Internal Medicine

0521779407-20 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 21:22

Thrombophilia 1425

management

Initial therapy for venous thromboembolism is usually unfractionated

heparin (UFH) or low-molecular-weight heparin (LMWH) followed by

long-term treatment with warfarin. Target INR for oral anticoagulation

is 2.0–3.0.

Duration of anticoagulation depends on the balance between recur-

rent thrombosis and risk of bleeding.

Guidelines for duration of anticoagulation:

■In the absence of contraindications, most patients with a first clot

require 3–6 months of anticoagulation.

■Underlying malignancy, AT deficiency, protein S and C deficiency,

homozygosity for factor V Leiden or the prothrombin gene mutation

or double heterozygosity, or persistent antiphospholipid antibodies,

may require longer, perhaps indefinite, duration of therapy.

■A second spontaneous thrombosis, or a first clot with two or more

biochemical/genetic thrombophilic risk factors might also warrant

indefinite anticoagulation.

Consider thrombolytic therapy, if no contraindications in the following

circumstances:

■For local lytic therapy, a large thrombus in the following areas:

➣portal system

➣mesenteric system

➣vena cava

➣upper extremity

➣limb-threatening thrombosis

■For a hemodynamically-significant PE, consider systemic lytic ther-

apy.

Once thrombophilia is diagnosed, need prophylaxis for high-risk situ-

ations – i.e., pregnancy, surgery, prolonged bed rest, prolonged car

or plane trips

specific therapy

Lupus Anticoagulant (LA)

■Women with the LA may have recurrent spontaneous miscarriages.

➣Heparin plus aspirin has been shown to improve outcomes.

➣No benefit with steroids

■Patients with the LA that have a baseline prolongation of the pro-

thrombin time and INR may require monitoring of FXa by chro-

mogenic method (keep levels between 10–30%).

Hyperhomocysteinemia – Vitamin therapy can decrease levels of

homocysteine