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Chapter 2
•
Cardiovascular Care
PICTURING
PATHO
Virchow Triad
—
is a theory
delineating the pathogenesis of venous
thromboembolism (VTE), often called
Virchow triad which proposes that VTE
occurs as a result of:
•
Alterations in blood flow (i.e.,
stasis)
•
Vascular endothelial injury
•
Alterations in the constituents
of the blood (i.e., inherited or
acquired hypercoagulable state)
Embolus (a piece of
thrombus that breaks off)
Venous
thrombus
(blood clot)
Clumping of:
fibrin
platelet
red blood cells
Damage to the
blood vessel’s inner
lining
External
elastic
membrane
Tunica
media
Internal elastic
membrane
Tunica intima
(endothelium)
Valve
Tunica
adventitia
Looking at Venous Thrombosis
Characteristics of Patients
Who Develop Venous
Thromboembolism
•
More than 48 hours of immobility
in the preceding month
•
Hospital admission in the past
3 months
•
Surgery in the past 3 months
•
Malignancy in the past 3 months
•
Infection in the past 3 months