Test Code INRT 
Methodology Clot-based 
Description Useful for monitoring Coumadin® therapy.

NOTE: This test, when ordered on Medicare patients, is subject to the National Coverage Determination (NCD) policy "Prothrombin Time (PT)". Please verify that the diagnosis code (ICD-9) you have chosen demonstrates medical necessity for the test as documented in the physician's patient record. The CMS web site or the NorDx Limited Coverage Documentation Guide are available to assist you with this verification. A properly executed Advance Beneficiary Notice (ABN) must be submitted with the specimen if medical necessity is not demonstrated by the ICD-9 code chosen. 

Specimen Draw blood in a light blue-top (3.2% sodium citrate) tube. Forward promptly at ambient temperature only. SPECIMEN MUST ARRIVE WITHIN 24 HOURS OF DRAW.

1. Specimens will be rejected if underfilled (< 90%), clotted, high hematocrit (> 55%), or grossly hemolyzed.
2. Follow "Special Procedure for Drawing Specimen from an A-line".
3. If specimen will arrive > 24 hours of draw, spin down and send 1.0 mL of sodium citrate plasma FROZEN in plastic vial on dry ice. 

Reference Values 0.9 - 1.2 
Analytic Time 1 Day - Available STAT 
Day(s) Test Set Up Monday through Sunday 
CPT Code(s) 85610  

Special Instructions