Page 1769 - Saunders Comprehensive Review For NCLEX-RN

c. It is used for long-term anticoagulation
and is used mainly to prevent
thromboembolic conditions such as
thrombophlebitis, pulmonary
embolism, and embolism formation
caused by atrial fibrillation,
thrombosis, myocardial infarction, or
heart valve damage.
2. Blood levels
a. The normal PT is 11 to 12.5 seconds
(conventional and SI units).

b. Warfarin sodium prolongs the

PT; the therapeutic range is 1.5 to 2
times the control value.
3. INR
a. The normal INR is 0.81 to 1.2 (0.81 to
1.2).
b. The INR is determined by multiplying
the observed PT ratio (the ratio of the
client’s PT to a control PT) by a
correction factor specific to a particular
thromboplastin preparation used in
the testing.
c. The treatment goal of warfarin sodium
is to raise the INR to an appropriate
value.
d. An INR of 2 to 3 is appropriate for
standard warfarin therapy; an INR of 3
to 4.5 is appropriate for high-dose
warfarin therapy.

e. If the PT value is longer than 30

seconds and the INR is greater than 3.0
in a client receiving standard warfarin
therapy, initiate bleeding precautions.
f. If the INR is below the recommended
range, warfarin sodium should be
increased.
g. Clients may sometimes be prescribed
“bridge therapy,” whereby heparin
sodium is used concurrently with
warfarin sodium until the INR reaches
the recommended range. Once this
occurs, the heparin is discontinued.
4. Interventions
a. Monitor PT and INR.

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