Venous Thromboembolic Disease

disease that involves the development of DVT and/or PE

a thrombus or foreign substance from the systemic circulation that lodges in the pulmonary artery or its branches

complete or partial occlusion of pulmonary blood flow

thrombus that forms most commonly in the politeal or femoral veins, veins fo the calf, or upper leg

PE
dyspnea, cough, hemoptysis, tachypnea, tachycardia, pleuritic chest pain, diaphoresis, and overwhelming anxiety

DVT
pain, tenderness, edema, erythema of affected extremity

Venous thrombi form where areas of flow are slow - near valve cusp pocket of calves or thigh.

Factors that can → thrombus
1) Trauma to vessel → release of tissue factor → activation of coagulation cascade
2) immobility
3) hypercoagulability

Age > 40
prolonged immobility
surgery, trauma, malignancy
pregnancy
previous VTE
CHF, Stroke, aMI, indwelling catheter
Estrogen therapy
Obesity
Inflammatory bowel dz

VTE suspected
- baseline APTT, PT, CBC
- check for CIs, order imaging study
- consider 5000 IU IV

VTE confirmed
- rebolus w/ 80IU/kg IV
- maintenance infultion at 18IU/kg
- APTT at 6h
- platelets b/w days 3-5
- start warfarin tx on day 1 5mg
-adjust subsequent dose via INR
- stop heparin after 4-5 days of
combined tx when INR is > 2
- anticoagulate w/warfarin for 3months
- INR 2-3

VTE suspected
- baseline APTT, PT, CBC
- check for CIs, order imaging study
- consider 5000 IU IV hep or LMWH or
fondaparinux (fond)

VTE confirmed
- give LMWH or fond
- check platelets b/w days 3-5
- start warfarin tx on day 1 5mg
-adjust subsequent dose via INR
- stop after 4-5 days of combined tx
when INR is > 2
- anticoagulate w/warfarin for 3months
- INR 2-3

dalteparin (Fragmin)

enoxaparin (Lovenox)

tinzaparin (Innohep)

pentasaccharide
fondaparinux (Arixtra)

LMWH
have fewer interactions w/plasma proteins so have more predictable response

much longer half-life so SC q12-24

lower incidence of osteoporosis and heparin-induced thrombocytopenia (HIT)

lepirudin (Refludan)
- DVT
- HIT
argatroban
- HIT
- PCI

single VTE w/reversible, time-limited rfs
- 3-6 months
- ? what time-limited rfs are and don't
particularly care right now
single idiopathic VTE
- 6 months or longer

recurrent VTE or VTE w/cancer
- 12 months to lifetime

Aspirin
Clopidogrel
aspirin/dipyridamole

ie antiplatelet tx not anticoag tx

warfarin to INR of 2-3 is more effective a preventing stroke than aspirin