Lancaster Physician Summer 2021 - 23

SUMMER 2021
D
eep Vein Thrombosis (DVT) is a serious
and potentially life-threatening medical
condition. It is one that has received
recent media attention related to possible
complications of certain vaccines.
But what is a DVT?
Deep vein thrombosis is a blood clot that
occurs in a vein that is located deep inside the
body. It can be in your skull, chest, or abdominal
cavities. DVTs happen more commonly
in the larger veins in the extremities that
are associated with or paired with a named
artery. Lower extremity deep vein thrombosis
is much more common than upper extremity
DVT. Deep vein thromboses are serious not
only because of the feared complication of
pulmonary embolism but also because they
can cause long-term morbidity in the form
of the postphlebitic syndrome.
According to the CDC, venous thromboembolism
is a leading cause of preventable
hospital death. Deep vein thrombosis diagnosed
in the outpatient setting can be linked
to a hospitalization or recent surgery in more
than half of the cases. In 1973, Coon and
associates calculated the incidence of DVT
to be 250,000 cases per year in the United
States. A community-based study in 1992
by Nordstrom et al published in the Journal
of Internal Medicine reported an incidence
of 1.6 per 1,000 residents.
How does one get a deep vein thrombosis?
There are three primary factors involved
in formation of a blood clot. These were first
outlined by Virchow, a German physician
and pathologist. Virchow's triad of stasis,
damage to the vein, and hypercoagulable
state are important to the understanding
of how blood clots form. It is not enough
to have just one of these factors. It requires
at least two of them to form a blood clot.
1) Venous stasis means that the blood is
not moving properly. Most thrombi start
in areas of low flow such as behind valve
cusps in a vein or in the soleal veins in the
calves. Low blood flow occurs after surgery
or during hospitalization when bedridden
or lower activity. Stasis can also occur with
varicose veins and venous insufficiency.
2) Damage to a vein can be the result
of direct trauma but is more often due to
biochemical injury to the endothelium
or lining of the vein. Surgery or illness
increases the circulation of tissue factor,
tumor necrosis factor, interleukin-1, as well
as other inflammatory mediators. These
circulating factors lead to damage of the
intima of the vein wall, which can contribute
to thrombosis.
3) The final factor is a hypercoagulable
state. This can be hereditary. Genetic disorders,
such as factor V Leiden, prothrombin gene
mutation, depressed levels of antithrombin or
protein C or S, as well as dysfibrinogenemia,
are examples of inherited hypercoagulability.
A hypercoagulable state may also be acquired
and can be temporary. This often occurs with
illness, injury, or surgery.
There are risk factors that can increase
a person's susceptibility to DVT.
These
can usually be related to one of the factors
stated below.
INCREASED AGE
IMMOBILIZATION
HISTORY OF VENOUS
THROMBOEMBOLISM
MALIGNANCY (CANCER)
SURGERY
TRAUMA
PRIMARY HYPERCOAGULABLE STATE
PREGNANCY
ORAL CONTRACEPTIVES
BLOOD GROUP
(RISK IS GREATER IN TYPE A AND
LESS IN TYPE O)
PRESENCE OF CENTRAL
VENOUS CATHETERS
INFLAMMATORY BOWEL DISEASE
In addition, based on a paper by Shaydakov,
Comerota, and Lurie in the Journal of
Vascular Surgery, two thirds of patients with
acute DVT have preexisting chronic venous
insufficiency. Therefore, venous reflux may
be considered a novel risk factor for deep
vein thrombosis.
Why is deep vein thrombosis bad?
Most deep vein thromboses cause pain and
swelling. These often improve or resolve with
treatment of the DVT. However, postphlebitic
or postthrombotic syndrome leads to
long-term consequences of DVT. This is characterized
by pain, edema, hyperpigmentation
of the skin, or ulceration. Postthrombotic
changes occur in up to 5 percent of the U.S.
population. This includes 6 to 7 million
people with stasis changes of the skin and
up to 500,000 people with leg ulcers after
DVT. Pulmonary embolism with its associated
mortality is the most catastrophic event
following deep vein thrombosis.
It can be hard to estimate the prevalence of
symptomatic pulmonary embolism. Hospital
studies overestimate the prevalence, whereas
community studies exclude the very ill and
therefore underestimate cases of symptomatic
pulmonary embolism. Dalen and Alpert
have calculated an incidence of 630,000
symptomatic pulmonary embolisms in the
United States per year. In patients with symptomatic
pulmonary emboli, death occurs
within one hour of the onset of symptoms
in 11 percent of patients. Up to 30 percent
of patients will die within three hours if a
diagnosis is not made. If diagnosed properly
and treatment is started, only 8 percent of
patients die. Therefore, accurate diagnosis
of deep vein thrombosis is critical!
The first part of proper diagnosis is to
suspect deep vein thrombosis. You cannot
make the diagnosis if you do not think of it.
The most common symptoms are pain and
swelling. These symptoms, along with risk
stratification, can help decide if a DVT is a
low, moderate, or high probability. Physical
exam and clinical evaluation are not enough.
Some type of imaging study is necessary.
Continued on page 24
LANCASTER 23 PHYSICIAN

Lancaster Physician Summer 2021

Table of Contents for the Digital Edition of Lancaster Physician Summer 2021

Lancaster Physician Summer 2021 - 1
Lancaster Physician Summer 2021 - 2
Lancaster Physician Summer 2021 - 3
Lancaster Physician Summer 2021 - 4
Lancaster Physician Summer 2021 - 5
Lancaster Physician Summer 2021 - 6
Lancaster Physician Summer 2021 - 7
Lancaster Physician Summer 2021 - 8
Lancaster Physician Summer 2021 - 9
Lancaster Physician Summer 2021 - 10
Lancaster Physician Summer 2021 - 11
Lancaster Physician Summer 2021 - 12
Lancaster Physician Summer 2021 - 13
Lancaster Physician Summer 2021 - 14
Lancaster Physician Summer 2021 - 15
Lancaster Physician Summer 2021 - 16
Lancaster Physician Summer 2021 - 17
Lancaster Physician Summer 2021 - 18
Lancaster Physician Summer 2021 - 19
Lancaster Physician Summer 2021 - 20
Lancaster Physician Summer 2021 - 21
Lancaster Physician Summer 2021 - 22
Lancaster Physician Summer 2021 - 23
Lancaster Physician Summer 2021 - 24
Lancaster Physician Summer 2021 - 25
Lancaster Physician Summer 2021 - 26
Lancaster Physician Summer 2021 - 27
Lancaster Physician Summer 2021 - 28
Lancaster Physician Summer 2021 - 29
Lancaster Physician Summer 2021 - 30
Lancaster Physician Summer 2021 - 31
Lancaster Physician Summer 2021 - 32
Lancaster Physician Summer 2021 - 33
Lancaster Physician Summer 2021 - 34
Lancaster Physician Summer 2021 - 35
Lancaster Physician Summer 2021 - 36
Lancaster Physician Summer 2021 - 37
Lancaster Physician Summer 2021 - 38
Lancaster Physician Summer 2021 - 39
Lancaster Physician Summer 2021 - 40
https://www.nxtbook.com/hoffmann/Lancaster_Physician/LPSummer21
https://www.nxtbook.com/hoffmann/Lancaster_Physician/LPSpring21
https://www.nxtbook.com/hoffmann/Lancaster_Physician/LPWinter21
https://www.nxtbook.com/hoffmann/Lancaster_Physician/LPFall20
https://www.nxtbook.com/hoffmann/Lancaster_Physician/LancasterPhysicianSummer2020
https://www.nxtbook.com/hoffmann/Lancaster_Physician/LPSpring20
https://www.nxtbook.com/hoffmann/Lancaster_Physician/LPWinter20
https://www.nxtbook.com/hoffmann/Lancaster_Physician/LPFall19
https://www.nxtbook.com/hoffmann/Lancaster_Physician/LPSummer19
https://www.nxtbook.com/hoffmann/Lancaster_Physician/LPSpring2019
https://www.nxtbook.com/hoffmann/Lancaster_Physician/LPWinter2019
https://www.nxtbook.com/hoffmann/Lancaster_Physician/LPFall2018
https://www.nxtbook.com/hoffmann/Lancaster_Physician/LPSummer2018
https://www.nxtbook.com/hoffmann/Lancaster_Physician/LPSpring18
https://www.nxtbook.com/hoffmann/Lancaster_Physician/LPWinter18
https://www.nxtbook.com/hoffmann/Lancaster_Physician/Fall2017
https://www.nxtbook.com/hoffmann/Lancaster_Physician/Summer2017
https://www.nxtbook.com/hoffmann/Lancaster_Physician/LPSpring17
https://www.nxtbookmedia.com