VTE pre Flashcards
Venous Thromboembolism
-clots formed in areas of slow/distrubed flow
-stasis blood promotes thrombus = dec clotting factor clearance
Venous thrombi composition
-RBCs
-fibrin
-some platelets
-“red thrombi”
thrombi sx start when
-flow obstructed
-vascular tissue inflammation
-thrombus occurs and affects venous blood flow
-emboli occur and enter pulmonary circulation
not all DVTs lead to PEs
-all PEs come from DVTs
=need to be blood clot somewhere that becomes dislodged
Virchow’s triad
-three conditions that inc risk of clot
1. hypercoaguable state
2. Endothelial injury
3. Circulatory stasis
Hypercoaguable state
-abnormalities of clotting components
-pregnancy, cancer
Endothelial injury
-abnormality of surfaces in contact with blood flow
-injury to blood vessel
Circulatory stasis
-abnormal blood flow
-long periods of immobility
-common in AFIB
Slide 5
slide 5
Injury to healing
- endothelium
- platelet adhesion and aggregation
- Coagulation cascade activation
- Thrombin
- Fibrin formation
- stabilized fibrin clot
- Fibrinolysis and clot degradation
- Healing
Agents that affect platelet adhesion and aggregation
-activators:VonW factor
-inhibitors: heparin, thrombomodulin
Coagulation cascade activation
-tissue factor
-Factor VIIa, Xa, XIIa
-Thrombin (Factor II)
Coagulation cascade inhibition
-antithrombin
-protein C
-protein S
-tissue factor pathway inhibitor
Fibrin formation activator
-Factor XIIIa
Fibrinolysis affected by
-activators: tissue plasminogen activator
-inhibitor: plasminogen-activator inhibitor-1
Coagulation Cascade
- initiation
- amplification
- propogation
-slide 5 bc i didnt explain well
Coagulation cascade initiation
-tissue factor bearing cell
-IX to IXa and X to Xa by TF/VIIa
-prothrombin to thrombin by Xa
Amplification of coagulation cascade
-collagen-activated platelet
-V to Va
-VIII to VIIIa
-XI to XIa
-all by thrombin
Collagen/thrombin activated platelet
-IX to IXa by XIa
-X to Xa by IXa/VIIa
-prothrombin to thrombin by Xa/Va
-fibrinogen to fibrin
coagulation cascade intrinsic factors
-kms
coagulation cascade extrinsic
kys
coagulation common pathway
kys
Postthrombotic syndrome
-long term complications of DVT caused by damage to venous valves
-chronic V obstruction
-caused by venous HTN
-chronic pain and swelling
-stasis ulcers
-development of infection
-rule out recurrent thrombosis before diagnosis
DVT risk factors
->40
-fam hx
-HF
-immobilization
-malignancy
-MI
-obesity
-orthopedic injury
-estrogen
-paralysis
-postop
-pregnancy
-prior DVT
-varicose veins
Nonpharma tx DVT
-bed rest
-elevate feet
-pain management
-compression stockings
nonpharma PE tx
-oxygen
-mechanical ventilation
-compression stockings
