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PROTHROMBIN TIME

Test Name
PROTHROMBIN TIME
Test Code
PT
Synonyms
PT-INR
Avail Stat?
Y
Test Type
Executable
Res. Names
PT,  INR
Interferences
Gross hemolysis, clot, insufficient quantity in tube.
Specimen
Plasma
Container
Blue 5ml. .  Collection: Must be received within two
hours of drawing.
Days Perf.
7 days.   Analytic turn-around time: Stat: 90 min.
Processing
Do not save.
Ref. Range
- - - Normal- - -
Result   Specimen      Sex   Age Range       Ref Range     Units
-------- ----------    ---- -------------  -------------   ------
PT       PLASMA        Both        Adult     9.2 - 11.8    SEC
- - - Critical - - -
Result   Specimen      Sex   Age Range       Ref Range     Units
-------- ----------    ---- -------------  -------------   ------
         PLASMA        Both        Adult      > 38.0	      SEC
					      -
Billing Codes
04740410   PT-INR        Routine Priority: Bill on Verify
04900410   PT-INR        Stat Priority: Bill on Verify

ATTENTION ALL USERS:
FROM: Sheri Hoffmann
**PROTHROMBIN TIME ALERT**
REAGENT CHANGE TO AFFECT PT SECONDS
The Coagulation Laboratory at Sinai Hospital will change to ultra-sensitive INNOVIN reagent for Prothrombin Time (PT) determinations on Thursday 12/9/04 at 0800 am . At the time of change, an oral anticoagulated patients PT results in seconds may show a dramatic shift upward (more prolonged time), BUT the INR value should remain about the same.
It is important that you monitor individuals receiving oral anticoagulant therapy with the INR value, NOT the PT result in seconds.
We are making the switch to the new reagent for two reasons. First, the new thromboplastin (Innovin) is synthetic using recombinant gene technology and consequently will be available unaltered in the future. Second, the new reagent is very sensitive to coumadin. This high sensitivity results in optimum reproducibility of the patient INR. In other words, INRs determined on the basis of our new reagent will be less variable and more accurate.
Recommended Therapeutic Ranges
International INR guidelines for acceptable oral anticoagulant effect were published in the October 1995 issue of CHEST, Vol. 108. Those guidelines are as follows:
Indication INR
Prophylaxis/treatment of:Venous Thrombosis, Pulmonary Embolism.....2.0-3.0

Prevention of systemic embolism from: Tissue heart values......2.0-3.0
Acute myocardial infarction (to present Systemic embolism)*.......2.0-3.0
Valvular heart disease......2.0-3.0
Atrial fibrillation......2.0-3.0

Mechanical prosthetic valves (high risk)......2.5-3.5
*If oral anticoagulant therapy is elected to prevent recurrent myocardial infarction, an INR of 2.5-3.5 is recommended, consisted with Food and Drug Administration recommendations.
Questions regarding the Prothrombin Time change and monitoring of oral anticoagulated patients and questions regarding PT results and INR values on specific individuals may be directed to the Coagulation Laboratory or Dr. Nuckols.
Coagulation Reference Ranges:
PT: 9.2 - 11.8 seconds
APTT: 22.0 - 33.0 seconds
Fibrinogen: 214 - 521 mg/dL
Critical Values:
PT: >/= 38.0 seconds, INR: >/= 4.0
APTT: 100.0
Fibrinogen: <100, >71000 mg,dL

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