1. BLOCK 2 Lecture Professor Nora Martin Vetto
DEEP VEIN THROMBOSIS
Review: venous thrombosis is the formation of a thrombus in association with inflammation of the vein. It is the most common disorder of the veins and is classified as either superficial vein thrombosis or deep vein thrombosis.
BLOCK 2 Lecture
Professor Nora Martin Vetto

2. Venous Thrombosis
Superficial Venous Thrombosis: is formation of a thrombus in a superficial vein, usually the greater or lesser saphenous vein (largest vein in body, runs from top of foot to groin)
Deep Vein Thrombosis: is a disorder involving a thrombus a deep vein, most commonly the iliac & femoral veins

3. Etiology
Virchow’s triad: Three important factors in the etiology of venous thrombosis are:
Venous stasis
Damage of the endothelium lining (inner lining of the vein)
Hypercoagulability of the blood

4. Etiology Continued
Venous Stasis: normal venous blood flow depends on the actions of muscles in the extremities and the functional adequacy of venous valves, which allow flow in one direction. Critical thinking, which direction in veins?
Endothelial Damage: Two types of injury
Direct: surgery, trauma, burns, intravascular catheters
Indirect: chemo, diabetes, sepsis
Damaged endothelium stimulates platelet activation & starts the coagulation cascade, which predisposes the patient to thrombus development

5. Pathophysiology of Venous Thrombus
Localized platelet aggregation & fibrin entrap RBCS, WBCs, and more platelets to form a thrombus
Frequent site of thrombus formation is the valve cusps of veins, where venous stasis occurs
As thrombus enlarges, increased number of blood cells & fibrin collect behind it
This process produces a clot with a “tail” that eventually blocks the lumen of the vein
If thrombus only partially blocks the vein, endothelial cells cover the thrombus & stop the thrombotic process

6. Pathophysiology continued
If the thrombus does not detach, it undergoes lysis or firmly organized & adhered within 5-7 days
The organized thrombus may detach & result in a n embolus
Turbulence of blood is major factor to embolization
The thrombus may become an embolus that flows through venous circulation & to the heart & lodges in the pulmonary circulation becoming a PE

7. Clinical Manifestations of VTE
Lower extremities: may or may not have unilateral leg pain, edema, tenderness with palpation, sense of fullness in the calf, parasthesias, warmth, erythema, or elevated systemic temperature >100.4
Critical Thinking: If inferior vena cava is involved which extremities affected?
If superior vena cava involved, which parts of body? (only 5-10% of VTE involve this area)
Diagnosis- may be done with D-dimer, (normal <250) and ultrasound

8. Collaborative Care Anticoagulants:
Vitamin K antagonist (one is oral-warfarin/Coumadin) takes effect in hours
Indirect thrombin inhibitors unfractionated (one is Heparin) monitor aPTT (antidote is protamine)
Low molecular weight Heparin (enoxaparin/Lovenox-regular coag studies not needed, nursing note-air bubble not expelled from sub-q needle before admin)
Direct thrombin inhibitor synthetic (dabigatran/Pradaxa-do need to check aPTT), Factor Xa inhibitor (rivoroxaban/Xarelto) (coag studies not needed)
Anticoagulants do not dissolve clots, but prevent formation of more and decrease spread of existing clot(s)
Implantable filters-inserted right femoral or right internal jugular veins, trap clots & allow blood flow, critical thinking? Complication?
(Greenfield Filter is popular brand name)
Surgical Therapy- venous thrombectomy, but most patients are managed with meds

9. Nursing Management Assessment: patient presenting with thrombus
Subjective: past med hx, meds, injuries, is patient obese, prolonged bed rest, etc., ask prolonged travel?
Objective: general-fever? Pain? Integumentary? Increased size of extremity compared to opposing, warm, red, tender, but remember some patients present no observable changes
Diagnostics: CBC, clotting times, d-Dimer, duplex ultrasound
Nursing Diagnoses: one is “acute pain related to venous congestion, impaired venous return & inflammation”
Nursing Plan: pain relief, decreased edema, no bleeding complications
Nursing Implementation: acute care is reduction of inflammation, and preventing more clots, with medication therapy? Observe for increased bleeding- where? What changes in VS with bleeding?
Home Care-teach modification of risk factors, wt loss, smoking cessation compression stockings, teach side effects of meds, may eat Vitamin K enriched foods (but avoid supplements & green tea), hydrate well to avoid hypercoagulability of blood, physical activity such as walking and swimming (water has even pressure on body, so is gentle)