DVT Research Paper

While the overwhelming majority of physical therapy education is centered on Musculoskeletal and Neuromuscular practice patterns, it is extremely important for physical therapists to have a breadth of knowledge in other aspects of health as well. In an era of Direct Access, it is the duty of the physical therapist to recognize signs and symptoms of cardiopulmonary diseases and disorders, and understand how they affect the aging population in the United States1. One example of a potentially dangerous condition that physical therapists need to be aware of and understand is a Deep Vein Thrombosis (DVT). With an increased understanding of the clinical manifestations and practice patterns of DVT, Physical Therapists will be better equipped to react
to the signs and symptoms as well as prevent subsequent DVT, creating a safer environment for the patient. Thrombosis is a condition in which there is an accumulation of platelets, blood components, and fibrin (considered a “thrombus” as a whole) inside the walls of a blood vessel2. When a thrombus is formed within one of the deep veins in the body, the condition is then considered a Deep Vein Thrombosis. This deeper or more distal form most often occurs in the veins of the lower extremities3. In many cases the cause of a DVT is unknown, which is accentuated by the reality that many patients living with a DVT are not aware that they have the condition and show no symptoms whatsoever4. In other cases, a DVT is thought to develop in the presence, or as the result of, other underlying conditions and circumstances, such as a major trauma or surgery, prolonged bed rest or an autoimmune disease5. Other factors that may put a patient at a heightened risk for a DVT include increased age, limb paresis, history of past DVT and obesity. While the presence of a DVT itself may not be life threatening, an embolus may become dislodged from the thrombus and travel to the lungs – known as a pulmonary embolism (PE) – where effects may become fatal4. Due to both the uncertainty in diagnostic testing, and the commonality that a person may be asymptomatic with a DVT, the number of people affected by a Deep Vein Thrombosis each year is undetermined4.
Although the precise value of people affected each year is unknown, estimates have been made over time based on clinical data. The Centers for Disease Control and Prevention states that as many as 1-2 of every 1,000 persons (or 0.1-0.2%) in the United States could be affected by a DVT or PE each year6. In a 25-year longitudinal study of a cohort of patients from Olmsted County, Minnesota, Silverstein et al. found the incidence of Venous Thromboembolism – which is a combination of the incidence of DVT and PE – to be 0.12%, while the incidence of DVT alone was 0.05%7. Although population studies generally report similar incidences of DVT, it has also been shown that samples from hospital settings as well as those with acute injuries have higher incidence of DVT – this may be due to a higher prevalence of DVT risk factors in subjects in acute care facilities and those who have recently undergone surgery8,9. Although many patients with a DVT are asymptomatic, there are a number of signs and symptoms that may be seen in a symptomatic patient with a DVT. Pain with or without palpation (especially in the calf), swelling, and discoloration in the affected extremity are some of the most common signs that a physical therapist may note during examination and
treatment10.
There are a number of different techniques that are commonly used in practice today that assist with the diagnosis of DVT. The quickest but less objective approach is a clinical model that stratifies patients into different categories of likelihood based on the combination of personal factors and the presence or absence of the aforementioned DVT risk factors and symptoms11. Alternatively, one of the most widely accepted diagnostic tests used with suspected DVT is the D-Dimer Test, which measures the process of fibrinolysis associated with blood clots. The D-Dimer Test has great negative predictive value, but has low specificity – a patient with a negative test can be relatively sure that they do not have a DVT, while a patient with a positive test should receive further testing to determine if they truly have a DVT. Another diagnostic test that is commonly used for those with an expected DVT is venous ultrasonography. A positive venous ultrasonography test is indicated by an inability to bring the walls of the vein together using light pressure from a probe. Magnetic resonance imaging is yet another method that can be used diagnostically, as it shows high sensitivity for revealing clots in certain veins in the body11,12. Experiencing a DVT puts a patient at a 20-50% risk for developing postthrombotic syndrome, which can result in swelling, pain, and hardening of the skin. If a more distal DVT moves proximally in the veins, the patient is at risk for a pulmonary embolism, which is fatal in 10% of cases4,13. Following diagnosis or determination of an increased likelihood of DVT, patients are given pharmacological intervention in order to treat symptoms and prevent further clot formation. The most common medications that a patient may take following diagnosis are unfractionated heparin (UFH), low-molecular-weight heparins (LMWH) and warfarin. All three medications are anti-thrombotic agents that work to decrease clot formation14.
Physical therapists generally see each patient multiple times throughout each week, and therefore must play a critical role in the detection of the signs and symptoms of disorders such as DVT. The therapist must be prepared to refer the patient to a physician for further assessment upon noticing such signs. In addition to the role in patient screening and assessment, physical therapists are a pivotal part of the team of health professionals that work together with patients to reduce symptoms and prevent future DVT. In the management of DVT, the physical therapist should work on increasing range of motion, breathing exercises, and getting the patient up and walking as soon as allowed by the physician. The patient should also receive educational information from the Physical Therapist which will allow the patient to better advocate for his or her own health throughout each day. Patient education should include informing the patient about the need to change positions often and the importance of wearing compression stockings in order to facilitate consistent movement of blood through the veins4. The patient should be made aware of what physical symptoms could be signs of a subsequent DVT, and who should be contacted if those symptoms were to occur. Ultimately, a physical therapist with a great understanding of DVT and its treatment patterns will have an increased chance of not only keeping patients safe, but will also help patients return to participation in all aspects of life following the experience of a DVT.