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PTT
PARTIAL THROMBOPLASTIN TIME (PTT), PLASMA

Test Code PTT 
Test PARTIAL THROMBOPLASTIN TIME (PTT), PLASMA 
Methodology Clot-Based 
Description Useful for monitoring heparin (unfractionated) therapy; screening for intrinsic and common pathway factor deficiencies.

NOTE: This test, when ordered on Medicare patients, is subject to the National Coverage Determination (NCD) policy "Partial Thromboplastin Time (PTT)". 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 Collect specimen as follows:
1. Draw blood in light blue-top (3.2% sodium citrate) tube(s). Separate plasma from cells within 4 hours of collection in a centrifuge at 2,500 rpm for 15 minutes or 3,000 rpm for 10 minutes.
2. Using a plastic transfer pipette (do not use a glass pipette) decant the plasma to a screw-capped, plastic (polypropylene) vial. (Glass vials will not be accepted.)
3. Divide the specimen into as many 0.5 - 1.0 mL aliquots as possible and cap the vial(s) tightly.
4. Freeze specimen(s) immediately at >= -40 C.
5. Send specimen(s) FROZEN on dry ice.

NOTE:
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". 

Reference Values 24 - 34 seconds
Critical value, outpatient >= 60 seconds
inpatient >= 150 seconds 
Analytic Time 1 Day - Available STAT 
Day(s) Test Set Up Monday through Sunday 
CPT Code(s) 85730  

Special Instructions