|
|
Anticoagulant therapy
On 5/28/10 4:21 AM, "Ken Serota" wrote:
> SINGLE FIXTURE PLACEMENT - do you need to discontinue anticoagulant
> therapy???
>
> kendo
From Osseo News
Nicholas Toscano DDS MS December 17th, 2007
In my opinion below are some helpful go-bys in the Dental management of the
anticoagulated patient. REMEMBER TO ALWAYS CONSULT WITH THE PATIENTS
PHYSCIAN PRIOR TO ALTERING ANY PRESCRIBED MEDS:
Management is dependent on the type of procedure being performed, lab test
results and type of medication the patient is taking. Aspirin or Plavix®
therapy can be discontinued 7 days prior to surgery which should result in
better hemostasis. These drugs can then be restarted safely 48 to 72 hours
post-operatively. For patients taking Coumadin®, proper lab tests should be
done and a consult to the physician may be required depending on lab
results, medical condition, type of surgery being performed and the possible
need for drug dosage reduction. Studies have shown that extractions can be
done in patients with an INR of 2.5 to 3.5 safely, however the higher the
INR, the more the need for hemostatic measures. Jeske found that the
literature does not support the routine withdrawal of anticoaugulation
therapy. Dentists should be prepared for bleeding that exceeds normal and
may have to provide hemostatic measures. Giglio suggested that single tooth
extractions or minimally invasive procedures such as crown lengthening where
minimal bleeding is expected, are indicated if the INR is less then 4. In
procedures where moderate bleeding is expected, such as block or gingival
grafts, an INR of less then 3 is necessary. Little and Falace¹s review of
the literature, recommends that surgery may be performed with an INR of 2.0
to 3.0. For INR values of 3.0 to 3.5, it is recommended that the dosage of
anticoagulant be altered depending on bleeding expected during the surgical
procedure. Surgery should be delayed for values of 3.5 until the INR is
within the therapeutic range of 2.0 to 3.5.
Key labs tests to know:
The platelet count provides a quantitative evaluation of platelet function.
A normal platelet count should be 100,000 to 400,000 cells/mm3. A platelet
count of less than 100,000 cells/mm3 is called thrombocytopenia and often
can be associated with major postoperative bleeding. The average lifespan of
a platelet ranges from 7-12 days.
The bleeding time provides an assessment of adequacy of platelet count and
function. The test measures how long it takes a standardized skin incision
to stop bleeding by the formation of a temporary hemostatic plug. The normal
range of bleeding time depends on the way the test is performed, but is
usually between 1 and 6 minutes. The bleeding time is prolonged in patients
with platelet abnormalities or taking medications which affect platelet
function. This test assesses platelet function.
The prothrombin time (PT) measures the effectiveness of the extrinsic
pathway to mediate fibrin clot formation. It is performed by measuring the
time it takes to form a clot when calcium and tissue factor are added to
plasma. A normal prothrombin time indicates normal levels of Factor VII and
those factors common to both the intrinsic and extrinsic pathways (V, X,
prothrombin, and fibrinogen). A normal prothrombin time is usually between
10 and 15 seconds. Prothrombin time is most often used by physicians to
monitor oral anticoagulant therapy such as warfarin.
The partial thromboplastin time (PTT) measures the effectiveness of the
intrinsic pathway to mediate fibrin clot formation. It tests for all factors
except for Factor VII. The test is performed by measuring the time it takes
to form a clot after the addition of kaolin, a surface activating factor,
and cephalin, a substitute for platelet factor, to the patient¹s plasma. A
normal partial thromboplastin time is usually 25 to 35 seconds. Partial
thromboplastin time is most often used by physicians to monitor heparin
therapy.
The INR was designed for patients on chronic anticoagulant therapy. It
allows comparisons from one hospital to another. A patient with normal
coagulation parameters has an INR of 1.0. The therapeutic range for a
patient on anticoagulant therapy is between 2.0 and 3.5.
|
