Lipp Vis Nursing ChaptLWBK1630_C02_p013-068

26  Chapter 2 • Cardiovascular Care

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)

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

Looking at Venous Thrombosis

PICTURING PATHO

Embolus (a piece of thrombus that breaks off)

External elastic membrane

Tunica adventitia

Internal elastic membrane

Tunica media

Tunica intima (endothelium)

Venous thrombus (blood clot)

Valve

Clumping of: fibrin platelet

red blood cells

Damage to the blood vessel’s inner lining