potentially life threatening illness, which may result in death for up to 8 percent of cases that are diagnosed (Flavell, 2008). A pulmonary embolism is a blockage of the main artery in the lung or one of its branches by a substance that travels from another part of the body through the bloodstream (Goldhaber, 2004). Pulmonary emboli are most commonly caused from deep vein thrombosis, genetic clotting disorders, surgery, or from taking oral contraceptive pills. Blood clots are uncommon in young, healthy individuals. Athletes are generally healthy and well-conditioned individuals, but can be at a greater risk of developing a blood clot because symptoms may be misinterpreted as something less serious. Due to the severity of a pulmonary embolism, many complications may occur.  The primary focus of this paper is to present the literature that reviews the leading causes of pulmonary emboli in the athletic population.

Historical Perspective

Despite advances in medical technology, pulmonary emboli remain a cardiovascular emergency with a high mortality rate of (30%) (Cloutier, 2007). With a suspected pulmonary embolism, treatment is essential because immediate diagnosis and therapy can lower mortality rates. Annually, pulmonary emboli are diagnosed in every 150 to 200 cases per 100,000 patients (Schelihaa, Walther, Konstantindies, & Bottiger, 2010). When a pulmonary embolism is identified, it is characterized as either an acute or chronic illness. Patients with an acute pulmonary embolism develop signs and symptoms immediately after an obstruction of a pulmonary vessel. On the other hand, patients with a chronic pulmonary embolism develop dyspnea (difficult or labored breathing; shortness of breath) over a short period of time due to pulmonary hypertension (Schellhaa et al., 2010). Unfortunately, pulmonary emboli are commonly undiagnosed due to nonspecific signs and symptoms.  For example, some of the common signs and symptoms of a pulmonary embolism mock other illnesses such as pneumonia, acute respiratory distress, chronic obstructive pulmonary disease, or myocardial infarction. Other signs and symptoms of pulmonary emboli that may occur are chest pain, shortness of breath, tachycardia, and hypoxia. Although an individual can develop a blood clot leading to a pulmonary embolism, certain factors can increase the risk of the development of a pulmonary embolism. For example, prolonged immobility, age, family history, surgery, and current medical conditions can predispose an individual to develop a pulmonary embolism (Cloutier, 2007). Due to the nonspecific signs, symptoms, and risk factors, patients must undergo diagnostic testing until the diagnosis is confirmed. Along with the historical perspective, this paper will present the etiology, diagnosis, treatment, prevention, and epidemiology of pulmonary emboli. The following paragraphs will address specific details of pulmonary emboli and how athletes can be exposed.

Etiology Information

A pulmonary embolism is a common and highly lethal condition that is a leading cause of death in all age groups and is the most common cause of unexpected death (Goldhaber, 2004). Pulmonary emboli are the most serious complication of venous thrombosis and third-most common cardiovascular problem. More than 400,000 cases go undiagnosed in the United States, resulting in 100,000 deaths. Several risk factors can lead an individual to be more likely to develop a blood clot that may potentially break lose and travel to the lungs and cause immediate death if not diagnosed (Cloutier, 2007).  

There are four specific genetic factors that may predispose an individual in developing a pulmonary embolism.  Protein C, protein S, antithrombin, and factor V Leiden are all genetic factors that may predispose an individual to pulmonary emboli. Any individual that has a genetic clotting disorder is ten times more likely to develop a pulmonary embolism than an individual without a genetic clotting disorder (Garcia-Noblejas, 2005). An individual that has the genetic mutation factor V Leiden is three to eight times more likely to develop a pulmonary embolism than an individual without it (Charafeddine et al., 2012).

Factor V Leiden is a genetic mutation that can predispose an individual to blood clots.  Factor V Leiden is a hereditary genetic mutation that causes a hypercoagulability disorder. Hypercoagulability is a disorder when the body has an abnormality of blood coagulation, which increases the risk of developing a blood clot. The prevalence of the Factor V Leiden mutation increases the risk of developing abnormal blood clotting, leading to a possible development of a pulmonary embolism (Perez-Pujol, Aras & Escolar, 2012). A study presented by Garcia-Noblejas, a 26 year-old man previously diagnosed with the Factor V Leiden mutation presented with pain and swelling in his right knee. The patient had a past medical history of two episodes of rectorrhage during childhood, two hemarthroses, and a gastrointestinal tract bleeding.  The patient was treated with fresh frozen plasma while he was admitted in the hospital. After three days of treatment, the patient complained of chest pain, shortness of breath, and wheezing.  These episodes were resolved with bronchodilators. Two days following, the patient complained again of shortness of breath. The patient's pulmonary examination was normal and equal bilaterally. A computed tomography was completed, resulting in bilateral pulmonary emboli. The patient was treated with anticoagulant therapy with low molecular weight Heparin. Patients with inherited clotting factor deficiencies can develop pulmonary emboli. Factor V Leiden can predispose a patient to develop a pulmonary embolism, due to the abnormal blood clotting (Garcia-Noblejas et al., 2005).

Other non-genetic factors that are risk factors for pulmonary embolisms include the use of oral contraception, complications of deep vein thrombosis, immobilization, surgery, travel, and trauma. Oral contraceptive pills are used to treat a number of conditions. One main use of oral contraceptive pills is to help prevent woman from becoming pregnant. Combined oral contraception can increase the chance of blood clots such as pulmonary embolism or deep vein thrombosis (Flavell, 2008). The risk of having a blood clot depends on a number of factors.  Blood clots increase in females four to eight percent when taking oral contraceptive pills and if they have a previous history of pulmonary embolism or deep vein thrombosis. The risk of a pulmonary embolism increases with age and also depends on the kind of oral contraceptive pill that is being taken. Most oral contraceptives contain both estrogen and progestogen. The combination between these two hormones raises the levels of clotting factors and increased platelet aggregation. Due to the increased levels of clotting factors and increased platelet aggregation from oral contraception using estrogen and progestogen combinations, women are more susceptible for deep vein thrombosis or a pulmonary embolism (Goldhaber, 2004).

Deep vein thrombosis can cause the serious complication of a pulmonary embolism. Flavell (2008) described deep vein thrombosis as a blood clot in a deep vein that is caused by a combination of slow blood flow, hypercoagulability, and blood vessel damage. When symptoms are present, non-specific signs include pain, swelling, redness, warmness, and inflamed superficial veins. Risk factors for deep vein thrombosis are old age, surgery, trauma, pregnancy, oral contraception pills, and genetic factors (Flavell, 2008).  

Other possible risk factors for a pulmonary embolism are immobilization, travel, recent surgery, trauma, and heart disease (Goldhaber, 2004). Blood clots are commonly sighted after orthopedic surgeries such as knee replacements, back surgery, and joint surgery or fracture repair. Trauma and surgery provide a pool of blood to the wounded site due to the body's natural instinct. Conditions that increase clotting of the blood, can potentially lead to a pulmonary embolism.

Diagnosis

Due to the unsuspected signs and symptoms, there needs to be a high level of suspicion that pulmonary emboli may be present. After taking a descriptive past medical history, if medical professionals suspect a pulmonary embolism, they will order a series of tests to help find the leading cause of the problem. The first screening tool the doctor would order is a chest X-ray. An X-ray is a noninvasive test and shows images of the heart and the lungs. Although an X-ray cannot diagnose a pulmonary embolism, it can rule out conditions that mimic the illness, such as pneumonia (Schellhaa et al., 2010). Another diagnostic tool a medical professional may use is called a lung scan, also known as a ventilation-perfusion scan. This scan uses a small amount of radioactive material to study the airflow and blood flow in the lungs (Cloutier, 2007). During this test, the patient has to inhale a small amount of radioactive material while a camera is used to detect the movement of radioactive substances throughout the lungs. Next, a small amount of radioactive material is injected into a vein in the arm. Images are taken after the injections to distinguish if there is normal or diminished blood flow to the lungs. A third useful diagnostic tool to diagnose a pulmonary embolism is a pulmonary angiogram. During this specific test, a catheter is inserted into a large vein and threaded through the heart's right atrium, ventricle, and then into the pulmonary arteries. A special dye is injected into the catheter, and X-rays are taken as the dye travels along the arteries to the lungs (Cloutier, 2007). This test will highlight visible clots in the lungs.

Treatment

Once an individual has been diagnosed with a pulmonary embolism, it is important to begin treatment and therapy immediately to prevent complications or death. Medications that are used to treat pulmonary emboli include anticoagulants and clot dissolvers. Anticoagulants are drugs such as Heparin, Lovenox, and Coumadin that prevent new clots from forming (Goldhaber, 2004). Heparin is fast-acting drug that is administered through a needle to help prevent new clots from forming. Coumadin is administered orally and does not start working until five days after the first dose and has to be monitored weekly through blood tests to monitor the levels of the blood viscosity. Coumadin is used to help prevent new clots from forming by thinning the blood to a therapeutic level that is safe for the individual. Risks of taking anticoagulants include bleeding and bruising. Lovenox is a medication that is administered intravenously, and the purpose of Lovenox is to help get rid of current clots in the body and help prevent new ones from forming. Clot dissolvers are used as a fast acting treatment that is used to help dissolve clots quickly. This medication is not typically used unless a life-threatening situation is present due to the possibility of sudden and severe bleeding (Cloutier, 2007). Lovenox, Heparin, and Coumadin can be discontinued when the blood clots are dissolved, or an individual may remain on one of these medications for life depending on the medical history of the individual. If individuals have a clotting disorder, they may remain on a blood thinner to help prevent new blood clots from forming.

In more severe cases, doctors may recommend clot removal, vein filter, or surgery. If there is a large clot in the lungs and the patient is in shock, the doctor may thread a catheter through the blood vessels and suction out the clot. This procedure will help the individual receive full blood circulation. Another treatment method is a vein filter where surgeon will place a catheter in the inferior vena cava. This filter catches and prevents blood clots from moving through the blood stream toward the lungs. This filter is typically reserved for individuals who cannot take anticoagulant drugs or when the drugs are not effective. This procedure may lead to possible complications such as heart attack, stroke, severe bleeding, or death. Surgical removal of a clot is known as an embolectomy, but it is a last resort treatment and is rarely used. This surgery is performed to remove a blood clot, which is blocking blood circulation. This treatment is used if all other treatment options are unsuccessful. Surgery increases the risk of forming new blood clots that can cause another pulmonary embolism or permanent occlusion of blood flow to an organ or body part, leading to necrosis (an irregular breakdown of cells) (Schellhaa et al., 2010).

Prevention

There are many methods that can be used to prevent an individual from developing a pulmonary embolism. Preventative steps that can be used in a hospital before or after an operation are anticoagulant therapy, graduated compression stockings, pneumatic compression cuffs, and physical activity (Hoxie et al., 2008). An anticoagulant drug, such as Heparin or Coumadin can be administered to an individual at risk of blood clots. These drugs are mentioned earlier as a treatment, but they can also be used to prevent the development of blood clots during surgery in individuals with a previous history of blood clots, genetic disorders, and clotting deficiencies (Schelihaa et al., 2010). Anticoagulant drugs help thin the blood to a therapeutic level where an individual would not be at risk for the development of new blood clots. Graduated compression stockings squeeze the legs, helping the veins and muscles move blood more efficiently. This technique is used to keep blood from pooling after surgery.  Pneumatic compression cuffs are used to automatically inflate with air every few minutes to massage and squeeze the veins to help improve blood flow. It is also important that an individual is moving as much as possible after surgery to help the blood circulate throughout the body.

Protein deficiencies and genetic mutations are not typically tested in every individual. However, these deficiencies and mutations are diagnosed by laboratory means. If an individual is diagnosed with a protein deficiency or genetic mutation, precaution should be used to prevent blood clots during an illness, surgery, extended hospital stays, and prolonged reduced activity.  Neither protein deficiencies nor genetic mutations can be prevented but taking precautions and maintaining treatment will help prevent any possibilities for developing blood clots.

Blood clots are rare in healthy woman taking contraceptive pills, but some risk factors include a past history of blood clots, family history of blood clots, obesity, blood disorders, and cancer. If the risk factors are too high for a woman to take oral contraception, there are a number of different contraceptives available. Therefore, women who are taking oral contraceptive pills should discuss their risk of blood clots with their doctor. 

Epidemiological Studies Specific to Athletes and Pulmonary Embolisms

Like other individuals, athletes have also suffered from pulmonary emboli. The following epidemiological studies will provide the reader with reported evidence. In a study conducted by Janssen, Harm, and Sala in 2007, a 19 year-old female soccer player died 12 days after her anterior cruicate ligament reconstruction from bilateral pulmonary emboli. The patient had no past medical history and her preoperative screenings performed by the anesthesiologist did not reveal any coagulopathy or bleeding disorders. The only medication the patient was taking was an oral contraceptive pill for two months before her surgery. During the surgery, the patient received an anterior cruicate ligament reconstruction using a hamstring graft and showed no surgical complications. Eleven days after her surgery, the patient complained of increased pain in the reconstructed knee. The patient obtained medical attention and was diagnosed with a postoperative hematoma. The following day, the patient experienced an increase in pain, and was taken by ambulance to a hospital where she was resuscitated. The patient underwent tests at the hospital to determine the onset of the problem and died the same day. After the patient died, her family was analyzed for thromboembolic risk factors. Her sister was diagnosed with a protein S deficiency, demonstrating a possible inherited predisposition to pulmonary embolism in this patient. The risk factors for a deep vein thrombosis and fatal pulmonary emboli in this patient were a possible protein S deficiency and the use of oral contraceptives (Janssen et al., 2007).

Risk factors for developing pulmonary emboli have been discussed and death may result from pulmonary emboli following surgical procedures. Developing a pulmonary embolism after shoulder surgery varies from 0.17 percent for shoulder arthroplasty to 5.1 percent after proximal humerus fracture repair (Hoxie, Sperling, & Cofield, 2008). In a study on the risk of pulmonary emboli following the surgical management of rotator cuff tears, three patients or 0.26 percent of patients developed pulmonary emboli after rotator cuff reconstruction. In this study, two of the three patients had medical conditions that contributed to the development of a pulmonary embolism. One patient was treated for rheumatoid arthritis and the second tested positive for factor V Leiden gene mutation. Both of these medical conditions are leading causes of pulmonary emboli (Hoxie et al, 2008).

Additional risk factors such as deficiencies in antithrombin III, protein C, protein S, and homozygous mutations (e.g., factor V Leiden) can increase the risk of pulmonary emboli. A 19-year-old male athlete with a protein C deficiency developed proximal deep vein thrombosis and pulmonary emboli while abusing anabolic-androgenic steroids. Anabolic-androgenic steroids have been reported to have anticoagulatory and profibrinolytic effects in athletes that are diagnosed with a protein deficiency causing cardiovascular illnesses. Two years prior to a diagnosis of a pulmonary embolism, the athlete presented with swelling in the left leg. Genetic testing was performed, resulting in a diagnosis of a protein C deficiency. The athlete was treated with low-molecular-weight Heparin twice daily. Two years later, the athlete presented with shortness of breath on exertion, chest pain, fever, and haemoptysis. A computed tomography of the thorax showed bilateral pulmonary emboli of the lower lobe artery. The athlete was treated with low-molecular-weight Heparin and Coumadin. The abuse of the anabolic steroids and the protein C deficiency accelerated the haemostatic system, resulting with the athlete having a bilateral pulmonary emboli (Alhadad, Acosta, Sarabi, & Kolbel, 2010).

Oral contraceptive pills, pregnancy, and postmenopausal hormone replacement therapy can increase the risk of pulmonary emboli in women. An oral contraceptive pill is taken by mouth once daily, to prevent women from becoming pregnant. There have been many different types of contraceptive pills created to help prevent women from becoming pregnant. Oral contraception pills contain a combination of estrogen and progestogen hormones. First and second generation contraception pills were removed from the market due to the large dose of estrogen, which predisposed women to massive pulmonary emboli. Third generation contraceptive pills contain lower progestogen, which can also help improve acne and hair growth (Goldhaber, 2004). In a case presented by Westgate and FitzGerald (2005), a 25 year-old female athlete presented with bilateral pulmonary emboli while taking oral contraceptive pills. The patient is a non-smoker, with no past family history of blood clots. One month prior to diagnosis, the athlete presented with a herniated nucleus pulposus at C5-C6 vertebrae of her spine. The athlete was prescribed Valdecoxib for her neck pain. Towards the end of the treatment period, the athlete presented with left pleuritic chest and shoulder pain after a six-hour car ride. She was prescribed a muscle relaxant and continued taking her Valdecoxib for pain. Eighteen days later, the athlete developed right pleuritic chest and shoulder pain. The athlete was then diagnosed with iliac vein thrombosis and bilateral pulmonary emboli. The athlete discontinued her oral contraceptive pill and was prescribed Coumadin for six months (Westgate & FitzGerald, 2005). Risk factors related to oral contraceptive pills pertained to this athlete's case. 

Summary

In general, the history, predispositions, and etiology information of pulmonary emboli have been presented including epidemiology studies. Of particular interest was research of pulmonary emboli in the athletic population. As the literature indicates pulmonary emboli have been associated with athletes, even though they are deemed physically healthy prior to participation. Due to the severity of obstructed blood vessels in the lungs, many complications such as difficulty breathing, heart failure, or death may occur. This study discussed the historical perspective, epidemiological studies, and etiological information on pulmonary emboli.

Pulmonary emboli are a leading cause of unexpected death in the United States (Kahanov & Daly, 2009). The obtained data confirmed that surgery, oral contraception pills, protein deficiencies, and genetic mutations are leading causes of pulmonary emboli in the general and athletic population. A pulmonary embolism is a known complication following many types of surgical procedures. Several cases have been reported with complications following shoulder surgeries. Women taking oral contraception pills are at higher risk of a blood clot due to the increased levels of clotting factors and increased platelet aggregation. Protein C, protein S, antithrombin, and factor V Leiden are all genetic factors that may predispose an individual to pulmonary emboli. An individual that has a genetic clotting disorder is ten times more likely to develop a pulmonary embolism than one would without a genetic clotting disorder. If individuals have two or more of these leading causes, they will increase their chance of developing pulmonary emboli (Perez-Pujol, Aras, & Escolar, 2012)

This study supported other authors' research that surgery, oral contraceptive pills, protein deficiencies, and genetic mutations are significant contributors to the development of pulmonary emboli. There is a need for further research to gain knowledge and understanding as to why these causes predispose athletes to developing pulmonary emboli. Studies need to be conducted to determine whether athletes are at a higher or lower risk for developing blood clots than non-athletes. Also, studies are needed to investigate the influence of physical training and performance on blood clot formation. This study highlighted the historical perspective, epidemiological studies, etiological information, diagnosis, treatment, and prevention of pulmonary emboli.

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