Deep Vein Thrombosis: Prevention And Prognosis · PDF fileDeep Vein Thrombosis: Prevention And Prognosis ... Deep vein thrombosis is a blood clot ... may also observe swelling or a

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Deep Vein Thrombosis:

Prevention And

Prognosis

Jassin M. Jouria, MD

Dr. Jassin M. Jouria is a medical doctor,

professor of academic medicine, and

medical author. He graduated from Ross

University School of Medicine and has

completed his clinical clerkship training in

various teaching hospitals throughout New

York, including King’s County Hospital

Center and Brookdale Medical Center,

among others. Dr. Jouria has passed all

USMLE medical board exams, and has served as a test prep tutor and instructor for

Kaplan. He has developed several medical courses and curricula for a variety of

educational institutions. Dr. Jouria has also served on multiple levels in the academic

field including faculty member and Department Chair. Dr. Jouria continues to serves

as a Subject Matter Expert for several continuing education organizations covering

multiple basic medical sciences. He has also developed several continuing medical

education courses covering various topics in clinical medicine. Recently, Dr. Jouria

has been contracted by the University of Miami/Jackson Memorial Hospital’s

Department of Surgery to develop an e-module training series for trauma patient

management. Dr. Jouria is currently authoring an academic textbook on Human

Anatomy & Physiology.

Abstract

Although there are a number of risk factors associated with deep vein

thrombosis (DVT), it can strike anyone regardless of age, physical

fitness, or other factors. However, DVT has an excellent prognosis

when caught early and treated aggressively. Additionally, there are a

number of strategies for reducing DVT risk. Nurses should familiarize

themselves with these strategies in order to be prepared to advise

their patients on lifestyle adjustments and other actions that can lower

this risk. This course also aims to increase the awareness and clinical

acumen of nurses in their evaluation of deep vein thrombosis.


Continuing Nursing Education Course Planners

William A. Cook, PhD, Director, Douglas Lawrence, MA, Webmaster,

Susan DePasquale, MSN, FPMHNP-BC, Lead Nurse Planner

Policy Statement

This activity has been planned and implemented in accordance with

the policies of NurseCe4Less.com and the continuing nursing education

requirements of the American Nurses Credentialing Center's

Commission on Accreditation for registered nurses. It is the policy of

NurseCe4Less.com to ensure objectivity, transparency, and best

practice in clinical education for all continuing nursing education (CNE)

activities.

Continuing Education Credit Designation

This educational activity is credited for 1.5 hours. Nurses may only

claim credit commensurate with the credit awarded for completion of

this course activity.

Statement of Learning Need

Patients with DVT may or may not exhibit symptoms. Its important

health professionals help patients understand DVT prevention, risks

and symptoms to avoid future complications.

Course Purpose

To provide nursing professionals with knowledge of DVT prevention,

recognition and treatment options.


Target Audience

Advanced Practice Registered Nurses and Registered Nurses

(Interdisciplinary Health Team Members, including Vocational Nurses

and Medical Assistants may obtain a Certificate of Completion)

Course Author & Planning Team Conflict of Interest Disclosures

Jassin M. Jouria, MD, William S. Cook, PhD, Douglas Lawrence, MA,

Susan DePasquale, MSN, FPMHNP-BC – all have no disclosures

Acknowledgement of Commercial Support

There is no commercial support for this course.

Activity Review Information

Reviewed by Susan DePasquale, MSN, FPMHNP-BC

Release Date: 1/1/2016 Termination Date: 4/1/2018

Please take time to complete a self-assessment of knowledge,

on page 4, sample questions before reading the article.

Opportunity to complete a self-assessment of knowledge

learned will be provided at the end of the course.


1. A pulmonary embolism occurs when a clot becomes

dislodged and travels to the ________. a. Respiratory system

b. Lung

c. Digestive system

d. Immune system

2. Compression stockings that will be used to treat DVT

should be a grade ___________. a. 1

b. 2

c. 3

d. 4

3. This is the procedure that injects medication directly into the blood clot via catheter to dissolve the clot.

a. Angioplasty

b. Thrombolytic Therapy

c. Bypass

d. Laparoscopy

4. Which of the following is NOT a risk factor for DVT?

a. Smoking

b. Strength Training

c. Pregnancy

d. Age

5. Which of the following is a long-term complication of DVT

that causes damage to the vein? a. Pulmonary Embolism

b. Heart Attack

c. Post-Thrombotic Syndrome

d. Blockage


Introduction

Deep vein thrombosis is a blood clot that forms deep in the vein. Most

deep vein thrombosis occurs in the lower extremities, but it can also

occur in other areas of the body. Deep vein thrombosis is typically the

result of lack of movement or vein injury, and is especially common in

patients who have recently had surgery.1

Deep vein thrombosis can cause long term damage if not treated

properly, but has an excellent prognosis when caught early and

treated aggressively.2 While the clot itself is not a concern, the

potential complications that it can cause are of concern. Some patients

will experience a pulmonary embolism if the clot breaks free and

travels to the blood vessels of the lung. When this occurs, the risk of

morbidity is high. In some instances, patients will develop post-

thrombotic syndrome, which impacts the patient’s mobility and level of

basic functioning.

Increasing Patient Awareness Of DVT


thrombosis, it can strike anyone regardless of age, physical fitness, or

other factors. However, DVT has an excellent prognosis when caught

early and treated aggressively. Additionally, there are a number of

strategies for reducing DVT risk. It is important for health care

providers to familiarize themselves with these strategies in order to be

prepared to advise their patients on lifestyle adjustments and other

actions that can lower this risk. The following fact sheet, produced by

the Vascular Disease Organization, provides a thorough overview of

deep vein thrombosis and the potential complications.3 This fact sheet


can be distributed to healthcare professionals or patients to increase

awareness of deep vein thrombosis.

Deep Vein Thrombosis Fact Sheet

Overview

Deep vein thrombosis, commonly referred to as “DVT,” occurs when a blood clot or

thrombus, develops in the large veins of the legs or pelvic area. Some DVTs may

cause no pain, whereas others can be quite painful. With prompt diagnosis and

treatment, the majority of DVTs are not life threatening. However, a blood clot

that forms in the invisible “deep veins” can be life threatening. A clot that forms in

the large, deep veins is more likely to break free and travel through the vein. It is

then called an embolus. When an embolus travels from the legs or pelvic areas and

lodges in a lung artery, the condition is known as a “pulmonary embolism,” or PE,

a potentially fatal condition if not immediately diagnosed and treated.

Symptoms

Approximately one-half of those with a DVT never have recognizable symptoms.

The most common symptom is leg pain and tenderness in the calf muscles. One

may also observe swelling or a change in color of one leg to purple or blue. These

signs and symptoms may appear suddenly or may steadily develop over a short

period of time. Symptoms are quite different if the clot breaks loose and travel to

the lungs, causing a pulmonary embolism (PE). The symptoms of PE include chest

pain, shortness of breath, rapid pulse, or a cough. There may also be a feeling of

apprehension, sweating, or fainting. Such symptoms are not specific to a PE, and

can occur with pneumonia, heart attack, and other medical conditions.

Underlying Causes Of DVT

Deep vein thrombosis is typically caused by lack of movement or a

vein injury. In both instances, DVT will develop if an individual does

not take appropriate preventative measures.4


Lack of Movement

Lack of movement is the most common cause of DVT, yet it is easily

preventable. In most instances, the cause is immobility after surgery

or during extended periods of travel.5 However, any situation that

involves immobility is a potential risk for the development of DVT.

Lack of movement causes blood flow to become sluggish, which can

result in the development of blood clots.6

Surgery

Patients are at risk of developing DVT after any type of

surgery, but it is most common in instances of lower

extremity surgery.7 The following chart shows the three

factors most associated with the development of DVT after

surgery:8

Factor Description

Stasis, or

stagnant

blood flow

through veins

This increases the contact time between blood and vein wall

irregularities. It also prevents naturally occurring

anticoagulants from mixing in the blood. Prolonged bed rest or

immobility promotes stasis.

Coagulation Coagulation is encouraged by the presence of tissue debris,

collagen or fats in the veins. Orthopedic surgery often releases

these materials into the blood system. During hip replacement

surgery, reaming and preparing the bone to receive the

prosthesis can also release chemical substances (antigens)

that stimulate clot formation into the blood stream.

Damage to the

vein walls

This can occur during surgery as the physician retracts soft

tissues as part of the procedure. This can also break

intercellular bridges and release substances that promote

blood clotting.


The above chart provides the three main factors that

contribute to the development of DVT in individuals who have

had surgery. However, there are other factors that may

increase the risk for surgery patients. These factors include

the following:9

o Age

o Previous history of DVT or pulmonary emboli

o Metastatic malignancy

o Vein disease (such as varicose veins)

o Smoking

o Estrogen usage or current pregnancy

o Obesity

o Genetic factors

Long Trips

There is a lower risk of developing DVT during travel, but it is

still a concern. Recent studies have produced conflicting results.

In some instances, studies have shown an increase in the risk of

developing DVT during extended periods of travel, while other

studies have shown no increased risk.2

In most instances of travel related DVT, the individual has other

risk factors that make them more susceptible to DVT, which

include:10

o Age

o Previous history of DVT or pulmonary emboli

o Metastatic malignancy

o Vein disease (such as varicose veins)

o Smoking


o Estrogen usage or current pregnancy

o Obesity

o Genetic factors

In many travel related DVT cases, the individual may have

asymptomatic, or mild, DVT. This type of DVT tends to resolve

on its own after the patient begins moving again.2

Vein Injury

A patient’s chance of developing DVT increases when the patient’s vein

is already damaged from another cause. Damage to the inside of the

vein increases the risk of blood clot formation.11 In some instances,

damage is caused by a previous DVT. Therefore, a patient who has a

history of DVT is at an increased risk of developing another DVT due to

the permanent damage caused to the vein.12

Vein damage may also occur as the result of increased inflammation

from other health conditions or prescription drugs.13 Another cause of

vein damage is needle injection, which can occur in a healthcare

setting or during injection drug use.3

Diagnosis

Deep vein thrombosis can be difficult to diagnose as it is not easily

identifiable upon an initial exam.14 When a patient is at risk of

developing DVT, or when a patient presents symptoms of DVT,

diagnostic imaging techniques will be used to identify any damage.15


The following table provides information regarding the diagnostic

imaging techniques used in the identification of DVT.1

Imaging

Technique

Attributes

Compression

Ultrasonography

Sensitivity and specificity exceed 95% and 98%

respectively for symptomatic proximal DVT

Sensitivity of 11–100% and specificity of 90–100% for

symptomatic distal DVT

Noninvasive: can be performed relatively rapidly and a

portable technique allowing for the bedside ssessment

of critically ill patients

Does not visualize the pelvic veins well and cannot be

used in obese patients or in patients whose limbs are in

plaster casts

Computerized

Tomography

Sensitivity and specificity of 96% and 95% respectively

in a meta-analysis of studies predominantly examining

its use for the diagnosis of proximal DVT

Can visualize the pelvic veins, define the upper limit of

thrombus extension into the iliac veins and inferior vena

cava

Requires the injection of contrast medium, exposes the

patient to radiation, may be difficult to interpret when

artifact and insufficient venous filling is present, and is

more expensive than ultrasonography

Limited by availability and technical expertise

Magnetic

Resonance

Imaging

Sensitivity and specificity for the diagnosis of

symptomatic DVT is 96% and 93% respectively

Sensitivity for distal DVT is much lower (about 62%)

Can be performed without the use of contrast medium

Can visualize the pelvic veins, define the upper limit of

thrombus extension into the iliac veins and inferior vena

cava

Limited by availability and technical expertise


Venography

(phlebography)

Reliably detects isolated distal DVT and thrombosis in

the iliac veins and inferior vena cava

Cumbersome to perform, requires the injection of

contrast medium, exposes the patient to radiation, may

be difficult to interpret when insufficient venous filling is

present

Primary Risk Factors For Developing DVT

As noted above, the primary risk factors for developing DVT include

lack of movement and vein injury. However, an individual will have an

increased risk of developing DVT if he or she has any of the following

factors:9

Age

Smoking

Pregnancy

Birth Control Pills

Obesity

High Blood Pressure

While the above factors increase a patient’s risk of developing DVT,

not all risk factors are equally problematic. Some risk factors will have

a stronger impact on the likelihood of developing DVT than others.

The following table breaks the risk factors into three categories: strong

clinical risk factors, moderate clinical risk factors, and weak clinical risk

factors.1


Strong clinical risk factors (odds ratio >10)

Fracture of the hip or lower limb

Hip or knee replacement surgery

Major general surgery

Major trauma

Spinal cord injury

Moderate clinical risk factors (odds ratio 2–9)

Arthroscopic knee surgery Hormonal therapy (i.e., oral contraceptives,

hormone replacement therapy)

Pregnancy – postpartum

Paralytic stroke

Previous venous thromboembolism

Weak clinical risk factors (odds ratio <2)

Immobilization (i.e., bed rest >3 days, air travel >8 hours)

Pregnancy – antepartum

Obesity

Advancing age

Complications Of DVT

Deep vein thrombosis is not a significant concern on its own.

However, it can cause some complications that can be life threatening

to the patient. Therefore, any potential complications must be

identified and treated early.

Pulmonary Embolism

A pulmonary embolism is caused by a blood clot that travels from a

region in the body to the lungs. The blood clot blocks one of the blood

vessels in the lung, causing potential problems.16 A pulmonary

embolism is extremely dangerous and can be life threatening if not

identified and treated immediately.17 Therefore, a treating provider


should be aware of the following signs and symptoms of a pulmonary

embolism:18

Unexplained sudden onset of shortness of breath

Chest pain or discomfort that worsens with a deep breath or

cough

Feeling lightheaded or dizzy, or fainting

Rapid pulse

Sweating

Coughing up blood

A sense of anxiety or nervousness

Deep vein thrombosis is the most common cause of a pulmonary

embolism. Once a clot has formed, usually in the leg, it may

immediately break off and travel to the lungs, or it may not happen for

a number of days after the formation of the clot.19 It is important to

identify the problem as soon as possible as early treatment can reduce

the likelihood that the embolism will be life threatening.20 The

following diagnostic procedures are often used to identify a pulmonary

embolism:16

Chest X-ray:

A type of diagnostic radiology procedure used to assess the lungs, as well as the

heart. Chest X-rays may provide important information regarding the size, shape,

contour, and anatomic location of the heart, lungs, bronchi, great vessels (aorta

and pulmonary arteries), and mediastinum (area in the middle of the chest

separating the lungs).

Ventilation-perfusion scan (V/Q scan):

A type of nuclear radiology procedure in which a tiny amount of a radioactive

substance is used during the procedure to assist in the examination of the lungs. A

ventilation scan evaluates ventilation, or the movement of air into and out of the

bronchi and bronchioles. A perfusion scan evaluates blood flow within the lungs.


Pulmonary angiogram:

An x-ray image of the blood vessels used to evaluate various conditions, such as

aneurysm, stenosis (narrowing of the blood vessel), or blockages. A dye (contrast)

will be injected through a thin flexible tube placed in an artery. This dye makes the

blood vessels visible on X-ray.

Spiral computed tomography (also called CT or CAT scan):

A diagnostic procedure that uses a combination of x-rays and computer technology

to produce cross-sectional images (often called slices). CT with contrast enhances

the image of the blood vessels in the lungs. Contrast refers to a substance injected

into an intravenous (IV) line that causes the particular organ or tissue under study

to be seen more clearly.

Magnetic resonance imaging (MRI):

A diagnostic procedure that uses a combination of large magnets,

radiofrequencies, and a computer to produce detailed images of organs and

structures within the body.

Duplex ultrasound (US):

A type of vascular ultrasound procedure done to assess blood flow and the

structure of the blood vessels in the legs. Blood clots from the legs often dislodge

into the lung. Since the treatment of DVT or deep venous thrombosis and PE are

the same, US is a portable, less risky and cheaper alternative that gives your

doctor the same information.

Laboratory tests: Blood tests to check the blood's clotting status. Other blood

work may include testing for genetic (inherited) disorders that may contribute to

abnormal clotting of the blood. In addition, arterial blood gases may be checked to

determine the amount of oxygen in the blood.

Electrocardiogram (ECG or EKG): One of the simplest and fastest procedures

used to evaluate the heart. Electrodes (small, plastic patches) are placed at certain

locations on the chest, arms, and legs. When the electrodes are connected to an

ECG machine by lead wires, the electrical activity of the heart is measured,

interpreted, and printed out for the physician's information and further

interpretation.


Early detection and treatment is imperative in instances of deep vein

thrombosis and pulmonary embolism. Therefore, the Surgeon General

released the following fact sheet to be distributed to individuals to

increase awareness about the relationship between the two

conditions.21 The following fact sheet should be provided to all patients

who are at risk of developing either condition.

Fact Sheet: Deep Vein Thrombosis and Pulmonary Embolism

Who is at risk for Deep Vein Thrombosis and Pulmonary Embolism?

Almost anyone can have deep vein thrombosis or pulmonary embolism. In most

cases, deep vein thrombosis or pulmonary embolism develops in a person who

has an inherited blood clotting disorder or other risk factor, and who experiences

a triggering event. The risk increases even more for someone who has more than

one risk factor at the same time.

Factors that increase risk are:

Certain inherited blood disorders or factors that make your blood thicker or

more likely to clot as well as a family history or previous deep vein

thrombosis or pulmonary embolism

Overweight and obesity

Cancer and its treatment

Pregnancy and childbirth

In women, use of hormones for birth control or menopause

Smoking

Age: those aged 50 or older are more likely to develop deep vein

thrombosis

Ethnicity: African Americans and Whites are more likely than other groups

to develop deep vein thrombosis

How can Deep Vein Thrombosis and Pulmonary Embolism be prevented?

If you're at risk, you can help prevent blood clots from forming by:

Seeing your doctor for regular checkups

Taking all medicines your doctor prescribes


Getting out of bed and moving around as soon as possible after surgery or

illness

Exercising your lower leg muscles during long trips

Exercising regularly, maintaining a healthy weight, and not smoking

If you have had deep vein thrombosis or pulmonary embolism before, you

can help prevent future blood clots by following the above steps and:

o Taking all medicines, such as blood thinners, that your doctor

prescribes to prevent or treat blood clots

o Using graduated compression stockings (sometimes called support

hose or medical compression stockings) as your doctor directs to

help prevent blood from pooling and clotting in the lower leg

o Following up with your doctor for tests and treatment

o In some cases, blood-thinning medications and compression

stockings might also be used in individuals considered at high risk

but without a history of deep vein thrombosis

Contact your doctor at once if you have any signs or symptoms:

Swelling in one leg or along a vein in the leg

Pain or tenderness in one leg (might be felt only when standing or walking)

Warmth in one leg in the swollen or painful areas

Red or discolored skin in one leg

Unexplained shortness of breath or difficulty breathing

Coughing up blood

Tips for travelers:

Your risk of developing deep vein thrombosis while traveling is small. The risk

increases if the travel time is longer than 4 hours, or if you have other risk factors

for deep vein thrombosis.

During long trips, it may help to:

Frequently walk up and down the aisles of the bus, train, or airplane. If

traveling by car, stop about every hour and walk around

Move your legs and flex and stretch your feet often while you’re sitting by:

Raising and lowering your heels while keeping your toes on the floor

Raising and lowering your toes while keeping your heels on the floor


Tightening and releasing your leg muscles

Wear loose and comfortable clothing

Drink plenty of fluids, especially water, and avoid alcohol and caffeine

If you're at high risk for deep vein thrombosis, your doctor may also

recommend wearing compression stockings during travel or taking a

blood-thinning medicine before traveling.

Post-Thrombotic Syndrome

Post-thrombotic syndrome, also referred to as post phlebitic

syndrome, is a long-term complication of deep vein thrombosis. It

occurs when DVT is left untreated, thereby causing damage to the calf

tissue.22 Damage occurs as the result of increased flow and pressure of

diverted blood into other veins.23 Approximately two-thirds of

individuals with untreated DVT will develop post-thrombotic

syndrome.24 Post-thrombotic syndrome can occur as the result of DVT

in any area of the lower extremity, but it is most common in instances

where the DVT occurs in a thigh vein or when it extends into a thigh

vein from a calf vein.25 It is especially common in overweight

individuals, as well as those with multiple deep vein thromboses.26

In a normal vein, the blood flows freely. However, in a vein with a

deep vein thrombosis, the clot prevents the free circulation of the

blood. The clot causes blood to be diverted into other areas, thereby

causing complications. The symptoms of post-thrombotic syndrome,

which range from mild to severe, include:22


Calf pain

Discomfort

Swelling of the legs (edema)

Leg pain

Skin discoloration

Rashes

Ulcer on the skin of the calf (only in severe instances)

Diagnosis

Post-thrombotic symptoms can be caused by a number of other

unrelated factors, so it is important to properly identify and diagnose

post-thrombotic syndrome before administering treatment.27 Typically,

the syndrome is diagnosed using the following diagnostic techniques:

Compression ultrasound:

Compression ultrasound is a simple and easy test to determine if

there is a clot in the veins. It is generally the first type of test

that a physician will use because it works best soon after

thrombosis has occurred.

Continuous-wave doppler ultrasound:

This test is a simple and fast way to detect whether the valves in

veins are working properly and the blood is flowing normally.

Color duplex scanning:

This test uses color scans to visualize blood vessels and uses

Doppler ultrasound to detect the direction of blood flow. It is a


test that takes longer than doppler ultrasound but it can also

measure how much damage there is to the veins and exactly

where the damage is located.22

Treatment

When a patient is diagnosed with post-thrombotic syndrome, it is

important to begin treatment immediately to prevent further damage.

Treatment typically includes one or more of the following:28

wearing elastic compression stockings

exercising regularly

elevating leg(s) while resting

medication (aspirin or diuretics), rarely used

Heart Attack and Stroke

Heart attacks and strokes are not commonly associated with deep vein

thrombosis, as they occur as the result of clots in the arteries instead

of the veins.29 However, recent studies have shown that there is a

connection between the development of clots in deep veins and the

development of subsequent clots in arteries.30 When compared to

patients who have never had deep vein thrombosis or a pulmonary

embolism, those who had a history of the conditions showed an

increase in the incidence of heart attack and stroke.31 In fact, the risk

of heart attack or stroke in patients with deep vein thrombosis or

pulmonary embolism was thirty percent higher than it was in those

who had never had the condition.30


In patients with deep vein thrombosis or pulmonary embolism, heart

attacks and strokes occur most frequently in the first year following an

incident of DVT or pulmonary embolism. Patients are two times more

likely to experience a stroke and three times more likely to experience

a heart attack in the year following a DVT.4 The risk decreases after

the first year, but still remains twenty to forty percent higher than it is

for an individual with no history of DVT or pulmonary embolism.1

DVT Prevention

Once a patient develops deep vein thrombosis, he or she is at risk of

developing additional complications. In addition, both deep vein

thrombosis and pulmonary embolism can be difficult to detect, as they

are often asymptomatic. Therefore, prevention is very important.

Most practitioners will focus on prevention in instances where there is

a risk of DVT or pulmonary embolism, using both pharmaceutical and

mechanical strategies. In instances where preventative strategies are

used, a patient’s risk of developing DVT or pulmonary embolism

decreases from eighty percent to less than twenty percent.25

Prevention is a multifaceted approach and includes both mechanical

and pharmaceutical strategies. In most instances, a number of

strategies will be used together. However, in some situations, a

patient may only require one strategy. Specific strategies will depend

on the level of risk and the type of situation. Some prevention

strategies will be used for a short duration, while other strategies may

extend for a number of months. Common prevention strategies

include:


Anticoagulants

Movement

Compression stockings

In each situation, the provider will assess the patient and develop a

prevention plan that best meets the patient’s needs.

Anticoagulants

Anticoagulants are often used to prevent clot formation, especially

after surgery. However, while anticoagulants are effective at

preventing clot formation, they also increase the risk of bleeding,

which can be problematic in some patients.32 Therefore, each patient

is assessed before being administered anticoagulants. The following

table provides information regarding the three most common

anticoagulants:8

Anticoagulant Description

Aspirin

Aspirin is easy to administer, costs little, has few bleeding

complications, and does not need to be monitored.

However, it has not been proven more effective than other

agents and may not be advisable for all patients. Studies

have shown that aspirin has a greater protective effect for

men than for women.

Warfarin

(also called

Coumadin)

Warfarin is the most commonly used agent for hip and knee

replacement patients. Warfarin interferes with vitamin K

metabolism in the liver to prevent formation of certain

clotting factors. Because warfarin takes at least 36 hours to

start working, and four to five days to reach its maximum

effectiveness, it is usually started the day before surgery.


Low doses are used because higher doses can cause

episodes of bleeding, but the dose response is difficult to

predict and warfarin must be administered through an

outpatient clinic. Warfarin can cause fetal damage.

Heparin

Heparin is a naturally occurring substance that inhibits the

clotting cascade. It can come in high (standard

unfractionated heparin) or low (fractionated heparin)

molecular weights.

Recent emphasis has been on low molecular weight

heparins (LMWH) because they are more predictable and

effective, with fewer bleeding complications than standard

unfractionated heparin. LMWH is effective after both hip

and knee joint replacement surgeries, but there is a higher

incidence of bleeding when it is used after knee

replacement surgery. The most commonly used and

researched LMWH are enoxaparin, ardeparin, dalteparin,

and fraxiparine. Heparin works much faster than warfarin,

so it is often administered initially and followed by warfarin

therapy, or administered as a single agent.

Movement

Movement is a common prevention strategy for deep vein thrombosis

and pulmonary embolism. Movement is crucial to prevention as it

keeps the blood circulating throughout the body. Since DVT is often

caused by increased immobility, it is important to ensure that a patient

moves around as frequently as possible.33 This may be difficult with

patients who are immobile due to surgery or other health

complications. However, even modified movements and stretching can

decrease the risk of developing deep vein thrombosis.6 When


movement is restricted, circulation is interrupted, thereby causing

DVT.34

Compression Stockings

In many instances, a patient will be prescribed compression stockings

as a preventative measure. This is especially true if the patient has a

history of deep vein thrombosis, as compression wear will reduce the

risk of recurrent DVT.35 Most patients are advised to wear compression

stockings for two or more years, or until the risk of developing a clot

has been eliminated.36

Compression stockings are specially made to provide different levels of

pressure at different regions of the leg, which helps move fluid in the

appropriate direction. The stockings use special elastic to apply various

amounts of pressure to the leg. They are available in different grades,

depending on the amount of pressure needed. However, while the

amount of pressure differs between grades, the stockings still use the

same pressure pattern. Stockings are tightest at the ankle, and the

pressure gradually decreases as the stocking moves up the calf. This

helps to move fluid up the leg and prevent it from collecting in

different areas.

Patients will require specially fitted compression stockings that are

intended to prevent the formation of a blood clot. In some instances,

the patient will require a prescription to purchase compression

stockings from a medical supply store. However, some compression

stockings can be purchased over the counter at a pharmacy.37


There are two different types of compression stockings that are used

to treat or prevent deep vein thrombosis.37

1. To reduce the risk of deep leg vein thrombosis in people who are

at high risk. This kind of compression stocking is less expensive

than those used to help treat existing deep leg vein thrombosis.

2. To relieve symptoms associated with existing deep leg vein

thrombosis, especially swelling and pain, and prevent post-

thrombotic syndrome. This type of stocking may also help

prevent new clots from forming, although this is not its primary

function.

Treatment

Once deep vein thrombosis is identified, it is important to administer

treatment as soon as possible to prevent severe, long-term

complications from developing. The specific treatment will vary

depending on the location of the clot, the severity of the clot and any

other health conditions the patient may have. Typically, treatment will

involve a combination of different therapies specifically tailored to the

patient’s needs.

Some treatment will be administered in an outpatient capacity, while

other forms of treatment will require a short hospital stay with

constant monitoring.20 The primary goal of treatment is to prevent a

pulmonary embolism and reduce the risk of morbidity.5


Anticoagulants

In addition to helping prevent DVT, anticoagulants are also effective in

treating deep vein thrombosis. Once a clot has formed, anticoagulants

are used to break it apart and increase blood flow.38 However, since

anticoagulants can also cause excessive bleeding, they should be used

with caution.39 The previous table on anticoagulants provides

information regarding the three most common anticoagulants.8

Thrombolytic Therapy

Thrombolytic therapy dissolves blood clots using medications that are

administered via catheter directly into the area where the clot has

formed.40 However, thrombolytic therapy is not used in mild cases of

deep vein thrombosis as the medication must be administered by a

team of trained physicians, nurses and technicians.41 Instead,

thrombolysis is used to treat large clots that are causing severe

symptoms and that pose a risk to the patient. Thrombolytic therapy is

also used to treat clots that cause massive swelling or occur in the

lungs.40 Thrombolytics increase the risk of bleeding, so they should

only be used in extreme situations after a patient has been assessed.42

Thrombolytics are administered via catheter in a catheterization

laboratory using specialized equipment. In most situations, the patient

will be sedated prior to the procedure.43 Once the patient is sedated,

the catheter is inserted into the area where the clot is located, and

thrombolytics are infused directly into the clot, thereby dissolving it.40

It can take a number of hours or a number of days for the clot to

dissolve completely.41 The patient is monitored using a genogram or

duplex ultrasound.40


Compression

In many instances, compression stockings are used to treat deep vein

thrombosis. Compression stockings reduce the risk of developing post-

thrombotic syndrome, and they also help prevent the patient from

developing additional deep vein thrombosis.44 As mentioned earlier,

typically, treatment with compression stockings will continue for at

least two years to ensure that the deep vein thrombosis has been

resolved and to prevent further complications.36 Some patients may be

advised to wear compression stockings indefinitely after experiencing a

bout of deep vein thrombosis.33

While compression stockings are used for both prevention and

treatment of deep vein thrombosis, the type of stockings used for

treatment differs for each. As stated above, there are two types of

compression stockings that are used to treat or prevent deep vein

thrombosis:37

1. To reduce the risk of deep leg vein thrombosis in people who are

at high risk. This kind of compression stocking is less expensive

than those used to help treat existing deep leg vein thrombosis.

2. To relieve symptoms associated with existing deep leg vein

thrombosis, especially swelling and pain, and prevent post-

thrombotic syndrome. This type of stocking may also help

prevent new clots from forming, although this is not its primary

function.

Patients will require specially fitted compression stockings that are

intended to prevent the formation of a blood clot. Patients should not


purchase compression stockings for DVT treatment over the counter at

a pharmacy, as accurate sizing and measurement is imperative when

using them for treatment.44 In most instances, patients are advised to

wear grade three strength stockings, as these have the best level of

compression for the reduction of deep vein thrombosis.45 However,

some patients will be unable to tolerate grade three stockings due to

the amount of squeezing force they produce. In these instances,

patients will be prescribed grade two stockings, which are not as

effective as the grade three stockings.44

Prognosis

The prognosis for deep vein thrombosis depends on the severity of the

DVT and the condition of the patient. In most instances, deep vein

thrombosis will resolve quickly and without any additional

complications.10 However, many patients will experience recurring

deep vein thrombosis once they have had an initial case of it.46

Recurring deep vein thrombosis is often the result of vein damage

caused by the initial incidence, but it can also be caused by secondary

health conditions or lifestyle habits.9

Deep vein thrombosis does not pose a risk of morbidity.30 However, if

DVT causes a pulmonary embolism, patients have a high risk of short-

term morbidity.16 Overall, pulmonary embolisms account for 300,000

deaths annually.19 Long-term morbidity is typically associated with

post phlebitic syndrome, which causes a number of complications for

the patient.23


When treated, the prognosis for deep vein thrombosis is quite positive.

Most patients will experience no long-term complications and will be

able to resume normal activities and level of function quickly.47 Most

patients will recover completely, although the risk of recurrence will

always be a concern. This risk can be minimized if the patient wears

compression stockings. However, if a patient develops a pulmonary

embolism or post phlebitic syndrome, the prognosis is not as positive.

Post Phlebitic Syndrome

Post phlebitic syndrome, also referred to as post-thrombotic

syndrome, is a long-term complication of deep vein thrombosis. It

occurs when DVT is left untreated, thereby causing damage to the calf

tissue.22 Damage occurs as the result of increased flow and pressure of

diverted blood into other veins.23 Approximately two-thirds of

individuals with untreated DVT will develop post phlebitic syndrome.24

Post phlebitic syndrome can occur as the result of DVT in any area of

the lower extremity, but it is most common in instances where the

DVT occurs in a thigh vein or when it extends into a thigh vein from a

calf vein.25 It is especially common in overweight individuals, as well

as those with multiple deep vein thromboses.26

Post phlebitic syndrome typically develops within two years of an

episode of deep vein thrombosis and will range in severity. In extreme

instances, it will cause painful leg ulcers, which will require continuous

medical care.24 Patients with less severe cases will still experience lack

of function and long term mobility issues.23

The risk of developing post phlebitic syndrome increases if any of the

following factors are present:22


older age

obesity

history of previous ipsilateral DVT

iliac-femoral location of the current thrombosis

failure to recover promptly from the acute symptoms

insufficient quality of oral anticoagulant therapy

Summary

Deep vein thrombosis is a blood clot that forms deep in the vein of the

lower extremity typically as the result of lack of movement or vein

injury. DVT can strike anyone regardless of age, physical fitness, or

other factors; however, it is especially common in patients who have

recently had surgery. It can cause long-term damage if not treated

properly and has an excellent prognosis when caught early and treated

aggressively. While the clot itself is not a concern, the potential

complications that it can cause are of concern. Some patients will

experience a pulmonary embolism if the clot breaks free and travels to

the blood vessels in the lung. When this occurs, the risk of morbidity is

high. In some instances, patients will develop post-thrombotic

syndrome, which impacts the patient’s mobility and level of basic

functioning.


thrombosis, it can strike anyone regardless of age, physical fitness, or

other factors. However, DVT has an excellent prognosis when caught

early and treated aggressively. Additionally, there are a number of

strategies for reducing DVT risk. It is important for health care


providers to familiarize themselves with these strategies in order to be

prepared to advise their patients on lifestyle adjustments and other

actions that can lower this risk.

Recent studies have shown that there is a connection between the

development of clots in deep veins and the development of subsequent

clots in arteries. When compared to patients who have never had deep

vein thrombosis or a pulmonary embolism, those who had a history of

the conditions showed an increase in the incidence of heart attack and

stroke. The risk of heart attack or stroke in patients with deep vein

thrombosis or pulmonary embolism has been found to be thirty

percent higher than it was in those who had never had the condition.

There are a number of strategies for reducing DVT risk. It is important

for health care providers to familiarize themselves with these

strategies in order to be prepared to advise their patients on lifestyle

adjustments and other actions that can lower this risk. Prophylaxis for

DVT can often prevent disease and avoid complications later on.

Nurses are able to educate colleagues and patients in health practice

settings where the risk of DVT is known to be at higher risk to occur.

The key to prevent DVT is to recognize who is at risk and to start

preventive measures.

Please take time to help NurseCe4Less.com course planners

evaluate the nursing knowledge needs met by completing the self-assessment of Knowledge Questions after reading the

article, and providing feedback in the online course evaluation.

Completing the study questions is optional and is NOT a course requirement.


1. A pulmonary embolism occurs when a clot becomes

dislodged and travels to the ________.

a. Respiratory system

b. Lung

c. Digestive system

d. Immune system

2. Compression stockings that will be used to treat DVT

should be a grade ___________.

a. 1

b. 2

c. 3

d. 4

3. This is the procedure that injects medication directly into

the blood clot via catheter to dissolve the clot.

a. Angioplasty

b. Thrombolytic Therapy

c. Bypass

d. Laparoscopy

4. Which of the following is NOT a risk factor for DVT?

a. Smoking

b. Strength Training

c. Pregnancy

d. Age


5. Which of the following is a long-term complication of DVT

that causes damage to the vein?

a. Pulmonary Embolism

b. Heart Attack

c. Post-Thrombotic Syndrome

d. Blockage

CORRECT ANSWERS:

1. b

2. c

3. b

4. b

5. c


References Section

The reference section of in-text citations include published works

intended as helpful material for further reading. Unpublished works

and personal communications are not included in this section, although

may appear within the study text.

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2. Kesieme E, Kesieme C, Jebbin N, Irekpita E, Dongo A. Deep vein

thrombosis: a clinical review. J. Blood Med. 2011;2:59–69.

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http://vasculardisease.org/flyers/deep-vein-thrombosis-flyer.pdf

4. Bandyopadhyay G, Roy SB, Haldar S, Bhattacharya R. Deep vein

thrombosis. J. Indian Med. Assoc. 2010;108:866–7.

5. Lottenberg R, Soucie JM, Grant AM, Atrash HK, Raskob GE,

Silverstein R, et al. Surveillance for Deep Vein Thrombosis and

Pulmonary Embolism. Am. J. Prev. Med. 2010. p. S502–S509.

6. Eikelboom JW, Karthikeyan G, Fagel N, Hirsh J. American

Association of Orthopedic Surgeons and American College of

Chest Physicians guidelines for venous thromboembolism

prevention in hip and knee arthroplasty differ: what are the

implications for clinicians and patients? Chest. American College

of Chest Physicians; 2009 Feb 1;135(2):513–20.

7. Yamaki T, Hamahata A, Soejima K, Kono T, Nozaki M, Sakurai H.

Factors predicting development of post-thrombotic syndrome in

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8. Deep Vein Thrombosis -OrthoInfo - AAOS [Internet]. Available

from: http://orthoinfo.aaos.org/topic.cfm?topic=a00219

9. Eichinger S, Heinze G, Jandeck LM, Kyrle PA. Risk assessment of

recurrence in patients with unprovoked deep vein thrombosis or

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2010 Apr 13;121(14):1630–6.

10. Yamaki T, Nozaki M, Sakurai H, Takeuchi M, Soejima K, Kono T.

Presence of Lower Limb Deep Vein Thrombosis and Prognosis in

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11. Halvorson JJ, Anz A, Langfitt M, Deonanan JK, Scott A, Teasdall

RD, et al. Vascular injury associated with extremity trauma:

initial diagnosis and management. J. Am. Acad. Orthop. Surg.

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12. Deroo S, Deatrick KB, Henke PK. The vessel wall: A forgotten

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13. Tovey C, Wyatt S. Diagnosis, investigation, and management of

deep vein thrombosis. BMJ Br. Med. J. 2003;326:1180–4.

14. Scarvelis D, Wells PS. Diagnosis and treatment of deep-vein

thrombosis. CMAJ. 2006 Oct 24;175(9):1087–92.

15. Wells PS, Owen C, Doucette S, Fergusson D, Tran H. Does this

patient have deep vein thrombosis? JAMA. American Medical

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16. Pulmonary Embolism [Internet]. Available from:

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g_diseases/lung/embolism/Pages/index.aspx


17. Acute Pulmonary Embolism — NEJM [Internet]. Available from:

http://www.nejm.org/doi/full/10.1056/NEJMra0907731

18. Headley CM, Melander S. When it may be a pulmonary embolism.

Nephrol. Nurs. J. 2011;38:127–37.

19. Humenberger M, Lang IM. Pulmonary embolism.

Hamostaseologie. 2008;28:40–3.

20. Brenner B, Hoffman R. Emerging options in the treatment of deep

vein thrombosis and pulmonary embolism. Blood Rev.

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21. (OSG) O of the SG. Fact Sheet: Deep Vein Thrombosis and

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22. The facts on post-thrombotic syndrome [Internet]. Available

from: http://www.inate.org/en/1/2/6/23/default.aspx

23. Brenner B, Greer IA, Kahn SR. The post thrombotic syndrome.

Thromb. Res. 2011;127:S89–S92.

24. Galanaud JP, Holcroft CA, Rodger MA, Kovacs MJ, Betancourt MT,

Wells PS, et al. Predictors of post-thrombotic syndrome in a

population with a first deep vein thrombosis and no primary

venous insufficiency. J. Thromb. Haemost. 2013 Mar;11(3):474–

80.

25. Guanella R, Kahn SR. Post-thrombotic syndrome: current

prevention and management strategies. Expert Rev. Cardiovasc.

Ther. 2012;10:1555–66.

26. Elman EE, Kahn SR. The post-thrombotic syndrome after upper

extremity deep venous thrombosis in adults: A systematic

review. Thromb. Res. 2006;117(6):609–14.

27. Roumen-Klappe EM, Janssen MCH, Van Rossum J, Holewijn S,

Van Bokhoven MMJA, Kaasjager K, et al. Inflammation in deep

vein thrombosis and the development of post-thrombotic


syndrome: a prospective study. J. Thromb. Haemost. 2009

Apr;7(4):582–7.

28. Morling JR, Yeoh SE, Kolbach DN. Rutosides for treatment of

post-thrombotic syndrome. Cochrane Database Syst. Rev.

2013;4:CD005625.

29. Rathbun S. Cardiology patient pages. The Surgeon General’s call

to action to prevent deep vein thrombosis and pulmonary

embolism. Circulation. 2009 Apr 21;119(15):e480–2.

30. Goldhaber SZ, Bounameaux H. Pulmonary embolism and deep

vein thrombosis. Lancet. 2012 May 12;379(9828):1835–46.

31. Naccarato M, Chiodo Grandi F, Dennis M, Sandercock PA. Physical

methods for preventing deep vein thrombosis in stroke. Cochrane

database Syst. Rev. 2010 Jan;(8):CD001922.

32. Franchini M, Mannucci PM. A new era for anticoagulants. Eur. J.

Intern. Med. 2009;20:562–8.

33. Galanaud J-P, Laroche J-P, Righini M. The history and historical

treatments of deep vein thrombosis. J. Thromb. Haemost. 2013.

p. 402–11.

34. Friedman RJ, Gallus AS, Cushner FD, FitzGerald G, Jr FAA,

Investigators for the GOR. Physician compliance with guidelines

for deep-vein thrombosis prevention in total hip and knee

arthroplasty. Informa UK Ltd UK; 2007 Nov 19;

35. MJ C, S H, E J, A E, M K. Compression stockings for preventing

deep vein thrombosis (DVT) in airline passengers. John Wiley and

Sons, Ltd. for The Cochrane Collaboration; 2010.

36. Kahn SR, Shbaklo H, Lamping DL, Holcroft CA, Shrier I, Miron MJ,

et al. Determinants of health-related quality of life during the 2

years following deep vein thrombosis. J. Thromb. Haemost. 2008

Jul;6(7):1105–12.


37. Sachdeva A, Dalton M, Amaragiri S V, Lees T. Elastic compression

stockings for prevention of deep vein thrombosis. Cochrane

database Syst. Rev. 2010 Jan;(7):CD001484.

38. Mavrakanas T, Bounameaux H. The potential role of new oral

anticoagulants in the prevention and treatment of

thromboembolism. Pharmacol. Ther. 2011;130(1):46–58.

39. Gross PL, Weitz JI. New anticoagulants for treatment of venous

thromboembolism. Arterioscler. Thromb. Vasc. Biol. 2008 Mar

1;28(3):380–6.

40. Schermerhorn M, Mewissen MW. Thrombolysis for Lower-

Extremity Deep Vein Thrombosis. Semin. Vasc. Surg.

2010;23(4):228–34.

41. L W, MP A. Thrombolysis for treatment of acute deep vein

thrombosis. John Wiley and Sons, Ltd. for The Cochrane

Collaboration; 2010.

42. Gogalniceanu P, Johnston CJC, Khalid U, Holt PJE, Hincliffe R,

Loftus IM, et al. Indications for Thrombolysis in Deep Venous

Thrombosis. Eur. J. Vasc. Endovasc. Surg. 2009;38(2):192–8.

43. Comerota AJ. Thrombolysis for deep venous thrombosis. J. Vasc.

Surg. 2012;55(2):607–11.

44. Aschwanden M, Jeanneret C, Koller MT, Thalhammer C, Bucher

HC, Jaeger KA. Effect of prolonged treatment with compression

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45. Kahn SR. The post-thrombotic syndrome. Hematology Am. Soc.

Hematol. Educ. Program. 2010 Jan 1;2010(1):216–20.

46. Jiménez D, Aujesky D, Díaz G, Monreal M, Otero R, Martí D, et al.

Prognostic Significance of Deep Vein Thrombosis in Patients


Presenting with Acute Symptomatic Pulmonary Embolism.

American Thoracic Society; 2012 Dec 20;

47. Spencer FA, Gore JM, Lessard D, Douketis JD, Emery C, Goldberg

RJ. Patient outcomes after deep vein thrombosis and pulmonary

embolism: the Worcester Venous Thromboembolism Study. Arch.

Intern. Med. American Medical Association; 2008 Feb

25;168(4):425–30.


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