Learn about Blood Clotting
Blood clotting is a normal process that prevents bleeding when a blood vessel is injured.
- Clots can form within both, arteries and veins.
- There are situations when blood clotting is seen as abnormal condition.
- Clots forming in the arteries can cause strokes and heart attacks, clots that form in the veins are often referred to as deep venous thrombosis (DVT).
What is Blood Clotting and How Does it Affect Your Body?
Formation of deep venous thrombosis can lead to a complication of pulmonary embolism (PE) which is a clot that dislodged from its origination and travels to organs such heart and lung. The spectrum of disease which includes both DVT and PE is inclusively known as Venous Thromboembolism (VTE). The presentation of deep venous thrombosis and its complication pulmonary embolism is often variable, and may range from very subtle symptoms such as mild shortness of breath to very severe chest pain, and sudden death.
How Serious is it?
Prompt recognition of and diagnosis of DVT and PE can be of life – saving importance and prevention of other complications associated with this potentially fatal condition.
Symptoms, Causes and Risk Factors
There are numerous risk factors for blood clot formation and some of the most common are: immobility related to surgery, hospitalization or stroke.
The symptoms of deep venous thrombosis are localized to the lower extremities with swelling and pain of the leg, unusual redness and “Charlie horse” like throbbing described by some patients. A blood clot that traveled, pulmonary embolus, may cause sensation of breathlessness, chest pain and dizziness, accompanied by feeling of anxiety and rapid heartbeat.
Because symptoms of pulmonary embolism may be confused for heart attack, pneumonia and other conditions that present with cough, chest pain, and rapid heartbeat a wide clinical diagnostic panel may be utilized to evaluate your complaints.
Causes and Risk Factors
Bone fractures, major surgery, and catheterization may increase chance of blood clot formation. Birth control and pregnancy are known to increase risk because of estrogen hormone rising. Other significant contributors are obesity, cancer, chemotherapy and personal history of previous episode of a blood clot.
When to See Your Doctor
You should see your doctor if you have unexplained onset of shortness of breath, swelling of one of your extremities, more commonly a lower extremity. Additionally, development of chest pain and sensation of racing heart should prompt a discussion and possibly a visit with your healthcare provider. Persons with prior history of blood clots and/or strong family history of DVT, the patient should consult their clinician for counseling and testing.
Diagnosing and Treating
During the course of a work up your healthcare professional may utilize questionnaire and history, blood tests and imaging studies to provide most likely diagnosis to fit with your presentation and complaints.
What to Expect
Medical professionals may want to check a blood test called D – Dimer that is commonly found in elevated quantity in PE with deep venous thrombosis condition and has a very good predictive value if it is in normal range. If the blood test is within normal range the chances of having a blood clot are slim to none.
How is it Diagnosed?
In addition to utilizing history, physical examination and blood testing healthcare providers rely on medical imaging which consists of computerized tomography also known as CAT scan and non–invasive sonography referred to as Duplex/Doppler Ultrasound. The CAT scan examination of the chest utilizes a contrast agent that provides additional aid in the visual search for pulmonary embolism and delivers a small dose of radiation to the patient. It remains one of the most important tools in the work up and diagnosis of pulmonary embolisms condition. Non–invasive Doppler ultrasound is an excellent test, without side – effects and trauma, but is limited by its ability to diagnose only deep venous thrombosis, therefore it is not able to exclude pulmonary embolism. Your healthcare professional will explain each test and indication prior to undergoing the procedure.
Additionally, for persons with allergy to contrast agents and iodine containing products a ventilation– perfusion scans are available for investigation of pulmonary embolism. A ventilation-perfusion scan is commonly called V/Q scan and utilizes radioisotope with delivery of medically approved radiation dose.
How is it Treated?
The treatment for DVT/PE most commonly involves administration of blood thinners, either in injectable or oral, pill form. The variety of available agents and preparations ranges from convenient once a day dosing for novel oral anticoagulants, to traditional medication known as warfarin. In the hospital setting traditional initiation is in the form of injectable anticoagulant, enoxaparin or heparin which will be transitioned into pill regimen prior to discharge. With advent of novel oral anticoagulants many patients are found to be good candidates for convenient regimen of blood thinner in a form of a tablet which does not require routine monitoring of levels. Your healthcare professional will work with you to find the best possible therapeutic regimen for your condition.
Living with Blood Clots
While PE can be life-threatening, commonly patients will survive the initial event and need to learn how to live with the disease, whether it is a DVT or PE. Anticoagulation remains the mainstay of that therapy, and will continue as short as three months or as long as for a patient’s lifetime. The duration of the anticoagulation depends on the underlying cause of the VTE. Appropriate caution must be taken during this time, given the bleeding risk on anticoagulation. Appropriate follow up should occur with the patient’s physician. During this time, depending on your method of anticoagulation, regular blood tests may be required.
What to Expect
Post-thrombotic syndrome (PTS) can occur in some patients after DVT. Often, the more severe and extensive the DVT is, then the greater likelihood of developing PTS. However, some patients can have complete resolution even after massive DVT. Symptoms of PTS can include swelling, pain, aching, heaviness, and cramping. To prevent this, physicians may often prescribe compression stockings to help decrease swelling and prevent PTS. If your physician does prescribe it for you, then be sure to follow his/her instructions, even if the stockings not the most attractive piece of clothing that you own. Your physician may also advise you to keep your feet elevated whenever possible.
Pulmonary hypertension is a rare complication that can occur in some patients after a PE. The majority of patients with PE have gradual resolution of those embolisms. However, sometimes the PE process leads to an increase in the blood pressure in the pulmonary artery, which is non-invasively measured with an echocardiogram. Your physician may order this test to evaluate your pulmonary artery pressure, especially if you have worsening shortness of breath despite treatment with anticoagulants.
Managing the Disease
Your physician may complete a “hypercoagulability” workup on you at some point after your diagnosis. This could include a number of blood tests looking for a genetic cause to your VTE. However, this often depends on the cause of your blood clot, especially if there is not a clear predisposing event (such as surgery, prolonged travel, etc.). However, there is no high level data at the current time to assess the risk of recurrent VTE.
In the rare circumstances in which blood thinners cannot be utilized, sometimes your physician may suggest an inferior vena cava (IVC) filter. This is placed in the body utilizing minimally invasive techniques, and has its own pros and cons. If your physician suggests this as an appropriate device for you, be sure to have an in-depth discussion to fully understand the risks and benefits.
After a VTE, especially if there is no identifiable risk factor, your physician may put you through a number of tests to search for a hidden cancer. Data indicate that up to 10% of patients will be diagnosed with a cancer within 1 year of VTE diagnosis. However, there is no high level data at the current time to support a mortality benefit from screening all patients with a DVT or PE.
Questions to Ask Your Doctor About
What online resources are available?
There are many resources available to patients for more information. Some include the National Blood Clot Alliance (www.stoptheclot.org), and The US National Library of Medicine
(https://www.nlm.nih.gov/medlineplus/deepveinthrombosis.html), the Mayo Clinic website (http://www.mayoclinic.org/diseases-conditions/deep-vein-thrombosis/basics/definition/con-20031922), and many others. A simple Google search reveals many options for more information.
What Happens During Pregnancy?
VTE during pregnancy can be its own textbook. Pregnant females are at an increased risk of DVT/PE for up to many weeks after delivery. If you have an underlying risk factor that makes you even more at risk during pregnancy (such as previous DVT, thrombophilia, etc.), often your physician will have you see a specialist with expertise on this topic. Professional societies such as the American College of Chest Physicians and the American College of Obstetrics and Gynecology have specific recommendations around the prevention and treatment of VTE in pregnant females.
What Can Be Done to Reduce the Risk of Developing a DVT During Prolonged Travel?
There is data to suggest that each additional 2-hour increase in travel leads to an ~20% higher risk of developing a DVT. Some patients may benefit from the compression stockings during travel. In addition, frequent ambulation, maintaining hydration, and even sitting in an aisle seat are techniques which may help reduce the chance of developing a DVT during prolonged travel.
When are Clot-busting Medications (Thrombolytics) Used?
Thrombolytics are used occasionally in the hospital, but are traditionally reserved only for the sickest patients. At the time of their administration, the physician will have a discussion to delineate the risks and benefits of their usage.
What do Hospitals Have in Place to Prevent VTE in Their Patients?
All hospitals have protocols to assure that appropriate patients receive DVT prophylaxis to prevent clot formation while patients are hospitalized. In addition, national statistics on the rate of hospital acquired VTE of Medicare-certified hospitals can be seen on websites such as Hospital Compare (https://www.cms.gov/medicare/quality-initiatives-patient-assessment-instruments/hospitalqualityinits/hospitalcompare.html)
Jason M. Golbin, DO, MS, FCCP
Aleksander Shalshin, MD, MS, FCCP
Date Last Reviewed