文档介绍：4/99
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Venous Thromboembolism State of the Art
American Journal of
Respiratory and Critical Care Medicine
Vol 159, 1999
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Venous Thromboembolism
Two major clinical manifestations
deep venous thrombosis (DVT)
pulmonary embolism (PE)
30% DVT pts develop symptomatic PE 50%-60% DVT pts develop asymptomatic PE
VTE affects 1/1000 persons yearly
PE causes 50,000 death in the . yearly
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DVT - Risk factors and Prevalence
DVT most often originates in the deep veins of the major calf muscles
venous stasis
trauma
surgery
childbirth
increasing age
all cancers
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Thrombophilia
Definition
recurrent venous or arterial thrombosis from inherited or acquired causes
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Inherited Thrombophilic States
Prevalence (%)
Patients with VTE 1st
Event
Activated protein C resistance 3-4 20 50 3-7
Hyperhomocysteinemia - 15 - -
Protein C deficiency - 3 1-9 5-12
Protein S deficiency 2 1-13 4-11
Antithrombin deficiency 1 -7 15-20
General Population
Recurrence RR*
* Relative Risk for recurrent VTE. Relative to an index case no inherited thrombophillia.
Am J Respir Crit Care Med. Vol 159: 1-14; 1999
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Activated Protein C Resistance
Inheritated abnormality known as factor V Leiden
involves a point mutation (adenine for guanine) that results in the substitution of glutamine for arginine at position 506 on factor V
activated protein-C es resistant to degradation
the heterozygous state (5% of Caucasians) carries a 3 to 5 fold increased risk for VTE
Factor V Leiden can be identified in 20% of patients with one episode and 50% of those with recurrent VTE
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Prevention of Venous Thromboembolism
Without Prophylaxis (%) mended With Prophylaxis (%)
Risk Group Prox DVT Fatal PE Prophylaxis Prox DVT Fatal PE
Hip replacement 20-30 2-4 WAR, LMWH 5 -
Knee replacement 20-30 2-4 WAR, LMWH, IPC 5 -
Hip fracture 25-35 2-4 WAR, LMWH 10 -
Major trauma 20 - LMWH, IPC 10 <
Abdominal or pelvic
can