Specimen

Plasma

Collection Medium:

Minimum:

Full draw; any size blue top(mix well). Tube must be at least 90% full.

Analytic Time:

2 hours (upon receipt in laboratory)

Reference Range:

9-12 seconds

INR Critical Reference Value: greater than 6.0

Comments:

The INR corresponding to the PT is reported to assist in the monitoring 
of oral anticoagulants.  Must be drawn swiftly with a clean 
venipuncture (no hematoma).  Time drawn must be indicated on 
requisition.  Obtain special tube from lab if hematocrit is over 55%.  
Sample should be kept at room temperature, unopened to be delivered to 
lab within 24 hours.

Prothrombin Time may be performed on the same collection tube as 
Activated Partial Thromboplastin time (aPTT) and Fibrinogen.

Methodology:

Optical clot detection.

CPT Code:

85610

See also:
Activated Partial Thromboplastin Time (aPTT), Plasma

See Additional Information:
Hematology Critical Lab Values
International Normalized Ratio (INR)
Phlebotomy Tubes and Order of Draw
Specimens Requiring Immediate Delivery